Principles of fertilizer application in the single-season rice zone of the southwestern highlands and mountainsh

Including all of Yunnan Province, southwestern Sichuan Province, most of Guizhou Province, western Hunan Province, and northern Guangxi Zhuang Autonomous Region.

Fertilizer application principles

1. According to the soil nutrient status, adjust the ratio of base chasing and reduce the amount of nitrogen fertilizer in the early stage.

2. Give preference to calcium-magnesium phosphate or common calcium for phosphate fertilisation.

3. For rice fields with low potassium supply capacity, pay attention to potassium supplementation at the later stage.

4. Combining organic and inorganic fertilizers is recommended. Increase organic nutrient inputs by returning straw to the field and applying organic fertilizers.

5. Apply soil conditioner with acid-regulating effect or base lime to acidic soils.

Fertiliser recommendations

1. For yield levels below 500 kg/mu, use 7-11 kg/mu of nitrogen fertilizer (N), 3-4 kg/mu of phosphorus fertilizer (P2O5) and 3-5 kg/mu of potassium fertilizer (K2O); for yield levels 500-600 kg/mu, use 11-13 kg/mu of nitrogen fertilizer (N). N) dosage 11-13 kg/mu, phosphorus fertilizer (P2O5) 4-5 kg/mu, potassium fertilizer (K2O) 5-6 kg/mu; yield level 600 kg/mu or more, nitrogen fertilizer (N) dosage 13-15 kg/mu, phosphorus fertilizer ( P2O5) 5-6 kg/mu, potash (K2O) 6-9 kg/mu.

2. Nitrogen fertilizer base fertilizer accounts for 40%-50%, tiller fertilizer accounts for 20%-30%, spike fertilizer accounts for 20%-30%; phosphorus fertilizer and organic fertilizer all base application; potassium fertilizer all base application, if the yield level is 600 kg/mu or more, base fertilizer accounts for 85%, spike grain fertilizer accounts for 15%.

3. 17-13-15 (N-P2O5-K2O) or similar formula is recommended as base fertilizer.

4. Reduce the amount of potassium fertilizer by 30% for the full amount of straw returned to the field; reduce the amount of base fertilizer for fields with organic fertilizer.

5. For fields with soil pH below 5.5, apply 30-50 kg/mu of silica-containing alkaline fertiliser or lime when preparing the land.

6. Apply 1-2 kg/acre of zinc sulphate in zinc-deficient areas.