Onion is the key to high yield, reduced nitrogen and potassium
In recent years, some vegetable farmers blindly increased the use of chemical fertilizers, especially nitrogen fertilizers, in order to increase the production of green onions. According to the survey, the average nitrogen fertilizer application rate is as high as 40-50 kilograms per mou, and phosphorus phosphorus pentoxide is 10-15 kilograms. However, the application of potash fertilizer is very low, even if it is not applied. As a result, the onion yield does not increase, and root rot increases. Excessive application of nitrogen fertilizer on the green onion and little application of potassium fertilizer, it is easy to lead to nitrogen and potassium nutrition imbalance of onion. Onion on the nitrogen and potassium fertilizer technology, can make green onion yield increased by an average of more than 20% per mu, specific fertilization methods are as follows: Onion yield per acre of 3000-6000 kilograms is a high yield, high yield welsh onion nitrogen, phosphorus, potassium nutrient absorption ratio of about 1:0.4:1.3. From this we can see that green onions have a greater demand for potassium and nitrogen, followed by phosphorus. Therefore, in the proportion of fertilization, we must pay attention to the balanced supply of potassium. Especially in the conditions of high-yield cultivation and no application of organic fertilizers, more attention should be paid to applying potassium fertilizer. Specific attention to three aspects: First, the soil itself for the supply of potassium, such as sandy soil for low potassium capacity, to properly increase the use of potash. The second is to determine the target output of green onions. If the output per mu exceeds 5,000 kg, the output of scallion from the soil will be more potassium. Therefore, the potash fertilizer should be increased accordingly. The third is the amount of other fertilizers. For example, the amount of straw returned to the field, the amount of nitrogen fertilizer. If you put a lot of organic fertilizer, you can use less potassium fertilizer. The amount of nitrogen fertilizer should be appropriate, and it should be balanced with the corresponding potash fertilizer before there is a good increase in production. Otherwise, blind investment will not only be of no benefit to the high yield of green onions, but also cause the quality of green onions to decline, such as small proportion of light blue, leafy, not strong onion, and even bitter. The general recommended amount of nitrogen fertilizer is 20-26 kg of pure nitrogen per mu. Applying too much nitrogen fertilizer, coupled with a large amount of water, not only waste nitrogen fertilizer, but the output of green onions is not resistant to storage, quality decline. It also has a negative effect on the environment because of the loss of nitrogen. Therefore, the amount of nitrogen fertilizer to be applied properly, in the selection of nitrogen fertilizer varieties, the most common is urea, but the most suitable nitrogen fertilizer is ammonium sulfate, because the onion is like sulfur crops. In the fertilization method also has stress. Full fertilization should be divided into two parts: base fertilizer and top dressing. The best basal fertilizer is 4000-5000 kilograms of cooked organic fertilizer. Spread the ground and plow into the soil. Fertilizer base fertilizer should be applied to all phosphate fertilizers, 40% nitrogen fertilizer and 60% potassium sulfate fertilizer, and the varieties can be compound fertilizer or single fertilizer. In the selection of compound fertilizer, sulfur-based general-purpose or special-purpose type can be used, and high-nitrogen type compound fertilizer is not suitable. The base fertilizer must have a depth of about 15 cm. The top-dressing of green onions can be carried out in 2-3 times, and the remaining 60% of nitrogen fertilizer and 40% of potassium fertilizer of base fertilizer are applied as top-dressing in the mid-to-middle stages of the Shengye and Scallion formation stages, respectively. The top-dressing method is the best for water-fertilizer blending. Avoid large-water large nitrogen fertilizers, otherwise it will cause low fertilizer utilization. In summer, urea is scattered on the surface of the ground, and nitrogen volatilization can easily cause smoked leaf sprouts. Zhejiang Industrial Group Co., Ltd. , https://www.xingyeseafood.com