How to manage the later stage of rice growth?

How to manage the later stage of rice growth? What should I pay attention to? In the later stage of rice growth, it is especially necessary to prevent premature senescence. Premature senescence occurs in rice from heading to maturity, which will lead to poor grain filling, increase of blighted grain and decrease of yield. There are many factors leading to premature senescence in the later stage of rice growth. First, improper cultivation and management. The planting density is too high, the plant growth is weak; in the early and middle stages, the application of nitrogen fertilizer is too much, the application of phosphorus and potassium fertilizer and trace element fertilizer is insufficient, the aboveground growth of the plant is too prosperous, the leaves are weak, the field is shaded, and the lower leaves die in advance; at the same time, the root growth is seriously hindered, the new roots are few and short, and the ability to absorb nutrients is weakened, resulting in premature senescence. In the case of long-term flooding and lack of fertilizer, premature senility is also easy to occur. Second, the soil is anoxic and hardened. In the land with low-lying terrain, high groundwater level, poor permeability and strong reducibility, there are many anoxic and toxic reducing substances in the soil, which reduces the root activity of rice, causes poor root development, blackening and rot, and loses the ability to absorb nutrients, resulting in early senescence of roots and leaves. Soil consolidation, poor permeability, poor root development of rice, and premature senescence due to lack of nutrients in the later growth stage. Third, adverse climatic conditions. The influence of adverse climate such as low temperature and cold wave in autumn will hinder the physiological activities of rice roots and leaves and cause premature senescence. Especially when Cold Dew wind comes earlier, rice is more likely to have premature senescence. During the grain filling period, the temperature was too low or the sunshine hours were too few, and the formation and transfer rate of assimilation substances slowed down. In September, rice encountered a low temperature of 5-6 ℃, resulting in discoloration and premature senescence of varieties with poor cold tolerance or plants with poor root system development. The fourth is the factor of variety. Generally short-stalked and precocious rice varieties are prone to premature senescence. The premature senescence of rice has a great effect on the yield, so measures should be taken to prevent it as soon as possible. (1) Scientific irrigation. Long-term flooding irrigation is strictly prohibited in the later stage of rice growth, wet irrigation should be put off, intermittent irrigation and alternation of dry and wet should be achieved in order to enhance root activity and prolong the functional period of leaves. Prevent the water from being cut off too early, advocate old-age rice, raise roots and protect leaves. In the heading and flowering stage and filling stage, there is a shallow water layer in the field in normal weather. in case of continuous high temperature, the method of daily irrigation and night drainage is adopted to prevent premature senility. For the fields with heavy clay and poor permeability, the fields should be irrigated intermittently in the later stage, that is, shallow water should be irrigated once, and then irrigated after 2-3 days of natural drying. (2) improve the soil. For low-lying land or saline-alkali land, timely trench drainage, improve soil permeability, and apply a large amount of high-quality farm manure at the same time. For the paddy field with soil consolidation, increase the number of ploughing, loosen the soil, enhance the aeration capacity of the soil, and promote the rice to take root and absorb nutrients. (3) rational fertilization. For paddy fields that are short of fertilizer and early senescence, grain fertilizer or extra-root topdressing can be applied at heading stage. 100 grams of potassium dihydrogen phosphate and 50 kilograms of water per mu are sprayed once every 5 to 7 days. For the lack of trace elements of rice, only need to spray once. Fertilizers should be applied to the paddy fields with heavy yellowing in the later stage and the sandy soil with poor fertilizer conservation. Generally, 2kg of urea and 2kg of potassium chloride are applied per mu, while 15 grams of potassium dihydrogen phosphate and 50kg of water are sprayed per mu. Click to get more rice planting techniques click to get more food crop planting techniques