Watermelon is the main fruit-based melon in China, with a large planting area and high yield. In recent years, the quality of watermelon has decreased significantly, which is a growing concern of consumers and producers. Reasonable fertilization has a great impact on the quality and yield of watermelon. The following five problems should be paid attention to: 1. Determine reasonable nutrient input ratio and key fertilization period Watermelon absorbs the most potassium during the whole growth period, followed by nitrogen and phosphorus. For the production of 1000 kg of watermelon at the middle level, it is necessary to absorb nitrogen (N) 2.5 to 3.3 kg, phosphorus (P2O5) 0.8 to 1.3 kg, potassium (K2O) 2.9 to 3.7 kg, and N:P2O5:K2O to 1:0.36:1.14. The ratio of application of nitrogen, phosphorus and potassium may be 1:0.5:1 in the soil with high soil available phosphorus content, 1:1:1 in soil with low soil available phosphorus content, and appropriate adjustment in low potassium area. The ratio of high potassium application, such as 1:0.5:1.2. The whole growth period of watermelon is 80-120 days, which can be divided into germination stage, seedling stage, pumping period and flowering result period. At the end of flowering to the stage of expanding melon, it is the peak period of absorption of nutrients. Therefore, on the basis of applying the base fertilizer, the seedlings and fertilization should be stably pursued, and the melon fertilizer should be chased again. Second, we must timely adjust and meet the balance requirements of nitrogen, phosphorus and potassium in different growth and development periods. The proportions of nitrogen, phosphorus and potassium absorbed during different growth and development periods vary greatly. Before the vine was 1:0.21:0.83, the most absorbed nitrogen and the least phosphorus. In the six and seven days of fruit fading, the ratio of phosphorus uptake was greatly increased by 1:0.8:0.87. The fruit expansion period was 1:0.3:1:13, the proportion of phosphorus uptake decreased, and the proportion of potassium absorbed increased. The ratio of maturity is 1:0.26:1.22. In the early stage of the whole growth period, more nitrogen, more potassium, less phosphorus, and more nitrogen and potassium in the middle and late stages. Therefore, ensuring the supply of nitrogen nutrients in the early stage of watermelon growth, with appropriate phosphorus and potassium, to promote the vegetative growth of plants, and ensuring nitrogen and potassium nutrients after sitting on the melon is very important to improve the yield and quality of watermelon. Disclaimer: Some articles on this website are transferred from the Internet. If legal rights of third parties are involved, please inform this website. phone Microscope Camera and Scopepad Microscope Camera And Scopepad,Industrial Camera,Industry Digital Microscope Camera,Usb Microscope Electronic Eyepiece NINGBO VANCO INSTRUMENT CO.,LTD , https://www.vancoscope.com