A fertilization method for improving corn yield and nitrogen utilization rate in black soil

Abstract

This invention relates to the field of planting technology and provides a fertilization method to improve maize yield and nitrogen utilization in black soil. The method includes the following steps: after the previous season's maize harvest, simultaneously return all straw to the field and apply 15,000 kg / ha of well-rotted organic fertilizer. Specifically, straw return involves crushing the straw and evenly compacting it into the 30cm tillage layer. The maize planting density is 80,000 plants / ha, with 400 kg / ha of basal fertilizer applied simultaneously. During the maize seedling stage, 400 kg / ha of urea is applied as topdressing. The maize is then harvested uniformly after maturity. This invention optimizes the nitrogen speciation in the 0-20cm black soil layer, reducing the content of nitrate nitrogen and soluble organic nitrogen, while increasing the content of ammonium nitrogen, microbial biomass carbon, microbial biomass nitrogen, and soluble organic carbon. This promotes nitrogen translocation from maize vegetative organs to the grains, significantly enhancing the nitrogen supply capacity and fertility of black soil, achieving a synergistic effect of black soil fertilization, increased maize yield, and efficient utilization of chemical fertilizer nitrogen.

Description

Technical Field

[0001] This invention belongs to the field of planting technology, and in particular relates to a fertilization method for improving corn yield and nitrogen utilization in black soil. Background Technology

[0002] Black soil is a non-renewable, high-quality arable land resource. As a food crop, the stable and high yield of corn is crucial to ensuring national food security. Long-term application of chemical fertilizers has not only exacerbated the degradation of black soil and reduced the soil's nitrogen supply capacity, but also reduced the nitrogen utilization rate of corn. Furthermore, the loss of unabsorbed fertilizer nitrogen can easily lead to agricultural non-point source pollution and other problems.

[0003] Currently, farmers in the black soil region primarily use chemical fertilizers for fertilization. However, long-term, high-intensity chemical fertilizer input has not only failed to continuously increase crop yields but has also exacerbated black soil degradation, leading to a decline in crop nitrogen use efficiency and posing a potential threat to national food security. Simultaneously, a large amount of unabsorbed chemical nitrogen fertilizer is lost, causing agricultural non-point source pollution. Therefore, clarifying the optimization mechanism of organic matter return to the field on nitrogen forms (nitrate nitrogen, ammonium nitrogen, microbial biomass nitrogen, etc.) in black soil, balancing yield increase with black soil conservation, and creating practical fertilization techniques suitable for the Northeast black soil region have become top priorities in current research. Summary of the Invention

[0004] The purpose of this invention is to provide a fertilization method for improving corn yield and nitrogen utilization in black soil, thereby addressing the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A fertilization method for improving maize yield and nitrogen use efficiency in black soil includes the following steps:

[0007] After the previous corn harvest, all straw was returned to the field and 15,000 kg / ha of well-rotted organic fertilizer was applied simultaneously, and the soil was plowed to a depth of 30 cm.

[0008] During the sowing period, the corn planting density is 80,000 plants / ha, and 400 kg / ha of base fertilizer is applied. During the corn seedling stage, 400 kg / ha of urea is applied as top dressing. The corn is harvested uniformly after it is fully mature.

[0009] Compared with the prior art, the specific beneficial effects of the present invention are as follows:

[0010] This invention optimizes the nitrogen form composition of black soil by increasing the application of organic materials, reduces the content of nitrate nitrogen and soluble organic nitrogen in the soil, and increases the content of ammonium nitrogen, microbial biomass carbon, microbial biomass nitrogen and soluble organic carbon in the soil. It promotes the translocation of nitrogen from maize vegetative organs to grains, significantly enhances the nitrogen supply capacity and soil fertility of black soil, and achieves synergistic effects of black soil fertilization, maize yield increase and efficient utilization of chemical fertilizer nitrogen.

[0011] The technical solution of this invention is suitable for the cold temperate climate and albic soil texture of the Northeast black soil region, and is compatible with local conventional fertilization levels. It does not require complicated equipment and is suitable for large-scale promotion and application. Attached Figure Description

[0012] Figure 1 The yields of different maize organs under different treatments provided in this embodiment of the invention are shown in the figures. a represents root, b represents stem, c represents leaf, and d represents kernel. Different lowercase letters indicate significant differences between treatments (p < 0.05). Error bars represent the mean plus one standard deviation. *** p < 0.001, ** p < 0.01, * p < 0.05;

[0013] Figure 2 The nitrogen utilization rate of corn organs at different growth stages is provided in the embodiments of the present invention; different lowercase letters indicate significant differences between treatments for the same organ at the same time, and different uppercase letters indicate significant differences between treatments for the whole plant at the same time (p < 0.05); error bars represent the mean + 1 standard deviation;

[0014] Figure 3 The soil physicochemical index results for the R1 period under different treatments provided in the embodiments of the present invention are shown below. a represents nitrate nitrogen, b represents ammonium nitrogen, c represents microbial biomass carbon, d represents microbial biomass nitrogen, e represents soluble organic carbon, and f represents soluble organic nitrogen. Different lowercase letters indicate significant differences between treatments (p < 0.05). Error bars represent the mean plus 1 standard deviation. *** p < 0.001, ** p < 0.01, * p < 0.05. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0016] 1. Overview of the test site and environment:

[0017] The experiment was conducted at Youyi Farm, Youyi County, Shuangyashan City, Heilongjiang Province, with geographical coordinates of 46°79′N, 131°88′E. It is located in the typical black soil region of Northeast China and belongs to the cold temperate continental monsoon climate. The region has an average annual temperature of 4.6℃, an average annual precipitation of 508mm, and an average annual frost-free period of 140~150d. The climatic conditions are suitable for single-season maize planting.

[0018] 2. Basic physical and chemical properties of soil:

[0019] The tested soil was a typical albic soil from the Northeast Black Soil Region. The basic physicochemical properties of the topsoil layer (0-20cm) before the experiment were as follows: total nitrogen content 1.30 g / kg, organic matter content 33.34 g / kg, available nitrogen content 102.3 mg / kg, available phosphorus content 10.62 mg / kg, available potassium content 187.12 mg / kg, soil pH 7.31, and soil bulk density 1.16 g·cm³. -3 ;

[0020] 3. Test materials:

[0021] The tested maize variety was Songyu 438 (a major variety cultivated in the black soil region of Northeast China, a northern early-maturing spring maize hybrid bred jointly by China Seed International Co., Ltd. and Jilin Songhuajiang Seed Industry Co., Ltd., with the approval number Guoshenyu20190054 and the parent combination being W6199Z×A0095Z).

[0022] Fertilizer materials:

[0023] Base fertilizer: Sakef (27-13-10 (MOP) urea-based one-time topdressing fertilizer, purchased from China-Arab Fertilizer Co., Ltd.);

[0024] Topdressing: Urea (nitrogen content N≥46.0%, particle size range: d (1.18mm-3.35mm), purchased from Yunnan Yuntianhua Group Co., Ltd.

[0025] All corn stalks (for returning to the field, after the previous autumn crop is harvested, the stalks are crushed to a depth of 3-4 cm and turned into the soil to a depth of 30 cm or more; for removing from the field, most of the stalks are baleed and removed from the field using a stalk collection and baling machine, and the remaining part is removed by mechanical digging).

[0026] Well-rotted organic fertilizer (for FSO treatment, apply to the soil 30cm below the surface simultaneously with straw return; household chicken manure, organic matter content 41.34%, total nitrogen 2.31%, moisture content ≤30%).

[0027] Isotope-labeled fertilizer: 10.06% abundance 15 N-labeled urea, analytical grade, purchased from Thermal Technology (Shanghai) Co., Ltd., for tracking the destination of fertilizer nitrogen;

[0028] 4. Field cultivation and community design:

[0029] All treatments were uniformly tilled to a depth of 30cm. The experiment adopted a large-area comparative design, with 9 ridges for each treatment and 1 blank isolation ridge between different treatments. The ridges were 200m long and 1.3m wide, with a maize plant spacing of 20cm. Planting management was uniformly carried out in accordance with local high-yield cultivation standards.

[0030] 5. 15 Ni isotope micro-region setup:

[0031] To accurately track the fate of fertilizer nitrogen, each treatment was set up 15 N isotope micro-regions: The micro-regions were constructed using sheet metal frames measuring 1.1m long, 0.9m wide, and 0.7m high, and were vertically buried in the soil with the top of the frame protruding 10cm above the ground surface; each treatment had 4 replicate micro-regions, and 8 corn plants were planted in each micro-region; 15 N-labeled urea is calculated at 1% of the amount used for base fertilizer and top dressing, dissolved in distilled water and sprayed evenly.

[0032] 6. Sample collection and measurement methods:

[0033] Plant samples: Samples were taken at the seedling stage (V6), jointing stage (V12), silking stage (R1), grain filling stage (R3), and maturity stage (R6) of maize. The samples were separated into root, stem, leaf, ear, and grain organs. The samples were blanched at 105℃ for 30 minutes, dried at 65℃ to constant weight, weighed, and crushed through a 0.15mm sieve for later use.

[0034] Soil samples: Soil samples were collected simultaneously from the 0-20cm layer below the plants. After removing impurities, the samples were separated, air-dried, sieved, and tested for total nitrogen. 15 N recovery rate; physicochemical properties were measured after storage at -20℃; microbiological properties were measured after storage at -80℃.

[0035] Measurement methods: Total nitrogen in soil and plants, 15 N recovery was determined using a stable isotope mass spectrometer; soil nitrate nitrogen (NO3) - -N), ammonium nitrogen (NH4) + Soil microbial biomass carbon / nitrogen (MBC / MBN) was extracted with 2 mol / L KCl and measured using a continuous flow analyzer; soluble organic carbon / nitrogen (DOC / DON) was extracted with 0.5 mol / L K2SO4 and measured using a TOC / N analyzer; fertilizer nitrogen utilization rate was determined according to... 15 N tracer recovery rate calculation formula.

[0036] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0037] Comparative Example 1: A fertilization method for maize yield and nitrogen use efficiency in black soil, with single application of chemical fertilizer (F), as follows:

[0038] 1. Fertilization parameters and field operations:

[0039] Sowing date: May 8, 2025; corn planting density: 80,000 plants / ha.

[0040] Base fertilizer: Apply conventional chemical fertilizer at 400 kg / ha during the sowing period, without adding straw or applying organic fertilizer;

[0041] Topdressing: On June 18, 2025 (corn seedling stage), apply 400 kg / ha of urea.

[0042] Straw management: No straw should be returned to the field after the previous season's corn harvest;

[0043] Harvest date: September 12, 2025, after the corn is fully mature, a unified actual yield measurement will be conducted;

[0044] 2. Sample collection and measurement:

[0045] Following a unified method based on experimental design, maize plant and soil samples were collected at each growth stage to determine grain yield, fertilizer nitrogen utilization rate of each organ, soil nitrogen form and microbial biomass.

[0046] 3. Measurement indicators and results:

[0047] Plant yield: Vigorous vegetative growth, high root, stem, and ear yields, but the average grain yield was 10506 kg / ha, the lowest among the three treatments (e.g., ...). Figure 1 (as shown)

[0048] Nitrogen utilization: At maturity, the nitrogen utilization rate of chemical fertilizers in grains is 14.38%. While the total nitrogen accumulation in the plant is high, the nitrogen allocation to the grains is low, leading to nitrogen competition between vegetative organs and grains (e.g., ...). Figure 2 (as shown)

[0049] Soil characteristics: Soil nitrate nitrogen (NO3) - The content of nitrogen (-N) was significantly high, making nitrogen leaching and loss likely; the contents of soil microbial biomass nitrogen (MBN) and microbial biomass carbon (MBC) were the lowest among the three groups, indicating weak soil nitrogen supply capacity and low soluble organic carbon content (e.g., ...). Figure 3 (As shown).

[0050] Comparative Example 2: A fertilization method to improve maize yield and nitrogen use efficiency in black soil, using chemical fertilizer + full straw return treatment (FS), as detailed below:

[0051] 1. Fertilization parameters and field operations:

[0052] The sowing period, planting density, basal fertilizer application rate, topdressing time and application rate, and harvest period were completely the same as those in Comparative Example 1;

[0053] Straw management: After the previous corn harvest, all straw should be returned to the field and evenly plowed into the 30cm tillage layer;

[0054] Organic fertilizer management: No organic fertilizer is applied; only the combination of chemical fertilizer and straw is used.

[0055] 2. Sample collection and measurement:

[0056] The sampling period, sampling method, measurement indicators, and instruments and equipment are completely identical to those in Comparative Example 1 to ensure the comparability of experimental data;

[0057] 3. Measurement Indicators and Results

[0058] Plant yield: Root yield was the lowest among the three groups; grain yield was slightly higher than the single fertilizer (F) treatment, and the yield was between that of the F and FSO treatments (e.g., Figure 1 (as shown)

[0059] Nitrogen utilization: The nitrogen utilization rate of the whole plant during the silking stage of maize reached 30.59%, the highest among the three treatments, indicating a significant improvement in the nitrogen transport capacity of vegetative organs (e.g., Figure 2 (as shown)

[0060] Soil characteristics: Soil nitrate nitrogen (NO3) - The contents of -N and soluble organic nitrogen (DON) were significantly reduced compared to the F treatment, thus reducing the risk of inorganic nitrogen loss; soil microbial biomass was increased compared to the F treatment (e.g., ...). Figure 3 (As shown).

[0061] Example 1: A fertilization method to improve maize yield and nitrogen use efficiency in black soil, consisting of chemical fertilizer + full straw return to the field + organic fertilizer treatment (FSO), as detailed below:

[0062] 1. Fertilization parameters and field operations:

[0063] The sowing period, planting density, basal fertilizer application rate, topdressing time and application rate, and harvest period were completely the same as those in Comparative Example 1;

[0064] Straw management: After the previous corn harvest, all straw should be returned to the field and evenly plowed into the 30cm topsoil layer;

[0065] Organic fertilizer management: After the previous corn harvest, apply 15,000 kg / ha of well-rotted organic fertilizer at the same time as returning straw to the field. Spread the fertilizer evenly and then plow it in thoroughly.

[0066] 2. Sample collection and measurement:

[0067] The sampling period, sampling method, measurement indicators, and instruments and equipment are completely identical to those in Comparative Example 1 to ensure the comparability of experimental data;

[0068] 3. Measurement Indicators and Results

[0069] Plant yield: Stem and leaf yields decreased significantly compared to F, but grain yield was 13,500 kg ha. -1 Compared to the single fertilizer application (F) treatment, the yield increased by 29.33%, which was the highest value among the three treatment groups (e.g., Figure 1 (as shown)

[0070] Nitrogen utilization: At maturity, the nitrogen utilization rate of chemical fertilizers in grains was 19.52%, an increase of 35.77% compared to treatment F. Nitrogen was efficiently transported from vegetative organs to the grains, with no nitrogen competition (e.g., ...). Figure 2 (as shown)

[0071] Soil characteristics: Soil ammonium nitrogen (NH4) + The contents of microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and soluble organic carbon (DOC) were significantly higher than those of the F and FS treatments, indicating that easily lost inorganic nitrogen was converted into stable organic nitrogen, resulting in optimal soil nitrogen supply and fertilizer retention capacity (e.g., ...). Figure 3 (As shown).

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A fertilization method for improving maize yield and nitrogen use efficiency in black soil, characterized in that, Includes the following steps: After the previous corn harvest, all straw was returned to the field and 15,000 kg / ha of well-rotted organic fertilizer was applied simultaneously, and the soil was plowed to a depth of 30 cm. During the sowing period, the corn planting density is 80,000 plants / ha, and 400 kg / ha of base fertilizer is applied. During the corn seedling stage, 400 kg / ha of urea is applied as top dressing. The corn is harvested uniformly after it is fully mature.

2. The fertilization method for improving maize yield and nitrogen use efficiency in black soil according to claim 1, characterized in that, During the process of returning all straw to the field, the straw is crushed to 3-4cm.

3. The fertilization method for improving maize yield and nitrogen use efficiency in black soil according to claim 1, characterized in that, The corn variety mentioned is Songyu 438.

4. The fertilization method for improving maize yield and nitrogen use efficiency in black soil according to claim 1, characterized in that, The base fertilizer is urea-based compound fertilizer.

5. The fertilization method for improving maize yield and nitrogen use efficiency in black soil according to claim 1, characterized in that, The urea contains ≥46.0% nitrogen and has a particle size of 1.18-3.35 mm.

6. The fertilization method for improving maize yield and nitrogen use efficiency in black soil according to claim 1, characterized in that, The decomposed organic fertilizer has an organic matter content of ≥41%, total nitrogen of ≥2%, and a moisture content of ≤30%.

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