How is soil testing and formulated fertilization carried out for rice cultivation?

I. Technology Introduction

Based on the fertilizer requirement characteristics of major crops and formulated fertilization technology, soil testing and formulated fertilization mainly follows three principles: first, combining organic fertilizer with inorganic fertilizer; second, combining macro, secondary and trace elements; third, combining land use with land maintenance, with input and output in balance. The methods for determining fertilizer application rates mainly include the soil and plant testing recommended fertilization method, the fertilizer effect function method, the soil nutrient abundance-deficiency index method and the nutrient balance method.

II. Operating Procedures

For medium-fertility fields with a rice yield of 460-510 kg per mu, the soil testing and formulated fertilization model is as follows:

(1) Total fertilizer application and ratio

The applied nitrogen:phosphorus:potassium ratio is about 1:0.5:0.8, with a total of about 13-15 kg of urea; 6-8 kg of phosphorus pentoxide; and 9-13 kg of potassium oxide.

(2) Fertilization plan

1. Base fertilizer

(1) Apply 1000-1600 kg of fresh green manure or 800-1400 kg of farmyard manure per mu.

(2) 35-40 kg of chemical fertilizer special for rice, 40-50 kg of superphosphate, 5-7 kg of potassium sulfate, and 2 kg of zinc sulfate.

2. Topdressing

(1) Tillering fertilizer: apply 8-10 kg of urea and 2-3 kg of potassium sulfate per mu;

(2) Booting fertilizer: apply 5-6 kg of urea and 4-5 kg of potassium sulfate per mu;

(3) Flower-preserving fertilizer: apply 0.7 kg of urea plus 0.2 kg of potassium dihydrogen phosphate per mu, diluted in 50 kg of water for spraying, to prevent premature senescence.

III. Conclusion

Using soil testing and formulated fertilization technology greatly reduces production costs, increases per-unit yield and raises total output.