Water-saving nitrogen-reducing green efficient cultivation method for ratooning rice

Abstract

The invention belongs to the technical field of agricultural planting, and particularly relates to a ratooning rice water-saving nitrogen-reducing green efficient cultivation method which comprises the steps of variety selection, sowing and transplanting. First season rice fertilization management and ratooning rice fertilization management; wherein the application amounts of nitrogen fertilizers (pure nitrogen) of the first season rice and the ratooning rice are 243kg / hm < 2 > and 184.5 kg / hm < 2 > respectively; the application ratio of N to P to K in first season rice fertilization is 2: 1: 2; first season rice moisture management and ratooning rice moisture management. According to the water-saving, nitrogen-reducing, green and efficient cultivation method for ratooning rice, a mild dry-wet alternate irrigation technology is introduced into ratooning rice production by establishing a dry-wet alternate irrigation water management mode in the whole growth period of the ratooning rice, and the purposes of reducing the irrigation water consumption for planting the ratooning rice and improving the water utilization rate are achieved. And the influence of the ratooning rice whole-growth-period mild dry-wet alternate irrigation technology on the first season and regeneration season yield, regeneration axillary bud germination and growth and the related physiological mechanism are ascertained. The water-saving nitrogen-reducing green efficient cultivation mode of ratooning rice is established by using water to adjust the fertilizer and fully exerting the water-fertilizer interaction effect.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural planting, and specifically relates to a green and efficient cultivation method for regenerated rice that saves water and reduces nitrogen. Background Art

[0002] Rice production has a large demand for water resources and nitrogen fertilizers. The amount of water used for rice field irrigation accounts for about 70% of the total agricultural water use. With the growth of my country's population and the continuous development of urbanization and industrialization, the amount of industrial and domestic water use has gradually increased, seriously threatening the safety of agricultural irrigation water.

[0003] Nitrogen fertilizer input plays a very important role in increasing rice yields. At present, China's rice nitrogen fertilizer consumption accounts for about 37% of the world's total rice nitrogen fertilizer consumption, and the average nitrogen fertilizer consumption per rice season in China is 180kg / hm2. 2 , which is about 75% higher than the average nitrogen fertilizer usage per unit area in rice fields in the world. This results in the utilization rate of nitrogen fertilizer in rice fields in my country being slightly lower than the world average, but significantly lower than that in Japan, the Philippines and other countries. Excessive input of nitrogen fertilizer will lead to groundwater pollution and eutrophication of rivers and lakes, and increase the emission of greenhouse gas N2O. Over the past half century, the long-term single pursuit of increasing yields has led to the formation of a fertilizer and water management method based on "large amounts of water and fertilizer" in my country's rice production, which has put great pressure on resources and the environment and is not conducive to the sustainable development of agriculture.

[0004] Raised rice is the main means to increase the rice field multiple cropping index in the middle and lower reaches of the Yangtze River in my country. Because of its characteristics of double harvests, time-saving and labor-saving, green and efficient, the planting area has continued to increase in recent years. According to statistics, the planting area of ​​regenerated rice has increased by 10 million mu from 2010 to 2023, and the potential planting area of ​​regenerated rice is nearly 80 million mu. With the in-depth research on the planting technology of regenerated rice, its yield level has been continuously improved, and the maximum yield in two seasons can reach 15t / hm 2 .

[0005] However, at present, the production of regenerated rice also has problems such as unreasonable irrigation methods, large water requirements, high nitrogen fertilizer usage and low utilization rate, which also limits the further increase of regenerated rice yield. Therefore, the development of green and efficient cultivation technology for regenerated rice with water-saving and nitrogen-reducing is of great significance to promote the development of regenerated rice yield. Summary of the invention

[0006] In view of this, the present invention provides a green and efficient cultivation method and device for regenerated rice with water saving and nitrogen reduction to solve the above-mentioned problems recorded in the background technology.

[0007] In order to achieve the above object, the present invention is achieved through the following technical solutions:

[0008] The present invention provides a green and efficient cultivation method for regenerated rice with water saving and nitrogen reduction, comprising:

[0009] Variety selection and sowing and transplanting;

[0010] First-season rice fertilization management and regeneration rice fertilization management; the application rate of nitrogen fertilizer (pure nitrogen) for first-season rice and regeneration rice is 243kg / hm 2 and 184.5kg / hm 2 The ratio of N:P:K used in fertilization of first-season rice is 2:1:2;

[0011] Water management for first-season rice and regenerated rice, among which, water management for first-season rice includes: 5-7 days after transplanting the first-season rice, maintain a 3-4cm water layer in the field to promote tillering of live seedlings; 5-7 days after transplanting to 25-30 days during the peak tillering period, install a soil water potential meter in the field, irrigate with a 2-3cm water layer when the soil water potential reaches -15kPa, then drain and repeat; during the ineffective tillering period of 20-25 days, irrigate with a 2-3cm water layer when the field soil water potential meter reaches -25--30kPa, then drain and repeat; from jointing to maturity, irrigate with a 2-3cm water layer when the field soil water potential meter reaches -15kPa, then drain and repeat;

[0012] The water management of regenerated rice includes: 5-7 days after the first-season rice is harvested, the field is maintained in a moist environment with a soil water potential of 0kPa; 7 days after the first-season rice is harvested until the regeneration season is mature, when the field soil water potential meter reaches -15kPa, irrigate with a 2-3cm water layer, then let it dry, and repeat this cycle.

[0013] In the above-mentioned green and efficient cultivation method for regenerated rice with water saving and nitrogen reduction, as a preferred technical solution, the step of variety selection and cultivation includes:

[0014] Variety selection is as follows: medium-ripening varieties with a growth period of less than 130 days are selected;

[0015] The sowing and transplanting are as follows: the first-season rice is raised in a greenhouse in early March using seedling trays with 55-70g of dry grain seeds per tray. The rice is transplanted in early April with a row spacing of 30*15cm and 2 seedlings per hole.

[0016] In the above-mentioned green and efficient cultivation method for regenerated rice with water-saving and nitrogen-reducing properties, as a preferred technical solution, the varieties selected in the variety selection are Liangyouxiang No. 1, Taoyouxiangzhan, Tianliangyou 616 or Liangyou 6326.

[0017] In the above-mentioned green and efficient cultivation method of regenerated rice for saving water and reducing nitrogen, as a preferred technical scheme, in the fertilization management of the first-season rice, the nitrogen fertilizer for the first-season rice is applied to the field in four times, 60% of the nitrogen fertilizer is used as base tillering fertilizer, and the remaining 40% is used as ear and grain fertilizer; wherein the base fertilizer and tillering fertilizer are applied to the field in equal amounts 2-3 days before transplanting and 5 days after transplanting, respectively, and the ear and grain fertilizer is applied to the field in equal amounts twice when the 4th leaf is inverted and the 2nd leaf is inverted, respectively.

[0018] In the above-mentioned green and efficient water-saving and nitrogen-reducing cultivation method for regenerated rice, as an optimal technical solution, in the fertilization management of the first-season rice, phosphorus and potassium fertilizers are used as base fertilizers and applied uniformly to the field. The phosphorus and potassium fertilizers are superphosphate and potassium chloride, respectively, wherein the superphosphate contains 12% phosphorus and the potassium chloride contains 60% potassium.

[0019] In the above-mentioned green and efficient cultivation method for saving water and reducing nitrogen in regenerated rice, as a preferred technical solution, in the fertilization management of regenerated rice, the nitrogen fertilizer for regenerated rice is applied twice to the field, namely, bud-promoting fertilizer and seedling-promoting fertilizer; the two fertilizations are applied 15 days after the first-season rice has reached heading and within 3 days after the regenerated rice has been harvested, respectively, and the bud-promoting fertilizer is applied with pure nitrogen of 123.0 kg / hm 2 , apply 61.5kg / hm2 of pure nitrogen fertilizer to promote seedlings 2 , the nitrogen fertilizer is urea with a nitrogen content of 46.4%.

[0020] The present invention provides a green and efficient cultivation method for regenerated rice with water-saving and nitrogen-reducing properties, which has the following beneficial effects:

[0021] The invention discloses a green and efficient cultivation method for regenerated rice with water saving and nitrogen reduction. The method simply establishes a dry-wet alternating irrigation water management mode for the whole growth period of regenerated rice. The light dry-wet alternating irrigation technology is introduced into the production of regenerated rice, so as to reduce the irrigation water consumption of regenerated rice and improve the water utilization rate. The method also explores the influence of the light dry-wet alternating irrigation technology for the whole growth period of regenerated rice on the yield of the first season and the regenerated season, the germination and growth of the regenerated axillary buds, and the related physiological mechanisms.

[0022] The present invention uses water to adjust fertilizers, gives full play to the interaction effect of water and fertilizer, and establishes a green and efficient cultivation mode for regenerated rice that saves water and reduces nitrogen. It attempts to use mild dry-wet alternating irrigation to improve the physiological activity of rice roots and leaves, and at the same time improve the physical and chemical properties of paddy field soil, thereby increasing the absorption and utilization rate of nitrogen fertilizer by regenerated rice and reducing the amount of nitrogen fertilizer used.

[0023] Through the experimental analysis of water management, different irrigation methods have a great influence on the first-season yield of regenerated rice. Under the same nitrogen application conditions, the yield of WMD (mild wet-dry alternating irrigation) treatment was higher than that of CF (conventional water layer irrigation), and the difference in their average values ​​reached a significant level. From the perspective of yield components, compared with CF, the number of panicles, fruit setting rate and 1000-grain weight of WMD treatment were improved to varying degrees, but the difference did not reach a significant level. The number of grains per panicle and the number of spikelets in WMD treatment increased significantly, by 2.0% and 3.4%, respectively; this shows that the main reason why mild wet-dry alternating irrigation increases the yield of first-season rice is that it increases the number of grains per panicle and the number of spikelets in the first-season rice. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A diagram of a water-saving irrigation pattern for first-season rice provided by the present invention;

[0025] Figure 2 This is a diagram of the water connection and irrigation pattern of regenerated rice provided by the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Exemplary embodiments of the present invention will be described in detail with reference to the following drawings.

[0028] The exemplary embodiments of the present invention are described below in conjunction with specific circumstances:

[0029] Example 1: Combination Figure 1-Figure 2 As shown, the present invention provides a green and efficient cultivation method for regenerated rice with water saving and nitrogen reduction, comprising:

[0030] Variety selection, sowing and transplanting; 1. Variety selection: Select medium-ripening varieties with a growth period of less than 130 days (in the middle and lower reaches of the Yangtze River), such as Fengliangyouxiang No. 1, Taoyouxiangzhan, Tianliangyou 616 and Liangyou 6326. The variety used in this experiment is Liangyou 6326.

[0031] 2. Sowing and transplanting: The first season rice seedlings are raised in early March (in the greenhouse), using seedling trays with 55-70g of seeds (dry grain) per tray. They are planted in early April with a row spacing of 30*15cm and 2 seedlings per hole.

[0032] Fertilization management of first-season rice and regenerated rice; the application ratio of nitrogen fertilizer for first-season rice and regenerated rice is 4:3, and the application ratio of N:P:K in first-season rice fertilization is 2:1:2; specifically, the total amount of pure nitrogen applied per hectare of rice is 243kg, and the nitrogen fertilizer for first-season rice is applied to the field in four times. 60% of the nitrogen fertilizer is used as base tiller fertilizer, of which the base fertilizer and tiller fertilizer are applied to the field in equal amounts 2-3 days before transplanting and 5 days after transplanting, respectively. The remaining 40% is used as spike fertilizer, and the spike fertilizer is applied to the field in equal amounts twice at the 4th leaf and the 2nd leaf, respectively. Phosphorus and potassium fertilizers are all used as base fertilizers and uniformly applied to the field, and the application ratio of N:P:K is 2:1:2. Urea, superphosphate and potassium chloride are used for N, P and K fertilizers, respectively, of which urea contains 46.4% nitrogen, superphosphate contains 12% phosphorus, and potassium chloride contains 60% potassium.

[0033] The nitrogen fertilizer application rate in the regeneration season is 184.5 kg / hm 2The two fertilizers were applied to the field twice, namely, 15 days after the first season of heading and 3 days after the regenerated rice was harvested. The bud-promoting fertilizer was 123.0 kg / hm2 of pure nitrogen, and the seedling-promoting fertilizer was 61.5 kg / hm2 of pure nitrogen. 2 , urea (nitrogen content 46.4%) was used as nitrogen fertilizer.

[0034] Water management for first-season rice and water management for regenerated rice. Among them, water management for first-season rice includes: 5-7 days after transplanting the first-season rice, maintain a 3-4cm water layer in the field to promote tillering of seedlings; 5-7 days after transplanting to 25-30 days during the peak tillering period, install a soil water potential meter in the field, and when the soil water potential reaches -15kPa, irrigate with a 2-3cm water layer, then drain and repeat this cycle; during the ineffective tillering period of 20-25 days, when the field soil water potential meter reaches -25--30kPa, irrigate with a 2-3cm water layer, then drain and repeat this cycle; after jointing to maturity, when the field soil water potential meter reaches -15kPa, irrigate with a 2-3cm water layer, then drain and repeat this cycle.

[0035] The water management of regenerated rice includes: 5-7 days after the first-season rice is harvested, the field is maintained in a moist environment with a soil water potential of 0kPa; 7 days after the first-season rice is harvested until the regeneration season is mature, when the field soil water potential meter reaches -15kPa, irrigate with a 2-3cm water layer, then let it dry, and repeat this cycle.

[0036] Experimental design

[0037] The seeds were sown on March 4, seedlings were raised in seedling trays, and transplanted on April 15. The spacing between rows and plants was 30*15cm, with 2 seedlings per hole. The experiment adopted a split-plot design, with water treatment as the main plot and different nitrogen fertilizer application rates as the secondary plot. The water treatment set conventional water layer irrigation as the control (CF), that is, the field was sun-dried during the ineffective tillering period of the first-season rice, and the water layer of 2-3cm was maintained in the field at other times. Light dry-wet alternating irrigation (WMD) during the entire growth period of regenerated rice was carried out according to Figure 1 Management is carried out by installing a soil water potential meter in the field, and when the soil water potential reaches the corresponding threshold, a 2-3 cm water layer is irrigated, and then the soil is dried, and the cycle is repeated. A total of 5 nitrogen application rates were set for the nitrogen fertilizer treatment; the conventional nitrogen application rate N 100 :475kg / hm 2 (First season 270kg / hm 2 + Regeneration season 205kg / hm 2 ), reduction 10% N 90 :(First season 243kg / hm 2 + Regeneration season 184.5kg / hm 2 ), reduction of 20% N 80 :(First season 216kg / hm 2 + Regeneration season 164kg / hm 2 ), reduction of 30% N 70:(First season 189kg / hm 2 + Regeneration season 143.5kg / hm 2 ); reduction of 40% N 60 :(First season 162kg / hm 2 + Regeneration season 123kg / hm 2 ). At the same time, set up a 0 nitrogen zone N0. Phosphorus and potassium fertilizers in each plot are used as basal fertilizers and uniformly fertilized into the field. In the first season, 60% of nitrogen fertilizer is used as basal tillering fertilizer, of which basal fertilizer and tillering fertilizer are applied in equal amounts before transplanting and 5 days after transplanting respectively. The remaining 40% is used as ear and grain fertilizer, which is applied in equal amounts twice at the 4th leaf and 2nd leaf respectively.

[0038] Fertilizers for the regeneration season are divided into bud-promoting fertilizer and seedling-promoting fertilizer, which are applied 15 days after the first season of full heading and 3 days after the regeneration rice is harvested, respectively, with the ratio of bud-promoting fertilizer to seedling-promoting fertilizer being 2:1. The specific fertilizer application amount is shown in Table 1. At the same time, field pest and weed control work should be done well in accordance with the requirements of high-yield cultivation.

[0039] Table 1 Nitrogen fertilizer application amount in different treatments

[0040]

[0041] Experimental case investigation items:

[0042] ① Record of reproductive period;

[0043] Accurately record the sowing period, transplanting period, jointing period, heading period and maturity period of different varieties.

[0044] ②Dry matter weight and leaf area index;

[0045] At the transplanting and jointing stage of the first season, the heading and maturity stage of the first season and the regeneration season, according to the average level of the seedling conditions of the whole field, three holes of representative plants were selected at three points on the diagonal line, and the leaf area of ​​the plants was determined by the length-width coefficient method. All the above samples were separated according to different organs such as leaves, stems and sheaths, and ears (after heading), and the dry matter weight was determined after being fixed at 105℃ for 30min and dried in an oven at 80℃ to constant weight.

[0046] ③Nitrogen fertilizer utilization rate;

[0047] Agronomic utilization rate of nitrogen fertilizer (kg / kg) = (yield of nitrogen application area - yield of blank area) / nitrogen application amount;

[0048] Partial productivity of nitrogen fertilizer (kg / kg) = yield in nitrogen application area / amount of nitrogen applied.

[0049] ④Rice yield and its components;

[0050] At maturity, 10 holes were randomly sampled from each plot for seed testing. All rice ears were placed in plastic window screen bags, air-dried, and threshed to obtain the total number of grains in 10 holes and the total number of grains per ear. Empty grains were removed by water bleaching to obtain the fruit set rate. 1,000 solid grain samples were weighed and repeated three times (with an error of no more than 0.05 g) to obtain the thousand-grain weight. Each plot was harvested individually to calculate the actual yield. Rice samples were retained for rice quality analysis.

[0051] Experimental case survey project data analysis:

[0052] (1) Effects of alternating dry-wet irrigation on first-season rice yield;

[0053] As shown in Table 2, different irrigation methods have a great influence on the yield of the first season of ratoon rice. Under the same nitrogen application rate, the yield of the WMD treatment was higher than that of the CF treatment, and the difference in their average values ​​reached a significant level. From the perspective of yield components, compared with CF, the number of panicles, fruit setting rate and 1000-grain weight of the WMD treatment increased to varying degrees, but the difference did not reach a significant level, while the number of panicles and spikelets of the WMD treatment increased significantly, by 2.0% and 3.4%, respectively. This shows that the main reason why mild alternating dry-wet irrigation increases the yield of the first season rice is that it increases the number of panicles and spikelets of the first season rice.

[0054] With the decrease of nitrogen fertilizer application, the yield change trend was different between the two irrigation methods. In the WMD treatment, with the decrease of nitrogen fertilizer application, the number of ears, number of grains per ear and number of spikelets gradually decreased, and the fruit set rate and 1000-grain weight gradually increased, resulting in a trend of yield increasing first and then decreasing. 90 In the CF treatment, with the decrease of nitrogen fertilizer application, the number of ears, number of grains per ear and number of spikelets gradually decreased, and the fruit setting rate and 1000-grain weight gradually increased, resulting in a gradual decrease in yield. 100 The processing yield is the highest.

[0055] Table 2 Effects of different irrigation methods on first-season rice yield and its components

[0056]

[0057] (Note: WMD and CF represent mild wet-dry alternating irrigation and conventional water layer irrigation, respectively; N 100 、N 90 、N 80 、N 70 、N 60 Respectively represent nitrogen reduction of 0%, 10%, 20%, 30% and 40%; Mean represents the mean value, and different lowercase letters in the same column represent significant differences at the P = 0.05 level).

[0058] (2) The effect of alternating wet-dry irrigation on yield formation during the regeneration season;

[0059] As shown in the table below, different irrigation methods have a great impact on the yield in the regeneration season. Under the same nitrogen fertilizer application rate, the yield of the WMD treatment is higher than that of the CF treatment, specifically 14.3% higher. The reason why WMD promotes the increase in yield is that it increases the number of ears, the number of grains per ear, the number of spikelets, the fruit set rate and the thousand-grain weight. Among them, the differences in the number of ears, the number of grains per ear and the number of spikelets between the two irrigation methods reached a significant level.

[0060] Nitrogen fertilizer application also has a significant impact on the yield in the regeneration season. Under the WMD treatment, as the nitrogen fertilizer application rate decreases, the number of ears, number of grains per ear, and number of spikelets in the regeneration season gradually decrease, while the fruit setting rate and 1000-grain weight gradually increase, which leads to a change in the yield that first increases and then decreases, with the highest yield being 5.5t / hm 2 (N 90 ). In the CF treatment, with the decrease of nitrogen fertilizer application, the number of ears, number of grains per ear and number of spikelets gradually decreased, while the fruit setting rate and 1000-grain weight gradually increased, resulting in a gradual decrease in yield.

[0061] Table 3 Effects of different irrigation methods on yield and its components in the regeneration season

[0062]

[0063] (Note: WMD and CF represent mild wet-dry alternating irrigation and conventional water layer irrigation, respectively; N 100 、N 90 、N 80 、N 70 、N 60 Respectively represent nitrogen reduction of 0%, 10%, 20%, 30% and 40%; Mean represents the mean value, and different lowercase letters in the same column represent significant differences at the P = 0.05 level).

[0064] (3) Effects of alternating wet-dry irrigation on nitrogen fertilizer use efficiency of regenerated rice;

[0065] As shown in Table 4, different irrigation methods have a great influence on the nitrogen fertilizer utilization rate of rice. At the same nitrogen fertilizer level, the nitrogen fertilizer partial productivity and nitrogen fertilizer agronomic utilization rate of the WMD treatment were significantly higher than those of the CF treatment, with average values ​​of 12.9% and 13.3% higher, respectively. With the decrease of nitrogen fertilizer application rate, the nitrogen fertilizer partial productivity of the WMD treatment decreased, and the nitrogen fertilizer agronomic utilization rate first increased and then decreased. 90 In the CF treatment, with the decrease of nitrogen fertilizer application, nitrogen partial productivity gradually increased, and there was no obvious change pattern in the agronomic utilization rate of nitrogen fertilizer.

[0066] Table 4 Effects of different irrigation methods on nitrogen fertilizer utilization efficiency of regenerated rice

[0067]

[0068] (Note: WMD and CF represent mild wet-dry alternating irrigation and conventional water layer irrigation, respectively; N 100 、N 90 、N 80 、N 70 、N 60 Respectively represent nitrogen reduction of 0%, 10%, 20%, 30% and 40%; Mean represents the mean value, and different lowercase letters in the same column represent significant differences at the P = 0.05 level).

[0069] (4) Effects of alternating wet-dry irrigation on the physical and chemical properties of paddy soil;

[0070] As shown in Table 5, different irrigation methods have a great influence on the physical and chemical properties of paddy field soil. At the same nitrogen fertilizer level, compared with CF, the cracked nitrogen, available phosphorus, available potassium and cation exchange capacity of the soil in WMD treatment were significantly increased, with the average values ​​increased by 20.9%, 19.3%, 5.8%, 12.3% and 5.7%, respectively. In the same water treatment, with the decrease of fertilizer application, the cracked nitrogen, available phosphorus, available potassium and cation exchange capacity of the soil gradually decreased, while the pH value did not change significantly. It shows that different water and nitrogen fertilizer treatments have a great influence on the physical and chemical properties of the soil, and appropriate water and fertilization can improve the soil fertility level.

[0071] Table 5 Effects of different irrigation methods on the physical and chemical properties of regenerated rice soil

[0072]

[0073] (Note: WMD and CF represent mild wet-dry alternating irrigation and conventional water layer irrigation, respectively; N 100 、N 90 、N 80 、N 70 、N 60 Respectively represent nitrogen reduction of 0%, 10%, 20%, 30% and 40%; Mean represents the mean value, and different lowercase letters in the same column represent significant differences at the P = 0.05 level).

[0074] (5) Research results;

[0075] Compared with conventional water layer irrigation, alternating wet-dry irrigation during the entire growth period of regenerated rice increased the yield of the first-season rice by 11.9% through the fruiting rate and 1000-grain weight of the first-season rice. The mechanism by which WMD increases the yield of the first-season rice is that, on the one hand, WMD significantly increases the leaf area index of the first-season rice, delays leaf senescence, and thus improves the photosynthetic capacity of the leaves; on the other hand, WMD increases the population growth rate and net assimilation rate, resulting in a significant increase in the accumulation of dry matter in the population. The physiological mechanism by which WMD increases the yield of the regenerated season is that WMD significantly increases the number of panicles and panicles in the regenerated season, thereby increasing the yield of the regenerated season by 14.3%. Its yield-increasing mechanism is similar to that of the first-season rice. It not only increases the leaf area index and delays leaf senescence, but also increases the population growth rate and net assimilation rate, significantly improving the photosynthetic capacity and dry matter production capacity of the leaves, thereby showing a significant yield-increasing effect.

[0076] Compared with CF, WMD significantly improved the nitrogen fertilizer utilization rate of regenerated rice, and the partial productivity and agronomic utilization rate of nitrogen fertilizer increased by 12.9% and 13.3%, respectively. This may be because the WMD treatment improved the physical and chemical properties of paddy soil, increased root activity, and promoted the absorption and utilization of nutrients in the soil by the roots. There was an interactive effect between the nitrogen fertilizer application rate and the irrigation method. With the decrease of nitrogen fertilizer application rate, the yield of the first season and the regeneration season in the WMD treatment showed a trend of increasing first and then decreasing. The highest yield occurred in N 90 The total yield in two seasons can reach up to 15.9t hm -2 , compared with N treated with CF 100 The yield was 10.5% higher. In summary, compared with conventional irrigation methods, WMD during the entire growth period of ratoon rice significantly increased the total yield of ratoon rice in two seasons and the nitrogen fertilizer use efficiency. There was an interaction effect between nitrogen fertilizer application and irrigation method. When WMD irrigation method was used and nitrogen fertilizer application was reduced by 10% (243 kg hm in the first season), the yield was 10.5% higher. -2 + Regeneration season 184.5kg hm -2 ) is the highest in the two seasons of ratoon rice, which can reach 15.9t / hm 2 .

[0077] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0078] The above specific examples are used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A green and efficient cultivation method for regenerated rice with water saving and nitrogen reduction, characterized in that: include: Variety selection and sowing and transplanting; First-season rice fertilization management and regeneration rice fertilization management; the application rate of pure nitrogen for first-season rice and regeneration rice is 243kg / hm 2 and 184.5kg / hm 2 , the N:P:K application ratio in the first rice crop is 2:1:2; Water management for first-season rice and regenerated rice, among which, water management for first-season rice includes: 5-7 days after transplanting the first-season rice, maintain a 3-4cm water layer in the field to promote tillering of live seedlings; 5-7 days after transplanting to 25-30 days during the peak tillering period, install a soil water potential meter in the field, irrigate with a 2-3cm water layer when the soil water potential reaches -15kPa, then drain and repeat; during the ineffective tillering period of 20-25 days, irrigate with a 2-3cm water layer when the field soil water potential meter reaches -25--30kPa, then drain and repeat; from jointing to maturity, irrigate with a 2-3cm water layer when the field soil water potential meter reaches -15kPa, then drain and repeat; The water management of regenerated rice includes: 5-7 days after the first-season rice is harvested, the field is maintained in a moist environment with a soil water potential of 0kPa; 7 days after the first-season rice is harvested until the regeneration season is mature, when the field soil water potential meter reaches -15kPa, irrigate with a 2-3cm water layer, then let it dry, and repeat this cycle.

2. The green and efficient cultivation method for regenerated rice with water saving and nitrogen reduction according to claim 1, characterized in that: The step of variety selection and cultivation includes: Variety selection is as follows: medium-ripening varieties with a growth period of less than 130 days are selected; The sowing and transplanting are as follows: the first-season rice is raised in a greenhouse in early March using seedling trays with 55-70g of dry grain seeds per tray. The rice is transplanted in early April with a row spacing of 30*15cm and 2 seedlings per hole.

3. The green and efficient cultivation method for regenerated rice with water saving and nitrogen reduction according to claim 1, characterized in that: The varieties selected in the variety selection are Liangyouxiang No. 1, Taoyouxiangzhan, Tianliangyou 616 or Liangyou 6326.

4. The green and efficient cultivation method for regenerated rice with water saving and nitrogen reduction according to claim 1, characterized in that: In the fertilization management of the first-season rice, the nitrogen fertilizer for the first-season rice is applied to the field in four times, 60% of the nitrogen fertilizer is used as base tillering fertilizer, and the remaining 40% is used as ear and grain fertilizer; the base fertilizer and tillering fertilizer are applied to the field in equal amounts 2-3 days before transplanting and 5 days after transplanting, respectively, and the ear and grain fertilizer is applied to the field in equal amounts twice, when the 4th leaf is inverted and the 2nd leaf is inverted, respectively.

5. The green and efficient cultivation method for regenerated rice with water saving and nitrogen reduction according to claim 4, characterized in that: In the fertilization management of the first-season rice, phosphorus and potassium fertilizers are used as base fertilizers and uniformly applied to the field. The phosphorus and potassium fertilizers are superphosphate and potassium chloride, respectively. The superphosphate contains 12% phosphorus and the potassium chloride contains 60% potassium.

6. The green and efficient cultivation method for regenerated rice with water saving and nitrogen reduction according to claim 1, characterized in that: In the fertilization management of regenerated rice, nitrogen fertilizer for regenerated rice is applied twice to the field, namely, bud-promoting fertilizer and seedling-promoting fertilizer; the two fertilizers are applied 15 days after the first-season rice reaches full heading and 3 days after the first-season rice is harvested, respectively, and the bud-promoting fertilizer is applied with pure nitrogen of 123.0 kg / hm 2 , apply 61.5kg / hm2 of pure nitrogen fertilizer to promote seedlings 2 , the nitrogen fertilizer is urea with a nitrogen content of 46.4%.

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