Efficient alfalfa planting method based on water and fertilizer coupling optimization and precise regulation and control

Abstract

The invention discloses an accurate water and fertilizer regulation and control technology for an alfalfa seed field, and aims to improve the water and fertilizer utilization efficiency and seed yield of alfalfa by optimizing a water and fertilizer management strategy. The invention provides a precise regulation and control mode based on irrigation amount and fertilization amount coupling, the evaporation amount of a reference crop is calculated by using a Penman-Monteith formula, the optimal water and fertilizer ratio suitable for different alfalfa growth stages is provided based on a pot experiment and a field experiment, a comprehensive evaluation system is constructed, an economic benefit analysis model is combined, and the optimal water and fertilizer ratio is calculated. A scientific basis is provided for popularization and application. According to the technology, the growth indexes (such as plant height and leaf area) of alfalfa are remarkably improved, and the seed quality (such as thousand seed weight and germination rate) is improved. In addition, efficient utilization and sustainable development of resources are achieved, and remarkable economic and ecological benefits are achieved.

Description

Technical Field

[0001] The present technology relates to the field of agricultural technology, and specifically to an efficient production technology for alfalfa seed fields based on precise water and fertilizer regulation. Background Art

[0002] Alfalfa ( Medicago sativa ) is a perennial leguminous herb, known as the "king of grasses" and "green gold". Its high yield, high protein content and soil-improving properties make it widely used in ecological protection and animal husbandry production, and it is an important forage crop in northern my country. Especially in Inner Mongolia, the area of ​​alfalfa cultivation has expanded year by year, and the market demand has continued to grow. However, due to the natural conditions of the region, such as the semi-arid climate and poor soil, alfalfa production under the traditional extensive management model faces severe challenges.

[0003] Traditional irrigation and fertilization methods mainly use flooding and large-scale fertilization. This method not only cannot effectively meet the needs of alfalfa at different growth stages, but also leads to the following technical problems: (1) Serious waste of water and fertilizer resources: Traditional flooding leads to serious water loss and leakage, and low irrigation water utilization efficiency; excessive fertilization causes fertilizer leaching and volatilization, resulting in fertilizer resource waste. (2) Deterioration of soil environment: Long-term unreasonable fertilization leads to soil nutrient imbalance and structural damage, and even causes soil compaction and fertility decline, which in turn affects the sustained high yield of alfalfa. (3) Lack of synergistic effect: Water and fertilizer are complementary resources. The current management model fails to fully couple the synergistic effect of the two, resulting in the inability of nutrients to be efficiently converted and absorbed by plants, limiting the yield and quality improvement of alfalfa. (4) Imprecise fertilizer management: Phosphorus fertilizer is an important limiting nutrient element for the growth and development of alfalfa, and is widely involved in physiological processes such as energy metabolism, cell structure composition and signal transduction. However, current fertilization strategies lack accurate understanding of the demand for phosphorus fertilizers. Excessive application not only increases planting costs, but may also reduce crop quality and pollute the environment.

[0004] In recent years, in response to the demand for efficient production of alfalfa, some studies have attempted to optimize irrigation and fertilization technologies, such as the application of drip irrigation systems and the exploration of phased fertilization. However, these technologies still have limitations in actual promotion, such as high technical complexity, high costs, and lack of precise regulation methods suitable for different growth stages of alfalfa. Although alfalfa has a certain biological nitrogen fixation ability and can improve soil structure, its high-yield characteristics consume significant soil nutrients, especially the high demand for phosphorus absorption. Therefore, how to improve the efficiency of water and fertilizer utilization while meeting the nutrient needs of crops has become a technical problem that needs to be solved urgently in alfalfa cultivation.

[0005] To address the above problems, there is an urgent need for a refined water-fertilizer regulation technology based on the needs of alfalfa at different growth stages, to build a scientific and reasonable water-fertilizer coupling management model, to give full play to the synergistic effect of water and fertilizer, to improve resource utilization efficiency, and thus promote high-yield and high-quality alfalfa and sustainable agricultural development. Summary of the invention

[0006] In view of the current situation of low water and fertilizer resource utilization efficiency and extensive management in the process of alfalfa planting, the present invention constructs a systematic water and fertilizer regulation technology ( Figure 1 ): A water and fertilizer regulation model for alfalfa with efficient utilization of water and fertilizer resources as the core was established, and a dynamic regulation strategy was proposed by clarifying the key needs of the growth stage; an efficient water and fertilizer management method that can adapt to a variety of planting conditions was developed by innovatively combining variety screening and shallow buried drip irrigation technology; a comprehensive evaluation system was constructed to quantify the advantages and disadvantages of water and fertilizer regulation schemes from multiple dimensions such as biological effects, economic benefits and environmental friendliness; a production technology that is both efficient, economical and environmentally friendly was provided, providing technical support for the development of modern agriculture.

[0007] In order to achieve the above objectives, the present invention adopts the following core technical solutions: Figure 2 ): (1) Exploring the regulatory mechanism of different water-fertilizer combinations on alfalfa growth and clarifying the key factors affecting alfalfa high yield: The present invention analyzes the effects of different irrigation and fertilization combinations on alfalfa plant growth and development, yield per unit area and nutritional quality through an experimental system, and clarifies the key factors for water-fertilizer regulation; (2) Screening the best water-fertilizer coupling ratio and adaptable alfalfa varieties: In pot experiments, different water-fertilizer treatments were used to screen out varieties with the strongest adaptability and the best production performance; combined with field shallow buried drip irrigation experiments, the optimal water-fertilizer combination pattern was screened out under different combinations of irrigation levels and fertilization levels; (3) Construct an innovative quantitative evaluation system for water and fertilizer use efficiency: comprehensively analyze WUE, FUE and economic benefits, quantify the advantages and disadvantages of different water and fertilizer management schemes, and optimize resource allocation strategies.

[0008] Furthermore, the experiment adopted a two-factor randomized block design, with irrigation and fertilization as experimental factors, and set the following gradient water and fertilizer treatments: watering treatments included mild drought W1 (blank control), normal watering W2 (100% ETc), and excessive watering W3 (150% ETc); fertilization treatments included no fertilization F0 (blank control), low fertilization F1 (1 / 2 of the recommended fertilization amount), medium fertilization F2 (recommended fertilization amount), high fertilization F3 (1.5 times the recommended fertilization amount), and excessive fertilization F4 (2 times the recommended fertilization amount); each water and fertilizer treatment was repeated three times. By dynamically monitoring indicators such as plant height, leaf area, and biomass per unit area of ​​alfalfa at different growth stages, the water and fertilizer regulation strategy was optimized.

[0009] Furthermore, the alfalfa growth process is monitored based on multi-index measurement. Preferably, the plant height is measured regularly (every 5-7 days), and plants with uniform growth are selected for marking to obtain the average plant height. Preferably, the alfalfa leaf area is calculated using the tracing weighing method combined with a correction coefficient to accurately evaluate the photosynthetic capacity.

[0010] Preferably, the biomass per unit area and seed yield are calculated by random sample harvesting and the total amount method, respectively, and the seed quality is evaluated in combination with the thousand-grain weight and germination rate.

[0011] Furthermore, by integrating the production benefits, resource utilization efficiency and environmental impact of different water and fertilizer management schemes, a set of efficient, economical and environmentally friendly water and fertilizer management strategies for alfalfa cultivation is proposed, which is suitable for efficient alfalfa production under different planting conditions.

[0012] Preferably, the efficiency of different water-fertilizer schemes is quantitatively evaluated by the following method: Irrigation water use efficiency (WUE): calculated by the ratio of alfalfa hay yield per unit area to irrigation water volume; Fertilizer use efficiency (FUE): calculated by the ratio of alfalfa hay yield per unit area to the amount of fertilizer applied.

[0013] Compared with the prior art, the present invention has the following significant advantages: (1) Propose a refined water-fertilizer coupling model suitable for the needs of alfalfa at different growth stages, significantly improving the water and fertilizer resource utilization efficiency (WUE, FUE); (2) Innovatively combining multi-variety screening with shallow field drip irrigation technology to provide a scientific basis for optimizing water and fertilizer management; (3) Provide comprehensive biological monitoring indicators and economic benefit evaluation to lay the foundation for sustainable management of alfalfa cultivation; (4) Created a set of efficient, economical and environmentally friendly alfalfa cultivation technologies to meet the needs of modern agricultural development while reducing resource waste and environmental pollution pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is the technical roadmap of the present invention.

[0015] Figure 2 The following is a test plan for an embodiment.

[0016] Figure 3This is the principal component analysis of the water-fertilizer coupling effect on the growth indicators of five alfalfa species. The color points in the figure represent different water and fertilizer treatments, the color blocks represent different alfalfa varieties, and the size of the color blocks represents the 95% confidence limit. The distance between the sample points represents the similarity between each sample. The value of the original variable corresponding to the arrow after projection to the horizontal and vertical directions can reflect the correlation between the variable and PC1 and PC2 respectively. The distance between the sample point and the arrow reflects the relationship between the sample and the original variable.

[0017] Figure 4 The effect of water-fertilizer coupling on alfalfa seed yield and quality. The same lowercase letters indicate no significant difference among the groups, and different lowercase letters indicate significant difference among the groups. DETAILED DESCRIPTION

[0018] In conjunction with the accompanying drawings and specific implementation schemes, the technical solution of the present invention is now further described in detail.

[0019] (1) This technology uses systematic experiments to study the comprehensive effects of different irrigation and fertilization combinations on the growth and development of alfalfa plants, yield per unit area, and nutritional quality, and to identify the key factors and optimization strategies for water and fertilizer regulation. The experiment adopted a two-factor randomized block design, with irrigation amount and fertilization amount as the main variables, and set up 13 water and fertilizer treatments and 2 blank controls (Table 1). Each treatment was repeated three times, and the optimal water and fertilizer regulation strategy was determined by dynamically monitoring the entire growth process of alfalfa.

[0020] Table 1 Water and fertilizer treatment settings at different levels

[0021] The reference crop evaporation (Eapotranspiration, ETc) was calculated according to the Penman-Monteith formula (Table 2):

[0022] Where: ETc: reference crop evaporation (mm / d), R n : Net radiation (MJ / m² / d), which can be approximated as solar radiation, T: air temperature (°C), U2: daily average wind speed (m / s). G: soil heat flux (MJ / m² / d), which is usually negligible on a daily scale and is assumed to be 0.

[0023] Δ: Slope of saturated vapor pressure curve, in kPa / °C, calculated by:

[0024] es: saturated vapor pressure (kPa), calculated as: .

[0025] ea: Actual vapor pressure (kPa), which can be calculated from relative humidity: , where RH is the relative humidity and T is the air temperature.

[0026] Table 2 Meteorological data during the 2024 trial period (May-October) Daily maximum temperature ℃ Daily minimum temperature ℃ Maximum daily relative humidity% Daily minimum relative humidity% <![CDATA[Daily average wind speed m·s - 1 > Average effective rainfall (mm) 35 15 80 50 3 7

[0027] (2) Furthermore, the experiment selected cylindrical flower pots with a diameter of 15 cm and a height of 11 cm, and each pot was filled with 7.57 kg of mixed soil (grassland soil and Pin's peat soil in a ratio of 5:1). The experiment involved five alfalfa varieties (Womu No. 1, Zhongcao No. 3, Zhongcao No. 13, Gangjin and Zihua 238), and the best two varieties were selected through different water and fertilizer treatments.

[0028] (3) After selecting varieties with strong adaptability, a shallow buried drip irrigation experiment was carried out in the field ( Figure 2 ), combined with the combination of irrigation level and fertilization level, to optimize the water-fertilizer ratio. In traditional field experiments, the water use efficiency (WUE) is calculated by measuring the hay yield per unit area and the amount of irrigation water, and the fertilizer use efficiency (FUE) is calculated by measuring the hay yield and the amount of fertilizer applied. At the same time, the correlation between water and fertilizer use efficiency and economic benefits is analyzed to provide a basis for precise regulation.

[0029] (4) Furthermore, according to the growth and development stage of alfalfa, the height of alfalfa plants in pots was measured every 5-7 days. Three plants with uniform growth were randomly selected from each pot for marking and measurement, and the average value was calculated. Leaf area was estimated by the tracing and weighing method; the biomass per unit area was determined by the direct harvesting method. Seed quality analysis included thousand-grain weight and germination rate. The thousand-grain weight was calculated by the total weight method; the germination rate was calculated by recording the number of germinations using the conventional germination method.

[0030] (5) Preferably, R 4.3.0 was used for data processing and analysis, and principal component analysis (PCA) was used to determine the factors that had the greatest impact on alfalfa growth and yield, and to evaluate the effects of water and fertilizer treatments and varieties on growth indicators such as plant height and leaf area index. One-way ANOVA was used to evaluate the effects of water and fertilizer coupling on seed yield and quality indicators such as seed yield, 1000-grain weight, and germination rate. Multiple comparisons were performed using the Tukey HSD method to determine the significance of differences between groups. The ggplot2 package was used for visualization.

[0031] (6) Furthermore, the results of principal component analysis show that ( Figure 3), water and fertilizer treatments had significant effects on plant height, leaf area index and aboveground biomass. PC1 (plant height) explained 87.13% of the total variance, and PC2 (aboveground biomass) explained 7.71%. The high water and fertilizer treatment group (such as W2×F4) scored significantly higher on PC1 than the low treatment group, indicating that it significantly promoted growth. According to the comprehensive score and comprehensive ranking of principal component analysis (Table 3), the optimal treatment was W2×F4, the second optimal treatment was W2×F3, and the worst treatment was W1×F0.

[0032] Table 3 Comprehensive evaluation of the effects of different water and fertilizer on alfalfa seed quality Water and fertilizer treatment Principal component 1 Principal component 2 Principal component 3 Ranking W1×F0 -0.384 -0.043 -0.166 15 W1×F1 -0.259 0.029 -0.106 11 W1×F2 -0.018 0.008 0.021 9 W1×F3 -0.007 0.054 0.009 8 W1×F4 0.197 0.142 0.177 3 W2×F0 -0.026 0.127 0.023 10 W2×F1 0.041 0.044 -0.001 7 W2×F2 0.156 0.055 0.023 4 W2×F3 0.325 0.106 0.090 2 W2×F4 0.621 0.076 0.237 1 W3×F0 -0.268 -0.128 -0.107 12 W3×F1 -0.297 -0.034 -0.117 14 W3×F2 -0.274 -0.013 -0.123 13 W3×F3 0.049 -0.210 -0.007 6 W3×F4 0.143 -0.214 0.048 5

[0033] (7) Furthermore, the results of one-way ANOVA showed that ( Figure 4 ), the seed yield of W2×F2 and W2×F3 treatment groups was significantly higher than that of the control group, while that of W3×F0 and W3×F1 treatment groups was significantly lower.

[0034] (8) Furthermore, the results of principal component analysis showed that principal component PC1 (seed yield) explained 72.80% of the total variance, while principal component PC2 (1000-grain weight) explained 24.30% of the total variance (Table 4). Principal component 1 was dominated by germination rate and seed yield, which included most of the variability in the data, while principal component 2 was dominated by seed yield, which included minor variability in the data (Table 5). The optimal treatment was W2×F4, the second-best treatment was W2×F3, and the worst treatment was W1×F0 (Table 6).

[0035] Table 4 Principal components and variance contribution rates parameter Principal component 1 Principal component 2 Principal component 3 Standard Deviation 1.478 0.853 0.297 Variance ratio 0.728 0.243 0.029 Cumulative ratio 0.728 0.971 1.000

[0036] Table 5 Principal components and factor loadings

[0037] Table 6 Comprehensive evaluation of the effects of different water and fertilizer on alfalfa seed quality Water and fertilizer treatment Principal component 1 Principal component 2 Principal component 3 Ranking W1×F0 -1.073 0.773 0.001 15 W1×F1 -0.649 0.683 -0.126 13 W1×F2 -0.219 0.510 -0.193 10 W1×F3 0.102 0.475 -0.235 8 W1×F4 0.492 0.374 -0.316 4 W2×F0 -0.339 0.393 0.064 11 W2×F1 0.140 0.154 0.021 6 W2×F2 0.573 0.082 -0.012 3 W2×F3 0.863 -0.072 -0.119 2 W2×F4 1.218 -0.184 -0.154 1 W3×F0 -0.806 -0.825 0.402 14 W3×F1 -0.452 -1.035 0.337 12 W3×F2 -0.205 -0.651 0.193 9 W3×F3 0.136 -0.587 0.118 7 W3×F4 0.219 -0.089 0.020 5

[0038] (9) Furthermore, the results of the water and fertilizer utilization efficiency of the traditional water and fertilizer field experiment showed that the water utilization rate and fertilizer utilization rate of the treatment group were higher than those of the blank control group; in addition, the results of the effects of different water and fertilizer management schemes on the economic benefits of alfalfa seed fields showed that the economic benefits of alfalfa seed fields in the treatment group were higher than those in the blank control group (Table 7). The results showed that refined water and fertilizer regulation significantly improved the water and fertilizer utilization efficiency, and the economic benefits of the seed field were also significantly improved.

[0039] Table 7 Ecological and economic benefit evaluation Water and fertilizer treatment WUE (kg / mm) FUE (kg / kg) Economic benefits (yuan / ha) W1×F0 1.2 20 10000 W2×F3 2 30 15000 W2×F4 2.5 35 18000

[0040] (10) The water-fertilizer coupling control mode proposed in the present invention can effectively improve the growth and yield of alfalfa, optimize the utilization of water and fertilizer resources, and improve the efficiency of water and fertilizer utilization. Through the analysis of different water and fertilizer treatments, the optimal water and fertilizer management parameters and technical paths were determined, providing a scientific basis for the precise control of water and fertilizer in alfalfa production.

[0041] In response to the above problems, this technology proposes an innovative and systematic method for precise water and fertilizer control. Based on the different stages of alfalfa growth and development, it optimizes irrigation and fertilization strategies and constructs a refined management model for water and fertilizer coupling. Compared with traditional technologies, the innovation of this technology is reflected in: (1) Water and fertilizer demand model based on growth stage: By systematically studying the demand patterns of alfalfa for water and nutrients at different growth stages, a scientific water and fertilizer control plan is proposed to achieve on-demand supply of water and fertilizer resources. (2) Strengthening the synergistic effect of water and fertilizer: On the basis of optimizing irrigation and fertilization technology, the synergistic effect between water and fertilizer is fully utilized to improve resource utilization efficiency and reduce water and fertilizer waste. (3) Achieving environmentally friendly production: By precisely controlling water and fertilizer input, the risk of soil and environmental pollution is reduced, while reducing planting costs and promoting the sustainable development of alfalfa production.

[0042] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited thereto. Within the technical scope disclosed by the present invention, any simple changes or equivalent replacements made by technicians in this technical field based on the technical content of the present invention shall be deemed to fall within the protection scope of the present invention.

Claims

1. A method for efficiently planting alfalfa based on water-fertilizer coupling optimization and precise regulation, characterized in that: The following steps are involved: (1) By analyzing the water and fertilizer requirements of alfalfa at different growth stages and combining the coupling optimization method of irrigation level and fertilization level, the optimal water-fertilizer ratio was 2.22 to 3.33, which significantly improved water and fertilizer utilization efficiency, seed yield and quality. The optimal treatment was W2×F4, which was a combination of normal watering (W2) and excessive fertilization (F4). The suboptimal treatment was W2×F3, which was a combination of normal watering (W2) and high fertilization (F3). (2) The Penman-Monteith formula was used to calculate the reference crop evaporation and further determine the precise irrigation amount for alfalfa. Through randomized block design, gradient water and fertilization treatments were set up, and the amount of fertilizer was scientifically calculated based on soil nutrients and the fertilizer requirements of alfalfa to ensure the accuracy and rationality of water and fertilizer supply. (3) Use shallow buried drip irrigation or traditional watering technology to monitor alfalfa plant height, leaf area, seed yield and quality in real time, calculate water use efficiency (WUE), fertilizer use efficiency (FUE) and economic benefits, comprehensively optimize planting management strategies, and improve production efficiency.

2. The method according to claim 1, characterized in that Principal component analysis (PCA) was used to screen the key driving factors in the growth process of alfalfa, and one-way ANOVA was used to verify the significant effects of different water and fertilizer treatments on seed yield, 1000-grain weight and germination rate. Based on the analysis results, a precise water and fertilizer control strategy with W2×F4 (normal watering × excess fertilization) as the core was proposed, and the suboptimal effect of W2×F3 (normal watering × high fertilization) was verified at the same time, further optimizing the water-fertilizer coupling mode and improving planting efficiency and ecological benefits.

3. The method according to claim 1, characterized in that During the sowing, branching, flowering and fruiting periods of alfalfa, a multi-dimensional water and fertilizer control plan is adopted. By verifying the optimization application effect of shallow buried drip irrigation technology on the water-fertilizer ratio (mainly W2×F4 and W2×F3), the water and fertilizer utilization efficiency and crop growth quality are improved, further achieving a dual improvement in economic and ecological benefits.

4. The method according to claim 1, characterized in that: A dynamic economic benefit analysis model based on efficient water and fertilizer utilization was constructed, focusing on optimizing the two water and fertilizer management schemes W2×F4 and W2×F3, providing a basis for the quantitative comparison of different water and fertilizer management schemes, clarifying the differences in economic benefits of each scheme, and providing decision-making support for the promotion and application of technology and large-scale production.

5. The method according to claim 1, characterized in that: Applying the above-mentioned water-fertilizer coupling optimization strategy to alfalfa breeding experiments, seed yield evaluation and actual production can effectively improve water and fertilizer utilization efficiency, significantly reduce planting costs, and realize technology promotion in the fields of ecological agriculture and precision agriculture.

6. The method according to claim 1, characterized in that In view of the unique climate conditions and soil environment in Inner Mongolia, by optimizing the water and fertilizer management strategy, mainly using W2×F4 and combined with the auxiliary verification of W2×F3, the comprehensive planting benefits of alfalfa are improved, providing innovative technical support for regional ecological protection and agricultural development.

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