Medium and trace elements: targeted application is the key

Northeast China: The main production of zinc, iron and molybdenum in Northeast China is spring corn, rice and soybean. The "Opinions" suggest that the reason for the supplement of zinc and iron in this area is that these two elements are particularly effective in increasing the yield of rice and corn; molybdenum is a component of nitrogenase and nitrate reductase, and the molybdenum in this area is mainly considering the nodule of soybean. Nitrogen fixation. In general, the trace elements in the northeast are designed around local dominant crops.
Huanghuaihai area:
The crops to be supplemented with sulfur, zinc, iron, manganese and boron should be wheat and corn. The supplement of zinc, manganese and boron can increase the yield and improve the quality. For the sulfur element, Chen Qing believes that it can be supplemented by applying a sulfur-based compound fertilizer. According to the "Opinions", soil acidification in the orchard of Jiaodong Peninsula and soil salinization in facility agriculture are serious, and vegetables and fruit trees are seriously over-fertilized. Chen Qing believes that lime, calcium fertilizer or soil conditioner should be applied to the actual situation of Jiaodong Peninsula. Chen Qing said: "The soil conditioner is used to improve the soil, increase the supplement of calcium and magnesium fertilizer, adjust the pH value of the soil, and improve the quality of apples and other fruits." In vegetable production, due to the large amount of organic fertilizer, zinc, iron and manganese There are sufficient elements such as sulfur, but the magnesium leaching caused by a large amount of irrigation is very serious. In addition, some plants use excessive amounts of potassium fertilizer in vegetables, which leads to antagonism of potassium and magnesium and inhibits the absorption of magnesium by crops. Therefore, the facilities and vegetables need to be supplemented with calcium, magnesium and boron.
Middle and lower reaches of the Yangtze River:
It is necessary to cooperate with the application of sulfur, zinc and boron. The author believes that boron should be given priority when supplementing trace elements in the region, mainly due to the large area of ​​rapeseed crops in the region. In addition, the application of zinc in this area can promote rice and wheat production. The application of alkaline conditioners such as silicon and calcium can also play a certain role in rice.
South China:
It is necessary to cooperate with the application of calcium, magnesium, zinc and boron. The fertilizers in this area are easy to be leached, the fertilizer utilization rate is low, and the soil acidification is serious. Precipitation in the area is abundant, and calcium and magnesium will cause leaching, which will cause salt-based ions in the soil, especially acid ions, to remain in the soil. Therefore, in the southern region, the supplement of calcium and magnesium is conducive to improving the soil, so it is a good practice to promote lime, alkali residue and dolomite in the south. In addition, the addition of calcium and magnesium also increases the cations of the soil, enhances the exchange performance of the base, and enables the soil to better maintain nutrients. Calcium and magnesium in the south depend more on soil improvement than on foliar application. Zinc supplementation also has a similar effect. Boron supplementation also has a good effect on improving the sugar content and quality of agricultural products.
Southwest Region:
It is necessary to cooperate with the application of sulfur, zinc and boron in the region where there are seasonal droughts, soil erosion and soil acidification, and dry soil layers. The author believes that the problem in the southwestern region is more mountainous, focusing on the cultivation of soil fertility. In terms of supplementing trace elements, for economic crops, especially in citrus and vegetables, calcium and magnesium should always be placed in a more important position, and food crops should pay more attention to the role of sulfur, zinc and boron.
Northwest China: It is necessary to cooperate with the application of zinc and boron. The desertification in the northwestern region is relatively serious, so the calcium and magnesium elements in this area are sufficient. Zinc and boron supplementation in this area is mainly for cotton in the region, but it is more important to consider the problem of zinc in the wheat producing areas of Shaanxi. Fruit trees need to consider the application of boron.