Law of Fertilizer requirement and fertilization techniques for Rice

Law of fertilizer requirement for rice

Rice is one of the crops that need more fertilizer. Generally, nitrogen (N) 1.6-2.5kg, phosphorus (P2O5) 0.8kg-1.2kg, potassium (K2O) 2.1kg-3.0kg are needed for every 100kg rice production. The fertilizer ratio of nitrogen, phosphorus and potassium is about 2 ∶ 1 ∶ 3.

The nitrogen uptake of rice reached its peak at the peak tillering stage and heading and flowering stage. The application of nitrogen fertilizer can increase the yield of starch, and the yield of starch is positively correlated with the grain size, yield and quality of rice. If the nitrogen supply is insufficient before heading, it will result in reduced grain nutrition, insufficient grain filling and reduced rice quality.

There was no significant difference in phosphorus uptake among different growth stages of rice, and the maximum phosphorus uptake was from tillering to young panicle differentiation. Phosphate fertilizer can promote root development and nutrient absorption, enhance tillering, increase starch synthesis and promote grain filling.

The potassium uptake of rice was mainly from panicle differentiation to heading and flowering stage, followed by tillering to panicle differentiation stage. Potassium is a necessary nutrition for the synthesis and transportation of starch and cellulose, which can improve the vitality of roots, delay leaf senescence and enhance the ability to resist diseases and insect pests.

In addition, silicon and zinc have great effects on the yield and quality of rice. There is 10%-20% silicon dioxide in rice stems and leaves. The application of silicon fertilizer can enhance the resistance of rice to diseases and insect pests and lodging, increase the yield and improve the quality of rice. Zinc fertilizer can increase the number of effective panicles, grains per panicle and 1000-grain weight of rice, reduce the rate of empty grain and increase production, especially in calcareous soil. The application of silicon and zinc fertilizer plays a more significant role in newly modified paddy field, acid soil and cold soaking field.

Rice fertilization technology

1. Fertilization in seedling field

The base fertilizer of seedling field should be re-applied with high-quality organic fertilizer, which has long fertilizer effect and complete nutrients, and contains a large number of nutrients necessary for the growth of rice. Generally, 500kg / mu is applied, while urea 3kg / mu, diammonium phosphate 8kg / mu, potassium chloride 7kg / mu or compound fertilizer 20kg / mu is applied to achieve the goal of uniform fertilizer supply and make the seedlings strong. 4-5 days before transplanting, urea 6kg / mu or high nitrogen compound fertilizer 8kg / mu was applied as marriage fertilizer to facilitate the seedling to turn green and restore growth as soon as possible after transplanting.

2. Full application of field base fertilizer: field base fertilizer should also pay attention to the application of organic fertilizer, generally 10-15 kg per mu of Scheuer drip irrigation. And apply Chong Zhi Road to add a set of soil, in addition, increase the application of silicon fertilizer 6kg / mu and zinc sulfate 1kg / mu. The basic fertilizer in the field should be applied in combination with ploughing and raking rice fields before transplanting seedlings, and should be applied deeply to the soil of 12cm to 20cm, so as to keep the ammonium stable in the environment of lack of oxygen and prevent loss.

3. Topdressing

(1) early application of tiller fertilizer. After transplanting and turning green, tiller fertilizer should be applied as early as possible to promote the growth of low-node tillers and increase panicles. The tillering fertilizer is generally applied twice, and each mu of Scheuer drip irrigation is fertilized with 10kg to ensure the neat growth of the whole field and play the role of tillering and panicle formation.

(2) skillfully applying panicle fertilizer. The inverted second leaf of rice begins to produce leaves, and when the young panicle is about 1 cm long, it is the basic period of panicle formation and grain development, and ineffective tillering should be controlled. At this time, one barrel of fruit per mu can be applied to ensure that enough nutrients in the middle stage turn to reproductive growth, increase the number of spikelets, prevent spikelet degradation, promote large grain weight per spike, and have the functions of root maintenance, healthy leaves, strong culms and anti-lodging. The plots with too small population can be applied in advance to the stage of panicle differentiation.

(3) applying grain fertilizer. From heading to maturity, the main purpose is to increase the seed setting rate, ensure the complete maturity and increase the 1000-grain weight. Topdressing depends on the growth of rice, less rather than more, generally spraying 0.2%-0.3% potassium dihydrogen phosphate solution mixed with sesame alginate iodine 50-60 kg per mu; after zinc deficiency symptoms appear, spraying 0.1%-0.3% zinc sulfate solution 50% 60 kg per mu mixed flower and fruit doctor fruit can be multi-element; for the land with chlorotic and yellowing leaves before heading, the soil allocation of Chongzhi per mu is better than adding a set of soil. Supplementary application of grain fertilizer can effectively enhance the stress and disease resistance of plants, prolong the functional period of leaves, prevent premature senescence, improve the supply of oxygen to rice roots, increase root activity, accelerate grain filling, promote maturity and grain fullness, so as to increase rice yield and improve rice quality. It should be noted that grain fertilizer should not be applied to the fields with fat in the early stage, excessive tillering in the middle stage, thick green leaves, poor light among populations, and the trend of greedy green and late ripening.

In addition, saline-alkali land should be drained and washed with salt before fertilization. Pay attention to irrigation during the day and drainage at night about 3-4 days before fertilization to prevent temporary salt accumulation from affecting the fertilizer effect.