免耕条件下川香优9838氮磷钾吸收规律与氮肥合理施用

笔者于2005～2006年开展免耕条件下不同施氮量对川香优9838生长及产量形成的影响研究，探讨川香优9838在免耕条件下对N、P2O5、K20的吸收及氮肥的管理技术措施。

Study on Absorption Law of Nitrogen, Phosphorus and Potassium and Proper Nitrogen Application in Chuanxiangyou 9838 under No-tillage Culti- vation

The aim of the study is to investigate the absorption laws of nitrogen, phosphorus, and potassium, and proper nitrogen application in Chuanxian-gyou 9838 under no-tillage cultivation. Five nitrogen application treatments were designed to analyze the absorption laws of N, P and K, and to discuss the effects of different N fertilizer application amounts on yield and yield composition factors of Chuauxiangyou 9838. The results showed that gross nutrient ab-sorption in Chuunxiangyon 9838 was greatly varied at different developmental stages under rice-rape rotation with no-tillage. The maximum N absorption in Chuanxiangyou 9838 appeared at jointing stage followed by heading stage, thirdly the filleting stage; the P absorption in Chuanxiangyou 9838 presented the consecutively slight increase during seedling stage and mature stage; the K absorption in Chuanxiangyon 9838 was mainly conducted from jointing stage to heading stage, during which K absorption accounts for 73.4% of the total absorption in whole developmental stage. Consequently, N fertilizer should be applied earlier (before jointing stage), P fertilizer is suitable as base fertilizer and application of K fertilizer should be preferably conducted at esdy-middle period. When the yield reached 11 t/hm2, the optimal N application amount in Chunnxiangyon 9838 was about 165 kg/hm2.