Fertilizer requirement Law and fertilization techniques of Litchi

The main results are as follows: (1) according to the fertilizer requirement characteristics of litchi, for an orchard with a yield of 1000 kg per mu, for every 1000 kg of mature fruit, 9.8kg of nitrogen, 1.1kg of phosphorus and 6.6kg of potassium were needed, and the proportion of fertilizer needed was 10:1:7. Generally, flower bud differentiation begins from two or three shoots before heading, which requires more nitrogen; the growth and development of flower branches, flowers and male and female flowers are mainly from flower ear to Xie flower, and the proportion of phosphorus and potassium increases, but it is still dominated by nitrogen; from pollination to fruit ripening is mainly fruit growth and development, and the demand ratio of nitrogen, phosphorus and potassium is the same as that of the previous period. (2) the amount of ①-based fertilizer applied to litchi: generally, after fruit harvest, about 1000-2000 kg of mature organic fertilizer and 40-50 kg of general compound fertilizer (such as San'an) are applied per mu. After each new shoot leaf turns green, 0.3% potassium dihydrogen phosphate and other foliar fertilizer can be sprayed. ② pre-flowering fertilizer: generally applied before flowering, mainly phosphorus and potassium fertilizer, 30-40kg per mu (about 0.5-1kg per plant) high-potassium compound fertilizer, nitrogen fertilizer should not be excessive, in order to avoid "flushing" ③ strong fruit fertilizer: after fruit setting, applying 30-40kg per mu of high-potassium compound fertilizer will play an important role in strengthening fruit and reducing pre-harvest fruit drop.