Slow-mixing fertilizer suitable for yield increase and emission reduction of machine-transplanted late rice

Abstract

The invention discloses a slow-mixing fertilizer suitable for increasing yield and reducing emission of machine-transplanted late rice. The slow-mixing fertilizer is prepared from the following components in parts by mass: 4-6 parts of sulfur coated urea and 4-6 parts of 3-month resin coated urea. The invention further discloses application of the slow-mixing fertilizer in late rice planting, fertilization and rice transplanting are synchronously carried out, and the slow-mixing fertilizer is directly applied to the position 5 cm away from the rhizosphere side of a seedling and the position 3-5 cm deep in soil. Compared with an existing nitrogen fertilizer management scheme, by applying the slow-mixing fertilizer, the rice yield and the nitrogen fertilizer utilization efficiency are improved by 8.26% and 32.67% respectively, and meanwhile the global warming potential and the greenhouse gas emission intensity are reduced by 10.07% and 16.81% respectively.

Description

Technical Field

[0001] This invention belongs to the fields of fertilizer production and rice production, and relates to a slow-mixed fertilizer suitable for increasing yield and reducing emissions in machine-transplanted late rice. Background Technology

[0002] Late-season rice accounts for 25% of the total rice planting area in my country and is an important planting pattern in the southern rice-growing areas. Rational application of nitrogen fertilizer is crucial for increasing rice yield and reducing environmental pollution. Currently, the nitrogen fertilizer management scheme in late-season rice production generally involves applying conventional nitrogen fertilizer three times: basal fertilizer, tillering fertilizer, and panicle fertilizer. However, this scheme suffers from high labor costs, difficulty in mastering the technology, and challenges in mechanization, becoming a technical bottleneck for large-scale mechanized late-season rice production.

[0003] While promoting rice growth and development, nitrogen fertilizer increases greenhouse gas emissions from paddy fields. Specifically, nitrogen fertilizer application increases the abundance of methanogenic bacteria and other microorganisms involved in the decomposition of organic matter, inhibits the enzyme activity of methanogenic bacteria, and promotes methane production. Secondly, as a substrate for nitrification and denitrification, nitrogen fertilizer application not only directly promotes nitrous oxide emissions from paddy fields but also indirectly affects nitrous oxide emissions through its influence on the physicochemical properties of rice plants and soil.

[0004] Applying coated slow-release fertilizer is one of the main measures to improve nitrogen fertilizer utilization efficiency in rice, reduce labor costs, and decrease greenhouse gas emissions. Coated slow-release fertilizer is a type of fertilizer designed to precisely control and extend the release cycle of fast-acting nitrogen fertilizer based on the nitrogen requirements of rice growth. This synchronizes the fertilizer nutrient release pattern with the nutrient absorption pattern of rice, and is also an important vehicle for developing mechanized transplanting and single-application fertilization technology.

[0005] There have been many reports on slow-mixed fertilizers suitable for single-application fertilization technology in machine-transplanted rice. Chinese invention patent CN111348942A discloses a slow-mixed fertilizer for rice that targets and matches nitrogen demand. This slow-mixed fertilizer is composed of first and second plant oil-based polyurethane-coated urea mixed in a mass ratio of 3:7, which can meet the nutrient requirements of rice during its key growth stages. Patent CNCN111978127A discloses a slow-mixed fertilizer suitable for single-application fertilization technology in machine-transplanted rice in medium-to-high fertility soils. It is composed of large-particle urea, 4-month resin-coated urea, sulfur-coated urea, resin-coated diammonium phosphate, potassium chloride, and resin-coated potassium chloride. Most currently available slow-release fertilizers can only meet the nutrient requirements of single-season rice or rice under different soil fertility conditions. However, late-maturing rice is a late-ripening variety with a growth period of 150-180 days, significantly longer than early-season rice (about 120 days) and mid-season rice (about 145 days). Furthermore, late-season rice exhibits a temperature pattern of high temperatures before the jointing stage and low temperatures after the heading stage, which is beneficial for seedling growth and tillering. The release rate of slow-release fertilizers is affected by temperature; the higher the temperature, the faster the release. Therefore, the nitrogen release of current slow-release fertilizers cannot meet the nitrogen requirements of late-season rice during its critical growth stages, necessitating a more efficient and environmentally friendly slow-release fertilizer specifically for machine-transplanted late-season rice. Summary of the Invention

[0006] The purpose of this invention is to address the problems of existing nitrogen fertilizer management schemes for late-season rice failing to meet the nutrient requirements of the crop at different growth stages, the waste of fertilizer due to excessive nitrogen fertilizer application, increased greenhouse gas emissions, and the unsuitability of ordinary chemical fertilizers for mechanized fertilization of rice. Based on the nitrogen requirements of late-season rice at different growth and development stages, this invention provides a slow-mixed fertilizer for machine-transplanted rice, prepared by blending sulfur-coated urea with 3-month resin-coated urea. This slow-mixed fertilizer is suitable for machine-transplanted late-season rice, with fertilization and transplanting carried out simultaneously. The slow-mixed fertilizer is applied directly to the seedlings at a depth of 3-5 cm and 5 cm from the root zone, improving yield and nitrogen fertilizer utilization efficiency while reducing greenhouse gas emissions from paddy fields.

[0007] The present invention solves the above problems through the following technical solutions:

[0008] A slow-mixed fertilizer suitable for increasing yield and reducing emissions in machine-transplanted late rice is composed of the following parts by weight of sulfur-coated urea and 3-month resin-coated urea: 4-6 parts sulfur-coated urea and 4-6 parts 3-month resin-coated urea.

[0009] As a preferred technical solution of the slow-mixed fertilizer of the present invention, the slow-mixed fertilizer is composed of the following parts by weight of sulfur-coated urea and 3-month resin-coated urea: 4.8 to 5.5 parts of sulfur-coated urea and 4.8 to 5.5 parts of 3-month resin-coated urea.

[0010] As a further preferred technical solution of the slow-mixed fertilizer of the present invention, the slow-mixed fertilizer is composed of the following parts by weight of sulfur-coated urea and 3-month resin-coated urea: 5.0 parts sulfur-coated urea and 5.0 parts 3-month resin-coated urea.

[0011] The sulfur-coated urea is a slow-release fertilizer with a nitrogen mass percentage of 35% to 37%.

[0012] Preferably, the sulfur-coated urea is a slow-release fertilizer with a nitrogen mass percentage of 37%.

[0013] The 3-month resin-coated urea is a controlled-release fertilizer with a nitrogen mass percentage of 40% to 45% and a nutrient supply period of 3 months or a fertilizer effect period of 90 days.

[0014] Preferably, the 3-month resin-coated urea is a controlled-release fertilizer with a nitrogen mass percentage of 43% and a nutrient supply period of 3 months or a fertilizer effect period of 90 days.

[0015] Another object of the present invention is to provide a method for preparing the slow-mixed fertilizer, comprising: thoroughly stirring and mixing sulfur-coated urea and 3-month resin-coated urea according to the formula.

[0016] The slow-mixed fertilizer described is suitable for machine-transplanted late rice. When applied according to the local conventional nitrogen application rate, it can significantly reduce greenhouse gas emissions from paddy fields while increasing rice yield and nitrogen fertilizer absorption and utilization rate.

[0017] Another object of the present invention is to provide the application of the slow-mixed fertilizer described above, which is suitable for increasing yield and reducing emissions in machine-transplanted late rice, in the cultivation of late rice.

[0018] Preferably, the slow-mixed fertilizer is applied to machine-transplanted late rice.

[0019] Preferably, the nitrogen application rate of the slow-mixed fertilizer is the same as the local conventional nitrogen application rate.

[0020] Preferably, the application of the slow-mixed fertilizer is carried out simultaneously with rice transplanting, and the slow-mixed fertilizer is applied directly to the seedlings at a depth of 3-5 cm and 5 cm from the root zone.

[0021] Specifically, the application includes: applying the slow-mixed fertilizer according to the local conventional nitrogen application rate, with the application of the slow-mixed fertilizer being carried out simultaneously with rice transplanting, and the slow-mixed fertilizer being applied directly to the seedlings at a depth of 3-5 cm and 5 cm from the root zone.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] (1) This invention makes full use of the nutrient demand pattern of late rice and the nitrogen release characteristics of coated urea. It mixes sulfur-coated urea with resin-coated urea to make a slow-mixed fertilizer. One application of fertilizer can well meet the nitrogen demand of rice, solve the key problem of one application of fertilizer in machine-transplanted late rice fields, and greatly reduce fertilizer production costs and labor costs.

[0024] (2) The slow-mixed fertilizer of this invention can improve yield, nitrogen fertilizer use efficiency, and reduce greenhouse gas emissions. Experimental results at ecological sites in low-latitude regions show that, compared with conventional fast-acting nitrogen fertilizers applied in multiple applications for high yield, the application of the slow-mixed fertilizer of this invention increases rice yield and nitrogen fertilizer use efficiency by 8.26% and 32.67%, respectively, while reducing global warming potential and greenhouse gas emission intensity by 10.07% and 16.81%, respectively. Attached Figure Description

[0025] Figure 1 To mitigate the impact of mixed fertilizers on rice yield.

[0026] Figure 2 The effects of slow-mixed fertilizers on rice GWP and GHGI. Detailed Implementation

[0027] The technical solution of the present invention will be further described below through specific embodiments.

[0028] Example 1

[0029] Preparation of slow-mixed fertilizer suitable for machine-transplanted late rice

[0030] The sulfur-coated urea and the 3-month resin-coated urea were thoroughly mixed at a mass ratio of 5:5 to obtain a slow-release fertilizer. The sulfur-coated urea was a slow-release fertilizer with a nitrogen mass percentage of 37%, and the 3-month resin-coated urea was a controlled-release fertilizer with a nitrogen mass percentage of 43% and a nutrient supply period of 3 months.

[0031] Example 2

[0032] From July to November 2024, the inventors conducted field trials at the Shanggao Rice Science and Technology Courtyard (114.92E, 28.22N) in Yichun City, Jiangxi Province.

[0033] Experimental variety: Meixiangzhan No. 2.

[0034] Treatment group: The slow-mixed fertilizer used for machine-transplanted late rice in Example 1 was applied at a nitrogen application rate of 150 kg·ha. -1 Simultaneously with rice transplanting, slow-mixed fertilizer is applied in one go using a side-deep fertilization machine, 5cm from the base of the seedlings and 3-5cm deep in the soil; the amount of phosphate fertilizer used is 75kg·ha. -1 Potassium fertilizer application rate: 90 kg / ha -1One-time basal application. Alternating wet and dry water management is adopted, and disease, pest, and weed management is the same as in local high-yield areas.

[0035] Control group 1: Urea (46%) was used as the nitrogen source, and the application rate was 150 kg·ha. -1 For conventional high-yield crops, fertilizer is applied manually in multiple applications, using a ratio of basal fertilizer: tillering fertilizer: heading fertilizer (4:3:3). Phosphorus and potassium fertilizers are applied in the same amounts as in the treatment group, with a single basal application. Alternating wet and dry water management is adopted, and disease, pest, and weed management is the same as in local high-yield crops.

[0036] Control group 2: No nitrogen fertilizer was applied, and all other conditions were the same as the treatment group.

[0037] The experimental results of the treatment group, control group 1, and control group 2 were measured.

[0038] (1) Determination of actual rice yield: At the rice maturity period, 100 holes were actually cut at the center of each plot of the three treatments. After drying, the grain quality and moisture content were measured, and then the actual yield was calculated according to 13.5%.

[0039] (2) Biomass determination: At the rice maturity period, three plants from each of the three treatment areas were used as a sample, and the samples were replicated three times. The panicle and stem were separated, blanched at 105℃ for 30 minutes, and then dried at 70℃ to constant weight. The dry weight of the panicle and the total dry weight of the stem and leaves were obtained.

[0040] (3) Determination of nitrogen accumulation in plants: The dried samples of each treatment were crushed and the nitrogen content of the panicle and stems and leaves was determined by Kjeldahl method. The nitrogen accumulation of rice during the whole growth period was calculated.

[0041] (4) Greenhouse gas measurement: The static chamber-gas chromatography method was used to measure the concentrations of CO2 and CH4 in the paddy field every 7 days after rice transplanting. The cumulative greenhouse gas emissions during the entire growth period were calculated based on the greenhouse gas concentrations.

[0042] Calculation formula:

[0043] Nitrogen fertilizer use efficiency (NUE) = (Nitrogen uptake in nitrogen-applied area - Nitrogen uptake in blank area) / Nitrogen application rate × 100%;

[0044] In the formula, the nitrogen application zone refers to the treatment group and control group 1; the blank zone refers to control group 2.

[0045]

[0046] In the formula, f represents the total emissions of different greenhouse gases during the entire rice growing season. Since the CO2 fixed by crop photosynthesis returns to the atmosphere as CO2 from respiration, agriculture is generally considered a zero-cycle system for CO2. Therefore, the calculation of greenhouse gas emissions per unit area in this invention only considers the two main greenhouse gases, CH4 and N2O.

[0047]

[0048] In the formula, Y represents the total yield of rice.

[0049] Table 1. Effects of slow-mixed fertilizers on nitrogen accumulation and nitrogen uptake (NUE) in rice.

[0050]

[0051] The experimental results showed that the rice yield in the treatment group was 7528.79 kg ha. -1 The level was significantly higher than that of control group 1 (6954.55 kg ha). -1 Compared to control group 2, which had a blood sugar level of 5489.77 kg / ha -1 These figures represent increases of 37.14% and 8.26% respectively. Figure 1 The nitrogen accumulation and NUE results (Table 1) showed that the total nitrogen accumulation and NUE of the treatment group were significantly higher than those of the control group. Compared with control group 1, the nitrogen accumulation of the treatment group was significantly increased during the jointing to heading stage and the heading to maturity stage. In addition, the NUE of the treatment group was 44.22%, which was 32.67% higher than that of control group 2. This indicates that a single application of the slow-mixed fertilizer of this invention can better meet the nitrogen requirements of rice during the key growth stages. In addition, the analysis of rice GWP and GHGI revealed ( Figure 2 Compared with control group 1, the treatment group showed a reduction of 10.07% and 16.81% in GWP and GHGI, respectively, indicating that a single application of the slow-mixed fertilizer of this invention can effectively reduce greenhouse gas emissions from rice.

[0052] In summary, applying a slow-mixed fertilizer consisting of sulfur-coated urea and 3-month resin-coated urea in a 5:5 ratio during machine-transplanted late rice can significantly reduce total greenhouse gas emissions while improving yield and nitrogen fertilizer utilization efficiency. This is a cost-effective, efficiency-enhancing, and environmentally friendly nitrogen fertilizer management method.

Claims

1. A slow-mixed fertilizer suitable for increasing yield and reducing emissions in machine-transplanted late-season rice, characterized in that: It consists of the following parts by weight of sulfur-coated urea and 3-month resin-coated urea: 4-6 parts sulfur-coated urea and 4-6 parts 3-month resin-coated urea.

2. The slow-mixed fertilizer for increasing yield and reducing emissions in machine-transplanted late-season rice according to claim 1, characterized in that: The slow-mixed fertilizer is composed of the following parts by weight of sulfur-coated urea and 3-month resin-coated urea: 4.8-5.5 parts sulfur-coated urea and 4.8-5.5 parts 3-month resin-coated urea.

3. The slow-mixed fertilizer for increasing yield and reducing emissions in machine-transplanted late-season rice according to claim 2, characterized in that: The slow-mixed fertilizer is composed of the following parts by weight of sulfur-coated urea and 3-month resin-coated urea: 5.0 parts sulfur-coated urea and 5.0 parts 3-month resin-coated urea.

4. The slow-mixed fertilizer for increasing yield and reducing emissions of machine-transplanted late-season rice according to any one of claims 1-3, characterized in that: The sulfur-coated urea is a slow-release fertilizer with a nitrogen mass percentage of 35% to 37%; the 3-month resin-coated urea is a controlled-release fertilizer with a nitrogen mass percentage of 40% to 45% and a nutrient supply period of 3 months or a fertilizer effect period of 90 days.

5. The slow-mixed fertilizer for increasing yield and reducing emissions in machine-transplanted late-season rice according to claim 4, characterized in that: The sulfur-coated urea is a slow-release fertilizer with a nitrogen mass percentage of 37%; the 3-month resin-coated urea is a controlled-release fertilizer with a nitrogen mass percentage of 43% and a nutrient supply period of 3 months or a fertilizer effect period of 90 days.

6. A method for preparing a slow-mixed fertilizer as described in claim 1, suitable for increasing yield and reducing emissions in machine-transplanted late-season rice, characterized in that: The sulfur-coated urea and the 3-month resin-coated urea were thoroughly stirred and mixed according to the formula to obtain the final product.

7. The application of the slow-mixed fertilizer of claim 1, which is suitable for increasing yield and reducing emissions in machine-transplanted late rice, in late rice cultivation.

8. The application according to claim 7, characterized in that: The slow-mixed fertilizer is applied to machine-transplanted late rice.

9. The application according to claim 7, characterized in that: The nitrogen application rate of the slow-mixed fertilizer shall be in accordance with the local conventional nitrogen application rate.

10. The application according to claim 7, characterized in that: The slow-mixed fertilizer is applied simultaneously with rice transplanting, and is applied directly to the seedlings at a depth of 3-5 cm and 5 cm from the root zone.

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