A high-low ridge winter wheat nitrogen density coordination efficient cultivation method based on water consumption feedback

Abstract

This invention relates to the field of agricultural technology, specifically to a high-efficiency nitrogen-density cultivation method for winter wheat using a raised-and-low-ridge system based on water consumption feedback. The method includes: employing a raised-and-low-ridge cultivation pattern, wherein the top width of the high ridge is 45-55 cm, the bottom width is 55-65 cm, and the width of the low ridge is 85-95 cm; the total nitrogen application throughout the growth period is 227 kg / hm². 2 ~303 kg / hm 2 The planting density is 161 kg / hm. 2 ~236 kg / hm 2 The cultivation method provided by this invention sets a nitrogen density configuration range in the high and low ridge cultivation mode of winter wheat, which can simultaneously achieve more than 95% of the maximum values ​​of four key indicators: yield, aboveground biomass, water use efficiency and economic benefits, and nitrogen fertilizer partial productivity reaches more than 85% of its maximum value, thus overcoming the limitations of solely pursuing yield or a certain efficiency indicator.

Description

Technical Field

[0001] This invention relates to the field of agricultural technology, specifically to a high-efficiency cultivation method for high and low ridge winter wheat with nitrogen-density synergy based on water consumption feedback. Background Technology

[0002] The North China Plain is my country's most important winter wheat producing area, accounting for over 70% of the national total. The region experiences significant interannual and uneven seasonal precipitation, with winter wheat typically receiving only 100-180 mm of rainfall during its growing season, insufficient to meet the crop's water needs throughout its entire growth period. Under limited water resources, winter wheat production has long relied on irrigation and high levels of nitrogen fertilizer input to ensure canopy growth and yield formation. However, simply increasing nitrogen fertilizer input has not consistently led to a simultaneous increase in yield; instead, it easily results in a decline in nitrogen fertilizer partial productivity and utilization efficiency, exacerbating soil nitrogen residue accumulation, nitrogen leaching, and environmental risks. Therefore, under the dual constraints of rigid water resource requirements and the need for green agricultural development, how to achieve a synergistic improvement in winter wheat yield and efficient water and nitrogen resource utilization through optimized cultivation management has become a crucial issue that urgently needs to be addressed in agricultural production in the North China Plain.

[0003] Raised-low ridge cultivation, as a novel planting model, alters the collection, infiltration, and redistribution of rainfall and irrigation water in the field by creating a micro-topography with alternating high and low ridges, thereby affecting the spatial and temporal distribution of soil moisture in the root zone and the crop growth environment. Existing research indicates that raised-low ridge cultivation has certain advantages over flat cultivation in promoting plant population development, improving yield, and enhancing resource utilization efficiency. However, how to achieve a synergistic improvement in winter wheat yield and efficient water and nitrogen resource utilization through adjustments to cultivation management practices under raised-low ridge cultivation is a pressing issue that needs to be addressed. Summary of the Invention

[0004] To develop a cultivation method that achieves efficient utilization of water and nitrogen resources in winter wheat, this invention provides a high- and low-ridge winter wheat cultivation method based on water consumption feedback and nitrogen-density synergistic efficiency. The cultivation method provided by this invention sets nitrogen density configuration ranges in the high- and low-ridge winter wheat cultivation model, enabling four key indicators—yield, aboveground biomass, water use efficiency, and economic benefits—to simultaneously reach over 95% of their respective maximum values, with nitrogen fertilizer partial productivity reaching over 85% of its maximum value, overcoming the limitations of solely pursuing yield or a single efficiency indicator.

[0005] This invention provides a high-efficiency cultivation method for high- and low-ridge winter wheat with nitrogen-density synergy based on water consumption feedback, comprising the following steps: The high and low ridge cultivation model is adopted, wherein the top width of the high ridge is 45 cm ~ 55 cm and the bottom width is 55 cm ~ 65 cm, and the width of the low ridge is 85 cm ~ 95 cm. The total nitrogen application rate throughout the entire growth period was 227 kg / hm². 2 ~303 kg / hm 2 The planting density is 161 kg / hm. 2 ~236kg / hm 2 .

[0006] The cultivation method provided by this invention sets a nitrogen density configuration range in the high and low ridge cultivation mode of winter wheat, which can simultaneously achieve more than 95% of the maximum values ​​of four key indicators: yield, aboveground biomass, water use efficiency and economic benefits, and the nitrogen fertilizer partial productivity reaches more than 85% of its maximum value.

[0007] Furthermore, the total nitrogen application rate throughout the entire growth period is 240 kg / hm². 2 ~300 kg / hm 2 The planting density is 180 kg / hm. 2 ~225 kg / hm 2 .

[0008] Furthermore, the nitrogen application rate throughout the entire growth period is 246.38–268.07 kg / hm². 2 The planting density is 183.45–215.96 kg / hm². 2 .

[0009] Furthermore, the nitrogen fertilizer used is urea, of which 45% to 50% is applied as base fertilizer before sowing, and the remaining urea is applied as top dressing at the jointing stage. The base fertilizer is applied at a depth of 8 cm to 15 cm.

[0010] Furthermore, the topdressing is applied only to the low-ridge areas. The high-ridge surfaces remain relatively dry during irrigation, with irrigation water infiltrating through the low ridges and laterally replenishing the crop root zone on the high ridges to reduce ineffective evaporation from the high-ridge surfaces.

[0011] Furthermore, it also includes water consumption feedback irrigation during the greening period: irrigation is carried out when the soil moisture content of the 0cm~100cm soil layer in the center of the high ridge and the center of the low ridge drops to 55%~65% of the field capacity, with a single irrigation quota of 75mm~90mm.

[0012] Furthermore, it also includes basal application of phosphate and potash fertilizers, both at a rate of 100 kg / hm². 2 ~120 kg / hm 2 .

[0013] Furthermore, the winter wheat variety mentioned is "Zhoumai 22".

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention, through multi-year, multi-objective comprehensive optimization analysis, obtained the suitable nitrogen density range for winter wheat under raised bed cultivation conditions: nitrogen application rate 227 kg / hm². 2 ~303 kg / hm 2 Planting density: 161 kg / hm 2 ~236 kg / hm 2 The optimal nitrogen application rate is 246.38–268.07 kg / hm². 2 Planting density: 183.45–215.96 kg / hm² 2 Within this range, it is possible to achieve more than 95% of the maximum values ​​for four key indicators: yield, aboveground biomass, water use efficiency, and economic benefits. Furthermore, nitrogen fertilizer partial productivity can reach more than 85% of its maximum value, overcoming the limitations of solely pursuing yield or a single efficiency indicator.

[0015] The optimized nitrogen density configuration of this invention can effectively coordinate the relationship between "high yield, high water and nitrogen efficiency, and high profitability" in winter wheat: Yield and biomass: The highest four-year average yield can reach 9.61 t / hm. 2 Compared with other treatments, the efficacy was increased by 0.56% to 36.45%; Water use efficiency: up to 1.91 kg / m³, which is 6.87% to 13.91% higher than other density treatments; Nitrogen fertilizer partial productivity: up to 41.64 kg / kg, increasing productivity by 8.46% to 63.73% compared to lower nitrogen levels; Economic benefits: The highest average net profit over four years can reach 9859.6 CNY / hm. 2 It is 2.76 times the lowest value.

[0016] This invention also provides a targeted optimization scheme: when maximizing water use efficiency and economic benefits, the preferred nitrogen application rate is 260~300 kg / hm². 2 Planting density: 180-190 kg / hm 2 When aiming to maximize nitrogen fertilizer productivity, the preferred nitrogen application rate is 180 kg / hm². 2 Planting density: 180-200 kg / hm 2 This provides flexible options for precise management under different production goals and soil fertility conditions.

[0017] The nitrogen-dense coupling method provided by this invention has specific parameters and is easy to operate. It does not require additional complex facilities or management procedures. It can significantly improve the overall production efficiency simply by adjusting the recommended amounts during the sowing and fertilization stages. It is suitable for large-scale promotion in the high and low ridge cultivation areas of winter wheat in the North China Plain and is of great significance for promoting green, sustainable and high-efficiency wheat production in the region. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a planting pattern with high and low ridges in an embodiment of the present invention; In the figure, (a) is a schematic diagram of the high and low ridge planting pattern; (b) is a real photo of the high and low ridge planting pattern.

[0020] Figure 2 The effects of different nitrogen application rates and planting densities on water consumption of winter wheat; In the figure, (a) shows the effect of different nitrogen application rates and planting densities on water consumption of winter wheat in 2020-2021; (b) The effects of different nitrogen application rates and planting densities on water consumption of winter wheat in 2021-2022; (c) The effects of different nitrogen application rates and planting densities on water consumption of winter wheat in 2022-2023; (d) shows the effects of different nitrogen application rates and planting densities on water consumption of winter wheat in 2024-2025.

[0021] Figure 3 The effects of different nitrogen application rates and planting densities on aboveground biomass, yield, and yield components of winter wheat; In the figure, (a) shows the effects of different nitrogen application rates and planting densities on aboveground biomass, yield, and yield components of winter wheat from 2020 to 2021. (b) The effects of different nitrogen application rates and planting densities on aboveground biomass, yield, and yield components of winter wheat in 2021-2022; (c) The effects of different nitrogen application rates and planting densities on aboveground biomass, yield, and yield components of winter wheat in 2022-2023; (d) The effects of different nitrogen application rates and planting densities on aboveground biomass, yield, and yield components of winter wheat in 2024-2025.

[0022] Figure 4 The effects of different nitrogen application rates and planting densities on water use efficiency (WUE) and nitrogen fertilizer partial productivity (NPFP); In the figure, (a) shows the effects of different nitrogen application rates and planting densities on water use efficiency (WUE) and nitrogen fertilizer partial productivity (NPFP) from 2020 to 2021; (b) The effects of different nitrogen application rates and planting densities on water use efficiency (WUE) and nitrogen fertilizer partial productivity (NPFP) in 2021-2022; (c) The effects of different nitrogen application rates and planting densities on water use efficiency (WUE) and nitrogen fertilizer partial productivity (NPFP) in 2022-2023; (d) The effects of different nitrogen application rates and planting densities on water use efficiency (WUE) and nitrogen fertilizer partial productivity (NPFP) in 2024-2025.

[0023] Figure 5 The impact of different nitrogen application rates and planting densities on economic benefits; In the figure, (a) shows the impact of different nitrogen application rates and planting densities on cost and economic benefits; (b) The effect of different nitrogen application rates and planting densities on the yield-to-input ratio (I / O) of winter wheat in 2020-2021; (c) The effect of different nitrogen application rates and planting densities on the yield-to-input ratio (I / O) of winter wheat in 2021-2022; (d) The effect of different nitrogen application rates and planting densities on the yield-to-input ratio (I / O) of winter wheat in 2022-2023; (e) shows the effect of different nitrogen application rates and planting densities on the yield-to-input ratio (I / O) of winter wheat in 2024-2025.

[0024] Figure 6 The nitrogen density co-optimization interval map is determined based on the 95% and 85% optimal isotropic regions of each objective variable (yield, aboveground biomass, WUE, economic benefit, and nitrogen fertilizer partial productivity). In the figure, (a) the nitrogen density co-optimization interval selection based on the 95% and 85% optimal isotropic regions of each objective variable in 2020-2021; (b) Screening of nitrogen density co-optimization intervals determined based on the 95% and 85% optimal isotropic regions of each objective variable for 2021-2022; (c) Screening of nitrogen density co-optimization intervals determined based on the 95% and 85% optimal isotropic regions of each objective variable for 2022-2023; (d) Screening of nitrogen density co-optimization intervals determined based on the 95% and 85% optimal isotropic regions of each objective variable in 2024-2025.

[0025] Figure 7 This is a graph showing the intersection of the optimal nitrogen application rate and planting density ranges for the four growing seasons. In the figure, (a) is the intersection of the optimal nitrogen application rate and planting density ranges for 2020-2021; (b) is the intersection of the optimal nitrogen application rate and planting density ranges for 2021-2022; (c) is the intersection of the optimal nitrogen application rate and planting density ranges for 2022-2023; (d) Intersection of the optimal nitrogen application rate and planting density ranges for 2024-2025. Detailed Implementation

[0026] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise specified, the experimental methods described in the embodiments of the present invention are conventional methods, and the materials and reagents used in the following embodiments are commercially available unless otherwise specified.

[0027] Example 1: A high-efficiency cultivation method for high and low ridge winter wheat with nitrogen density synergy based on water consumption feedback.

[0028] I. Materials and Methods 1. Overview of the test site Field trials were conducted from October 2020 to June 2023 and from October 2024 to June 2025 at the Xinxiang Comprehensive Experimental Base of the Chinese Academy of Agricultural Sciences (35.15°N, 113.80°E). The experimental area had an altitude of 81 m, an average annual precipitation of 582 mm, an average annual temperature of 14 ℃, and a frost-free period of 210 days. The soil type was loam, with an average bulk density of 1.51 g / cm³ in the 0–100 cm soil layer. 3 The field water holding capacity was 31% (v / v). The organic matter, total nitrogen, available phosphorus, and available potassium in the 0–40 cm soil layer were 16.1 g / kg, 1.05 mg / kg, 23.4 mg / kg, and 229.5 mg / kg, respectively. The groundwater level in this area was greater than 5 m. The main cropping pattern was winter wheat-summer maize rotation. The total precipitation for the four winter wheat growing seasons was 174.8 mm, 60.1 mm, 147.2 mm, and 64.9 mm, respectively.

[0029] 2. Experimental Design Cultivation: A raised bed cultivation model is adopted, and the optimal nitrogen application rate and planting density are selected for sowing and fertilization. Specific steps are as follows:

[0030] The wheat variety used in the experiment was "Zhoumai 22," and the nitrogen, phosphorus, and potassium fertilizers were urea (≥46%), superphosphate (P2O5≥12%), and potassium chloride (K2O≥60%), respectively. Two factors were considered in the experiment: nitrogen application rate and planting density. Four nitrogen application rates were set: extra-high nitrogen (F1, 360 kg / hm²). 2 High nitrogen (F2, 300 kg / hm) 2 ), medium nitrogen (F3, 240 kg / hm) 2 Low nitrogen (F4, 180 kg / hm) 2 Planting density was set at three levels, including high planting density (M1, 225 kg / hm). 2 Medium planting density (M2, 180 kg / hm) 2 Low planting density (M3, 135 kg / hm) 2 The experiment consisted of 12 treatments, replicated 3 times, for a total of 36 plots, each plot measuring 135 m². 2 (15 m × 9 m). In this experiment, winter wheat was cultivated using a raised-and-low-ridge cultivation model. Figure 1 The raised beds are 50 cm wide at the top and 60 cm wide at the bottom, while the low beds are 90 cm wide. The average row spacing for wheat is 25 cm. Phosphate and potassium fertilizers are applied as a single basal application before sowing, at a rate of 120 kg / hm². 2 Urea was applied twice, as basal fertilizer and topdressing. 50% was applied as basal fertilizer before sowing, at a depth of approximately 10 cm, while the remaining 50% was applied as topdressing during the jointing stage in conjunction with irrigation. Topdressing was only applied to low-lying areas. In the four-year trial, wheat was sown in mid-to-late October and harvested in early June of the following year.

[0031] Irrigation: Starting from the winter wheat greening stage, the soil moisture content at a depth of 100 cm in the center of both raised and low-ridged fields was measured every 7 days using the oven-drying method. Irrigation was initiated when the weighted average soil moisture content dropped to approximately 60% of field capacity. Each irrigation was a localized application, with water applied only to the low-ridged areas, and the irrigation quota controlled at 90 mm, allowing the root zone soil moisture to recover to 85% of field capacity. The raised ridges were kept relatively dry throughout the process. Irrigation was stopped after the mid-grain-filling stage.

[0032] 3. Measurement Items and Methods (1) Aboveground biomass At the winter wheat maturity stage, 20 representative winter wheat plants were collected from both high-ridge and low-ridge fields. The samples were placed in an oven for 30 minutes to kill the enzymes, then dried at 75℃ to constant weight. The weight of the samples was measured using a balance, and the aboveground biomass per unit area (kg / hm²) was calculated based on the winter wheat population density. 2 ).

[0033] (2) Output and its components During the wheat ripening period, 1 m sections were selected in both high-ridged and low-ridged fields. 2 Harvesting was carried out in undisturbed quadrats (1 m × 1 m), and the number of ears was counted and the grains were threshed and the yield was calculated (grain moisture content was converted to 13%). Thirty wheat plants near the harvested quadrats were selected to measure the number of grains per ear and the thousand-grain weight.

[0034] (3) Farmland water consumption and water and nitrogen use efficiency Soil moisture content was measured before and after each winter wheat sowing season, with sampling depths of 0–20 cm, 20–40 cm, 40–80 cm, 80–120 cm, 120–160 cm, and 160–200 cm, respectively. One sampling point was set at the center of both the raised and low-ridged fields in each plot, and the average value of the two points was used. Crop water consumption (ET, mm) was calculated using the water balance equation.

[0035] ET = P + I – D – R –Δ W (1); In the formula, P Rainfall (mm) I Irrigation volume (mm). D The depth of leakage is measured in mm. R ΔW represents the surface runoff (mm), and ΔW represents the change in soil water storage before and after the growing season (mm). Since each plot in the experimental area is ridged, rainfall or irrigation will not cause surface runoff. R =0; Irrigation and precipitation infiltration depth is less than 200 cm of soil thickness, therefore D =0.

[0036] Water use efficiency (WUE, kg / m³) 3 The formulas for calculating nitrogen fertilizer partial productivity (NPFP, kg / kg) are as follows: WUE = Y / ET (2); NPFP = Y / N(3); In the formula Y Grain yield (kg / hm) 2 ), N This refers to the nitrogen application rate, in kg / hm². 2 .

[0037] (4) Economic benefit analysis Agricultural production inputs include seeds, fertilizers, irrigation, pesticides, and machinery; agricultural production output is the grain yield. Net Profit (NP, CNY / hm²) 2 Value-Cost Ratio (VCR) is the difference between production output and production input.

[0038] NP=T O -T I (4); VCR=T O / T I (5); In the formula T O Income from winter wheat grain yield (CNY / hm) 2 ), T I Total inputs for winter wheat production, including seeds, fertilizers, and machinery (CNY / hm²) 2 ).

[0039] (5) Data processing Data analysis and analysis of variance (ANOVA) were performed using Excel 2022 and SPSS 25.0. Multiple comparison (LSD) analysis was used to analyze the differences in yield, water and nitrogen use efficiency and economic benefits under different nitrogen density treatments. Origin 2024 was used to fit the bivariate quadratic surface regression equation.

[0040] II. Experimental Results 1. Effects of nitrogen application rate and planting density on water consumption of winter wheat In the 2020–2021, 2021–2022, and 2022–2023 fiscal years, nitrogen application rate, planting density, and their interaction all had highly significant effects on water consumption of winter wheat. P <0.01); In the 2024-2025 fiscal year, the main effects of nitrogen application rate and planting density were both highly significant. P<0.01), and the interaction between the two was not significant. Overall, under the same planting density, the water consumption of winter wheat decreased with decreasing nitrogen application level, mostly showing the order F1 > F2 > F3 > F4; under the same nitrogen application level, the water consumption of treatments M1 and M2 was usually higher than that of treatment M3. In terms of interannual variation, the overall water consumption of winter wheat showed the following pattern: 2020–2021 > 2022–2023 > 2021–2022 > 2024–2025 (…). Figure 2 ).

[0041] 2. Effects of nitrogen application rate and planting density on aboveground biomass, yield, and their components of winter wheat Depend on Figure 3 It can be seen that nitrogen application rate and planting density have significant effects on aboveground biomass and yield of winter wheat. P <0.01). Overall, winter wheat yield and aboveground biomass showed a trend of first increasing and then decreasing with increasing nitrogen application rate and planting density. The four-year average values ​​were highest in the F2M2 treatment, at 9.61 and 23.66 t / ha, respectively, which were 0.56%–36.45% and 0.27%–33.39% higher than other treatments, respectively. P <0.01). Under the same planting density, the yield and aboveground biomass of the moderate nitrogen application treatment were generally higher than those of the low and high nitrogen treatments; under the same nitrogen application level, the M2 treatment was generally higher than the M1 and M3 treatments, with the yield of the M1 and M3 treatments decreasing by 5.06% and 14.38% respectively, and the aboveground biomass decreasing by 0.51% and 13.99% respectively compared to the M2 treatment. Interannual variation analysis showed that both winter wheat yield and aboveground biomass were significantly affected by the year (…). P <0.01%, with the highest yield in 2020-2021 and the lowest in 2024-2025, while the aboveground biomass was highest in 2024-2025 and the lowest in 2021-2022. Figure 3 ).

[0042] Nitrogen application rate and planting density also have a significant impact on the components of winter wheat yield. P <0.05), and the interaction effect was not entirely consistent across different years. The 4-year average results showed that the number of spikes and grains per spike were highest in the F2M2 treatment and lowest in the F4M3 treatment, with the latter decreasing by 18.24% and 12.41% respectively compared to the former. P<0.01). Overall, under the same nitrogen application level, with increasing planting density, both the number of spikes and the number of grains per spike showed a trend of first increasing and then decreasing; under the same planting density, a similar pattern was observed with increasing nitrogen application, and in most cases, the F2M2 treatment performed best. The 4-year average of 1000-grain weight was highest in the F3M2 treatment and lowest in the F4M1 treatment, at 50.57 g and 47.14 g, respectively. This indicates that different nitrogen application rates and planting density configurations jointly affect winter wheat yield formation by adjusting the number of spikes, the number of grains per spike, and the 1000-grain weight. Interannually, the number of spikes, 1000-grain weight, and the number of grains per spike were all significantly affected by the year ( P <0.01), the overall trend is 2020-2021 > 2022-2023 > 2021-2022 > 2024-2025 ( Figure 3 ).

[0043] 3. Effects of nitrogen application rate and planting density on water use efficiency and nitrogen fertilizer partial productivity of winter wheat Nitrogen application rate, planting density, and their interaction have a significant impact on water use efficiency (WUE). P <0.05)( Figure 4 Over the four winter wheat growing seasons, the overall WUE ranged from 1.46 to 1.93 kg / m³. 3 The average results over four years showed that the F3M2 treatment had the highest WUE, at 1.91 kg / m³. 3 The F4M3 treatment was relatively low, at 1.53 kg / m³. 3 Overall, under the same nitrogen application level, WUE increased with increasing planting density in the order M2 > M1 > M3, with M2 showing an increase of 6.87%–13.92% compared to other density treatments (P<0.01). Under the same planting density, WUE generally showed a trend of first increasing and then decreasing with increasing nitrogen application, with the F3 treatment showing the highest WUE, increasing by 2.24%–13.65% compared to other nitrogen application levels. In terms of interannual variation, WUE was significantly affected by the year, with the highest values ​​in 2024–2025 and the lowest in 2020–2021. Figure 4 ).

[0044] Nitrogen partial productivity (NPFP) ranged from 22.42 to 41.64 kg / kg across the four growing seasons. Nitrogen application rate, planting density, and their interactions had a highly significant impact on NPFP. P <0.01)( Figure 4 The average results over four years showed that, at the same nitrogen application level, NPFP generally increased first and then decreased with increasing planting density, exhibiting the order M2 > M1 > M3; at the same planting density, NPFP gradually decreased with increasing nitrogen application, exhibiting the order F4 > F3 > F2 > F1, with F4 showing an increase of 8.46%–63.73% compared to other nitrogen application levels. P<0.01. Interannually, NPFP is also significantly affected by the year ( P <0.01), its trend is opposite to that of WUE, showing the highest in 2020-2021 and the lowest in 2024-2025. Figure 4 ).

[0045] 4. The impact of nitrogen application rate and planting density on economic benefits Cost structure and net profit of winter wheat under different nitrogen application rates and planting densities, as follows: Figure 5 As shown, the four-year average total input cost for each treatment ranged from 14,348.9 to 16,110.8 CNY / hm². 2 The average net income over four years was CNY 18,177.1 to 25,022.5 per hm². 2 The main differences in total cost stem from fertilizer and seed inputs. Different nitrogen application rates and planting densities affect total input costs by altering fertilizer and seed usage. The average economic benefit over four years ranged from 3568.3 to 9859.6 CNY / hm². 2 The highest value was 2.76 times the lowest value, indicating that different nitrogen density configurations have a significant impact on the net profit of winter wheat. Overall, under the same nitrogen application level, the economic benefits with varying planting density were M2 > M1 > M3; under the same planting density, the overall economic benefits were F3 > F2 > F1 > F4, with the F3M2 treatment having the highest net profit, while the F4 treatment had a lower overall net profit.

[0046] Nitrogen application rate, planting density, and their interactions all significantly affected the input-output ratio (I / O) of winter wheat. The average I / O ratio over four years ranged from 1.24 to 1.66, with the highest ratio in treatment F3M2, reaching 1.99 in 2021-2022; and the lowest in treatment F4M1, reaching only 1.00 in 2024-2025. Overall, under the same nitrogen application level, the I / O ratio of treatment M2 was higher than that of M1 and M3, and increased by 7.19% to 14.45% compared to other density levels. Under the same planting density, the overall I / O ratio showed the order F3 > F2 > F1 > F4. This indicates that appropriate nitrogen application and reasonable planting density are beneficial to improving the input-output level, while low nitrogen or excessively high density are not conducive to improving economic benefits. From an interannual perspective, the economic benefits and output-input ratio of winter wheat are significantly affected by the year, showing the following order: 2021–2022 > 2020–2021 > 2022–2023 > 2024–2025. Figure 5 ).

[0047] 5. Effects of nitrogen application rate and planting density and their interaction on the optimal nitrogen density range for winter wheat. Table 1. Regression equations of nitrogen application rate and planting density on winter wheat yield, aboveground biomass, water use efficiency, and economic benefits. Note: z is the target variable, x is the nitrogen application rate, and y is the planting density.

[0048] To determine the optimal nitrogen density for water-saving, high-yield, and high-efficiency winter wheat cultivation under raised-ridge and low-ridge conditions, binary quadratic regression models were established between yield, aboveground biomass, water use efficiency, economic benefits, and nitrogen fertilizer partial productivity as target variables, and between each indicator and nitrogen application rate and planting density. The results showed that the coefficients of determination (R²) for each model were greater than 0.80, indicating that the regression equations effectively reflected the response relationship between nitrogen application rate and planting density to each target indicator. Based on the regression equations, the high-value regions for different indicators and their corresponding nitrogen application rate and planting density ranges were further obtained (Table 1).

[0049] Depend on Figure 6 It can be seen that the optimal nitrogen application rate and planting density ranges corresponding to different target indicators are not entirely consistent. Among them, the 95% optimal equivalent ranges for yield, aboveground biomass, water use efficiency, and economic benefits show significant overlap, while the high-value range for nitrogen fertilizer partial productivity overlaps less with the above indicators, indicating a certain difference between single-indicator optimization and multi-objective synergistic optimization. To balance high yield, high biomass, high water use efficiency, high economic benefits, and a relatively high nitrogen fertilizer input-output level, this invention uses 95% of the maximum values ​​for yield, aboveground biomass, water use efficiency, and economic benefits, and 85% of the maximum value for nitrogen fertilizer partial productivity, as comprehensive optimization criteria to screen suitable ranges for nitrogen application rate and planting density in different years. Figure 7 The results showed that the optimal nitrogen application rate and planting density range for 2020–2021 was 246.38–299.25 kg / hm². 2 and 170.74~236.61kg / hm 2 The figures for 2021 and 2022 were 227.79–303.7 kg / hm², respectively. 2 and 166.15~226.66kg / hm 2 The figures for 2022 and 2023 were 242.63–268.07 kg / hm², respectively. 2 and 183.45~216.48kg / hm 2 The figures for 2024 and 2025 were 232.46–276.91 kg / hm², respectively. 2 and 161.21~215.96kg / hm 2 Based on the intersection of the four growing seasons, the optimal nitrogen application rate is 246.38–268.07 kg / hm². 2 The optimal planting density is 183.45–215.96 kg / hm². 2This nitrogen-dense planting scheme can simultaneously achieve 95% of the maximum yield, aboveground biomass, water use efficiency, and economic benefits, as well as 85% of the maximum nitrogen fertilizer partial productivity.

[0050] In summary, based on continuous observation data from four winter wheat growing seasons, this study analyzed the effects of nitrogen application rate and planting density on water consumption, yield formation, water and fertilizer use efficiency, and economic benefits of winter wheat under raised and low-ridge cultivation conditions, and drew the following conclusions: (1) Nitrogen application rate and planting density have significant effects on water consumption, yield, aboveground biomass, water use efficiency (WUE), nitrogen partial productivity (NPFP), and economic benefits of winter wheat. Overall, water consumption increases with increasing nitrogen application level, and treatments M1 and M2 are generally higher than treatment M3 at the same nitrogen application level. Yield and aboveground biomass both show an initial increase followed by a decrease with increasing nitrogen application rate and planting density, with treatment F2M2 having the highest yield, averaging 9.61 t / hm² over 4 years. 2 WUE showed a trend of first increasing and then decreasing with increasing nitrogen application, while NPFP gradually decreased with increasing nitrogen application. Both showed a trend of first increasing and then decreasing with increasing planting density, with the F3M2 and F4M2 treatments being the best.

[0051] (2) The economic benefits of winter wheat varied significantly under different nitrogen application rates and planting densities. The average economic benefit over 4 years was highest in the F3M2 treatment, at 9859.6 CNY / hm². 2 This indicates that moderate nitrogen application combined with moderate density is more conducive to achieving a coordinated balance between yield formation, resource utilization efficiency, and economic benefits.

[0052] (3) Based on the multi-objective comprehensive optimization analysis of yield, aboveground biomass, WUE, economic benefits and NPFP, the suitable nitrogen density configuration range for winter wheat under high and low ridge cultivation conditions was found to be: nitrogen application rate of 246.38–268.07 kg / hm. 2 Planting density: 183.45–215.96 kg / hm² 2 Within this range, yield, aboveground biomass, water use efficiency, and economic benefits can reach over 95% of their respective maximum values, while NPFP can reach over 85% of its maximum value. The suitable nitrogen density range proposed in this invention can provide a reference for nitrogen density management in high and low ridge cultivation of winter wheat in the North China Plain.

[0053] Although preferred embodiments of the invention have been described, those skilled in the art, once they have learned the basic inventive concept, can make other changes and modifications to these embodiments.

[0054] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A high-efficiency cultivation method for high- and low-ridge winter wheat with nitrogen-density synergy based on water consumption feedback, characterized in that, Includes the following steps: The high and low ridge cultivation model is adopted, wherein the top width of the high ridge is 45 cm ~ 55 cm and the bottom width is 55 cm ~ 65 cm, and the width of the low ridge is 85 cm ~ 95 cm. The total nitrogen application rate throughout the entire growth period was 227 kg / hm². 2 ~303 kg / hm 2 The planting density is 161 kg / hm. 2 ~236 kg / hm 2 .

2. The high-efficiency cultivation method for high and low ridge winter wheat with nitrogen-density synergy based on water consumption feedback as described in claim 1, characterized in that, The total nitrogen application rate throughout the entire growth period is 240 kg / hm². 2 ~300 kg / hm 2 The planting density is 180 kg / hm. 2 ~225kg / hm 2 .

3. The high-efficiency cultivation method for high and low ridge winter wheat with nitrogen-density synergy based on water consumption feedback as described in claim 2, characterized in that, The total nitrogen application rate during the entire growth period was 246.38 kg / hm². 2 ~268.07 kg / hm 2 The planting density was 183.45 kg / hm². 2 ~215.96 kg / hm 2 .

4. The high-efficiency cultivation method for high and low ridge winter wheat with nitrogen-density synergy based on water consumption feedback as described in claim 1, characterized in that, The nitrogen fertilizer used is urea, of which 45% to 50% is applied as base fertilizer before sowing, and the remaining urea is applied as top dressing at the jointing stage. The base fertilizer is applied at a depth of 8 cm to 15 cm.

5. The high-efficiency cultivation method for high and low ridge winter wheat with nitrogen-density synergy based on water consumption feedback as described in claim 4, characterized in that, The topdressing fertilizer is only applied to low-ridge areas.

6. The high-efficiency cultivation method for high and low ridge winter wheat with nitrogen-density synergy based on water consumption feedback as described in claim 1, characterized in that, It also includes water consumption feedback irrigation during the greening period: irrigation is carried out when the soil moisture content of the 0cm~100cm soil layer in the center of the high ridge and the center of the low ridge drops to 55%~65% of the field capacity, and the quota for a single irrigation is 75mm~90mm.

7. The high-efficiency cultivation method for high and low ridge winter wheat with nitrogen-density synergy based on water consumption feedback as described in claim 1, characterized in that, This also includes basal application of phosphate and potash fertilizers, each at a rate of 100 kg / hm². 2 ~120 kg / hm 2 .

8. The high-efficiency cultivation method for high and low ridge winter wheat with nitrogen-density synergy based on water consumption feedback as described in claim 1, characterized in that, The winter wheat variety mentioned is "Zhoumai 22".

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