Micro-irrigation covering water-saving cultivation method for leaf vegetables

Abstract

The invention belongs to the field of vegetable planting, and particularly relates to a leaf vegetable micro-irrigation covering water-saving cultivation method which comprises the following steps: S1, adjusting sowing soil according to a preset standard; s2, applying a base fertilizer, and sowing according to a preset planting interval; s3, taking water-saving irrigation and maintenance measures in the field; and S4, harvesting. According to the leaf vegetable micro-irrigation covering water-saving cultivation method, the influence of different planting modes and covering modes on the yield, quality and water utilization efficiency of spinach in a plastic greenhouse is explored, the soil moisture change and the growth and development law of spinach in the growth period are analyzed, and the optimal planting mode and the evaporation-reducing water-saving covering cultivation mode are screened out; the dry matter content in the spinach growth process can be increased, the crop yield can be increased, the water consumption can be reduced, and the water utilization rate can be increased.

Description

Technical Field

[0001] The invention belongs to the field of vegetable planting, and in particular relates to a water-saving cultivation method for leafy vegetables through micro-irrigation and covering. Background Art

[0003] Vegetables are crops with high water requirements. Water accounts for 60% to 95% of their composition. During the growth of vegetable crops, too much or too little irrigation will affect the growth of vegetables.

[0004] Spinach is recognized as one of the healthiest vegetables. It is rich in many beneficial ingredients that can be provided to the human body, such as β-carotene and vitamin C, which can provide various nutrients to the human body; it contains trace elements such as calcium, iron, and phosphorus, which promote human metabolism. Therefore, spinach is a green leafy vegetable crop with high nutritional value. There are two types of regional vegetable planting modes for spinach: open field and facility. At present, the research on its water-saving technology focuses on the impact of different irrigation methods on yield and water use efficiency, such as flooding, micro-spraying, micro-moisture alternating irrigation, negative pressure irrigation and other irrigation methods. It is extremely rare in the research on spinach planting mode and covering method. Summary of the invention

[0005] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a water-saving cultivation method for leafy vegetables by micro-irrigation and covering, which is helpful to increase the dry matter content of spinach during its growth, increase crop yield, reduce water consumption, and improve water utilization rate.

[0006] The specific technical solution adopted by the present invention is:

[0007] A method for water-saving cultivation of leafy vegetables by micro-irrigation and covering, comprising the following steps:

[0008] S1. Adjust the sowing soil according to the predetermined standards;

[0009] S2. Apply base fertilizer and sow seeds according to the predetermined planting spacing;

[0010] S3. Take water-saving irrigation and maintenance measures in the field;

[0011] S4. Harvesting;

[0012] The predetermined standard of the sowing soil is that the basic nutrient content of the 0-30 cm soil tillage layer includes 23-28 mg / kg nitrate nitrogen, 0.65-0.85 g / kg available nitrogen, 18-22 mg / kg available phosphorus and 90-110 mg / kg available potassium.

[0013] The water-saving irrigation maintenance measures are as follows: in step S2, sowing is carried out with an equal row spacing of 20 cm and a sowing rate of 30 kg / hm2.2 The total amount of irrigation water in the whole growth period in step S3 is 1075.2m 3 / hm 2 .

[0014] The water-saving irrigation maintenance measure is that in step S2, wide-narrow row sowing is adopted, and the sowing amount is 30kg / hm 2 The planting belt width is 15 cm, the spacing between planting belts is 20 cm, drip irrigation belts are laid in the planting belts, and the spacing between drip irrigation belts is 35 cm. The total amount of irrigation water in the whole growth period in step S3 is 1075.2m 3 / hm 2 .

[0015] The water-saving irrigation maintenance measure is that in step S2, wide-narrow row sowing is adopted, and the sowing amount is 30kg / hm 2 The planting belt width is 15 cm, the spacing between planting belts is 20 cm, drip irrigation belts are laid in the planting belts, and the spacing between drip irrigation belts is 35 cm. The total amount of irrigation water in the whole growth period in step S3 is 1075.2m 3 / hm 2 , and cover the ground to form a covering layer, the covering material is rice husk or corn stalks, with a thickness of 1-2cm.

[0016] The covering material is corn stalks, and the stalks are crushed to a length of 0.3-0.5 cm.

[0017] In the step S2, wide and narrow row sowing is carried out in a ridge-forming manner. There are three sowing rows in the planting belt, two of which are arranged on the left slope and one on the right slope. A drip irrigation belt is laid at the top of the slope along the length direction of the ridge, wherein a water storage layer with a thickness of 1-2 cm and parallel to the left slope is arranged under the soil on the left slope, the water storage layer is connected to the covering layer, and the drip irrigation belt is arranged at the connecting point between the water storage layer and the covering layer.

[0018] The ridge forming direction is north-south.

[0019] The lower end of the aquifer extends to the bottom of the left slope.

[0020] The beneficial effects of the present invention are:

[0021] The present invention adopts a micro-irrigation and covering water-saving cultivation method for leafy vegetables. By exploring the effects of different planting patterns and covering methods on the yield, quality and water use efficiency of spinach in plastic greenhouses, the soil moisture changes and growth and development laws during the growth period are analyzed, and the optimal planting pattern and evaporation-reducing and water-saving covering cultivation pattern are screened out. This helps to increase the dry matter content of spinach during growth, increase crop yield, reduce water consumption, and improve water use efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a design diagram for the experiment with different planting row spacings in Example 1;

[0023] Figure 2 Changes in the average growth rate of spinach leaf area under different planting row spacings;

[0024] Figure 3 Changes in the average growth rate of spinach plant height under different planting row spacings;

[0025] Figure 4 This is a design diagram for the experiment of different planting patterns in Example 2;

[0026] Figure 5 It is the leaf area of ​​a single spinach plant during the whole growth period;

[0027] Figure 6 This is the trend chart of the average growth rate of leaf area per spinach plant;

[0028] Figure 7 It is the dry matter accumulation of spinach during the whole growth period;

[0029] Figure 8 Leaf area growth rate of spinach under different mulching methods;

[0030] Fig. 9 Growth rate of plant height of spinach under different mulching methods;

[0031] Fig.10 Soil moisture content in the 0-10cm soil layer during the entire growth period;

[0032] Fig.11 Soil moisture content in the 10-20cm soil layer during the entire growth period;

[0033] Fig.12 Soil moisture content in the 20-30cm soil layer during the entire growth period;

[0034] Fig.13 Soil moisture content in the 30-40cm soil layer during the entire growth period;

[0035] Fig.14 is a schematic diagram of the aquifer;

[0036] In the attached figure, 1, drip irrigation tape, 2, covering layer, 3, water storage layer. DETAILED DESCRIPTION

[0037] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments:

[0038] Specific implementation examples Figure 1 As shown, the present invention is a method for water-saving cultivation of leafy vegetables by micro-irrigation and covering, comprising the following steps:

[0039] S1. Adjust the sowing soil according to the predetermined standards;

[0040] S2. Apply base fertilizer and sow seeds according to the predetermined planting spacing;

[0041] S3. Take water-saving irrigation and maintenance measures in the field;

[0042] S4. Harvesting;

[0043] The predetermined standard of the sowing soil is that the basic nutrient content of the 0-30 cm soil tillage layer includes 23-28 mg / kg nitrate nitrogen, 0.65-0.85 g / kg available nitrogen, 18-22 mg / kg available phosphorus and 90-110 mg / kg available potassium.

[0044] Specific embodiment 1: The water-saving irrigation maintenance measure is that in step S2, equal row spacing of 20 cm is used for sowing, and the sowing rate is 30 kg / hm 2 The total amount of irrigation water in the whole growth period in step S3 is 1075.2m 3 / hm 2 .

[0045] Specifically, the spinach variety tested was 'Mexico No. 2', which has oval leaves, thick and wrinkled leaf surfaces, early maturity, cold resistance, heat resistance, bolting resistance, and is suitable for direct seeding.

[0046] The test site is located at the Dahe Comprehensive Experimental Station of the Institute of Agricultural Information and Economics of the Hebei Academy of Agricultural and Forestry Sciences (38°07′38.82″N, 114°23′8.86″E). The test station is located in Luquan District, Shijiazhuang City, which belongs to the temperate semi-humid and semi-arid continental monsoon climate, with an average daily temperature of 13.5℃, an annual precipitation of 543mm, 2554h of sunshine, and a frost-free period of 230d. The plastic greenhouse of the test site is 28m long and 13m wide. The soil of the test site is clay loam flood-impacted calcareous brown soil, and the bulk density of 0-20cm and 0-40cm soil is 1.35g / cm 3 , 1.54g / cm 3 The field water holding capacity of 0-20cm and 0-40cm soils is 21.40% and 20.87% respectively. The basic nutrient content of 0-30cm soil tillage layer includes 25.22mg / kg nitrate nitrogen, 0.79g / kg available nitrogen, 19.81mg / kg available phosphorus and 100.00mg / kg available potassium.

[0047] This example sets three different planting row spacing treatments, including T1 treatment (planting row spacing 10cm), T2 treatment (planting row spacing 15cm) and T3 treatment (planting row spacing 20cm), with CK (broadcasting) as the control, a total of 4 treatments, each treatment is repeated three times, and the area of ​​each treatment is 27m2. The sowing time is March 19, 2022, and the yield is measured on April 26, 2022. The whole growth period is 38d. Direct seeding is adopted, and the sowing rate is 30kg / hm 2 The drip irrigation method was adopted, and the irrigation amount was the same between each treatment. The total irrigation amount during the whole growth period was 1075.2m 3 / hm 2 Before sowing, use bio-organic fertilizer as base fertilizer at a dosage of 15,000 kg / hm2. 2 There is no difference in management between different treatments, and weeding, pest control and agricultural operation measures are carried out in combination with local actual conditions. This experiment divides the entire growth period of spinach into five stages: germination, early growth, mid-growth, maturity and harvest. The germination period is when spinach is sown and the seeds break through the soil from the seed coat, and begin to germinate and grow until the first pair of true leaves grow; the early growth period is when spinach grows the first true leaf, the root system gradually expands, the leaves become larger, and about 2 leaves grow; the mid-growth period is when the roots and leaves gradually grow to form a relatively complete plant, and about 5 to 6 leaves grow; the maturity period is when the color of spinach leaves gradually darkens and the leaves become thicker, reaching maturity, and about 7 to 11 leaves grow; the harvest period is the period for harvesting and measuring the yield of spinach in this experiment.

[0048] A plot experiment with different planting row spacings of spinach (10 cm equal row spacing, 15 cm equal row spacing, 20 cm equal row spacing) was set up, and the broadcasting treatment was used as the control. The growth indicators, soil moisture changes, and yield indicators of spinach under different planting row spacings during their growth and development were measured to study the effects of different planting row spacings on the growth characteristics, yield, and water use efficiency of spinach; the dynamic changes in soil moisture content and water consumption during the growth period of spinach under different planting row spacings were clarified; the effects of different planting row spacings were compared, and the optimal planting row spacing for spinach production was screened out.

[0049] Soil moisture changes: Soil is collected from each plot using a soil drill at different soil depths of 0-10cm, 10-20cm, 20-30cm, and 30-40cm during the germination period, early growth period, mid-growth period, maturity period, and harvest period. The drilling points are selected in the middle of the planting row. Soil moisture is measured by drying and weighing. Soil moisture content is calculated by soil field water holding capacity and bulk density; farmland water consumption is calculated using the farmland water balance equation:

[0050] Soil moisture content = soil layer thickness × soil bulk density × 10 × (water mass / dry soil mass) / water density

[0051] ET=ΔW+P+I+URF (1)

[0052] Where: ΔW is the soil water storage consumption (mm); P is the effective precipitation in this period (mm); I is the irrigation volume (mm); U is the amount of groundwater that moves upward through the capillary to replenish crop water (mm); R is the surface runoff (mm); F is the amount of groundwater replenished (mm). Under the test conditions of the facility, rainfall was isolated and the water infiltration under drip irrigation conditions was unsaturated infiltration. The test plot was flat and the groundwater level was deep. Therefore, U, R, and F in the calculation formula can be ignored.

[0053] Water consumption intensity is calculated as follows: Water consumption intensity in a certain period (mm / d) = water consumption in that period (mm) / number of days in that period (d)

[0054] Determination of spinach growth traits: After spinach seedlings emerge, select 3 plants with uniform growth at each time in the early growth period, middle growth period, maturity period and harvest period for sampling, and repeat three times. Use a ruler to measure the plant height and calculate the average growth rate of plant height in each growth period. Record the number of leaves of each spinach plant, use a ruler to measure the length (the distance from the base of the petiole to the tip of the leaf) and width (the maximum width in the vertical direction of the main vein) of the leaf, record the number of leaves of the plant, and calculate the leaf area of ​​a single plant, which is leaf area of ​​a single plant = leaf length × leaf width × correction coefficient (the coefficient of expanded leaves is 0.75).

[0055] Plant height growth rate at each stage = plant height growth amount at each stage (g) / stage time (d)

[0056] Leaf area growth rate in each stage = leaf area growth in each stage (g) / stage time (d)

[0057] Determination of spinach dry matter: Three plants with uniform growth were selected in each plot for sampling at the early growth stage, middle growth stage, maturity stage and harvest stage of spinach, and the sampling was repeated three times. The fresh weight of the aboveground and underground parts of the plants was determined by weighing method. The fresh samples were divided into aboveground and underground parts, and then washed clean at 105℃ for 30 minutes and dried at a constant temperature of 80℃ to constant weight. The dry matter of the aboveground and underground parts of the plants was weighed with an electronic scale. The total dry matter content of spinach = aboveground dry matter + underground dry matter.

[0058] Determination of spinach yield: During the spinach harvest period, yield sampling was carried out for each treatment plot. Three rows were sampled in each treatment plot, and the sampling length of each row was 1m. The test was repeated three times, and the number of plants was weighed and recorded.

[0059] Calculation of water use efficiency of spinach: The calculation formula for crop water use efficiency WUE (kg / mm) is:

[0060] WUE=Y / ET (2)

[0061] Where: Y is the yield (kg / hm 2 ), ET is the total water consumption of crops during their entire growth period (mm / hm2) 2 )

[0062] Effects of different planting row spacings on the growth of spinach leaves in plastic greenhouses: As shown in Table 1, under different planting row spacings, the leaf area of ​​spinach per plant was as follows: T2 treatment > T3 treatment > T1 treatment > CK treatment. The treatment with the largest leaf area was T2 treatment, with a leaf area of ​​376.23 cm 2 ; followed by T3 treatment and T1 treatment, with leaf areas of 375.63 cm 2 and 372.94cm 2 ; The treatment with the smallest leaf area was CK treatment, with a leaf area index of 331.0 cm 2 Among the equal-row-spacing treatments, the leaf area of ​​spinach in the T1 treatment was slightly smaller than that in the T2 and T3 treatments. There was no significant difference in leaf area between the different equal-row-spacing treatments, but they were all significantly higher than the CK treatment. Compared with the CK treatment, the equal-row-spacing treatments significantly promoted the leaf area of ​​spinach per plant, with an average increase of 11.50%. The T2 treatment had the largest leaf area, which increased by 12.01% compared with the CK treatment.

[0063] Figure 2 This is a graph showing the average growth rate of leaf area per spinach plant under different planting row spacings. Figure 2 It can be seen that the leaf area of ​​a single spinach plant shows a trend of slow growth in the early and middle stages and rapid growth in the late stages. The starting point of the rapid increase in the growth rate of spinach leaf area during the whole growth period is in the middle stage of growth, and the peak occurs in the mature stage. The leaf area growth rate in this stage is 30.44cm 2 ~35.82cm 2 , which is 2.34 times the average growth rate of other stages. The leaf area accumulation rate of T2 treatment was the fastest during the rapid growth period, reaching 35.82 cm 2 , which is 1.04 times the average rate during this period. The average leaf area growth rate in the early growth period was 1.53 cm 2 ; The average growth rate of leaf area in the middle growth period is 15.43cm 2 The leaf area growth rate of the equal-row-spacing treatment from the middle growth stage to the mature stage of spinach during the whole growth period was significantly higher than that of the CK treatment, indicating that the equal-row-spacing treatment can effectively increase the leaf area growth rate during the rapid growth period of spinach.

[0064] As shown in Table 1, under different planting row spacing, the height of spinach plants was as follows: T2 treatment > T3 treatment > CK treatment > T1 treatment. The treatment with the highest spinach plant height was T2 treatment, which was 46.17 cm. The treatments T3 and CK were followed, with plant heights of 42.2 cm and 39.33 cm respectively. The treatment with the smallest plant height was T1 treatment, with a plant height of 38.33 cm. There was no significant difference in plant height between the treatments with equal row spacing, and the difference with the CK treatment was not significant. Figure 3 As shown in the figure, with the growth process of spinach, the accumulation of plant height in each treatment is gradually increasing, and the growth rate shows a trend from steady increase to gradual rapid increase with the passage of planting time. The starting point of the rapid increase in the growth rate of spinach plant height during the whole growth period is in the middle growth period, and the peak occurs in the maturity period. The plant height growth rate in this stage is 2.83cm / d~3.23cm / d. The plant height accumulation rate of T2 treatment in the rapid growth period is the fastest, reaching 3.23cm / d, which is 1.07 times the average rate of this period; the plant height accumulation of each treatment gradually increases with the growth process of spinach, with an average rate of 0.72cm / d in the early growth period and 2.03cm / d in the middle growth period. There is no significant difference in the accumulation of plant height among the treatments in the maturity period, indicating that different planting row spacings have little effect on the growth of spinach plant height.

[0065] Table 1 Leaf area per spinach plant under different planting row spacing (cm 2 ) and plant height (cm)

[0066]

[0067] Note: The values ​​in the table are mean ± standard deviation, different letters indicate significant differences among treatments, P ≤ 0.05, the same below.

[0068] Effect of different planting row spacing on the dry matter content of spinach in plastic greenhouses: As shown in Table 2, equal row spacing planting effectively increased the dry matter content of spinach. Compared with CK, the dry matter content of spinach under different planting row spacing treatments at different stages of the whole growth period increased to varying degrees.

[0069] The dry matter accumulation of spinach is mainly composed of leaves. From the germination stage to the early growth stage, the early growth of spinach plants is mainly based on plant height growth, and the leaf growth is relatively slow. Therefore, the dry matter accumulation rate is relatively slow at this stage. The treatment with the largest dry matter content in the early growth stage is T2 treatment, with a content of 7.53 kg / hm 2 From the early growth stage to the middle growth stage, the growth of spinach plants gradually accelerated, and the dry matter content increased significantly and began to show a pattern of higher content with larger row spacing. The highest content was 1604.26 kg / hm in the T3 treatment. 2Compared with CK, the dry matter content increased by 14.76%; the dry matter content of spinach continued to increase from the middle growth stage to the mature stage, mainly because the spinach leaves began to grow rapidly from the middle growth stage, and the leaf area increased significantly, but the difference between the treatments was not significant; the average dry matter content of the equal row spacing treatment from the mature stage to the harvest stage was 3864.78 kg / hm 2 , which was 6.52% higher than that of CK, and the highest content was found in T3 treatment, which was 4038.45 kg / hm 2 Compared with CK, the dry matter content increased by 10.55%, and the dry matter content gradually decreased with the decrease of planting row spacing. In summary, equal row spacing will affect the dry matter content of spinach during the whole growth period. Too narrow planting row spacing will affect the growth of leaves during the growth process, resulting in a decrease in dry matter accumulation. Because appropriately increasing the planting row spacing is beneficial to the growth of spinach plants, the equal row spacing of 20 cm can more effectively increase the dry matter accumulation of spinach during the rapid growth period, laying a material foundation for increasing yield.

[0070] Table 2 Dry matter content of spinach at different growth stages (kg / hm 2 )

[0071]

[0072] Water consumption characteristics of spinach in the whole growth period of plastic greenhouses with different planting row spacing: As shown in Table 3, the water consumption of spinach in the whole growth period is 87.40mm~107.69mm. Compared with CK, equal row spacing planting can significantly reduce the water consumption of spinach in the whole growth period, and the water consumption in the whole growth period tends to decrease gradually with the increase of planting row spacing, but different growth periods show different water consumption patterns. The water consumption of spinach in the whole growth period of different treatments is as follows: T1 treatment>T2 treatment>T3 treatment, among which T3 treatment has the least water consumption, which is 87.40mm, a decrease of 18.84% compared with CK. This may be because the soil space distribution of 20cm row spacing planting is more uniform, which is conducive to the absorption and utilization of soil water and reduces ineffective water consumption. The T3 treatment reduced the daily water consumption of spinach to varying degrees at different growth stages, reducing it by 15.78%, 0.72%, 20.95%, 23.34% and 64.81% in the germination stage, early growth stage, middle growth stage, maturity stage and harvest stage, respectively.

[0073] The water consumption in different growth periods was 31.65-38.01 mm in the germination period, 25.70-28.09 mm in the early growth period, 8.13-10.35 mm in the middle growth period, 15.43-20.12 mm in the maturity period, and 4.02-11.36 mm in the harvest period. The water consumption of spinach during the germination period was 31.65-38.01 mm, among which the daily water consumption intensity of the CK treatment was the largest, which was 3.80 mm / d. As shown in Table 4, the daily water consumption intensity of each treatment with equal row spacing was less than that of the broadcast treatment, and the larger the row spacing, the smaller the daily water consumption intensity. The water consumption of spinach in the early growth period was 25.70-28.09 mm, and there was no significant difference or pattern in the daily water consumption intensity among the treatments. In order to ensure the smooth emergence of spinach and the survival of seedlings during the germination period after sowing, the soil should be kept moist, so the amount of irrigation during the germination period and the early growth period was large, and the evaporation of the exposed soil in the early stage was large, and the soil water consumption was large. The water consumption of spinach in the middle growth period was 8.13-10.35 mm, among which the daily water consumption intensity of CK treatment was the highest, which was 1.48 mm / d. The daily water consumption intensity of each treatment with equal row spacing was less than that of the broadcasting treatment, and the smaller the row spacing, the smaller the daily water consumption intensity. The water consumption of spinach in the mature period was 15.43-20.12 mm, among which the daily water consumption intensity of CK treatment was the highest, which was 1.48 mm / d. The daily water consumption intensity of each treatment with equal row spacing was less than that of the broadcasting treatment, and the larger the row spacing, the smaller the daily water consumption intensity. In the mature stage, the height and leaves of spinach are growing rapidly, and the water demand of the plant increases. Maintaining sufficient water and light can promote the growth of spinach and the absorption of nutrients. The water consumption of spinach in the harvest period was 4.02-11.36 mm, and the daily water consumption intensity of each treatment with equal row spacing was less than that of the broadcasting treatment. During the whole growth period of spinach, the water consumption of spinach in the germination period, early growth period and mature period was higher than that in other periods.

[0074] Table 3 Water consumption of spinach at different growth stages (mm)

[0075]

[0076] Table 4 Water consumption intensity of spinach at different growth stages (mm / d)

[0077]

[0078] Effects of different planting row spacing on the yield and water use efficiency of spinach in plastic greenhouses: As shown in Table 5, different planting row spacings have a significant effect on the yield and water use efficiency of spinach in plastic greenhouses. Compared with CK, equal row spacing planting has a significant effect of increasing yield and saving water, with an increase rate of 4.20% to 10.04%, and water use efficiency increased by 12.87% to 26.52%. Under different planting row spacings, the yield of spinach is as follows: T3 treatment>T2 treatment>T1 treatment, and the yield of T3 treatment is 60166.97kg / hm 2, the yield of T2 treatment is 57555.84kg / hm 2 , T1 treatment yield is 56500.28kg / hm 2 CK treatment yield is 54125.4kg / hm 2 .

[0079] The yield of the treatments with different row spacings was significantly increased compared with CK. There were also significant differences in yield between the treatments with equal row spacings. The yield of T3 treatment was the highest and significantly higher than that of CK, T1 treatment and T2 treatment, increasing by 10.04%, 6.09% and 4.34% respectively. Under different row spacings, the water use efficiency of spinach was proportional to the yield. The water use efficiency of spinach was as follows: T3 treatment > T2 treatment > T1 treatment. The water use efficiency of T3 treatment was 45.89kg / mm, that of T2 treatment was 40.19kg / mm, that of T1 treatment was 38.70kg / mm, and that of CK treatment was 33.72kg / mm. The water use efficiency of the treatments with different row spacings was significantly increased compared with CK. The water use efficiency of T3 treatment was the highest and significantly higher than that of CK, T1 treatment and T2 treatment, increasing by 26.52%, 15.67% and 12.42% respectively. Under different planting row spacings, the dry weight of spinach plants was as follows: T3 treatment > T2 treatment > T1 treatment. The dry weight of T3 treatment plants was 33.06 g, the dry weight of T2 treatment plants was 31.62 g, the dry weight of T1 treatment plants was 31.05 g, and the dry weight of CK treatment plants was 29.74 g. The dry weight of spinach plants and the yield of the group showed the same trend, that is, as the planting row spacing increased, the individual and group yields gradually increased, and the water use efficiency gradually improved. Spinach needs a reasonable spatial structure during its growth. Too dense growth is not conducive to the accumulation of leaf products, thus affecting individual and group yields. Properly increasing the planting row spacing can improve the quality of spinach plants and group yields, thereby improving water use efficiency.

[0080] Table 5 Spinach yield (kg / hm2) under different planting row spacing 2 ), dry weight per plant (g) and water use efficiency (kg / mm2)

[0081]

[0082] In summary, this embodiment shows that too narrow planting row spacing will affect the accumulation of leaves per spinach plant, poor group growth and development, and ultimately affect the yield; the yield increases with the increase of planting row spacing, and the T3 treatment with a planting row spacing of 20 cm has the highest yield, which is significantly different from the CK, T1 and T2 treatments.

[0083] As the growth period of plastic greenhouse spinach progresses, the plant height and leaf area of ​​each treatment of spinach increase with the change of the growth period, and the leaf area of ​​spinach shows a trend of slow growth in the early and middle stages and rapid growth in the late stages. The leaf area and plant height change greatly from the middle growth stage to the mature stage, while they remain stable or slightly increase in the early growth stage and harvest stage; the plant height and leaf area under different planting row spacings are as follows: equal row spacing 15cm>equal row spacing 20cm>equal row spacing 10cm. Planting row spacing that is too wide or too narrow is not conducive to the growth of leaf area throughout the growth period, especially in the middle and late growth stages, when the development of spinach plants intensifies. Too narrow planting row spacing will cause poor growth and development of the plants and affect the accumulation of leaf area.

[0084] Under the row planting mode, the dry matter content of different planting row spacing treatments was significantly higher than that of traditional broadcast planting, which effectively increased the dry matter accumulation of spinach during its growth process to varying degrees. The treatment with the highest dry matter content was 20 cm spacing, which increased the dry matter content by 14.76% compared with CK. During the whole growth period, the relationship between different planting row spacing and dry matter accumulation showed that the smaller the planting row spacing, the less dry matter content. The growth law of spinach during the whole growth period was that the dry matter accumulation rate was slow from the germination stage to the early growth stage, and the plant accumulation rate gradually accelerated from the middle growth stage to the harvest stage. The dry matter accumulation rate of 20 cm spacing was faster from the maturity stage to the harvest stage, indicating that the wider spacing was conducive to the dry matter accumulation of spinach in the later growth stage; the dry matter content was mainly composed of spinach leaves, and too narrow spacing affected the development of spinach leaves, which had a greater impact on the dry matter accumulation of spinach. The yield of spinach planted with different row spacings was significantly increased compared with CK. The yield of the treatment with 20 cm row spacing was the highest and significantly higher than that of CK, 10 cm row spacing and 15 cm row spacing, increasing by 10.04%, 6.09% and 4.34% respectively. The change trend of spinach yield with different row spacings was consistent with the change trend of dry matter accumulation, indicating that dry matter accumulation would significantly affect the final yield. The dry weight of spinach plant and group yield showed the same trend, that is, as the row spacing increased, the individual and group yields gradually increased, indicating that spinach needs a reasonable spatial structure during its growth. Too dense growth is not conducive to the growth of spinach leaves and the accumulation of products in the middle and late stages of growth, thus affecting the individual and group yields of the plants. Properly increasing the row spacing can improve the quality of spinach plants and group yields.

[0085] Under the row planting mode, different row spacing treatments can significantly reduce the water consumption of spinach during the entire growth period compared with the traditional broadcasting treatment. The water consumption during the entire growth period shows a trend of gradually decreasing with the gradual increase of the row spacing. The water consumption during the entire growth period is as follows: equal row spacing 10cm> equal row spacing 15cm> equal row spacing 20cm. Among them, the equal row spacing 20cm treatment has the least water consumption, which is 87.40mm, which is 18.84% less than CK. During the entire growth period of spinach, the water consumption of spinach in the germination period, early growth period and maturity period is significantly higher than that in other periods. Different planting row spacings have a significant effect on the water use efficiency of spinach. Compared with CK, equal row spacing planting has a significant effect of increasing production and saving water, and the water use efficiency has increased by 12.87% to 26.52%. Among them, the treatment with equal row spacing of 20 cm has the highest yield and water use efficiency, which is significantly higher than CK and equal row spacing of 10 cm and 15 cm, and the water use efficiency has increased by 26.52%, 15.67%, and 12.42%, respectively. Improving water use efficiency is mainly reflected in increasing spinach yield and reducing spinach water consumption. This experimental study shows that compared with traditional broadcast planting, different treatments of plastic greenhouse spinach strip planting can increase production and save water to varying degrees, and with the gradual increase of planting row spacing, the yield gradually increases and the water consumption gradually decreases, thereby effectively improving the water use efficiency of spinach throughout its growth period.

[0086] Specific embodiment 2: The water-saving irrigation maintenance measure is that in step S2, wide and narrow row sowing is adopted, and the sowing amount is 30kg / hm 2 The planting belt width is 15 cm, the spacing between planting belts is 20 cm, a drip irrigation belt 1 is laid in the planting belt, and the spacing between drip irrigation belts 1 is 35 cm. The total amount of irrigation water in the whole growth period in step S3 is 1075.2m 3 / hm 2 .

[0087] The test materials and test sites used in this embodiment are the same as those in Example 1. On the basis of screening out the best planting row spacing of 20 cm, this experiment has three different planting modes: S (broadcast planting), T (equal row spacing strip planting, planting row spacing of 20 cm) and TR (wide and narrow row strip planting, planting row spacing of 20 cm). Among them, there are three different tube-row ratios for wide and narrow row planting, namely TR3 (three rows in one tube, a planting belt width of 15 cm, and a drip irrigation tape spacing of 35 cm), TR4 (four rows in one tube, a planting belt width of 22.5 cm, and a drip irrigation tape spacing of 43 cm) and TR5 (five rows in one tube, a planting belt width of 30 cm, and a drip irrigation tape spacing of 50 cm). There are a total of five treatments in the experiment, and the area of ​​each treatment plot is 27 m2 (row length 4.5 m, width 6 m). Sowing was carried out on March 19, 2022, and the yield was measured on April 26, 2022. The whole growth period is 38 days. The sowing rate is 30 kg / hm 2The drip irrigation method was adopted, and the irrigation amount was the same between each treatment. The total irrigation amount during the whole growth period was 1075.2m3 / hm 2 Before sowing, use bio-organic fertilizer as base fertilizer at a dosage of 15,000 kg / hm2. 2 There is no difference in management between different treatments, and weeding, pest control and agricultural operation measures are carried out in combination with local actual conditions. This experiment divides the entire growth period of spinach into five stages: germination, early growth, mid-growth, maturity and harvest. The germination period is when spinach is sown and the seeds break through the soil from the seed coat, and begin to germinate and grow until the first pair of true leaves grow; the early growth period is when spinach grows the first true leaf, the root system gradually expands, the leaves become larger, and about 2 leaves grow; the mid-growth period is when the roots and leaves gradually grow to form a relatively complete plant, and about 5 to 6 leaves grow; the maturity period is when the color of spinach leaves gradually darkens and the leaves become thicker, reaching maturity, and about 7 to 11 leaves grow; the harvest period is the period for harvesting and measuring the yield of spinach in this experiment.

[0088] Determination of spinach growth traits: After spinach seedlings emerge, three plants with uniform growth are selected for sampling at the early, middle and mature stages of spinach growth, and repeated three times. The length (the distance from the base of the petiole to the tip of the leaf) and width (the maximum width in the vertical direction of the main vein) of each leaf are measured with a ruler, the number of leaves of the plant is recorded, and the leaf area of ​​each plant is calculated, which is leaf area of ​​each plant = leaf length × leaf width × correction coefficient (the coefficient of expanded leaves is 0.75).

[0089] Leaf area growth rate in each stage = leaf area growth in each stage (g) / stage time (d)

[0090] Determination of spinach dry matter: Three plants with uniform growth were selected in each plot for sampling at the mid-growth period, maturity period and harvest period of spinach, and the sampling was repeated three times. The fresh weight of the aboveground and underground parts of the plants was determined by weighing method. The fresh samples were divided into aboveground and underground parts, and then washed clean at 105℃ for 30 minutes and dried at a constant temperature of 80℃ to constant weight. The dry matter of the aboveground and underground parts of the plants was weighed with an electronic scale. The total dry matter content of spinach = aboveground dry matter + underground dry matter.

[0091] Determination of spinach quality indicators: Three spinach plants were selected for each treatment, and the samples were separated according to the aboveground and underground parts. After crushing, they were sieved with a 0.5 mm sieve and boiled with H2SO4-H2O2 for the determination of nutritional indicators. The soluble protein content was determined by Coomassie Brilliant Blue G-250 staining method; the vitamin C content was determined by 2,6-dichlorophenol indophenol method; and the soluble sugar content was determined by anthrone colorimetry.

[0092] Among them, the change of soil moisture, the determination of spinach yield, and the calculation of spinach water use efficiency are the same as those in Example 1.

[0093] Effects of different planting patterns on leaf area of ​​spinach in plastic greenhouses: Figure 5 As shown in the figure, different planting patterns have a significant effect on the leaf area per plant of spinach in plastic greenhouses. Compared with broadcasting (S) and equal row spacing planting (T), wide and narrow row planting significantly promoted the accumulation of leaf area per plant during the growth period of spinach, with an average increase of 3.24% to 14.73%. Among them, the leaf area of ​​TR3 treatment at maturity was the largest, 388.23 cm2, which was 14.73% higher than that of S treatment. The change of leaf area in the early growth period was as follows: TR5 treatment > TR4 treatment > TR3 treatment > T treatment > S treatment; the change of leaf area in the middle growth period was as follows: TR4 treatment > TR5 treatment > TR3 treatment > T treatment > S treatment; the change of leaf area in the mature period was as follows: TR3 treatment > T treatment > TR4 treatment > TR5 treatment > S treatment. The wide and narrow row planting treatments significantly promoted the accumulation of leaf area per plant in the early and middle growth period of spinach. The wide and narrow row planting patterns showed great differences at different stages of the whole growth period of spinach. At maturity, there were small differences between the different tube-row ratios in the wide-narrow row planting pattern, and the leaf area of ​​each treatment gradually decreased with the gradual increase of the tube-row ratio. The tube-row ratio of wide-narrow row planting would affect the accumulation of spinach leaf area and was inversely proportional. Figure 6 This is a graph showing the average growth rate of leaf area per spinach plant. Figure 5 It can be seen that the leaf area of ​​spinach shows a trend of slow growth in the early growth stage and rapid growth in the middle and late stages as the growth process progresses. The starting point of the rapid increase in the growth rate of spinach leaf area during the whole growth period is the middle growth stage, and the peak occurs in the mature stage. The leaf area growth rate in this stage is 32.00cm2~36.19cm2, among which the leaf area accumulation rate of TR3 treatment is the fastest, reaching 36.19cm2, which is 1.10 times the average rate of this period. The average growth rate in the early growth stage is 1.67cm2, and the average growth rate of leaf area in the middle growth stage is 16.69cm2. During the whole growth period of spinach, there are significant differences in growth rates between different planting patterns from the middle growth stage to the mature stage. The leaf area growth rate of different planting patterns is significantly higher than that of S treatment, indicating that both equal row spacing planting and wide and narrow row planting can effectively increase the leaf area growth rate during the rapid growth period of spinach growth period.

[0094] Effects of different planting patterns on dry matter quality of spinach at different growth stages in plastic greenhouses: Figure 7As shown in the figure, at different stages of the whole growth period, the dry matter accumulation of spinach increased to varying degrees compared with the S treatment in equal row spacing and wide and narrow row planting. As the spinach growth process reached the middle growth period, the spinach leaves began to grow rapidly, the leaf area increased significantly, and the dry matter accumulation rate of spinach increased significantly and reached the rapid growth period of the whole growth period. From the germination period to the middle growth period, the dry matter accumulation between the treatments of different planting patterns was as follows: TR3 treatment>T treatment>TR4 treatment>TR5 treatment>S treatment. The treatment with the highest accumulation was TR3 treatment, with an accumulation of 1647.78 kg / hm2. 2 There was no obvious pattern among the treatments of different planting patterns. From the middle growth period to the maturity period, the dry matter accumulation among the treatments of different planting patterns was as follows: TR4 treatment > TR5 treatment > TR3 treatment > T treatment > S treatment. The treatment with the highest accumulation was TR4 treatment, with an accumulation of 2486.09 kg / hm2. 2 There was no obvious pattern among the treatments of different planting patterns. From maturity to harvest, the dry matter accumulation among the treatments of different planting patterns was as follows: TR3 treatment > T treatment > TR4 treatment > TR5 treatment > S treatment. The treatment with the highest accumulation was TR3 treatment, with an accumulation of 4101.24 kg / hm2. 2 In the wide and narrow row planting, the dry matter accumulation tended to decrease gradually with the increase of the tube-row ratio. The treatments of equal row spacing planting and wide and narrow row planting at the harvest period were all improved compared with the S treatment. When the tube-row ratio of wide and narrow row planting was "one tube and three rows", the dry matter accumulation of the crop group increased significantly. When the tube-row ratio increased to "one tube and four rows" and "one tube and five rows", the dry matter accumulation decreased significantly. This may be due to the fact that the competition for resources between individual crops intensified due to the excessive number of suitable planting rows, and the dry matter accumulation capacity of individual plants decreased, resulting in a decrease in the dry matter accumulation of the group. In summary, the T treatment of equal row spacing and the TR treatment of wide and narrow row can affect the accumulation of dry matter to a certain extent. Among them, the TR3 treatment can more effectively increase the dry matter accumulation of spinach during the rapid growth period, laying a material foundation for increasing yield.

[0095] Effects of different planting patterns on the dynamic characteristics of water consumption of spinach in plastic greenhouses: As shown in Table 6, the water consumption of spinach in different treatments during the whole growth period was 84.30-107.69 mm. Compared with broadcast planting, different planting patterns, equal row spacing planting and wide and narrow row planting can significantly reduce the water consumption of spinach during the whole growth period. The water consumption of wide and narrow row planting with different pipe-row ratio configurations during the whole growth period showed a trend of gradual decrease with the gradual increase of pipe-row ratio, which was TR5 treatment>TR4 treatment>TR3 treatment. Among them, TR3 treatment had the least water consumption, which was 84.39 mm, which was 24.42% less than S treatment and 3.44% less than T treatment. The water consumption in different growth periods was 30.48-38.08 mm in germination period, 25.18-28.09 mm in early growth period, 8.01-10.35 mm in middle growth period, 14.59-20.12 mm in maturity period, and 4.02-11.36 mm in harvest period. Different planting patterns showed different water consumption patterns in different growth periods. As shown in Table 7, during the germination period, the daily water consumption intensity of the S treatment and the TR5 treatment was the highest, which was 3.80 mm / d and 3.81 mm / d, respectively; the daily water consumption intensity of the TR3 treatment was the lowest, which was 3.05 mm / d; the daily water consumption intensity of the TR3 treatment was reduced by 19.74% compared with the S treatment, and by 3.79% compared with the T treatment; during this period, the daily water consumption intensity of the wide and narrow row planting pattern gradually increased with the increase of the tube-row ratio. In the early growth period, the daily water consumption intensity of the S treatment and the T treatment was the highest, which was 2.79 mm / d and 2.81 mm / d, respectively; the daily water consumption intensity of the TR3 treatment was the lowest, which was 2.52 mm / d; the daily water consumption intensity of the TR3 treatment was reduced by 9.68% compared with the S treatment, and by 10.32% compared with the T treatment; during this period, there was no significant difference in the daily water consumption intensity between the treatments and no obvious pattern. In the middle growth period, the daily water consumption intensity of S treatment and TR5 treatment was the highest, which was 1.48mm / d and 1.39mm / d respectively; the daily water consumption intensity of TR3 treatment was the lowest, which was 1.14mm / d; the daily water consumption intensity of TR3 treatment was reduced by 22.97% compared with S treatment, and by 2.56% compared with T treatment; during this period, the daily water consumption intensity of wide-narrow row planting mode gradually increased with the increase of pipe-row ratio. In the mature period, the daily water consumption intensity of S treatment and TR4 treatment was the highest, which was 2.87mm / d and 3.05mm / d respectively; the daily water consumption intensity of TR3 treatment was the lowest, which was 2.08mm / d; the daily water consumption intensity of TR3 treatment was reduced by 27.53% compared with S treatment, and by 5.45% compared with T treatment. During the harvest period, the daily water consumption intensities of the S and TR5 treatments were the highest, at 1.62 mm / d and 1.67 mm / d respectively; the daily water consumption intensity of the T treatment was the lowest, at 0.57 mm / d; the daily water consumption intensity of the TR3 treatment was reduced by 46.04% compared with the S treatment; during this period, the daily water consumption intensity of the wide-narrow row planting pattern gradually increased with the increase of the tube-row ratio.In summary, different planting patterns have a significant impact on the water consumption of spinach during its growing period. Compared with broadcast planting, equal row spacing planting and wide and narrow row planting can significantly reduce the water consumption and daily water consumption intensity of spinach at different growing periods. Among them, the "one tube and three rows" drip irrigation configuration of the wide and narrow row planting pattern showed the lowest daily water consumption intensity from the germination stage to the maturity stage, effectively reducing water consumption.

[0096] Table 6 Water consumption of spinach at different growth stages (mm)

[0097]

[0098]

[0099] Table 7 Water consumption intensity of spinach at different growth stages (mm / d)

[0100]

[0101] Effects of different planting patterns on the yield and water use efficiency of spinach in plastic greenhouses: As shown in Table 8, different planting patterns have significant effects on yield and water use efficiency. The treatments of equal row spacing and wide and narrow row planting have significant yield-increasing and water-saving effects compared with broadcast planting (S), and the group yield increase rate is 5.6% to 12.28%. In the wide and narrow row planting pattern, the yield of spinach is as follows: TR3 treatment > TR4 treatment > TR5 treatment, and the yield of TR3 treatment is 61701.6kg / hm 2 The yield of TR4 treatment is 57583.04kg / hm 2 The yield of TR5 treatment is 57333.62kg / hm 2, the wide and narrow row planting with different pipe-row ratio configurations significantly increased the yield compared with CK, and there were also obvious differences between different treatments. Among them, the wide and narrow row planting "one pipe 3 rows" configuration (TR3) had the highest yield, which increased by 2.48%, 6.67% and 7.08% compared with the T treatment, TR4 treatment and TR5 treatment, respectively. Under the wide and narrow row planting mode, the water use efficiency of spinach was proportional to the yield. The water use efficiency of spinach was as follows: TR3 treatment > TR4 treatment > TR5 treatment. The water use efficiency of TR3 treatment was 48.74kg / mm, the water use efficiency of TR4 treatment was 40.43kg / mm, and the water use efficiency of TR5 treatment was 36.94kg / mm; the wide and narrow row planting with different pipe-row ratio configurations significantly improved the water use efficiency compared with CK, among which the wide and narrow row planting "one pipe 3 rows" configuration (TR3) had the highest water use efficiency, which increased by 5.85%, 17.05% and 24.21% compared with the T treatment, TR4 treatment and TR5 treatment, respectively. Under the wide-narrow row planting mode, the dry weight of spinach per plant was as follows: TR3 treatment > TR4 treatment > TR5 treatment, with the dry weight of TR3 treatment being 33.90g, TR4 treatment being 31.64g, TR5 treatment being 31.50g, and CK treatment being 29.74g. The dry weight of spinach per plant showed the same trend as the group yield, that is, as the tube-row ratio decreased, the individual and group yields gradually increased, and the water use efficiency gradually improved. In the pipe-row ratio configuration of wide-narrow row planting, as the pipe-row ratio of "one pipe and three rows" configuration gradually expanded to "one pipe and four rows" and "one pipe and five rows", the dry weight of spinach single plant and group yield gradually decreased, and the water use efficiency also gradually decreased. This may be because the spinach yield is mainly composed of leaves. Excessive expansion of the pipe-row ratio causes serious overlap of group leaves, which block each other and affect the accumulation of leaf products. At the same time, spinach farther away from the drip irrigation belt is subject to water stress, resulting in varying degrees of yield reduction. The "one pipe and three rows" drip irrigation configuration makes the water distribution in the soil more uniform. Compared with the configuration of a large pipe-row ratio, it reduces the difference in soil water distribution, improves the water condition of spinach farther away, and is more conducive to the accumulation of dry matter in the side rows of spinach.

[0102] Table 8 Spinach yield and water use efficiency under different planting patterns

[0103]

[0104] Effects of different planting patterns on the quality of spinach in plastic greenhouses: As shown in Table 3-4, different planting patterns have a significant effect on the quality of spinach. The effects of different planting patterns on vitamin C content are as follows: TR3 treatment > TR4 treatment > T treatment > S treatment > TR5 treatment. The vitamin C content of each treatment is significantly different, among which the vitamin C content of TR3 treatment is the highest, which is 26.69 mg / 100g; in the wide-narrow row planting pattern, the vitamin C content gradually decreases with the increase of the tube-row ratio. The effects of different planting patterns on TSS content are as follows: TR3 treatment > S treatment > T treatment > TR5 treatment > TR4 treatment. The TSS content of each treatment is significantly different, among which the TSS content of TR3 treatment is the highest, which is 2.1%; in the wide-narrow row planting pattern, the larger the tube-row ratio, the smaller the TSS content. The effects of different planting patterns on soluble protein content are as follows: TR3 treatment > S treatment > T treatment > TR5 treatment > TR4 treatment. The soluble protein content of each treatment in the wide-narrow row planting mode was significantly different, among which the soluble protein content of TR3 treatment was the highest, which was 5.16 mg / g; in the wide-narrow row planting mode, the larger the tube-row ratio, the lower the soluble protein content. The effects of different planting modes on the soluble sugar content were as follows: TR3 treatment>S treatment>T treatment>TR4 treatment>TR5 treatment. The soluble sugar content of each treatment was significantly different, among which the soluble sugar content of TR3 treatment was the highest, which was 5.54 mg / g; in the wide-narrow row planting mode, the soluble sugar content gradually decreased with the increase of the tube-row ratio. In summary, the planting mode of "one tube and three rows" configuration of wide-narrow row planting can effectively improve the vitamin C content, TSS content, soluble protein content, and soluble sugar content, and it performs best in all nutritional qualities. In the wide-narrow row planting mode, all quality indicators showed the rule of decreasing quality with the increase of the tube-row ratio. It may be because the larger the tube-row ratio, the dense growth of plants per unit area affects the absorption of spinach nutrients.

[0105] Table 9 Nutritional quality of spinach under different planting patterns

[0106]

[0107] The dry weight of spinach per plant and the group yield during the entire growth period were the highest in the TR3 treatment ("one tube, three rows"). The TR3 treatment is a suitable wide-narrow row configuration for spinach in plastic greenhouses, which can not only increase the yield of spinach, but also significantly improve the water use efficiency. Under this wide-narrow row configuration, the spinach yield increased by 12.28% compared with broadcast planting (S), the water use efficiency increased by 12.28%, and all nutritional quality indicators performed optimally. Therefore, in the process of spinach cultivation and production in plastic greenhouses, it is recommended to adopt the planting mode of "one tube, three rows" with wide-narrow row sowing.

[0108] Compared with broadcasting (S) and equal row spacing (T), wide-narrow row planting significantly promoted the accumulation of leaf area per plant in the early and middle stages of spinach growth, increasing by 3.24% to 14.73%. As the growth period progressed, the leaf area of ​​spinach in each treatment increased with the change of the growth period, and the leaf area of ​​spinach showed a trend of slow growth in the early stage and rapid growth in the middle and late stages with the growth process. The change trend of leaf area from the middle stage of growth to maturity was larger, while it remained stable or slightly increased in the early stage of growth and harvest. Under the wide-narrow row planting mode, the leaf area size of different tube-row ratio treatments was as follows: one tube 3 rows (TR3) > one tube 4 rows (TR4) > one tube 5 rows (TR5). There were certain differences between the different tube-row ratio treatments of wide-narrow row planting, and the leaf area of ​​each treatment gradually decreased with the gradual increase of the tube-row ratio. The tube-row ratio of wide-narrow row planting affected the accumulation of spinach leaf area and was inversely proportional.

[0109] Under different planting patterns, equal row spacing and wide and narrow row planting treatments effectively increased the dry matter accumulation of spinach growth to varying degrees. When the tube-row ratio of wide and narrow row planting was "one tube and three rows", the dry matter accumulation of the crop group increased significantly. When the tube-row ratio increased to "one tube and four rows" and "one tube and five rows", the dry matter accumulation decreased significantly. Exceeding the appropriate number of planting rows will lead to intensified competition for resources between individual crops, thereby affecting the accumulation of leaf area, resulting in a decrease in the dry matter accumulation capacity of individual plants and a decrease in the dry matter accumulation of the group. This is also the reason why the tube-row ratio is inversely proportional to the yield. Spinach yield is mainly composed of leaves. Excessive expansion of the tube-row ratio causes serious overlap of the group leaf configuration, blocking each other, and affecting the accumulation of leaf products.

[0110] Compared with traditional broadcast planting, different planting patterns can significantly reduce the water consumption of spinach during the whole growth period. Both equal row spacing planting and wide and narrow row planting can significantly reduce the water consumption of spinach during the whole growth period. The water consumption of different pipe-row ratio configurations of wide and narrow row planting during the whole growth period shows a trend of gradually decreasing with the increase of pipe-row ratio, which is TR5 treatment>TR4 treatment>TR3 treatment. Among them, the one pipe and three rows (TR3) treatment has the lowest water consumption, which is 84.39 mm, which is 24.42% less than broadcast planting and 3.44% less than equal row spacing. Compared with broadcast planting (S), equal row spacing planting and wide and narrow row planting have significant yield-increasing and water-saving effects, and the group yield increase rate is 5.6% to 12.28%; among them, the "one pipe and three rows" configuration (TR3) of wide and narrow row planting has the highest yield and water use efficiency, which is 2.48%, 6.67% and 7.08% higher than T treatment, TR4 treatment and TR5 treatment, respectively. The water use efficiency increased by 5.85%, 17.05% and 24.21% respectively. Specific embodiment 3:

[0112] The water-saving irrigation maintenance measure is that in step S2, wide-narrow row sowing is adopted, and the sowing amount is 30kg / hm 2 The planting belt width is 15 cm, the spacing between planting belts is 20 cm, a drip irrigation belt 1 is laid in the planting belt, and the spacing between drip irrigation belts 1 is 35 cm. The total amount of irrigation water in the whole growth period in step S3 is 1075.2m 3 / hm 2 , and the ground is covered to form a covering layer 2, the covering material is rice husk or corn stalk, and the thickness is 1-2cm.

[0113] The test materials and test sites used in this example are the same as those in Example 1. Two covering methods are set up in this test, namely T1 (rice husk covering) and T2 (corn stalk covering), with bare land as the control (T3, CK), a total of 3 treatments, each treatment is repeated 3 times. The plot area is 27m2. The sowing time is April 28, 2023, the yield measurement time is May 31, 2023, and the whole growth period is 33 days. The sowing rate is 30kg / hm 2 . A wide and narrow row planting mode is adopted, and a drip irrigation pipe configuration of 3 rows is used. The corn straw mulch is crushed corn straw and then covered. The thickness of rice husk and straw covering each plot is 1-2 cm. Drip irrigation is adopted, and the irrigation treatment is unified. The irrigation amount is the same between each treatment. Before sowing, bio-organic fertilizer is used as base fertilizer, and the amount used is 15000kg / hm 2 There was no difference in fertilization between different treatments, and other field management measures such as weeding, pest control and agricultural operations were carried out in combination with local conditions. This experiment divided the entire growth period of spinach into four stages: germination, early growth, mid-growth, and maturity. The germination period is when spinach is sown until the seeds break through the soil from the seed coat, begin to germinate and grow until the first pair of true leaves grow; the early growth period is when spinach grows the first true leaf, the root system gradually expands, the leaves become larger, and about 2 leaves grow; the mid-growth period is when the roots and leaves gradually grow to form a relatively complete plant, and about 5 to 6 leaves grow; the maturity period is when the color of spinach leaves gradually darkens and the leaves become thicker, reaching maturity, and about 7 to 11 leaves grow.

[0114] The detection items and methods of this embodiment are the same as those of Embodiment 1.

[0115] Effects of different covering treatments on the growth of spinach leaves in plastic greenhouses: As shown in Table 10, compared with the control (no covering), rice husk covering and straw covering significantly promoted the leaf area of ​​spinach per plant, with an average increase of 3.92% to 12.31%. Under different covering methods, the leaf area of ​​spinach per plant was T2 treatment>T1 treatment>CK treatment. The leaf area of ​​spinach under CK treatment was smaller than that of T1 treatment and T2 treatment. There was no significant difference between different coverings. The treatment with the largest leaf area per plant was straw covering, with a leaf area of ​​374.59 cm2, and the treatment with the smallest leaf area per plant was the control (no covering) treatment, which was 328.50 cm2; the straw covering treatment increased the leaf area per plant of spinach, which was an average of 12.30% higher than the no covering treatment. Figure 8 The average growth rate of leaf area per spinach plant under different planting modes is shown in the figure. Figure 8 It can be seen that the leaf area of ​​spinach shows a trend of rapid growth in the middle stage and gradual decline in the later stage as the growth process progresses. The starting point of the rapid increase in the growth rate of spinach leaf area during the whole growth period is from the early growth stage to the middle growth stage, and the peak occurs in the middle growth stage. The leaf area growth rate in this stage is 22.99cm2~25.56cm2, which is 2.22 times the average growth rate in other stages. The leaf area accumulation rate of T2 treatment in the rapid growth period is the fastest, reaching 25.56cm2, which is 1.07 times the average rate of this period. The average growth rate of leaf area in the early growth stage is 2.42cm2; the average growth rate of leaf area in the middle growth stage is 23.99cm2; and the average growth rate of leaf area in the late growth stage is 25.56cm2.

[0116] Effects of different treatments on the growth of spinach plant height in plastic greenhouses: As shown in Table 10, compared with the control (no covering), rice husk covering and straw covering significantly promoted the plant height of spinach. Under different covering methods, the plant height of spinach was T1 treatment>T2 treatment>CK treatment. The plant height of spinach under CK treatment was significantly smaller than that of T1 treatment and T2 treatment. There was no significant difference between rice husk covering and straw covering. The treatment with the largest plant height was rice husk covering, with a plant height of 41.13 cm, followed by straw covering, with a plant height of 39.31 cm. The treatment with the smallest plant height was the control (no covering) treatment, with a plant height of 29.02 cm. The rice husk covering treatment increased the leaf area per plant of spinach, which was an average of 29.44% higher than the no covering treatment. Fig. 9 is the growth rate of spinach plant height under different covering methods, Fig. 9It can be seen that with the growth process of spinach, the accumulation of plant height in each treatment is gradually increasing, and the plant height of spinach shows a trend of gradually rising slowly with the growth process. The peak of the growth rate of spinach plant height during the whole growth period appears in the mature stage, and the plant height growth rate in this stage is 1.28cm / d~2.10cm / d. The plant height growth rate of T2 treatment in the rapid growth period is the fastest, reaching 2.10cm / d, which is 1.17 times the average rate of this period. The average growth rate of plant height in the early growth stage is 1.46cm / d, and the average growth rate of leaf area in the middle growth stage is 1.53cm2 / d.

[0117] Table 10 Leaf area of ​​spinach per plant under different covering methods (cm 2 ) and plant height (cm)

[0118]

[0119] Effects of different covering modes on dry matter quality of spinach in plastic greenhouses at different growth stages: As shown in Table 4-2, both rice husk covering and straw covering effectively increased the dry matter content of spinach per plant. Compared with CK, the dry matter content of spinach per plant under different covering methods at different stages of the whole growth period increased to varying degrees. In the early growth stage, the dry matter content of spinach per plant under different covering methods was T2 treatment>T1 treatment>CK treatment, among which the dry matter content of straw covering was slightly greater than that of rice husk covering and no covering treatment, and the difference between the treatments was not significant. From the sowing period to the early growth stage, the dry matter accumulation rate of spinach per plant was slow, with an average growth rate of 0.03g / plant. In the middle growth stage, the dry matter accumulation of spinach per plant under different covering methods was T2 treatment>CK treatment>T1 treatment, among which the dry matter content of straw covering was slightly greater than that of rice husk covering and no covering treatment, and the difference between the treatments was not significant. From the early growth stage to the middle growth stage, the plant growth gradually accelerated, and the growth rate increased rapidly, with an average growth rate of 0.12g / plant. During the maturity period, the dry matter content of spinach plants under different mulching methods was as follows: T2 treatment>T1 treatment>CK treatment, among which the dry matter content of the plants covered with straw was greater than that of the treatments covered with rice husk and without mulching. The highest content was in the T1 treatment from the middle growth to maturity stage, which was 2.28g / plant, and the dry matter content of the plants increased by 29.83% compared with CK. The dry matter content of the T2 treatment was 2.16g / plant, which increased by 26.17% compared with CK; during this period, the dry matter content of spinach plants continued to increase, and the growth rates of the T1 and T2 treatments continued to increase, but the growth rate of the CK treatment decreased significantly. In summary, the mulching treatment affects the accumulation of dry matter per plant, among which rice husk mulching and straw mulching can effectively increase the dry matter content of spinach during the rapid growth period, laying a material foundation for increasing yield.

[0120] Table 11 Dry matter content of spinach per plant during the whole growth period under different covering methods (g)

[0121]

[0122] Effects of different covering treatments on soil moisture content of spinach in plastic greenhouses: Changes in soil moisture content at a depth of 0 to 40 cm during the growth period of spinach Fig.10As shown in the figure, soil moisture is significantly affected by the mulching method. With the increase of soil depth, the fluctuation difference of soil moisture under different treatments gradually decreases. At the depth of 0-10 cm soil layer, the average moisture content of T2 (straw mulching) treatment is 11.56% and 10.77% higher than that of CK and T1 treatments, respectively. The average soil moisture content of the whole growth period at the depth of 0-10 cm soil layer is as follows: T2 treatment>T1 treatment>CK treatment. During the whole growth period, the soil moisture content of straw mulching treatment from germination stage to mid-growth stage is higher than that of T1 treatment and CK treatment. At the depth of 10-20 cm soil layer, the average moisture content of T2 (straw mulching) treatment is 10.99% and 14.81% higher than that of CK and T1 treatments, respectively. The average soil moisture content of the whole growth period at the depth of 10-20 cm soil layer is as follows: T2 treatment>CK treatment>T1 treatment. The soil moisture content of straw mulching treatment at all stages of the whole growth period is higher than that of T1 treatment and CK treatment. At the depth of 20-30 cm soil layer, the average moisture content of T2 (straw mulching) treatment was 7.66% and 10.18% higher than that of CK and T1 treatments, respectively. The average soil moisture content of the whole growth period at the depth of 20-30 cm soil layer was as follows: T2 treatment > CK treatment > T1 treatment. The soil moisture content of straw mulching treatment in the germination period, early growth period and mature stage was higher than that of T1 treatment and CK treatment. At the depth of 30-40 cm soil layer, the average moisture content of T2 (straw mulching) treatment was 4.11% and 9.84% higher than that of CK and T1 treatments, respectively. The average soil moisture content of the whole growth period at the depth of 30-40 cm soil layer was as follows: T2 treatment > CK treatment > T1 treatment. The soil moisture content of straw mulching treatment in the germination period, mid-growth period and mature stage was higher than that of T1 treatment and CK treatment. The soil moisture content at maturity stage at the depth of 0-40cm soil layer was: T2 treatment>T1 treatment>CK treatment. Compared with the non-covering treatment and rice husk covering treatment, straw covering had a better water retention effect on the surface soil (0-10cm) from the germination stage to the mid-growth stage, because straw covering can reduce the direct sunlight and play a role of shading, so that the surface soil is at a relatively low temperature, thereby reducing the evaporation of water caused by high temperature, thereby better reducing the evaporation of water in the surface soil. As the soil depth deepens, spinach shows a better water retention effect on the deep soil during maturity. Overall, the soil moisture content of spinach showed a trend of first decreasing, then increasing, and then decreasing during the entire growth period. The order of average moisture content was mid-growth stage>germination stage>early growth stage>maturity stage.

[0123] Effects of different covering treatments on the dynamic characteristics of water consumption of spinach in plastic greenhouses: As shown in Table 12, the water consumption of spinach during the whole growth period is 107.34-120.43 mm. Compared with CK (no covering), different covering methods can significantly reduce the water consumption of spinach during the whole growth period. The water consumption is CK treatment>T1 treatment>T2 treatment, among which T2 treatment has the least water consumption, which is 107.34 mm, a decrease of 10.87% compared with CK. The water consumption of spinach in different growth periods is 44.15-46.70 mm in the germination period, 7.80-15.19 mm in the early growth period, 48.20-51.20 mm in the middle growth period, and 7.19-7.34 mm in the maturity period. The water consumption of spinach during the germination period was 44.15-46.70 mm, as shown in Table 13. The daily water consumption intensity of the CK treatment was the highest, which was 4.67 mm / d, and the daily water consumption intensity of the T2 treatment was the lowest, which was 4.41 mm / d. The daily water consumption intensity of the T2 treatment was 4.72% and 5.57% lower than that of the CK treatment and the T1 treatment, respectively. The water consumption of spinach in the early growth period was 7.80-15.19 mm, among which the daily water consumption intensity of the CK treatment was the highest, which was 2.17 mm / d; the daily water consumption intensity of the T2 treatment was the lowest, which was 1.11 mm / d. The daily water consumption intensity of the T2 treatment was 27.65% and 48.85% lower than that of the CK treatment and the T1 treatment, respectively. The water consumption of spinach in the middle growth period was 48.20-51.20 mm, among which the T1 treatment had the highest daily water consumption intensity of 5.75 mm·d-1; the T2 treatment had the lowest daily water consumption intensity of 5.36 mm / d, which was 5.80% lower than that of the T1 treatment. The water consumption of spinach in the mature period was 7.19-7.34 mm, among which the CK treatment had the highest daily water consumption intensity of 2.45 mm / d; the T1 treatment had the lowest daily water consumption intensity of 1.01 mm / d. During the whole growth period of spinach, the water consumption of spinach in the germination period and the middle growth period was significantly higher than that in other periods. Sufficient soil moisture in the germination period can ensure the growth of seedlings. The middle growth period is the period of rapid growth of spinach plants, and the plants require a large amount of water.

[0124] Table 12 Water consumption of spinach under different covering methods (mm)

[0125]

[0126] Table 13 Daily water consumption intensity of spinach under different covering methods (mm / d)

[0127]

[0128]

[0129] Effects of different covering treatments on the yield and water use efficiency of spinach in plastic greenhouses: As shown in Table 14, different covering methods have significant effects on yield and water use efficiency. Compared with CK (no covering), different covering methods have significant yield-increasing and water-saving effects, with an increase rate of 5.68% to 7.40%; water use efficiency increased by 13.60% to 17.46%. Under different covering methods, the yield of spinach is as follows: T2 treatment>T1 treatment>CK treatment. The yield of CK (no covering) treatment is 72798.29kg / hm 2 Among the mulching treatments, straw mulching had the most significant yield-increasing effect, with a yield of 78612.38 kg / hm 2 Compared with CK (no covering), the yield increase rate was 7.40%, and compared with T1 treatment (rice husk covering), the yield increase rate was 1.82%; the yield of rice husk covering was 77181.43kg / hm 2 , the yield increase rate was 5.68% compared with CK (no covering). Under different covering methods, the water use efficiency of spinach was as follows: T2 treatment>T1 treatment>CK treatment. The WUE of CK (no covering) treatment was 40.30kg / mm. Among the covering treatments, the T2 treatment had the best water-saving effect, with a WUE of 48.83kg / mm, which increased the water use efficiency by 17.46% compared with the CK treatment and 4.48% compared with the T1 treatment. The WUE of T1 treatment was 46.64kg / mm, which increased the water use efficiency by 13.60% compared with the CK treatment. Based on the above analysis, the rice husk covering treatment and the straw covering treatment had significant effects on increasing yield and saving water compared with the no covering treatment, among which the straw covering had the best effect.

[0130] Table 14 Spinach yield (kg / hm2) under different covering methods 2 ) and water use efficiency (kg / mm)

[0131]

[0132] By comparing the differences in plant height, leaf area index, dry matter accumulation, yield and soil moisture changes of spinach in plastic greenhouses under different covering treatments, the following results were obtained.

[0133] Compared with the control (no covering), rice husk covering and straw covering significantly increased the plant height and leaf area per plant of spinach, and the leaf area increased by an average of 3.92% to 12.31%. Covering treatments affect the accumulation of dry matter per plant, among which rice husk covering and straw covering can effectively increase the dry matter accumulation of spinach during the rapid growth period, laying a material foundation for increasing yield. Compared with the no covering treatment and rice husk covering treatment, straw covering has a better water retention effect on the surface soil (0-10 cm) from the germination stage to the middle growth stage. With the deepening of soil depth, spinach shows a better water retention effect on the deep soil during maturity. Compared with CK (no covering), different covering methods can significantly reduce the water consumption of spinach during the whole growth period, among which the water consumption is shown as no covering treatment > rice husk covering treatment > straw covering treatment.

[0134] Compared with CK (no covering), different covering methods all had significant effects of increasing yield and saving water, with an increase rate of 5.68% to 7.40%, and water use efficiency increased by 13.60% to 17.46%. Among the covering treatments, T2 treatment had the best water-saving effect, with WUE of 48.83 kg / mm, and water use efficiency increased by 17.46% compared with CK treatment. Both rice husk covering treatment and straw covering treatment had significant effects of increasing yield and saving water, among which straw covering had the best effect.

[0135] Furthermore, based on the present embodiment, the covering material is corn stalks, and the shredded stalks are 0.3-0.5 cm in length.

[0136] In step S2, wide and narrow row sowing is carried out in a ridge-forming manner. The number of sowing rows in the planting belt is three, of which two rows are arranged on the left slope and one row is arranged on the right slope. A drip irrigation belt 1 is laid along the length direction of the ridge at the top of the slope, wherein a water storage layer 3 with a thickness of 1-2 cm parallel to the left slope is arranged under the soil on the left slope, the water storage layer 3 is connected with the covering layer 2, and the drip irrigation belt 1 is arranged at the connection between the water storage layer 3 and the covering layer 2. The ridge-forming direction is north-south. The lower end of the water storage layer 3 extends to the bottom of the left slope. When the drip irrigation belt arranged at the upper end of the aquifer 3 drips water, the aquifer 3 will be quickly replenished with water because the aquifer 3 is looser than the soil, and the loose porous structure of the straw can hold water, slowing down the rate of water diffusion, so that the roots of the spinach seedlings on the left slope can get water after piercing the aquifer, and the water on the right slope infiltrates into the slope soil under the action of gravity in the aquifer 3, so that the single-row sowing row on the right can also get water conservation, and through the north-south setting of the ridge, the left slope of the two rows of sowing rows is sufficiently exposed to sunlight and accumulated temperature, the single-row sowing row on the right slope is close to the top of the slope, where the top height is 7-10cm, which can also better supplement the accumulated temperature and sunlight, and the lower side of the right slope is in the shade and mainly plays a ventilation role. The sowing distance and the spacing between the drip irrigation belts mentioned above are measured along the undulations of the slope, so that even if wide and narrow rows are used for sowing to increase the ventilation effect between rows, the utilization rate of the cultivated land is maximized, and the effective sowing area per unit area is increased.

Claims

1. A method for water-saving cultivation of leafy vegetables by micro-irrigation and covering, characterized in that: The steps include: S1. Adjust the sowing soil according to the predetermined standards; S2. Apply base fertilizer and sow seeds according to the predetermined planting spacing; S3. Take water-saving irrigation and maintenance measures in the field; S4. Harvesting; The predetermined standard of the sowing soil is that the basic nutrient content of the 0-30 cm soil tillage layer includes 23-28 mg / kg nitrate nitrogen, 0.65-0.85 g / kg available nitrogen, 18-22 mg / kg available phosphorus and 90-110 mg / kg available potassium.

2. The method for water-saving cultivation of leafy vegetables by micro-irrigation and covering according to claim 1, characterized in that: The water-saving irrigation maintenance measures are as follows: in step S2, sowing is carried out with an equal row spacing of 20 cm and a sowing rate of 30 kg / hm2. 2 The total amount of irrigation water in the whole growth period in step S3 is 1075.2m 3 / hm 2 .

3. The method for water-saving cultivation of leafy vegetables by micro-irrigation and covering according to claim 1, characterized in that: The water-saving irrigation maintenance measure is that in step S2, wide-narrow row sowing is adopted, and the sowing amount is 30kg / hm 2 The planting belt width is 15 cm, the spacing between the planting belts is 20 cm, the drip irrigation belt (1) is laid in the planting belt, and the spacing between the drip irrigation belts (1) is 35 cm. The total amount of irrigation water during the whole growth period in step S3 is 1075.2m 3 / hm 2 .

4. The method for water-saving cultivation of leafy vegetables by micro-irrigation and covering according to claim 1, characterized in that: The water-saving irrigation maintenance measure is that in step S2, wide-narrow row sowing is adopted, and the sowing amount is 30kg / hm 2 The planting belt width is 15 cm, the spacing between the planting belts is 20 cm, the drip irrigation belt (1) is laid in the planting belt, and the spacing between the drip irrigation belts (1) is 35 cm. The total amount of irrigation water during the whole growth period in step S3 is 1075.2m 3 / hm 2 , and the ground is covered to form a covering layer (2), the covering material is rice husk or corn stalk, and the thickness is 1-2 cm.

5. The method for water-saving cultivation of leafy vegetables by micro-irrigation and covering according to claim 4, characterized in that: The covering material is corn stalks, and the stalks are crushed to a length of 0.3-0.5 cm.

6. The method for water-saving cultivation of leafy vegetables by micro-irrigation and covering according to claim 4, characterized in that: In step S2, wide and narrow row sowing is carried out in a ridge-forming manner. The number of sowing rows in the planting belt is three, of which two rows are arranged on the left slope and one row is arranged on the right slope. A drip irrigation belt (1) is laid along the length direction of the ridge at the top of the slope, wherein a water storage layer (3) with a thickness of 1-2 cm and parallel to the left slope is arranged under the soil on the left slope, the water storage layer (3) is connected to the covering layer (2), and the drip irrigation belt (1) is arranged at the connection point between the water storage layer (3) and the covering layer (2).

7. The method for water-saving cultivation of leafy vegetables by micro-irrigation and covering according to claim 6, characterized in that: The ridge forming direction is north-south.

8. The method for water-saving cultivation of leafy vegetables by micro-irrigation and covering according to claim 6, characterized in that: The lower end of the water storage layer (3) extends to the bottom of the left slope.

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