Characteristics of Fertilizer requirement and fertilization techniques during Rice growth period

The main results are as follows: 1. The characteristics of fertilizer requirement of rice: nitrogen, phosphorus and potassium are the nutrient elements needed by rice but lacking in soil. In general, for every 100 kg of rice production, it takes about 1.6 to 1.9 kg of nitrogen, 0.8 to 1.3 kg of phosphorus and 1.8 to 3.8 kg of potassium, with a ratio of 10.5 kg to 1.3. Nitrogen was the highest from turning green to tillering stage, and phosphorus and potassium were the highest at jointing stage. The absorption of the three elements of rice formed two fertilizer absorption peaks at the peak tillering stage and the late stage of young panicle differentiation, respectively. Therefore, rice fertilization must be based on these nutrition rules and fertilizer absorption characteristics of rice to fully meet the needs of various nutrient elements in the peak of fertilizer absorption of rice. 2. Fertilization techniques for rice 1. Fertilization techniques for rice fields: one is to prepare nutritious soil: fertile dry soil and rotten pig manure are mixed and composted at the proportion of 7:3; the other is to apply fertilizer to seedlings: after 3 leaf stage, if the leaves generally turn green and yellow and lack of fertilizer, potassium dihydrogen phosphate or ammonium sulfate can be used for 20 kg per mu of seedling bed, and foliar spraying with water of 1200 to 1500 kg. After spraying, it is necessary to wash the seedlings with clean water to prevent seedling burning. The third is to send dowry fertilizer: it is best to apply it once two days before transplanting to ensure that the speed of turning green after transplanting is generally 10 kg of ammonium sulfate per mu or 5 kg of urea per mu. 2. Honda fertilization technology Honda fertilization should combine organic fertilizer with chemical fertilizer, topdressing with foliar spraying, and the principle of fertilization is to reduce nitrogen and increase phosphorus and potassium. Combined with soil preparation in autumn or spring, fully mature farm manure can be applied every other year, and high-quality rice formula fertilizer 15kg / ha can be applied in combination with harrowing land. Tillering fertilizer is applied twice, 50% of the total amount of the first tiller fertilizer is applied immediately after turning green, and no more than 6 leaves at the latest, promoting the early growth and rapid development of tillers and low tillering; the second tillering fertilizer is applied from the end of 7 leaves to the dew tip of the 8th leaf of rice; panicle fertilizer: panicle fertilizer is applied twice. For the first time, 60% of the total panicle fertilizer was applied when the top 3 leaves were just exposed, promoting the differentiation of panicles, branches and spikelets, and striving for large spikes; the second time, when the flag leaves (inverted 1 leaf) were exposed to the tip, the panicle fertilizer was mainly nitrogen fertilizer and an appropriate amount of potassium fertilizer was added.