How should major spring crops be fertilized? Hubei's Rural Agriculture Department issues guidance!
Spring is the season for sowing and also a critical period for fertilizing crops, as crops have a relatively high nutrient demand at this time. So, how should major crops be fertilized in spring? The Hubei Rural Agriculture Department provides guidance!
I. Fertilization Recommendations for Wheat
(1) Fertilization Principles
1. Scientifically determine the amount of topdressing and irrigation based on soil fertility, base fertilizer application, seedling condition and soil moisture, and apply fertilizer and irrigate according to local conditions and seedling condition.
2. Combine fertilizer and water management with drought relief and drainage as well as pest, disease and weed control.
(2) Fertilization Recommendations
1. For excessively vigorous wheat fields, control fertilizer and water to curb excessive growth and promote sturdy growth. For wheat fields that have already jointed, strictly manage fertilizer and water, and the jointing fertilizer can be delayed until the late jointing stage to when the flag leaf tip emerges. For wheat fields with small populations and weak, thin growth, apply jointing fertilizer as early as possible.
2. When base fertilizer is insufficient and growth is poor, for a target yield level below 300 kg/mu, apply 4-5 kg/mu of urea as topdressing combined with irrigation from the erect stage to the jointing stage; for a yield level of 300-400 kg/mu, apply 5-8 kg/mu of urea and 1-3 kg/mu of potassium chloride as topdressing combined with irrigation from the erect stage to the jointing stage; for a target yield level of 400-550 kg/mu, apply 8-12 kg/mu of urea and 3-5 kg/mu of potassium chloride as topdressing combined with irrigation from the erect stage to the jointing stage.
3. In areas deficient in certain trace elements, it is advocated to combine with “one spray, three preventions” and with the control of pests, diseases and weeds (aphids and fusarium head blight), spraying trace element foliar fertilizer at the jointing stage, booting stage and grain-filling stage of wheat; and at the grain-filling stage of wheat, spray 150-200 g of potassium dihydrogen phosphate plus 0.5 kg of urea diluted in 50 kg of water for foliar application. When spraying, avoid the hot, sunny midday period to prevent leaf burn.
II. Fertilization Recommendations for Rice
(1) Fertilization Principles
1. Following the principle of reducing nitrogen, controlling phosphorus and stabilizing potassium, appropriately reduce the total amount of nitrogen and phosphorus fertilizers. Recommended nutrient application rates: nitrogen fertilizer (N) 9-12 kg/mu, phosphorus fertilizer (P2O5) 4-6 kg/mu, potassium fertilizer (K2O) 3-5 kg/mu. The total nitrogen fertilizer application during the whole growth period of single-season rice should be controlled within 13 kg.
2. For nitrogen fertilizer application, the principle of small amounts applied multiple times is advocated: 60% of nitrogen fertilizer as base application, with tillering fertilizer and ear fertilizer each accounting for 20%, or 70% of nitrogen fertilizer as base application with ear fertilizer accounting for 30%; all phosphorus fertilizer as base application; potassium fertilizer mainly as base application, which can be applied as 80% base application and 20% ear fertilizer topdressing. It is recommended to use rice-specific fertilizer, controlled-release fertilizer, etc., and appropriate urea topdressing can be applied later according to the growth condition of rice.
3. In early-late rice areas, appropriately increase the amount of phosphorus fertilizer and reduce the amount of potassium fertilizer in the early rice season, and reduce the amount of phosphorus fertilizer and increase the amount of potassium fertilizer in the late rice season.
4. Increase the application of organic fertilizer and implement the practice of chopping and turning under straw to return it to the field. For fields where organic fertilizer is applied, the amount of base fertilizer can be appropriately reduced; for fields where straw has been returned to the field year after year, the amount of potassium fertilizer can be reduced by 10%-20%. For fields where leguminous green manure was planted in the first season, with the amount of fresh green manure returned to the field at more than 1500 kg/mu, reduce the nitrogen fertilizer application by 3 kg per mu.
5. It is recommended that qualified specialized cooperatives, agricultural enterprises and large-scale growers adopt the rice side-deep fertilization technology combined with machinery, which can reduce fertilizer application by 10%-20%.
5. Apply zinc fertilizer and silicon fertilizer in combination, especially in cold-waterlogged fields, early rice fields, fields with shallow mud depth and fields prone to lodging.
6. Specifically, fertilizers can be applied according to the soil-testing formula fertilization recommendations issued by the local soil and fertilizer technology extension department.
(2) Fertilization Recommendations
1. Double-season rice area in eastern and southeastern Hubei
1.1 Early rice
1.1.1 Medium-concentration formula fertilizer application plan
Recommended formula: 15-8-7 (N-P2O5-K2O) or a similar formula.
Fertilization recommendations: (1) For a general yield target, apply 50-60 kg/mu of formula fertilizer as base fertilizer, and apply 3-4 kg/mu and 2-3 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively. (2) For a high-yield target, apply 55-65 kg/mu of formula fertilizer as base fertilizer, apply 4-5 kg/mu of urea as topdressing at the tillering stage, and apply 3-4 kg/mu of urea and 2-3 kg/mu of potassium chloride at the ear-grain stage.
1.1.2 High-concentration formula fertilizer application plan
Recommended formula: 22-12-11 (N-P2O5-K2O) or a similar formula.
Fertilization recommendations: (1) For a general yield target, apply 30-40 kg/mu of formula fertilizer as base fertilizer, and apply 3-4 kg/mu and 2-3 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively. (2) For a high-yield target, apply 40-50 kg/mu of formula fertilizer as base fertilizer, apply 4-5 kg/mu of urea as topdressing at the tillering stage, and apply 2-3 kg/mu of urea and 2-3 kg/mu of potassium chloride at the ear-grain stage.
1.2 Middle rice
1.2.1 Medium-concentration formula fertilizer application plan
Recommended formula: 15-6-9 (N-P2O5-K2O) or a similar formula.
Fertilization recommendations: (1) For a general yield target, apply 50-60 kg/mu of formula fertilizer as base fertilizer, and apply 4-5 kg/mu and 3-4 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively. (2) For a high-yield target, apply 60-70 kg/mu of formula fertilizer as base fertilizer, apply 4-6 kg/mu of urea as topdressing at the tillering stage, and apply 3-5 kg/mu of urea and 2-3 kg/mu of potassium chloride at the ear-grain stage.
1.2.2 High-concentration formula fertilizer application plan
Recommended formula: 22-9-14 (N-P2O5-K2O) or a similar formula.
Fertilization recommendations: (1) For a general yield target, apply 35-45 kg/mu of formula fertilizer as base fertilizer, and apply 3-5 kg/mu and 2-3 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively; (2) For a high-yield target, apply 40-50 kg/mu of formula fertilizer as base fertilizer, apply 4-5 kg/mu of urea as topdressing at the tillering stage, and apply 2-3 kg/mu of urea and 2-3 kg/mu of potassium chloride at the ear-grain stage.
1.3 Late rice
1.3.1 Medium-concentration formula fertilizer application plan
Recommended formula: 15-6-10 (N-P2O5-K2O) or a similar formula.
Fertilization recommendations: (1) For a general yield target, apply 45-55 kg/mu of formula fertilizer as base fertilizer, and apply 3-4 kg/mu and 2-3 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively. (2) For a high-yield target, apply 50-60 kg/mu of formula fertilizer as base fertilizer, apply 4-5 kg/mu of urea as topdressing at the tillering stage, and apply 3-4 kg/mu of urea and 2-3 kg/mu of potassium chloride at the ear-grain stage.
1.3.2 High-concentration formula fertilizer application plan
Recommended formula: 22-11-12 (N-P2O5-K2O) or a similar formula.
Fertilization recommendations: (1) For a general yield target, apply 35-45 kg/mu of formula fertilizer as base fertilizer, and apply 3-5 kg/mu and 2-3 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively. (2) For a high-yield target, apply 40-50 kg/mu of formula fertilizer as base fertilizer, apply 4-5 kg/mu of urea as topdressing at the tillering stage, and apply 2-3 kg/mu of urea and 2-3 kg/mu of potassium chloride at the ear-grain stage.
2. Jianghan Plain rice area
2.1 Early rice
2.1.1 Medium-concentration formula fertilizer application plan
Recommended formula: 15-8-7 (N-P2O5-K2O) or a similar formula.
Fertilization recommendations: (1) For a general yield target, apply 50-60 kg/mu of formula fertilizer as base fertilizer, and apply 3-4 kg/mu and 3-4 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively. (2) For a high-yield target, apply 55-65 kg/mu of formula fertilizer as base fertilizer, and apply 4-5 kg/mu and 3-4 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively.
2.1.2 High-concentration formula fertilizer application plan
Recommended formula: 18-12-15 (N-P2O5-K2O) or a similar formula.
Fertilization recommendations: (1) For a general yield target, apply 35-45 kg/mu of formula fertilizer as base fertilizer, and apply 3-4 kg/mu and 3-4 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively. (2) For a high-yield target, apply 40-50 kg/mu/mu of formula fertilizer as base fertilizer, and apply 4-5 kg/mu and 3-4 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively.
2.2 Middle rice
2.2.1 Medium-concentration formula fertilizer application plan
Recommended formula: 15-6-9 (N-P2O5-K2O) or a similar formula.
Fertilization recommendations: (1) For a general yield target, apply 50-60 kg/mu of formula fertilizer as base fertilizer, and apply 4-5 kg/mu and 3-4 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively. (2) For a high-yield target, apply 55-65 kg/mu of formula fertilizer as base fertilizer, and apply 5-6 kg/mu and 3-4 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively.
2.2.2 High-concentration formula fertilizer application plan
Recommended formula: 22-9-14 (N-P2O5-K2O) or a similar formula.
Fertilization recommendations: (1) For a general yield target, apply 35-45 kg/mu of formula fertilizer as base fertilizer, and apply 4-5 kg/mu and 3-4 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively. (2) For a high-yield target, apply 40-50 kg/mu of formula fertilizer as base fertilizer, and apply 5-6 kg/mu and 3-4 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively.
2.3 Late rice
2.3.1 Medium-concentration formula fertilizer application plan
Recommended formula: 15-7-10 (N-P2O5-K2O) or a similar formula.
Fertilization recommendations: (1) For a general yield target, apply 45-55 kg/mu of formula fertilizer as base fertilizer, and apply 4-5 kg/mu and 3-4 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively. (2) For a high-yield target, apply 50-60 kg/mu of formula fertilizer as base fertilizer, and apply 5-6 kg/mu and 3-4 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively.
2.3.2 High-concentration formula fertilizer application plan
Recommended formula: 20-10-15 (N-P2O5-K2O) or a similar formula.
Fertilization recommendations: (1) For a general yield target, apply 40-50 kg/mu of formula fertilizer as base fertilizer, and apply 4-5 kg/mu and 3-4 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively. (2) For a high-yield target, apply 45-55 kg/mu of formula fertilizer as base fertilizer, and apply 5-6 kg/mu and 3-4 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively.
3. Middle rice area in the hilly and mound land of central and northern Hubei
3.1 Medium-concentration formula fertilization plan
Recommended formula: 16-6-8 (N-P2O5-K2O) or a similar formula.
Fertilization recommendations: (1) For a general yield target, apply 50-60 kg/mu of formula fertilizer as base fertilizer, and apply 4-6 kg/mu and 3-5 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively. (2) For a high-yield target, apply 55-65 kg/mu of formula fertilizer as base fertilizer, and apply 4-6 kg/mu and 3-5 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively.
3.2 High-concentration formula fertilization plan
Recommended formula: 23-10-12 (N-P2O5-K2O) or a similar formula.
Fertilization recommendations: (1) For a general yield target, apply 35-45 kg/mu of formula fertilizer as base fertilizer, and apply 3-5 kg/mu and 2-4 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively. (2) For a high-yield target, apply 40-50 kg/mu of formula fertilizer as base fertilizer, and apply 4-6 kg/mu and 3-4 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively.
4. Middle rice area in the mountainous region of western Hubei
4.1 Medium-concentration formula fertilization plan
Recommended formula: 15-8-9 (N-P2O5-K2O) or a similar formula.
Fertilization recommendations: (1) For a general yield target, apply 50-60 kg/mu of formula fertilizer as base fertilizer, and apply 4-6 kg/mu and 3-4 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively. (2) For a high-yield target, apply 55-65 kg/mu of formula fertilizer as base fertilizer, and apply 5-6 kg/mu and 3-4 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively.
4.2 High-concentration formula fertilization plan
Recommended formula: 22-11-12 (N-P2O5-K2O) or a similar formula.
Fertilization recommendations: (1) For a general yield target, apply 35-45 kg/mu of formula fertilizer as base fertilizer, and apply 4-6 kg/mu and 3-5 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively. (2) For a high-yield target, apply 40-50 kg/mu of formula fertilizer as base fertilizer, and apply 4-6 kg/mu and 3-5 kg/mu of urea as topdressing at the tillering stage and the ear-grain stage respectively.
5. Fertilization recommendations for ratoon rice
5.1 Fertilization plan for the first season
Recommended formula: 20-16-10-4 (zinc sulfate heptahydrate) or a similar formula.
Fertilization recommendations: Before transplanting the first-season rice, apply 40-60 kg/mu of 20-16-10-4 (zinc sulfate heptahydrate) or a similar formula as base fertilizer, and apply 5 kg of urea per mu as topdressing at the tillering stage.
5.2 Fertilization plan for the ratoon season
Recommended formula: 20-5-10-4 (zinc sulfate heptahydrate) or a similar formula.
Fertilization recommendations: Apply 30-40 kg per mu of 20-5-10-4 (zinc sulfate heptahydrate) or a similar formula.
6. Fertilization recommendations for rice in integrated rice-fishery co-cropping
Fertilization recommendations: For newly dug rice fields, apply 10-12 kg/mu of nitrogen fertilizer, 6-8 kg/mu of phosphorus fertilizer (P2O5), and 10-12 kg/mu of potassium fertilizer (K2O); for 3-5 year rice fields, apply 7-8 kg/mu of nitrogen fertilizer, 5 kg/mu of phosphorus fertilizer (P2O5), and 10-11 kg/mu of potassium fertilizer (K2O); for rice fields over 5 years, apply 6-8 kg/mu of nitrogen fertilizer, 3-4 kg/mu of phosphorus fertilizer (P2O5), and 5-6 kg/mu of potassium fertilizer (K2O). It is recommended to use shrimp-rice-specific fertilizer, or 18-10-12 (or similar) compound fertilizer as a one-time base application.
III. Fertilization Recommendations for Corn
(1) Fertilization Principles
1. Recommended nutrient application rates: nitrogen fertilizer (N) 13-15 kg/mu, phosphorus fertilizer (P2O5) 3-5 kg/mu, potassium fertilizer (K2O) 4-6 kg/mu.
2. Base fertilizer as the main application, topdressing as a supplement; among topdressing, ear fertilizer as the main application and grain fertilizer as a supplement. Nitrogen fertilizer applied in split applications, and high-yield fields should appropriately increase the proportion of potassium fertilizer applied.
3. Increase the application of organic fertilizer, encourage straw return to the field, and build up soil fertility.
4. It is advocated that high mountain areas and suburban fresh-eating corn planting areas combine with plastic film mulching, attach importance to the combined application of medium and trace elements such as sulfur and zinc, and it is recommended to apply 1-2 kg/mu of zinc sulfate heptahydrate as base fertilizer or other zinc-containing fertilizers.
5. For acidic soil, depending on the soil pH condition, apply 60-150 kg/mu of quicklime or 4-8 kg/mu of silicon fertilizer in combination, applied to the field 15 days before corn sowing.
(2) Fertilization Recommendations
1. Plain and mound corn area
1.1 Medium-concentration formula fertilization plan
Recommended formula: 15-6-9 (N-P2O5-K2O) or a similar formula.
Fertilization recommendations: (1) For a general yield target, apply 50-60 kg/mu of formula fertilizer as base fertilizer, and apply 7-9 kg/mu and 5-7 kg/mu of urea as topdressing at the large trumpet stage and the booting stage respectively. (2) For a high-yield target, apply 55-65 kg/mu of formula fertilizer as base fertilizer, apply 8-10 kg/mu of urea as topdressing at the large trumpet stage, and apply 5-7 kg/mu of urea and 3-4 kg/mu of potassium chloride at the booting stage.
1.2 High-concentration formula fertilizer application plan
Recommended formula: 22-9-14 (N-P2O5-K2O) or a similar formula.
Fertilization recommendations: (1) For a general yield target, apply 40-50 kg/mu of formula fertilizer as base fertilizer, and apply 6-8 kg/mu and 5-7 kg/mu of urea as topdressing at the large trumpet stage and the booting stage respectively. (2) For a high-yield target, apply 45-55 kg/mu of formula fertilizer as base fertilizer, apply 6-8 kg/mu of urea as topdressing at the large trumpet stage, and apply 5-7 kg/mu of urea and 2-3 kg/mu of potassium chloride at the booting stage.
2. Mountain and hilly corn area
2.1 Medium-concentration formula fertilization plan
Recommended formula: 15-7-8 (N-P2O5-K2O) or a similar formula.
Fertilization recommendations: (1) For a general yield target, apply 50-60 kg/mu of formula fertilizer as base fertilizer, and apply 6-8 kg/mu and 5-7 kg/mu of urea as topdressing at the large trumpet stage and the booting stage respectively. (2) For a high-yield target, apply 55-65 kg/mu of formula fertilizer as base fertilizer, apply 6-8 kg/mu of urea as topdressing at the large trumpet stage, and apply 5-7 kg/mu of urea and 2-3 kg/mu of potassium chloride at the booting stage.
2.2 High-concentration formula fertilizer application plan
Recommended formula: 22-10-13 (N-P2O5-K2O) or a similar formula.
Fertilization recommendations: (1) For a general yield target, apply 35-45 kg/mu of formula fertilizer as base fertilizer, and apply 6-8 kg/mu and 4-6 kg/mu of urea as topdressing at the large trumpet stage and the booting stage respectively. (2) For a high-yield target, apply 40-50 kg/mu of formula fertilizer as base fertilizer, apply 6-8 kg/mu of urea as topdressing at the large trumpet stage, and apply 4-6 kg/mu of urea and 2-3 kg/mu of potassium chloride at the booting stage.
IV. Fertilization Recommendations for Potato
(1) Fertilization Principles
(1) Determine the reasonable amounts of nitrogen, phosphorus and potassium fertilizers based on soil test results and target yield; optimize the amounts of nitrogen, phosphorus and potassium fertilizers based on soil fertility conditions. Potato is a potassium-loving crop, so attention should be paid to increasing potassium fertilizer application. Avoid using chlorine-containing fertilizers.
(2) Increase the application of organic fertilizer, and advocate the combined application of organic and inorganic fertilizers; avoid using organic fertilizers that have not been fully decomposed.
(3) Based on the soil potassium status, appropriately increase potassium fertilizer application.
(4) In terms of fertilizer distribution, base application combined with topdressing is the main approach, and topdressing mainly consists of nitrogen and potassium fertilizers.
(5) Based on the content of medium and trace element nutrients in the soil, appropriately spray medium and trace element fertilizers on the leaves during the vigorous growth period of potato.
(6) Fertilizer application should be combined with high-yield and high-quality cultivation techniques, with particular attention to disease control.
(2) Fertilization Recommendations
(1) It is recommended to use compound fertilizer with a formula of 13-15-17 (N-P2O5-K2O) or a similar formula or potato-specific compound fertilizer as base fertilizer, and urea with potassium sulfate (or nitrogen-potassium compound fertilizer) as topdressing; compound fertilizer with a formula of 15-10-20 (N-P2O5-K2O) or a similar formula can also be chosen as topdressing.
(2) Yield level above 3000 kg/mu: recommended formula fertilizer (base fertilizer) application rate of 60 kg/mu; apply 10-15 kg/mu of urea and 10-15 kg/mu of potassium sulfate as topdressing in split applications from the seedling stage to the tuber bulking stage, or apply 20-25 kg/mu of formula fertilizer (15-10-20) as topdressing.
(3) Yield level 2000-3000 kg/mu: recommended formula fertilizer (base fertilizer) application rate of 50 kg/mu; apply 5-10 kg/mu of urea and 8-12 kg/mu of potassium sulfate as topdressing in split applications from the seedling stage to the tuber bulking stage, or apply 15-20 kg/mu of formula fertilizer (15-10-20) as topdressing.
(4) Yield level 1500-2000 kg/mu: recommended formula fertilizer (base fertilizer) application rate of 40 kg/mu; apply 5-10 kg/mu of urea and 5-10 kg/mu of potassium sulfate as topdressing in split applications from the seedling stage to the tuber bulking stage, or apply 10-15 kg/mu of formula fertilizer (15-10-20) as topdressing.
(5) Yield level below 1500 kg/mu: it is recommended to apply formula fertilizer (base fertilizer) at a recommended rate of 40 kg/mu; apply 3-5 kg/mu of urea and 4-5 kg/mu of potassium sulfate as topdressing in split applications from the seedling stage to the tuber bulking stage, or apply 10 kg/mu of formula fertilizer (15-10-20) as topdressing.
(6) Apply 2-3 cubic meters of organic fertilizer per mu as base fertilizer; if organic fertilizer has been applied as base fertilizer, the amount of chemical fertilizer can be appropriately reduced.
(7) For soil deficient in boron or zinc, 1 kg/mu of borax or 1-2 kg/mu of zinc sulfate can be applied as base fertilizer; in areas with conditions, boron fertilizer can be applied as base fertilizer (or sprayed).
V. Fertilization Recommendations for Rapeseed
1. Fertilization Principles
(1) Provide classified guidance and scientifically apply fertilizer according to the soil nutrient status of different planting regions, combined with the current seedling condition and target yield level.
(2) Given that rapeseed has now closed its rows, pay attention to applying fertilizer with water during topdressing.
(3) Strengthen field management, promptly clear ditches to prevent spring waterlogging, and improve nutrient use efficiency.
2. Fertilization Recommendations
(1) In plots where the base fertilizer amount is insufficient and winter manure that should have been applied was not applied, especially for direct-seeded rapeseed with weaker growth, apply quick-acting fertilizer as early as possible, mainly nitrogen fertilizer, and water-soluble compound fertilizer can be appropriately applied, with nitrogen fertilizer (N) at 2-3 kg/mu;, phosphorus fertilizer (P2O5) at 0.5-1 kg/mu, potassium fertilizer (K2O) at 1-2 kg/mu, or compound fertilizer with corresponding nutrient amounts can be applied. For excessively vigorous rapeseed, it is recommended to postpone or skip the stem fertilizer application, and adopt the method of picking the stems to achieve “one vegetable, two uses” and control excessive growth.
(2) In plots where the amount of phosphorus and potassium fertilizer is insufficient, spray potassium dihydrogen phosphate at the pod-setting stage. Generally, foliar spray of 0.3-0.5 kg/mu of potassium dihydrogen phosphate can effectively prevent premature senescence of rapeseed.
(3) Based on the soil available boron status, supplement boron fertilizer, and pay attention to using qualified boron fertilizer. It can be sprayed together with fertilizer and pesticide for the control of sclerotinia. Generally, foliar spray of 0.2 kg/mu of borax at a concentration of about 0.2%, or other boron fertilizers with high content and good water solubility.
(4) In acidic soil areas and high-yield areas, magnesium deficiency has occurred from time to time in recent years. It can be sprayed together with fertilizer and pesticide for the control of sclerotinia at flowering. Generally, spray 0.5-1.0 kg/mu of magnesium sulfate at a concentration of 1-2%, and it can also be sprayed at the pod-setting stage.
VI. Fertilization Recommendations for Cotton
(1) Fertilization Principles
1. Recommended nutrient application rates: nitrogen fertilizer (N) 18-20 kg/mu, phosphorus fertilizer (P2O5) 5-7 kg/mu, potassium fertilizer (K2O) 10-12 kg/mu, borax 0.5-1 kg/mu. It is recommended to apply cotton-specific compound fertilizer. For cotton fields deficient in zinc, pay attention to supplementing 1-2 kg/mu of zinc sulfate.
2. Increase the application of organic fertilizer, adopt straw (wheat straw, rapeseed stalk shells, rice straw) mulching and return to the field to preserve moisture, increase fertility and suppress weeds, and implement the combination of organic and inorganic fertilizers.
3. For cotton fields with seedling transplanting in nutrient pots, the base fertilizer should be applied by hole application with soil padding before transplanting the pot seedlings, or no fertilizer should be applied when transplanting the pot seedlings, and timely topdressing should be applied after the pot seedlings survive. Topdressing should be applied by band application followed by intertillage and soil covering, or by band trench application with soil covering, or by applying diluted with water.
(2) Fertilization Recommendations
1. Recommended formula fertilizer formulas
Base application formula fertilizer formula: 23-8-14 (N-P2O5-K2O) or a similar formula; topdressing formula fertilizer formula: 20-9-16 (N-P2O5-K2O) or a similar formula.
2. Formula fertilizer application plan
(1) For a general yield target, apply formula fertilizer (23-8-14) or other cotton-specific compound fertilizer as base fertilizer at 20-25 kg/mu, and apply 4-5 kg/mu, 9-10 kg/mu and 7-8 kg/mu of urea as topdressing at the seedling stage, bud stage and full flowering stage respectively; at the flowering and boll stage, apply formula fertilizer (20-9-16) as topdressing at 40-45 kg/mu. For cotton fields severely deficient in boron, spray boron fertilizer in combination (concentration of 0.1%-0.2%). (2) For a high-yield target, apply formula fertilizer (23-8-14) or other cotton-specific compound fertilizer as base fertilizer at 25-30 kg/mu, and apply 4-5 kg/mu, 9-10 kg/mu and 7-8 kg/mu of urea as topdressing at the seedling stage, bud stage and full flowering stage respectively; at the flowering and boll stage, apply formula fertilizer (20-9-16) as topdressing at 45-50 kg/mu. For cotton fields severely deficient in boron, spray boron fertilizer in combination (concentration of 0.1%-0.2%).
VII. Fertilization Recommendations for Vegetables
(1) Leafy vegetables
1. Fertilization Principles
(1) Apply organic fertilizer reasonably, and apply organic fertilizer in combination with chemical fertilizer; the application of nitrogen, phosphorus and potassium fertilizers should follow the principle of controlling nitrogen, stabilizing phosphorus and increasing potassium.
(2) In terms of fertilizer distribution, base application combined with topdressing is the main approach; topdressing mainly consists of nitrogen fertilizer, with reasonable combination of nitrogen, phosphorus and potassium.
(3) Combine with high-yield and high-efficiency cultivation techniques, especially water-saving irrigation techniques, to fully leverage the water-fertilizer coupling effect and improve fertilizer use efficiency.
(4) Advocate the use of organic fertilizer. Generally apply 500 kg/mu of organic fertilizer or 2-3 cubic meters of harmlessly treated livestock and poultry manure. Increase the use of biogas slurry, apply it to the field after diluting 3 times, with an interval of more than 15 days between two applications, and the annual amount of biogas slurry per mu should not exceed 3 cubic meters.
2. Fertilization Recommendations
(1) Apply 2-3 cubic meters/mu of high-quality farmyard manure as a one-time base fertilizer, combined with the application of leafy vegetable-specific compound fertilizer.
(2) Yield level 4500-5500 kg/mu, nitrogen fertilizer (N) 13-15 kg/mu, phosphorus fertilizer (P2O5) 4-6 kg/mu, potassium fertilizer (K2O) 8-10 kg/mu; yield level 5500-6500 kg/mu, nitrogen fertilizer (N) 15-18 kg/mu, phosphorus fertilizer (P2O5) 6-10 kg/mu, potassium fertilizer (K2O) 12-14 kg/mu; yield level above 6500 kg/mu, nitrogen fertilizer (N) 18-20 kg/mu, phosphorus fertilizer (P2O5) 10-12 kg/mu, potassium fertilizer (K2O) 14-16 kg/mu. Apply 30%-40% of nitrogen and potassium fertilizers as base application, 60%-70% as topdressing, and all phosphorus fertilizer as base fertilizer by band or hole application.
(3) For plots deficient in boron, apply 0.5-1 kg/mu of borax as base fertilizer, or spray 0.2%-0.3% borax solution on the leaves 2-3 times. At the same time, spray 0.5% potassium dihydrogen phosphate 2-3 times in combination with pesticide spraying to improve the net vegetable rate and commercial rate.
(2) Solanaceous vegetables
1. Fertilization Principles
(1) Increase the application of high-quality organic fertilizer according to local conditions, and it is recommended to apply microbial organic fertilizer, fruit and vegetable-specific compound fertilizer, high-potassium compound fertilizer, water-soluble fertilizer, etc.
(2) Control fertilization during the flowering period. From the beginning of flowering to fruit setting on branches, except when the plants are severely deficient in fertilizer and a small amount of quick-acting fertilizer can be applied, fertilization should be controlled to prevent flower drop, leaf drop and fruit drop.
(3) Timely apply quick-acting fertilizer at the young fruit stage and harvest stage to promote the rapid expansion of young fruits.
(4) From after transplanting to before the flowering stage, combine promotion and control, and apply thin fertilizer frequently.
(5) Avoid using high-concentration fertilizers, avoid topdressing on wet soil, avoid topdressing at noon when the temperature is high, and avoid overly concentrated topdressing.
2. Fertilization Recommendations
(1) Apply 2-3 cubic meters/mu of high-quality farmyard manure as a one-time base fertilizer, combined with the application of fruit and vegetable-specific compound fertilizer.
(2) Yield level below 2000 kg/mu: apply nitrogen fertilizer (N) 6-8 kg/mu, phosphorus fertilizer (P2O5) 2-3 kg/mu, potassium fertilizer (K2O) 9-12 kg/mu; yield level 2000-4000 kg/mu: apply nitrogen fertilizer (N) 8-16 kg/mu, phosphorus fertilizer (P2O5) 3-4 kg/mu, potassium fertilizer (K2O) 10-18 kg/mu; yield level above 4000 kg/mu: apply nitrogen fertilizer (N) 16-20 kg/mu, phosphorus fertilizer (P2O5) 4-5 kg/mu, potassium fertilizer (K2O) 18-24 kg/mu.
(3) Under normal circumstances, 20%-30% of the total nitrogen fertilizer is applied as base fertilizer, and 70%-80% as topdressing. In cases of high temperature and high humidity, the amount of nitrogen fertilizer applied as base should be reduced, or even not applied; 60% of phosphorus fertilizer can be applied as base fertilizer, with 40% reserved for topdressing; 30%-40% of the total potassium fertilizer is applied as base fertilizer, and 60%-70% as topdressing.
VIII. Fertilization for Citrus
1. Fertilization Principles
(1) Increase the application of organic fertilizer, and adhere to the combined application of organic and inorganic fertilizers; citrus orchards with late-maturing varieties that did not apply organic fertilizer in autumn should pay attention to supplementary application in spring; advocate planting green manure between rows in citrus orchards, and turning it under or mulching it to return to the field in spring, to build up soil fertility and conserve soil and water. For orchards with severe soil acidification, apply quicklime, calcium-magnesium phosphate fertilizer, etc. for improvement.
(2) According to the soil fertility of the citrus orchard and the growth vigor and yield level of citrus varieties with different ripening periods, appropriately reduce the amount of nitrogen, phosphorus and potassium fertilizers; for medium and trace elements, adopt the fertilization strategy of “supplementing according to deficiency”, supplementing medium and trace elements such as magnesium, calcium, boron, zinc and iron, especially supplementing boron and zinc before citrus sprouting in spring and before and after flowering.
(3) Fertilizer and water management should be combined with green, high-yield and high-quality cultivation techniques. Before spring fertilization, pay attention to the shaping and pruning of fruit trees. In summer, high temperature and summer drought are likely to occur, so advocate the techniques of growing grass cover in citrus orchards and storing fertilizer and water in holes. Orchards with conditions should advocate integrated water and fertilizer technology; in autumn, pay attention to deep application of organic fertilizer.
2. Fertilization Recommendations
(1) Fertilization amount. It is recommended to apply citrus-specific compound fertilizer. For orchards with a yield above 3000 kg/mu, nitrogen fertilizer (N) 25-35 kg/mu, phosphorus fertilizer (P2O5) 8-12 kg/mu, potassium fertilizer (K2O) 20-30 kg/mu; for orchards with a yield of 1500-3000 kg/mu, nitrogen fertilizer (N) 20-30 kg/mu, phosphorus fertilizer (P2O5) 8-10 kg/mu, potassium fertilizer (K2O) 15-25 kg/mu; for orchards with a yield below 1500 kg/mu, nitrogen fertilizer (N) 15-25 kg/mu, phosphorus fertilizer (P2O5) 6-8 kg/mu, potassium fertilizer (K2O) 10-20 kg/mu. If integrated water and fertilizer technology is adopted, the fertilizer amount can be reduced by 30%-40%.
(2) Application method. Apply 30%-40% of nitrogen fertilizer, 30%-40% of phosphorus fertilizer, and 20%-30% of potassium fertilizer before and after flowering in February-March. Apply 30%-40% of nitrogen fertilizer, 20%-30% of phosphorus fertilizer, and 40%-50% of potassium fertilizer before fruit harvest in June-July. Apply 20%-30% of nitrogen fertilizer, 40%-50% of phosphorus fertilizer, 20%-30% of potassium fertilizer, and all organic fertilizer before and after fruit harvest in November-December. Apply 0.5-1 kg of borax and 1-1.5 kg of zinc sulfate per mu, mixed with organic fertilizer and applied in autumn.