A method to improve fertilizer utilization in drip-irrigated cotton fields in Xinjiang

Abstract

This invention provides a method for improving fertilizer utilization in drip-irrigated cotton fields in Xinjiang. The method mainly includes targeted soil improvement, phased nutrient management, and precise water and fertilizer control. It specifies that each drip irrigation topdressing process is carried out in three stages: Stage 1, drip irrigation with only clean water; Stage 2, simultaneous drip irrigation with clean water and fertilizer solution; Stage 3, drip irrigation with only clean water. Because this invention achieves targeted ultra-deep plowing by precisely controlling the deep plowing depth and plowshare angle, it effectively prevents the upturning of saline-alkali soil. Combined with phased topdressing and the synergistic management of water and fertilizer in each drip irrigation's three-stage precise water and fertilizer control, it not only ensures sustained high yields but also solves the current problems of low fertilizer utilization in Xinjiang's drip-irrigated cotton fields and the risk of non-point source pollution in cotton-growing areas due to deep fertilizer leaching. Furthermore, it reduces production costs, thus possessing significant economic, social, and ecological benefits.

Description

Technical Field

[0001] This invention belongs to the field of agricultural planting technology, and specifically relates to a method for improving fertilizer utilization in drip-irrigated cotton fields in Xinjiang. Background Technology

[0002] Xinjiang is my country's most important cotton-producing region, accounting for over 90% of the national cotton output. Drip irrigation under mulch film, as the primary irrigation method in the region, has been applied to over 30 million mu (approximately 2 million hectares), playing a crucial supporting role in ensuring high cotton yields. However, problems arising from improper water and fertilizer management in drip-irrigated cotton fields are becoming increasingly prominent, posing a significant bottleneck to the sustainable development of cotton fields. Specifically, while existing Xinjiang drip-irrigated cotton fields have consistently achieved high-input, high-output yields for machine-harvested seed cotton exceeding 500 kg / mu (approximately 333 kg / hectare) for many years, a considerable portion of these fields have used high-efficiency fertilizers such as urea, monoammonium phosphate, and potassium sulfate at levels exceeding 130 kg / mu (approximately 80 kg / hectare). Coupled with inappropriate water and fertilizer coordination measures, this has resulted in the following main problems in fertilizer utilization in these cotton fields:

[0003] 1. Severe fertilizer waste and low utilization rate: Cotton fields exhibit significant over-fertilization, with the average fertilizer usage per acre far exceeding the actual needs of cotton. In practice, due to water scarcity and ingrained water management practices, the irrigation volume for each drip irrigation is generally large and difficult to change. Under these circumstances, the commonly used "simultaneous water and fertilizer application" model (i.e., drip irrigation and fertilizer application begin simultaneously, but fertilizer application ends before irrigation) and other types of drip-applied fertilizers, even those that do not employ simultaneous application (such as drip irrigation with clean water), suffer from excessive irrigation volume during the simultaneous water and fertilizer application phase. This leads to unreasonable distribution and severe leaching of nitrogen and phosphorus nutrients with varying mobility in the soil. Data shows that the utilization rates of nitrogen, phosphorus, and potassium fertilizers in drip-irrigated cotton fields in this region are only 30-35%, 15-20%, and 40-45%, respectively, far below the average level of developed agricultural countries, resulting in substantial economic losses.

[0004] 2. The mobility of phosphate fertilizer is underestimated, and deep leaching is a prominent problem: Traditional views hold that phosphate fertilizer has poor mobility in the soil and is not easily leached, thus advocating or frequently using deep application of basal fertilizer. However, the inventors made a breakthrough discovery through systematic testing of 24 sample points in representative cotton fields in Xinjiang, a region with long-term high input and high output cotton: Under Xinjiang's special soil environment and the long-term high-frequency, high-water and high-fertilizer drip irrigation mode, phosphate fertilizer exhibits significant mobility and has accumulated in large quantities in deep soil layers (below 40cm).

[0005] Previous studies have reported that in the early stages of planting, these typical high-input, high-yield cotton fields had soluble total nitrogen (N) ≤30 mg / kg, available phosphorus (P2O5) ≤10 mg / kg, and available potassium (K2O) ≥190 mg / kg in the topsoil. Below the topsoil, the contents of soluble total nitrogen and available phosphorus were even lower, while the content of available potassium was relatively higher. However, after decades of high-input, high-yield cotton cultivation, the analysis of soil nutrients at different depths from 24 sampling points is shown in Table 1 below:

[0006] Table 1. Average nutrient content in soil layers at different depths

[0007] As shown in Table 1, compared with typical cotton fields at the early stage of cotton planting, the content of soluble total nitrogen and available phosphorus in the topsoil was significantly increased, while the content of available potassium decreased significantly. Although the nutrient content of the deep soil (below 40 cm) at the 24 sampling points was generally lower than that of the topsoil, it was significantly increased compared with the deep soil nitrogen and phosphorus content of cotton fields at the early stage of planting. This indicates that nitrogen and phosphorus leaching was severe in these cotton fields. Although the soil potassium content decreased to varying degrees, there were no obvious signs of leaching. This is obviously closely related to the long-term high input of nitrogen and phosphorus and the long-term insufficient input of potassium fertilizer in cotton fields.

[0008] The ratios of the average nutrient content of soil layers at different depths to the average nutrient content of the surface layer (above 20cm), calculated based on the data in Table 1, are shown in Table 2 below:

[0009] Table 2. Average nutrient content of soil layers at different depths as a percentage of the surface layer

[0010] Based on the data in Tables 1 and 2 above: Under the high-input, high-yield cotton drip irrigation conditions in Xinjiang, the average available phosphorus content in the soil layer below 40cm reached 18.2mg / kg, which is 82.7% of that in the topsoil layer (0-20cm). Table 2 shows that the average available phosphorus content in the 20-40cm soil layer is 98.7% of that in the 0-20cm layer, 88.1% in the 40-60cm layer, 73.6% in the 60-80cm layer, and still 79.7% in the 80-100cm layer. The soluble total nitrogen content in the 20-40cm, 40-60cm, 60-80cm, and 80-100cm soil layers is 80.0%, 79.6%, 78.5%, and 78.3% of that in the 0-20cm topsoil layer, respectively. The number of samples with nutrient content higher than that in the 0-20cm topsoil layer is shown in Table 3 below.

[0011] Table 3. Number of samples with nutrient content higher than the 0-20cm surface layer in different soil layers

[0012] As shown in Table 1, among the 24 sampling points, the contents of soluble total nitrogen, available phosphorus, and available potassium in different soil layers were higher than those in the surface layer in many sampling points. For example, the available phosphorus content in 20-40cm was higher than that in the surface layer in 10 sampling points, and the available phosphorus content in 80-100cm was higher than that in the surface layer in 3 sampling points.

[0013] In summary, it can be concluded that phosphate fertilizer exhibits significant mobility in cotton fields in Xinjiang, a conclusion that overturns the long-held industry consensus that "phosphate fertilizer has extremely poor mobility." The inventors' research revealed that Xinjiang oases possess a unique soil environment—heavy sandy soil with a loose structure, low clay and organic matter content, coarse particles, and interconnected soil pores (including capillary and non-capillary pores) with a relatively large overall pore size. Under these conditions, long-term, high-frequency, simultaneous application of large amounts of water and fertilizer, including excessive drip application of nitrogen and phosphate fertilizers, easily triggers a "preferred flow"—soluble fertilizers, including nitrogen and phosphorus, are easily carried away by the "preferred flow" of water. Furthermore, the large-scale application of humic acid fertilizers in recent years has increased the downward migration of nitrogen and phosphorus—rapidly penetrating the root layer—leading to continuous infiltration of nitrogen (nitrate nitrogen) into groundwater and phosphorus "displacement" to deeper layers, resulting in fertilizer leaching and deep-layer accumulation, thus reducing fertilizer utilization in the current season. In other words, fertilizer leaching through soil pores with water infiltration is an inevitable event. Although the available phosphorus content in the surface soil is generally higher than that in the deeper layers, under long-term, high-frequency water erosion, phosphorus is continuously fixed during migration, and its migration depth far exceeds traditional understanding. The gap between surface and deep soil phosphorus content is continuously narrowing, as confirmed by survey data obtained by the inventors (see Tables 1, 2, and 3). Further analysis shows that in the short term, the infiltration of phosphate fertilizer through soil gaps with water is very limited, which is basically consistent with existing research conclusions. However, after years of excessive water and fertilizer application, the phosphate fertilizer that has infiltrated into the deeper layers is difficult for crops to absorb and thus accumulates continuously. As a result, in some plots, the available phosphorus content in specific deep soil layers even exceeds that of the cultivated layer. This is clearly related to the fact that the phosphate fertilizer applied to the surface soil is often largely absorbed and consumed by cotton, while the available phosphorus in the deeper soil cannot be absorbed by cotton and accumulates.

[0014] During the development of this invention, the inventors discovered that the mobility of nitrogen fertilizer in drip-irrigated cotton fields with long-term high input and high output significantly exceeded conventional understanding. Test results showed that the severity of nitrogen fertilizer leaching far exceeded previous research reports (see Tables 1, 2, and 3). The soluble nitrogen content in deeper soil layers was higher, the reasons for which were largely the same as those for phosphorus leaching, namely, related to both the unique soil environment of cotton fields in Xinjiang and the long-term high water and fertilizer input methods. Although the available potassium content in all soil layers was high, and even in some samples where the available potassium content in deeper layers was higher than in the surface layer (as shown in Tables 1 and 3), this was related to potassium consumption in the surface soil of Xinjiang due to long-term high yields in cotton fields, coupled with insufficient potassium input. Considering the high background potassium content of Xinjiang soils and historical data comparison, it can be determined that the higher available potassium content in the middle and lower soil layers is inherent to the native soil and cannot be attributed to significant potassium leaching, contrary to the conclusion that nitrogen and phosphorus leaching is severe in deeper layers.

[0015] 3. Soil structure degradation and inefficient deep plowing: Long-term shallow plowing (20-25cm) leads to the formation of a compacted plow pan, hindering water infiltration and root development. Although ultra-deep plowing has been promoted in recent years, the focus is generally on plowing depth, neglecting precise adjustment of the plowshare angle. Furthermore, adjustments to the depth and plowshare angle are not made on-site based on the soil profile and salinity after deep plowing, resulting in the upturning of the subsoil. This not only exacerbates salinity damage during the seedling stage, affecting seedling survival and cotton growth, but also further weakens the soil's water and fertilizer retention capacity due to the destruction of soil aggregate structure, exacerbating fertilizer loss.

[0016] The above problems indicate that existing fertilization and irrigation methods and supporting agronomic measures are not conducive to improving fertilizer utilization. In traditional fertilization methods, phosphate fertilizer is generally applied as a base fertilizer and then deeply applied. When fertilizer is drip-irrigated in cotton fields, water and fertilizer are often applied simultaneously. Due to the large differences in the movement characteristics of different fertilizers, their movement trajectories in the soil are significantly different. In addition, due to the limitations of rotational irrigation in cotton fields and the frequent water shortages during the critical growth period of cotton, growers, fearing that they will not receive timely irrigation later, arbitrarily and significantly increase the amount of water for each irrigation. In production, there are significant differences in the amount of water for each irrigation in different cotton fields. In particular, the amount of water for the first and last irrigations in many cotton fields is as high as 40 m³ / mu or more, which exacerbates the deep leaching of fertilizer caused by the excessively long time of simultaneous water and fertilizer application.

[0017] In the process of drip irrigation in cotton fields, to reduce phosphorus leaching loss, the inventors conducted a study on preferential application of phosphorus alone with the irrigation water. The results showed that phosphorus was significantly fixed or leached in the soil. This analysis indicates that when phosphate fertilizer is applied to the soil as early as possible with drip irrigation, without competition or protection from other ions, it is more easily fixed by the soil or rapidly infiltrated by the "preferred flow" created by drip irrigation, exacerbating leaching or fixation rather than reducing it. Further research shows that once nitrogen and phosphorus nutrients leach below 60cm, since cotton roots in Xinjiang's drip-irrigated cotton fields are mainly distributed in the 0-60cm tillage layer, it is difficult for them to absorb and utilize nutrients in the soil layer below 60cm, inevitably leading to fertilizer waste. In severe cases, fertilizer leaching and infiltration may pollute groundwater, thus threatening the oasis ecosystem.

[0018] No similar high-input, high-output water and fertilizer management model has been observed in other cotton-growing regions both domestically and internationally, and therefore, their water and fertilizer management strategies cannot guide water and fertilizer input in Xinjiang cotton fields.

[0019] Current technical solutions for improving fertilizer waste in drip-irrigated cotton fields mostly focus on optimizing single parameters, such as adjusting fertilizer ratios or changing irrigation cycles, failing to form targeted systemic solutions. For example, Chinese patent CN202311569274.8 discloses a control method and system for cotton irrigation and fertilization, which only optimizes the decision-making efficiency of fertilization schemes through data backtracking; the master's thesis "Research on Fertilizer Utilization Rate and Optimal Nitrogen and Phosphorus Application Rate in Hami City" only focuses on the gradient optimization of nitrogen and phosphorus fertilization rates; Chinese patent CN120359887A proposes an IoT-based integrated water and fertilizer drip irrigation system, which only focuses on the regulation of irrigation volume adapted to the growth period; the journal article "The Influence of Drip Irrigation Technical Parameters on Cotton Growth and Soil Water and Salt in Southern Xinjiang" only improves the effect by adjusting irrigation quotas and dripper flow rates. None of these solutions involve targeted soil improvement, nutrient periodic management, and precise water and fertilizer application, nor can they solve the core problems of deep nitrogen and phosphorus leaching, low potassium fertilizer utilization, and soil structure degradation.

[0020] The core issue leading to low fertilizer utilization in cotton fields, as summarized above, lies in the fact that the existing extensive management model of "large-scale watering and fertilization + simultaneous application" is incompatible with the characteristics of Xinjiang's leaching-prone soils and nutrient movement patterns, and lacks a synergistic solution encompassing soil improvement and precise water and fertilizer delivery. Existing improvement technologies mostly focus on optimizing single parameters (such as adjusting fertilizer ratios and irrigation cycles), failing to systematically propose solutions to address the comprehensive problems of deep nitrogen and phosphorus leaching, low potassium fertilizer utilization efficiency, and soil structure degradation.

[0021] Based on the above problems, there is an urgent need to develop a set of efficient fertilizer utilization methods for drip-irrigated cotton fields with long-term high input and high output, in order to solve the current problems of low fertilizer utilization rate and high risk of soil environmental pollution caused by deep fertilizer leaching in Xinjiang drip-irrigated cotton fields. Summary of the Invention

[0022] This invention addresses systemic problems in Xinjiang drip-irrigated cotton fields, such as low fertilizer utilization, severe deep leaching of nitrogen and phosphorus, and soil structure degradation, which are characterized by long-term high input and high output. Through synergistic management involving targeted soil improvement, nutrient timing, and precise spatial and temporal regulation of water and fertilizer, this invention provides a method to improve fertilizer utilization in Xinjiang drip-irrigated cotton fields, thereby achieving the dual goals of high cotton yield and ecological environmental protection.

[0023] To address the aforementioned technical problems, this invention provides a method for improving fertilizer utilization in drip-irrigated cotton fields in Xinjiang, comprising the following steps:

[0024] 1. Targeted soil improvement: Before cotton sowing, implement targeted ultra-deep plowing every 2-3 years;

[0025] 2. Staged Nutrient Management: Based on the nutrient requirements of cotton, staged drip irrigation and topdressing are carried out throughout the entire growth period, including 2-3 topdressings during the budding stage and 6-8 topdressings during the flowering and boll-forming stage;

[0026] 3. Precise water and fertilizer management: During each drip irrigation topdressing process, the following three stages should be followed:

[0027] Phase 1: Drip irrigation with clean water only, used to moisten the water delivery pipeline and the soil at the front of the crop root zone, with a drip irrigation volume of [missing information]. ;

[0028] Phase Two: Simultaneous drip irrigation with clean water and fertilizer solution, with an irrigation volume of... ;

[0029] Phase Three: Drip irrigation with clean water only, used to diffuse the fertilizer solution from the main root distribution area to deeper or wider areas, with an irrigation volume of... ;

[0030] in: , This is a preset drip irrigation control volume, which is used to carry and seal nutrients and is set within a relatively independent and stable range; , This refers to the total drip irrigation volume for this drip irrigation topdressing. When the total drip irrigation volume needs to be increased, it is mainly achieved by increasing... To achieve this.

[0031] As a preferred embodiment of step 1, the directional ultra-deep plowing depth is 50-70 cm, and the plowshare inclination angle is adjusted to 15-22° to control the soil turning profile. More preferably, the plowshare inclination angle decreases as the salinity of the cotton field increases. For cotton fields with relatively light salinity in sandy soil and sandy loam, the plowshare inclination angle is adjusted to 18-22°; for cotton fields with relatively heavy salinity, the plowshare inclination angle is adjusted to 15-18°.

[0032] As a preferred option for step 2, the 6-8 topdressings during the flowering and boll-forming period include 3 consecutive intensive topdressings carried out after July 8th of the sowing year, and these 3 intensive topdressings are also implemented using precise water and fertilizer regulation.

[0033] As a preferred option for step 3, an inlaid patch drip irrigation tape is used, with a dripper spacing of 25cm, and the dripper flow rate is adapted to different soil types as follows: 1.38~1.8L / h for sandy cotton fields; 1.8~2.4L / h for sandy loam cotton fields; and 2.0~2.6L / h for loam cotton fields.

[0034] As another preferred embodiment of step 3, the fertilizer solution applied in stage two is prepared by pre-mixing and fully dissolving the highly water-soluble nitrogen fertilizer, phosphorus fertilizer, potassium fertilizer, and humic acid synergist required for the current topdressing. More preferably, the nitrogen fertilizer is urea; the phosphorus fertilizer comprises a combination of ammonium polyphosphate / monoammonium phosphate and potassium dihydrogen phosphate; to save costs, the ammonium polyphosphate applied with water in any one application can be replaced by an equal amount of available phosphorus (P2O5) in monoammonium phosphate; the potassium fertilizer is potassium sulfate; and the amount of solid humic acid added as the humic acid synergist is 100-200 grams per acre.

[0035] As another preferred option for step 3. Set at 11~17 m³ / mu, where: It is 8~12m³ / mu. The concentration is 3-5 m³ / mu. More preferably, the amount of water used for each drip irrigation is adjusted according to different soil types. and To implement coordinated control, including:

[0036] Sandy soil type cotton fields It is 20~28 m³ / mu. It is 11~13 m³ / mu;

[0037] Sandy loam type cotton fields, It is 22~35m³ / mu. It is 13~15 m³ / mu;

[0038] Loam-type cotton fields It is 25~40m³ / mu. It is 15~17 m³ / mu.

[0039] As a preferred embodiment of the aforementioned technical solution, the total amount of fertilizer applied to cotton throughout its entire growth period through steps 2 and 3 is: 55-65 kg / mu of urea, 12.5-17.5 kg / mu of ammonium polyphosphate (equivalent to P2O5), 8-12 kg / mu of potassium dihydrogen phosphate, and 10-20 kg / mu of potassium sulfate.

[0040] The technical solution described in this invention replaces "simultaneous water and fertilizer activation" and other water and fertilizer management modes with a "three-stage regulation": first, it uses clean water irrigation to eliminate preferential flow; then, it applies fertilizer solution via drip irrigation; and finally, it uses clean water drip irrigation to lock nutrients into the root layer; this is further combined with precise control of irrigation volume, especially for the second stage irrigation volume. Compared with the third stage of irrigation volume The total amount of water used is strictly controlled, mainly by increasing the amount of water used in the first stage of irrigation. Increase total irrigation volume Its beneficial effects are as follows:

[0041] 1. Innovative Principles, Precise Matching, and Promising Results: This technology physically restricts nutrient leaching pathways, enabling precise delivery of fertilizer nutrients to the core root layer of cotton, significantly improving fertilizer utilization. All key steps have quantifiable parameters, ensuring strong operability and controllability. It efficiently concentrates nitrogen, phosphorus, and potassium nutrients in the 15-50cm core root layer of cotton, significantly improving fertilizer utilization and reducing fertilizer leaching in the soil below 50cm. This maintains high yields while reducing production costs and environmental pollution risks, aligning with the national agricultural green development strategy. It also promotes deep application of potassium fertilizer. It is estimated that after its promotion in Xinjiang's drip-irrigated cotton areas, it can reduce fertilizer waste by approximately 700,000 tons annually, resulting in significant economic, social, and ecological benefits.

[0042] 2. Problem-oriented, systematic solution: The innovative "targeted ultra-deep tillage" solves the secondary hazards of topsoil turning; the targeted fertilizer combination (nitrogen, phosphorus, and potassium mixture + humic acid) optimizes its mobility in the soil; and the phased topdressing program matches the nutrient requirements of cotton. The entire solution systematically addresses the core issues revealed in the background technology.

[0043] 3. It not only improves the utilization rate of nitrogen, phosphorus, and potassium fertilizers applied in the current crop production, but also effectively utilizes nitrogen, phosphorus, and potassium fertilizers in deep soil, thereby reducing the amount of high-efficiency chemical fertilizer input per mu by more than 20 kg, saving about 70 yuan in costs, and achieving the long-term goal of stabilizing yield and improving quality. Attached Figure Description

[0044] The following figures are provided to further illustrate the invention and form part of the specification. They are used together with the detailed embodiments to explain the invention, but do not constitute a limitation thereof. They include:

[0045] Figure 1 This is a flowchart illustrating the steps of a method for improving fertilizer utilization in drip-irrigated cotton fields in Xinjiang, including targeted soil improvement, phased nutrient management, and precise three-stage regulation of water and fertilizer. Detailed Implementation

[0046] To make the technical problems, technical solutions, and advantages of the present invention clearer, a detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0047] This invention provides a method for improving fertilizer utilization in drip-irrigated cotton fields in Xinjiang, effectively addressing systemic problems such as deep nitrogen and phosphorus leaching, low fertilizer utilization, soil structure degradation, and high risks of soil environmental pollution. This method aims for ease of operation and controllable costs, achieving the dual goals of high cotton yield and ecological environmental protection.

[0048] To achieve the above technical solution, the embodiments of this invention are all aimed at high-input, high-yield drip-irrigated cotton fields with an annual yield of 500-600 kg / mu of machine-harvested seed cotton, equivalent to 120-150 kg / mu of high-efficiency fertilizers such as urea, monoammonium phosphate, and potassium sulfate. A method for improving fertilizer utilization in Xinjiang drip-irrigated cotton fields is provided, employing a synergistic scheme combining pre-sowing directional ultra-deep plowing, precise three-stage regulation of water and fertilizer during each drip irrigation, and periodic topdressing. The method includes the following steps:

[0049] P1. Targeted soil improvement: Before cotton sowing, implement targeted ultra-deep plowing every 2-3 years;

[0050] P2. Staged Nutrient Management: Based on the nutrient requirements of cotton, staged drip irrigation and topdressing are carried out throughout the entire growth period, including 2-3 topdressings during the budding stage and 6-8 topdressings during the flowering and boll-forming stage;

[0051] P3. Precise water and fertilizer management: During each drip irrigation topdressing process, follow these three stages:

[0052] S1: Drip irrigation with clean water only, drip irrigation volume is ;

[0053] S2: Simultaneous drip irrigation of clean water and fertilizer solution, with an irrigation volume of... ;

[0054] S3: Drip irrigation with clean water only, irrigation volume is ;

[0055] in: , This is the preset drip irrigation control volume; , This represents the total drip irrigation volume for this drip irrigation topdressing.

[0056] A better implementation method is as follows:

[0057] In P1, deep plowing to a depth of 50-70 cm is carried out every 2-3 years before cotton sowing. The depth can be 50, 55, 60, 65 or 70 cm. During deep plowing, the plowshare angle is adjusted within the range of 15-22° to control the soil turning profile and avoid excessive saline-alkali subsoil from being turned into the topsoil, which would affect the growth and development of cotton that year. The specific depth and plowshare angle are determined based on the relatively light salinity of sandy soil and sandy loam cotton fields, where the plowshare angle is adjusted to 18-22°; for cotton fields with relatively heavy salinity, the plowshare angle is adjusted to 15-18°.

[0058] In P2, based on the nutrient requirements of cotton, multiple topdressings are applied during the budding and boll-forming stages, including:

[0059] Apply top dressing 2-3 times during the budding stage, each time using 3.0-5.0g of urea (e.g., 3.0, 3.5, 4.0, 4.5, or 5.0g); and 1.2-2.5g of ammonium polyphosphate (N-P2O5-K2O 10-50-O) (e.g., 1.2, 1.5, 1.8, 2.1, 2.4, or 2.5g), or equivalently converted to monoammonium phosphate (N-P2O5-K2O) based on phosphorus content. 12-61-0) 1.0~2.0, for example, 1.0, 1.2, 1.4, 1.6, 1.7, 1.8, 1.9 or 2.0; potassium dihydrogen phosphate 0.5~1.0, for example, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0; potassium sulfate 0.5~1.0, for example, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0. The above application rates are all in kg / mu. During the budding stage, each drip irrigation topdressing should add 100~150 g / mu of solid humic acid synergist to the fertilizer solution, for example, 100, 110, 120, 130, 140 or 150.0 g / mu.

[0060] Top-dressing should be applied 6-8 times during the flowering and boll-forming stage, including three consecutive intensive top-dressings after July 8th of the same year. When applying top-dressing via drip irrigation during any of the following flowering and boll-forming stages, 150-200 grams / acre of solid humic acid synergist should be added to the fertilizer solution, for example, 150, 160, 170, 180, 190, or 200 grams / acre.

[0061] The types and amounts of fertilizer applied for each of the three enhanced topdressing applications are as follows (unit: kg / mu):

[0062] First application: Urea 8.0~10.5, for example, 8.0, 8.5, 9.0, 9.5, 10.0 or 10.5; Ammonium polyphosphate (N-P2O5-K2O 10-50-0) 4.0~4.5, for example, 4.0, 4.1, 4.2, 4.3, 4.4 or 4.5, or equivalently converted to monoammonium phosphate (N-P2O5-K2O 12-61-0) 3.3~3.7, for example, 3.3, 3.4, 3.5, 3.6 or 3.7; Potassium dihydrogen phosphate 1.0; Potassium sulfate 1.5~2.5, for example, 1.5, 1.7, 1.9, 2.1, 2.3 or 2.5;

[0063] Second: Urea 7.5~11.5, for example, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 10.0 or 11.5; Ammonium polyphosphate (N-P2O5-K2O 10-50-0) 5.5~7.0, for example, 5.5, 5.8, 6.1, 6.4, 6.7 or 7.0, or equivalently converted to monoammonium phosphate (N-P2O5-K2O) based on phosphorus content. 12-61-0) 4.5~5.7, for example, it can be 4.5, 4.7, 4.9, 5.1, 5.3, 5.5 or 5.7; potassium dihydrogen phosphate 1.5~1.8, for example, it can be 1.5, 1.6, 1.7 or 1.8; potassium sulfate 2.0~4.0, for example, it can be 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8 or 4.0.

[0064] Third: Urea 6.5~9.0, for example, 6.5, 7.0, 7.5, 8.0, 8.5 or 9.0; Ammonium polyphosphate (N-P2O5-K2O 10-50-0) 4.0~5.0, for example, 4.0, 4.2, 4.4, 4.6, 4.8 or 5.0, or equivalently converted to monoammonium phosphate (N-P2O5-K2O) based on phosphorus content. 12-61-0) 3.3~4.1, for example, it can be 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0 or 4.1; potassium dihydrogen phosphate 1.5~2.0, for example, it can be 1.5, 1.6, 1.7, 1.8, 1.9 or 2.0; potassium sulfate 2.0~3.5, for example, it can be 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4 or 3.5.

[0065] The type and application rate (unit: kg / mu) of the last top dressing during the flowering and boll-forming stage are as follows: urea 2.5~3.0, for example, 2.5, 2.6, 2.7, 2.8, 2.9 or 3.0; ammonium polyphosphate (N-P2O5-K2O 10-50-O) 2.0~2.5, for example, 2.0, 2.1, 2.2, 2.3, 2.4 or 2.5; or equivalent to monoammonium phosphate (N-P2O5-K2O) based on phosphorus content. 12-61-0) 1.6~2.0, for example, it can be 1.6, 1.7, 1.8, 1.9 or 2.0; potassium dihydrogen phosphate 0.5~1.0, for example, it can be 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0; potassium sulfate 0.5~1.0, for example, it can be 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0.

[0066] During the flowering and boll-forming stage, except for three intensive topdressings and the final topdressing, the types and application rates (all in kg / mu) of the remaining topdressings are as follows: Urea 6.0~8.0, for example, 6.0, 6.2, 6.4, 6.6, 6.8, 7.0, 7.2, 7.4, 7.6, 7.8 or 8.0; Ammonium polyphosphate (N-P2O5-K2O 10-50-O) 2.5~3.0, for example, 2.5, 2.6, 2.7, 2.8, 2.9 or 3.0, or equivalent to monoammonium phosphate (N-P2O5-K2O) based on phosphorus content. 12-61-0) 2.0~2.5, for example, it can be 2.0, 2.1, 2.2, 2.3, 2.4 or 2.5; potassium dihydrogen phosphate 1.0; potassium sulfate 1.0~1.5, for example, it can be 1.0, 1.1, 1.2, 1.3, 1.4 or 1.5.

[0067] In P3, drip irrigation uses inlaid patch drip tape with a dripper spacing of 25cm. The irrigation volume and dripper flow rate are adjusted according to soil type for each stage: For loam-type cotton fields, the irrigation volume for each stage is taken as the upper limit of local conventional high-yield cotton fields, and the dripper flow rate is 2.0~2.6L / h, for example, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5 or 2.6L / h; for sandy soil-type cotton fields, the irrigation volume for each stage is taken as the local standard. For high-yield cotton fields, the lower limit for drip irrigation flow rate is 1.38~1.8L / h, for example, it can be 1.38, 1.4, 1.45, 1.5, 1.6, 1.7 or 1.8L / h; for sandy loam cotton fields, the irrigation volume for each stage is taken as the median value of local conventional high-yield cotton fields, and the drip irrigation flow rate is 1.8~2.4L / h, for example, it can be 1.8, 1.9, 2.0, 2.1, 2.2, 2.3 and 2.4L / h.

[0068] Fertilizers applied via drip irrigation are all highly soluble fertilizers. The types and total dosages of fertilizers used for topdressing include (units are kg / mu): urea 55-65 kg / mu, for example, 55, 57, 59, 60, 62, 63, or 65 kg / mu; ammonium polyphosphate (N-P2O5-K2O 10-50-O) total dosage 25-35 kg / mu, for example, 25, 27, 29, 31, 33, or 35 kg / mu, or equivalent to monoammonium phosphate (N-P2O5-K2O) based on phosphorus content. 12-61-0) 20~29, for example, it can be 20, 22, 24, 25, 27 or 29; potassium dihydrogen phosphate 8~12, for example, it can be 8, 9, 10, 11 or 12; potassium sulfate 10~20, for example, it can be 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20;

[0069] like Figure 1 As shown, each drip irrigation is carried out in three stages:

[0070] S1: Drip irrigation with clean water, irrigation volume is... It is used to moisten the topsoil.

[0071] S2: Pre-mix the highly water-soluble nitrogen, phosphorus, and potassium fertilizers, along with humic acid synergists required for this irrigation, to prepare a homogeneous fertilizer solution. Apply this solution via drip irrigation, using a water volume of [missing information]. The fertilizer solution is prepared by pre-mixing and fully dissolving the required high water-soluble nitrogen fertilizer, phosphorus fertilizer, potassium fertilizer and humic acid synergist in the fertilizer tank.

[0072] S3: Drip irrigation with clean water, irrigation volume is... It is used to push the residual fertilizer solution from the pipe and the root zone surface to the target root layer;

[0073] The irrigation volume is controlled in a coordinated manner as follows: The concentration should be controlled at 8-12 m³ / mu, for example, it can be 8, 9, 10, 11 or 12 m³ / mu; The water volume should be controlled at 3-5 m³ / mu, for example, 3.0, 3.5, 4.0, 4.5 or 5.0 m³ / mu, and the amount of water used for carrying and storing nutrients should be controlled at 3-5 m³ / mu. The concentration should be controlled between 11 and 17 m³ / mu, for example, it can be 11, 12, 13, 14, 15, 16 or 17 m³ / mu; The specific amount needs to be determined based on soil texture, moisture content, cotton growth stage, and water conditions. Specific examples are as follows (all units are m³ / acre):

[0074] For cotton fields with sandy soil The value is 20-28 m³ / mu, which can be 20, 21, 22, 23, 24, 25, 26, 27, or 28. The value is 11~13 m³ / mu, which can be 11.0, 11.5, 12.0, 12.5 or 13.0;

[0075] For cotton fields with sandy loam soil type The range is 22 to 35, for example, it could be 22, 24, 26, 28, 30, 32, 34, or 35. It can be 13~15, for example, 13.0, 13.5, 14.0, 14.5 or 15.0;

[0076] For cotton fields with loam soil type The range is 25 to 40, for example, it could be 25, 27, 29, 31, 33, 35, 37, 39, or 40. It can be 15 to 17, for example, 15.5, 16.0, 16.5 or 17.0.

[0077] The above technical solution of the present invention is implemented in a specific manner, and compared with the surrounding cotton fields.

[0078] Example 1

[0079] 1. Trial period: 2024.

[0080] 2. Test location: Chaichang Village, Baojiadian Town, Manas County, Northern Xinjiang Cotton Region.

[0081] 3. Area and soil type: Approximately 350 mu, loam type cotton field, with organic matter content of 1.25%, total nitrogen of 0.08%, available phosphorus of 19.2 mg / kg, and available potassium of 165.0 mg / kg in the 0-25cm soil layer.

[0082] 4. Cotton variety: Xinluzao 82 (extra-early maturing variety, growth period of 120 days).

[0083] 5. Drip irrigation system: Use inlaid patch drip irrigation tape with a dripper spacing of 25cm and a dripper flow rate of 2.4L / h. Lay one drip irrigation tape every two rows of cotton, with the drip irrigation tape laid in the middle of the narrow rows.

[0084] 6. Fertilizer: The total amount of urea used is 55.0 kg / mu, the total amount of ammonium polyphosphate (N-P2O5-K2O 10-50-0) used is 22.5 kg / mu, the total amount of monoammonium phosphate is 2.0 kg / mu (equivalent to 2.5 kg / mu of ammonium polyphosphate (N-P2O5-K2O 10-50-0)), the total amount of potassium dihydrogen phosphate used is 8 kg / mu, and the total amount of potassium sulfate used is 10 kg / mu. The actual total amount of fertilizer used is 62.5 kg / mu, of which the available phosphorus of ammonium polyphosphate and monoammonium phosphate is equivalent to 25 kg / mu of ammonium polyphosphate (N-P2O5-K2O 10-50-0).

[0085] 7. Implementation process:

[0086] (1) Pre-broadcast preparation (April 14-19, 2024)

[0087] Ultra-deep plowing: Considering that this year is the third year since the last ultra-deep plowing (two years apart), this year we will use the Dongfanghong LPA3004 tractor with a deep plow, with a plowing depth of 65cm and the plowing angle adjusted to 16° to ensure that the subsoil is not turned over.

[0088] (2) Bud stage management (May 29 to July 2)

[0089] Two drip irrigation applications were carried out for topdressing. The first drip irrigation was on June 12th, with an interval of 7-8 days. The first irrigation volume was... It is 40m³ / mu, the second time. The irrigation rate is 35 m³ / mu. Each drip irrigation session is divided into three stages, with the irrigation volume, fertilizer application rate, and duration for each stage as follows:

[0090] First time: The irrigation volume for Phase 1 is , The duration is approximately 225 minutes; Phase Two irrigation volume The irrigation volume is 12.0 m³, the duration is approximately 110 minutes, and the following components are applied: 3.0 kg / mu of urea, 1.5 kg / mu of ammonium polyphosphate (N-P2O5-K2O 10-50-O), 0.5 kg / mu of potassium dihydrogen phosphate, 0.5 kg / mu of potassium sulfate, and 100 g / mu of solid humic acid synergist; the irrigation volume for stage three is... The volume is 3.0 m³, and the duration is approximately 28 minutes.

[0091] Second time: Phase 1 The duration is approximately 170 minutes; Phase Two, The volume is 12.0 m³, the duration is approximately 110 minutes, and the following ingredients are added: 5.0 kg / mu of urea, 2.0 kg / mu of ammonium polyphosphate (N-P2O5-K2O 10-50-O), 1.0 kg / mu of potassium dihydrogen phosphate, 1.0 kg / mu of potassium sulfate, and 150 g / mu of solid humic acid synergist; Stage 3. The volume is 4.0 m³, and the duration is approximately 35 minutes.

[0092] (3) Management during the flowering and boll-forming period (July 2 to August 23)

[0093] A total of 6 drip irrigation topdressings were carried out, of which the three consecutive topdressings after July 8 were intensive topdressings;

[0094] a. Two routine drip irrigation fertilization methods

[0095] In addition to three consecutive intensive topdressings and the final topdressing after July 8, there were also two regular drip irrigation topdressings, on July 2 and August 4 respectively.

[0096] On July 2nd, The volume is 25.0 m³, and the total drip irrigation time is approximately 225 minutes, divided into three stages. The water volume, fertilizer application amount, and duration for each stage are as follows:

[0097] Phase 1 The volume is 8.0 m³, and the duration is approximately 70 minutes.

[0098] Phase Two The volume is 12.0 m³, the duration is about 110 minutes, and the following top dressings are applied: 7.0 kg / mu of urea, 2.5 kg / mu of ammonium polyphosphate (N-P2O5-K2O 10-50-O), 1.0 kg / mu of potassium dihydrogen phosphate, 1.0 g / mu of potassium sulfate, and 150 g / mu of solid humic acid synergist.

[0099] Phase Three The volume is 5.0 m³, and the duration is approximately 45 minutes.

[0100] On August 4th, The total volume is 32.0 m³, and the total drip irrigation time is approximately 290 minutes, divided into three stages. The water volume, fertilizer application rate, and duration for each stage are as follows:

[0101] Phase 1 The volume was 17.0 m³, and the duration was approximately 154 minutes.

[0102] Phase Two The volume is 12.0 m³, the duration is about 110 minutes, and the following top dressings are applied: 8.0 kg / mu of urea, 2.5 kg / mu of ammonium polyphosphate (N-P2O5-K2O 10-50-O), 1.0 kg / mu of potassium dihydrogen phosphate, 1.5 kg / mu of potassium sulfate, and 150 g / mu of solid humic acid synergist.

[0103] Phase Three The volume is 5.0 m³, and the duration is approximately 45 minutes.

[0104] b. Three-stage enhanced drip irrigation fertilization method

[0105] The three intensive topdressing applications during the flowering and boll-forming stage were scheduled for July 10th, July 18th, and July 26th, respectively.

[0106] Drip irrigation was applied on July 10th. The volume is 25m³, divided into three stages. The irrigation amount, fertilizer amount, and duration for each stage are as follows:

[0107] Phase 1 The volume is 8.5 m³, and the duration is approximately 76 minutes;

[0108] Phase Two The volume is 12.0 m³, the duration is about 110 minutes, during which urea 10.0 kg / mu, ammonium polyphosphate (N-P2O5-K2O 10-50-0) 4.0 kg / mu, potassium dihydrogen phosphate 1.0 kg / mu, potassium sulfate 1.5 kg / mu and solid humic acid synergist 160 g / mu are applied.

[0109] Phase Three The volume is 4.5m³, and the rinsing time with clean water is approximately 40 minutes.

[0110] Drip irrigation was applied on July 18th. The volume is 30m³, divided into three stages. The irrigation amount, fertilizer amount, and duration for each stage are as follows:

[0111] Phase 1 The volume is 14.5 m³, and the duration is approximately 130 minutes;

[0112] Phase Two The volume was 11.5 m³, the duration was approximately 104 minutes, and during this period, 10.0 kg / mu of urea, 5.5 kg / mu of ammonium polyphosphate (N-P2O5-K2O 10-50-0), 1.5 kg / mu of potassium dihydrogen phosphate, 2.0 kg / mu of potassium sulfate, and 200 g / mu of solid humic acid synergist were applied.

[0113] Phase Three The volume is 4.0 m³, and the duration is approximately 35 minutes.

[0114] Drip irrigation was applied on July 26th. The volume is 28m³, divided into three stages. The irrigation amount, fertilizer amount, and duration for each stage are as follows:

[0115] Phase 1, for The volume is 11.0 m³, and the duration is approximately 100 minutes;

[0116] Phase Two The volume is 12.0 m³, the duration is about 110 minutes, during which urea 9.0 kg / mu, ammonium polyphosphate (N-P2O5-K2O 10-50-0) 4.5 kg / mu, potassium dihydrogen phosphate 1.5 kg / mu, potassium sulfate 2.0 kg / mu and solid humic acid synergist 200 g / mu are applied.

[0117] Phase Three The volume is 5.0 m³, and the duration is approximately 45 minutes.

[0118] (4) Other

[0119] The final topdressing on August 20: Follow the three-stage water and fertilizer application method of water-fertilizer solution-water, as described above. During this period, apply 3.0 kg / mu of urea, 2.0 kg / mu of monoammonium phosphate, 0.5 kg / mu of potassium dihydrogen phosphate, 0.5 kg / mu of potassium sulfate, and 150 g / mu of solid humic acid synergist.

[0120] Other management practices include: using drip irrigation under mulch throughout the process, timely prevention and control of diseases and pests such as bollworms and aphids, and carrying out topping and defoliation operations on July 5th in accordance with routine cotton field management.

[0121] 8. Implementation Results:

[0122] In this embodiment, the utilization rates of nitrogen, phosphorus, and potassium fertilizers in the cotton field were 44.2%, 23.6%, and 58.7%, respectively, which were 15.2%, 20.8%, and 5.4% higher than those in surrounding cotton fields that did not use the method described in the patent claims, achieving the expected technological advantages. The fertilizer input in this embodiment was reduced by more than 15 kg / mu compared to other surrounding cotton fields, while maintaining stable yields and increasing income by at least 60 yuan / mu.

[0123] Soil nutrient testing after cotton harvest in this embodiment showed that the average content of soluble total nitrogen in the 40-100cm soil layer was 42.5mg / kg and the average content of available phosphorus was 14.5mg / kg, which were 18.4% and 26.0% lower than before the implementation of this embodiment, respectively. The accumulation of nitrogen and phosphorus in the soil layer below 40-60cm was reduced by nearly 30%, which effectively reduced the risk of groundwater pollution and had significant ecological benefits.

[0124] In this embodiment, the cotton fiber length is 30.5 mm and the breaking strength is 29.8 cN / tex, which is an improvement over the cotton fiber length of 30.1 mm and the breaking strength of 29.4 cN / tex in the surrounding cotton fields that did not use the method described in the claims of this patent, and is consistent with the description of the technical advantages.

[0125] Example 2

[0126] 1. Trial period: 2025.

[0127] 2. Test location: Harbak Township, Luntai County, Southern Xinjiang Cotton Region.

[0128] 3. Area and soil type: ≥60 mu of sandy soil with heavy sandy soil, in which the organic matter content of the 0~25cm soil layer is 0.85%, total nitrogen is 0.05%, available phosphorus is 12.8mg / kg and available potassium is 140.0mg / kg.

[0129] 4. Cotton variety: Xinluzhong 84 (early to mid-maturing variety, growth period of 133 days).

[0130] 5. Drip irrigation system: Use inlaid patch drip irrigation tape with a dripper spacing of 25cm and a dripper flow rate of 1.38L / h. Lay one drip irrigation tape every two rows of cotton, with the drip irrigation tape laid in the middle of the narrow rows.

[0131] 6. Fertilizers: 65 kg / mu of urea, 16 kg / mu of ammonium polyphosphate (N-P2O5-K2O 10-50-0), 15.6 kg / mu of monoammonium phosphate (N-P2O5-K2O 12-61-0), 12 kg / mu of potassium dihydrogen phosphate, and 20 kg / mu of potassium sulfate. The available phosphorus of ammonium polyphosphate and monoammonium phosphate is equivalent to 35 kg / mu of ammonium polyphosphate (N-P2O5-K2O 10-50-0).

[0132] 7. Implementation process:

[0133] (1) Pre-broadcast preparation (April 7-10, 2025)

[0134] Ultra-deep plowing: Considering that this year is the 4th year since the last ultra-deep plowing (3 years apart), we used the Dongfanghong LPA3004 tractor with a deep plow, with a plowing depth of 65cm and the plow turning angle adjusted to 22° to ensure that the subsoil is not turned over.

[0135] (2) Sowing date: April 11, 2025.

[0136] (3) Bud stage management (May 24 to June 26)

[0137] A total of 3 drip irrigation topdressings were carried out, with an interval of 6-7 days between each application. The amounts are 28 m³ / mu, 28 m³ / mu, and 20 m³ / mu, respectively. Each drip irrigation session is divided into three stages, with the irrigation water volume, fertilizer application rate, and duration for each stage as follows:

[0138] a. First time

[0139] Phase 1, for , The duration was approximately 236 minutes;

[0140] Phase Two The volume is 10.0 m³, the duration is about 156 minutes, during which urea 4.50 kg / mu, ammonium polyphosphate (N-P2O5-K2O 10-50-0) 2.0 kg / mu, potassium dihydrogen phosphate 0.5 kg / mu, potassium sulfate 1.0 kg / mu and solid humic acid synergist 120 g / mu are applied.

[0141] Phase Three The volume is 3.0 m³, and the duration is approximately 46 minutes.

[0142] b. The second time, exactly the same as the first time.

[0143] c. The third time

[0144] Phase 1, for The volume is 8.0 m³, and the duration is approximately 125 minutes.

[0145] Phase Two The volume is 9.0 m³, the duration is about 140 minutes, during which urea 5.0 kg / mu, monoammonium phosphate 2.0 kg / mu, potassium dihydrogen phosphate 0.8 kg / mu, potassium sulfate 1.0 kg / mu and solid humic acid synergist 130 g / mu are applied.

[0146] Phase Three The volume is 3.0 m³, and the duration is approximately 46 minutes.

[0147] (4) Flowering and bell-forming period management (June 27 to August 17)

[0148] a. Four conventional drip irrigation topdressing methods

[0149] A total of 8 drip irrigation topdressings were carried out. Except for the three topdressings after July 8th, which were intensive topdressings and the final topdressing, there were 4 regular drip irrigation topdressings. Each irrigation cycle is 20.0 m³. Each routine drip irrigation cycle consists of three stages, with the following parameters for each stage: irrigation volume, fertilizer application rate, and duration:

[0150] Phase 1 The volume is 9m³, and the duration is approximately 140 minutes.

[0151] Phase Two The volume is 8.0 m³, the duration is about 125 minutes, and the top dressing consists of 6.0 kg / mu of urea, 2.0 kg / mu of monoammonium phosphate, 0.5 kg / mu of potassium dihydrogen phosphate, 1.5 kg / mu of potassium sulfate, and 160 g / mu of solid humic acid synergist.

[0152] Phase Three The volume is 3.0 m³, and the duration is approximately 46 minutes.

[0153] b. Three-stage enhanced drip irrigation fertilization method

[0154] The three intensive topdressing applications during the flowering and boll-forming stage were scheduled for July 8th, July 14th, and July 21st, respectively.

[0155] Drip irrigation on July 8th, that time The volume is 25m³, divided into three stages. The irrigation amount, fertilizer amount, and duration for each stage are as follows:

[0156] Phase 1 The volume is 14.0 m³, and the duration is approximately 220 minutes;

[0157] Phase Two The volume is 8.0 m³, the duration is about 126 minutes, during which urea 8.0 kg / mu, monoammonium phosphate 3.6 kg / mu, potassium dihydrogen phosphate 1.6 kg / mu, potassium sulfate 2.5 kg / mu and solid humic acid synergist 180 g / mu are applied.

[0158] Phase Three The volume is 3.0 m³, and the duration is approximately 46 minutes.

[0159] Drip irrigation was applied on July 14th. The volume is 25m³, divided into three stages. The irrigation amount, fertilizer amount, and duration for each stage are as follows:

[0160] Phase 1 The volume is 13.0 m³, and the duration is approximately 204 minutes;

[0161] Phase Two The volume is 8.0 m³, the duration is about 125 minutes, during which 7.5 kg / mu of urea, 7.0 kg / mu of ammonium polyphosphate (N-P2O5-K2O 10-50-0), 1.8 kg / mu of potassium dihydrogen phosphate, 4.0 kg / mu of potassium sulfate and 200 g / mu of solid humic acid synergist are applied.

[0162] Phase Three The volume is 4.0 m³, and the duration is approximately 62 minutes.

[0163] Drip irrigation was applied on July 21st. The volume is 25m³, divided into three stages. The irrigation volume and duration of each stage are exactly the same as those of the drip irrigation on July 14. The fertilizer application amounts are 6.5kg / mu of urea, 5.0kg / mu of ammonium polyphosphate (N-P2O5-K2O 10-50-0), 2.0kg / mu of potassium dihydrogen phosphate, and 3.5kg / mu of potassium sulfate.

[0164] (5) Other

[0165] The last topdressing was applied on August 15th, following the three-stage water-fertilizer-water application method, as described above. During this period, 3.0 kg / mu of urea, 2.0 kg / mu of monoammonium phosphate, 0.8 kg / mu of potassium dihydrogen phosphate, 1.0 kg / mu of potassium sulfate, and 150 g / mu of solid humic acid synergist were applied.

[0166] Other management practices include: using drip irrigation under plastic film throughout the entire process, timely prevention and control of diseases and pests such as bollworms and aphids, and carrying out topping and defoliation operations in accordance with conventional cotton field management.

[0167] 8. Implementation Results:

[0168] In this embodiment, the utilization rates of nitrogen, phosphorus, and potassium fertilizers in the cotton field were 38.3%, 17.4%, and 43.5%, respectively, which were 26.2%, 21.8%, and 4.2% higher than those in surrounding cotton fields that did not use the method described in the patent claims, achieving the expected technological advantages. The fertilizer input in this embodiment was reduced by more than 25 kg / mu compared to other cotton fields in the surrounding area, while maintaining stable yields and increasing income by at least 80 yuan / mu.

[0169] Soil nutrient testing after cotton harvest in this embodiment showed that the average content of soluble total nitrogen in the 40-100cm soil layer was 33.1mg / kg and the average content of available phosphorus was 14.2mg / kg, which were 29.4% and 20.0% lower than before the implementation of this embodiment, respectively. The accumulation of nitrogen and phosphorus in the soil layer below 40-60cm was reduced by nearly 33.6%, which effectively reduced the risk of groundwater pollution and had significant ecological benefits.

[0170] Yield and quality: In this embodiment, the cotton fiber length is 30.7 mm and the breaking strength is 30.5 cN / tex, which is an improvement over the cotton fiber length of 30.2 mm and the breaking strength of 29.8 cN / tex in the surrounding cotton fields that did not use the method described in the claims of this patent, and is consistent with the description of technical advantages.

[0171] Example 3

[0172] 1. Trial period: 2025.

[0173] 2. Test location: Harbak Township, Luntai County, Southern Xinjiang Cotton Region.

[0174] 3. Area and soil type: For cotton fields with sandy loam soil type of ≥260 mu, the organic matter content of the 0~25cm soil layer is 1.10%, total nitrogen is 0.06%, available phosphorus is 14.8mg / kg, and available potassium is 152.0mg / kg.

[0175] 4. Cotton variety: Xinluzhong 84 (early to mid-maturing variety, growth period of 133 days).

[0176] 5. Drip irrigation system: Use inlaid patch drip irrigation tape with a dripper spacing of 25cm and a dripper flow rate of 2.0L / h. Lay one drip irrigation tape every two rows of cotton, with the drip irrigation tape laid in the middle of the narrow rows.

[0177] 6. Fertilizers: 65 kg / mu of urea, 19.5 kg / mu of ammonium polyphosphate (N-P2O5-K2O 10-50-0), 8.6 kg / mu of monoammonium phosphate (N-P2O5-K2O 12-61-0), 10 kg / mu of potassium dihydrogen phosphate, and 15 kg / mu of potassium sulfate. The available phosphorus of ammonium polyphosphate and monoammonium phosphate is equivalent to 30 kg / mu of ammonium polyphosphate (N-P2O5-K2O 10-50-0).

[0178] 7. Implementation process:

[0179] (1) Pre-broadcast preparation (April 9-14, 2025)

[0180] Ultra-deep turn: Considering that an ultra-deep turn was conducted last year, no ultra-deep turn will be conducted this year;

[0181] (2) Sowing date: April 15, 2025.

[0182] (3) Bud stage management (May 26 to June 28)

[0183] A total of 3 drip irrigation topdressings were carried out, with an interval of 6-7 days between each application. The amounts are 35, 30, and 25 m³ / mu, respectively. Each drip irrigation session is divided into three stages, with the following amounts of water, fertilizer, and duration for each stage:

[0184] first:

[0185] Phase 1, for , The duration was approximately 217 minutes;

[0186] Phase Two The volume is 12.0 m³, the duration is about 130 minutes, and the following top dressings are applied: 3.0 kg / mu of urea, 2.0 kg / mu of ammonium polyphosphate (N-P2O5-K2O 10-50-O), 0.5 kg / mu of potassium dihydrogen phosphate, and 0.5 kg / mu of potassium sulfate.

[0187] Phase Three The volume is 3.0 m³, and the duration is approximately 33 minutes.

[0188] Second time:

[0189] Phase 1, for , The duration was approximately 163 minutes;

[0190] Phase Two The volume is 11.5 m³, the duration is about 125 minutes, during which urea 3.5 kg / mu, ammonium polyphosphate (N-P2O5-K2O 10-50-0) 2.5 kg / mu, potassium dihydrogen phosphate 0.5 kg / mu, potassium sulfate 1.0 kg / mu and solid humic acid synergist 100 g / mu are applied.

[0191] Phase Three The volume is 3.5 m³, and the duration is approximately 38 minutes.

[0192] The third time:

[0193] Phase 1, for , The duration was approximately 152 minutes;

[0194] Phase Two The volume is 8m³, the duration is about 87 minutes, during which urea 4.5kg / mu, ammonium polyphosphate (N-P2O5-K2O 10-50-0) 2.5kg / mu, potassium dihydrogen phosphate 0.5kg / mu, potassium sulfate 1.0kg / mu and solid humic acid synergist 150g / mu are applied.

[0195] Phase Three The volume is 5.0 m³, and the duration is approximately 54 minutes.

[0196] (4) Flowering and bell-forming period management (June 28 to August 27)

[0197] a. Three conventional drip irrigation topdressing methods

[0198] A total of 7 drip irrigation fertilizations were carried out. Except for the three consecutive intensive fertilizations and the final fertilization after July 8th, there were three regular drip irrigation fertilizations. Both are 30m 3 Each drip irrigation session lasts approximately 270 minutes. Each routine drip irrigation session is divided into three stages, with the following parameters for water volume, fertilizer application, and duration for each stage:

[0199] Phase 1 The volume is 16.0 m³, and the duration is approximately 174 minutes;

[0200] Phase Two The volume is 10.0 m³, the duration is about 108 minutes, during which 6.0 kg / mu of urea, 3.0 kg / mu of ammonium polyphosphate (N-P2O5-K2O 10-50-0), 1.0 kg / mu of potassium dihydrogen phosphate, about 1.5 kg / mu of potassium sulfate and 150 g / mu of solid humic acid synergist are applied.

[0201] Phase Three The volume is 4.0 m³, and the duration is approximately 43 minutes.

[0202] b. Three-stage enhanced drip irrigation fertilization method

[0203] The three intensive topdressing applications during the flowering and boll-forming stage were scheduled for July 10th, July 17th, and July 24th, respectively.

[0204] Drip irrigation was applied on July 10th. The volume is 25m³, divided into three stages. The irrigation amount, fertilizer amount, and duration for each stage are as follows:

[0205] Phase 1 The volume is 10.0 m³, and the duration is approximately 108 minutes;

[0206] Phase Two The volume is 10.0 m³, the duration is about 108 minutes, and during this period, 10.5 kg / mu of urea, 3.5 kg / mu of monoammonium phosphate, 1.0 kg / mu of potassium dihydrogen phosphate, 1.5 kg / mu of potassium sulfate and 200 g / mu of solid humic acid synergist are applied.

[0207] Phase Three The volume is 4.0 m³, and the duration is approximately 43 minutes;

[0208] Drip irrigation was applied on July 17th. The volume is 28m³, divided into three stages. The irrigation amount, fertilizer amount, and duration for each stage are as follows:

[0209] Phase 1 The volume is 12.0 m³, and the duration is approximately 130 minutes;

[0210] Phase Two The volume was 9.0 m³, the duration was about 97 minutes, and during this period, 11.5 kg / mu of urea, 5.5 kg / mu of ammonium polyphosphate (N-P2O5-K2O 10-50-0), 1.5 kg / mu of potassium dihydrogen phosphate, 2.5 kg / mu of potassium sulfate and 200 g / mu of solid humic acid synergist were applied.

[0211] Phase Three The volume is 4.0 m³, and the duration is approximately 43 minutes.

[0212] Drip irrigation was applied on July 24th. The volume is 25m³, divided into three stages. The irrigation amount, fertilizer amount, and duration for each stage are as follows:

[0213] Phase 1 The volume is 10.0 m³, and the duration is approximately 108 minutes;

[0214] Phase Two The volume is 11.0 m³, the duration is about 119 minutes, and the following are the top dressings: 6.5 kg / mu of urea, 3.5 kg / mu of monoammonium phosphate, 2.0 kg / mu of potassium dihydrogen phosphate, 3.0 kg / mu of potassium sulfate, and 100 g / mu of solid humic acid synergist.

[0215] Phase Three The volume is 4.0 m³, and the duration is approximately 43 minutes.

[0216] (5) Other

[0217] The last topdressing on August 20: The amount of water for this irrigation is 35m³. Specifically, refer to the three-stage water and fertilizer application method of the first water-fertilizer-water during the budding stage in this example. During this period, apply 2.5kg / mu of urea, 1.6kg / mu of monoammonium phosphate, 1.0kg / mu of potassium dihydrogen phosphate, 1.0kg / mu of potassium sulfate, and 100g / mu of solid humic acid synergist.

[0218] Other management practices include: using drip irrigation under plastic film throughout the entire process, timely prevention and control of diseases and pests such as bollworms and aphids, and carrying out topping and defoliation operations in accordance with conventional cotton field management.

[0219] 8. Implementation Results:

[0220] In this embodiment, the utilization rates of nitrogen, phosphorus, and potassium fertilizers in the cotton field were 42.3%, 20.4%, and 51.5%, respectively, which were 20.2%, 17.2%, and 6.2% higher than those in surrounding cotton fields that did not use the method described in the patent claims, achieving the expected technological advantages. The fertilizer input in this embodiment was reduced by more than 20 kg / mu compared to other cotton fields in the surrounding area, while maintaining stable yields and increasing income by at least 70 yuan / mu.

[0221] Soil nutrient testing after cotton harvest in this embodiment showed that the average content of soluble total nitrogen in the 60-100cm soil layer was 37.2mg / kg and the average content of available phosphorus was 10.2mg / kg, which were 28.7% and 27.1% lower than before the implementation of this embodiment, respectively. The accumulation of nitrogen and phosphorus in the soil layer below 40-60cm was reduced by nearly 32.5%, which effectively reduced the risk of groundwater pollution and had significant ecological benefits.

[0222] In this embodiment, the cotton fiber length is 31.2 mm and the breaking strength is 30.8 cN / tex, which is an improvement over the cotton fiber length of 30.7 mm and the breaking strength of 30.4 cN / tex in surrounding cotton fields that did not use the method described in the claims of this patent, and is consistent with the description of the technical advantages.

[0223] For the preferred embodiments of the present invention described above, common knowledge such as specific structures and characteristics in the technical solutions are not described in detail; each embodiment is described in a progressive manner, and the technical features involved in each embodiment can be combined with each other without conflicting with each other. The same or similar parts between the embodiments can be referred to each other.

[0224] It should be noted that, for those skilled in the art, the above embodiments can be improved and modified in various ways without departing from the principles of the present invention, and such improvements and modifications should also be considered to fall within the protection scope of the present invention.

Claims

1. A method for improving fertilizer utilization in drip-irrigated cotton fields in Xinjiang, characterized in that, Includes the following steps: Step 1. Targeted soil improvement: Before cotton sowing, implement targeted ultra-deep plowing every 2-3 years; Step 2. Nutrient management in stages: According to the fertilizer requirements of cotton, drip irrigation and topdressing are carried out in stages throughout the growth period, including 2-3 topdressings during the budding stage and 6-8 topdressings during the flowering and boll-forming stage; Step 3. Precise Water and Fertilizer Management: During each drip irrigation topdressing process, proceed in the following three stages: Phase 1: Drip irrigation with clean water only, with a drip irrigation volume of [missing information]. ; Phase Two: Simultaneous drip irrigation with clean water and fertilizer solution, with an irrigation volume of... ; Phase 3: Drip irrigation with clean water only, irrigation volume is ; in: , This is the preset drip irrigation control amount; , This represents the total drip irrigation volume for this drip irrigation topdressing.

2. The method according to claim 1, characterized in that, In step 1, the directional ultra-deep turning depth is 50~70cm, and the plowshare inclination angle is adjusted to 15~22°.

3. The method according to claim 2, characterized in that, The plowshare inclination angle is adjusted to decrease as the salinity of the cotton field increases.

4. The method according to claim 1, characterized in that, In step 2, the 6-8 topdressings during the flowering and boll-forming period include 3 consecutive intensive topdressings carried out after July 8th of the sowing year.

5. The method according to claim 1, characterized in that, In step 3, an inlaid patch drip irrigation tape is used, with a dripper spacing of 25cm. The dripper flow rate is adapted to different soil types as follows: 1.38~1.8L / h for sandy cotton fields; 1.8~2.4L / h for sandy loam cotton fields; and 2.0~2.6L / h for loam cotton fields.

6. The method according to claim 1, characterized in that, In step 3, the fertilizer solution applied in stage two is prepared by pre-mixing and fully dissolving the highly water-soluble nitrogen fertilizer, phosphorus fertilizer, potassium fertilizer and humic acid synergist required for the current topdressing.

7. The method according to claim 6, characterized in that, The nitrogen fertilizer is urea, the phosphate fertilizer is a combination of ammonium polyphosphate / monoammonium phosphate and potassium dihydrogen phosphate, the potassium fertilizer is potassium sulfate, and the amount of solid humic acid added as the humic acid synergist is 100-200 grams per acre.

8. The method according to claim 1, characterized in that, In step 3 Set at 11~17 m³ / mu, where: It is 8~12m³ / mu. It is 3~5 m³ / mu.

9. The method according to claim 8, characterized in that, Depending on the soil type, each drip irrigation session... and To implement coordinated control, including: Sandy soil type cotton fields It is 20~28 m³ / mu. It is 11~13 m³ / mu; Sandy loam type cotton fields, It is 22~35m³ / mu. It is 13~15 m³ / mu; Loam-type cotton fields It is 25~40m³ / mu. It is 15~17 m³ / mu.

10. The method according to any one of claims 1 to 9, characterized in that, The total amount of fertilizer applied to cotton throughout its entire growth period through steps 2 and 3 is as follows: urea 55-65 kg / mu, ammonium polyphosphate equivalent to P2O5 12.5-17.5 kg / mu, potassium dihydrogen phosphate 8-12 kg / mu, and potassium sulfate 10-20 kg / mu.

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