In the production of late rice, there are two seasons of late rice and single season of late rice. The growth period and nutrient requirements of these two late rice varieties are different, so the application of fertilizer in late rice, especially the application period of nitrogen fertilizer, is obviously different. Therefore, fertilization regulation should be carried out according to the two types of late rice.
Double-season late rice (post-season rice) fertilization double-season late rice has a short growth period, and it begins to differentiate into ears during tillering, and enters the tillering stage during ear differentiation. It appears in the whole life - the obvious absorption peak, that is, after transplanting The peak of absorption was formed in 2~3 weeks, which was earlier than the absorption peak of single-season late rice, and it was also overlapping type. The peak period of sucking fertilizer is not as obvious as that of early rice, and the amount of fertilizer absorbed in the late stage is more than that of early rice. Because the water temperature and soil temperature in the early stage of late rice are not conducive to the absorption of roots, it is necessary to pay attention to the increase of panicle fertilizer for double-season late rice, and to divide it twice during the differentiation from young panicle to meiosis. However, in the middle and lower reaches of the Yangtze River, the application of nitrogen fertilizer during flowering should be controlled in several stages. Because the temperature drops rapidly in the later period, excessive nitrogen fertilizer will cause rice to be greedy, delaying maturity and reducing production, and will also increase the occurrence of pests and diseases. According to the above characteristics, the base fertilizer and top dressing are applied in the double-season late rice fertilization technology, and the appropriate amount of topdressing is applied in the panicle differentiation stage. Under the condition of ensuring safe and uniform ear, it is expected that the seedling fertilizer will be applied in the later stage.
The single-season late-season fertilization single-season late-season rice has a longer growth period, generally 100 to 130 days in the growth period of the field, and the vegetative growth and reproductive growth of the single-season late rice are separate types. This type of late rice has two peak periods of fat absorption, one in the tillering stage and the other in the panicle differentiation stage, and the late stage of the fertilizer absorption is higher than the previous stage, indicating that the ear fertilizer of the single-season late rice is more important. In the different cultivation methods of late rice transplanting and transplanting, the suitable ratio of nitrogen fertilizer applied is 40%~50%, which can maintain high tillering rate and the development of the population is reasonable, which is beneficial to increase the photosynthetic material after heading. Accumulation and operation, obtain the appropriate number of kernels and 1000-grain weight. The total nitrogen of the fake facilities is 12~14 kg per mu, and the nitrogen application rate of throwing cultivation is: base fertilizer: manure: panicle fertilizer = 40%: 30%: 30%. The proportion of transplanted nitrogen fertilizer was: base fertilizer: manure: panicle fertilizer = 50%: 30%: 20%.
In short, there is a difference in the application period of nitrogen fertilizer between double-season late rice and single-season late rice. The principle of the former is: appropriate re-application of tiller fertilizer, reflecting the principle of pre-promotion, central control and post-protection, but the former promotion can not cause the seedlings to be too busy and invalid. There are many adverse consequences. The single-season late rice should reflect the principle of pre-stable, mid-attack and post-complementation. The appropriate control in the early stage, focusing on the big spike, the topdressing can be divided into 2~3 times.
In addition, late rice fields are prone to potassium deficiency in early rice fields. Potassium fertilizer application in late rice is important for growth of seedlings and later resistance to rice blast, and is also beneficial to increase the number of panicles, grain number per ear and yield. The amount of potassium applied per mu is preferably 4 to 6 kg. The application period can be used as a base fertilizer, or 50% as a base fertilizer and 50% as a panicle fertilizer.
(Senior Consultant of Sinofert, Professor of China Agricultural University, Cao Yiping)
Farmers Daily
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