Key Points of Fertilizer and Water Management Techniques for High-Yield Rice Cultivation

In high-yield rice cultivation, the level of yield is determined by fertilizer and water application as the core; fertilizer and water application should be decided according to the fertilizer requirements of the variety, the level of soil fertility, the planting time, etc. Generally, 100 kg of paddy rice requires 2 kg of pure N, 1.2 kg of pure P, and 1.5 kg of pure K. The fertilizer and water application measures are specifically proposed as follows:

1. Within 5-10 days after rice transplanting, apply topdressing fertilizer in time, requiring the N fertilizer applied per mu to account for 85-90% of the N fertilizer for the field period, P fertilizer to account for 100%, and potassium fertilizer to account for 30%, ensuring that 25-30 days after transplanting, the number of effective tillers reaches about 280,000-320,000.

2. In the middle and late growth stages, the main task is to apply ear fertilizer well; the application of ear fertilizer is generally appropriate at 45-50 days after transplanting in the field. The application of ear fertilizer should be determined by the variety, soil fertility, the amount of fertilizer applied earlier, the size of the seedling population, and the depth of leaf color grade. Fields with soil fertility below medium, insufficient early fertilizer application, and small populations are the key targets for ear fertilizer application. It is required to apply 5-8 kg of urea and 10-15 kg of potassium fertilizer per mu. Ear fertilizer application should be based on the seedlings: apply more where growth vigor is poor, and apply less or not at all where growth is good. For fields with good growth, large populations, deep leaf color grade, and a large amount of early fertilizer application, do not apply N chemical fertilizer; instead, apply potassium fertilizer as the main nutrient, with 15-20 kg of potassium fertilizer per mu. It is necessary to promptly regulate the nitrogen nutrient metabolism of rice plants to prevent excessive vegetative growth, balance nutrients, and achieve robust growth.

3. Water management: In the early stage, aim for shallow water to promote tillering, and drain the water in time to dry the field once enough tillers are reached. Field drying method: for muddy fields, heavy drying can be done, drying until the surface layer of the field shows white roots and the leaf color grade fades, which is appropriate. For sandy-bottomed and stony-bottomed fields, only light drying can be done, waiting until the soil is slightly hard. In the middle and late stages, water management should focus mainly on shallow water and moist conditions, and in the late stage, alternate dry and wet management should be carried out. This achieves root maintenance, leaf protection, increased grain number, and increased grain weight.

During the rice growth period, deep-water seedling protection management is prohibited, as it leads to poor root development of rice plants, premature aging of the plants, and decreased grain weight.