Effects of different fertilization modes on the growth and grain yield of maize in Three Gorges Region.

The effects of different fertilization modes and levels on the growth and production of maize are studied.On the fertilization ratio(N∶P=1∶1) the 1000-grain weight increases on all levels of fertilization compared with the non-fertilization and increases to the maximum on the middle fertilization level,while it decreases on both the low fertilization and high fertilization levels;while on the fertilization ratio(N∶P=0.5∶1) the production increases with higher fertilization levels and the 1000-grain weight gets to the maximum on the low fertilization level.The diameter,shoot height and number of the leaves increase in the similar pattern on different fertilization modes.The fertilization has significant effects on them compared with the non-fertilization.The three indicators have little changes on the middle and higher levels.The two different fertilization modes have significant difference in the low fertilization level.It can be concluded that in low ratio of N and P the production increases with the fertilization level and the N is the limitting factor.While in the high ratio of N and P the production increases at first and decreases,the P becomes the limiting factor.To get high production the fertilization levels should be on the middle level on two different fertilization modes from the economic prospect.The study is to provide theoretical guidance for the proper fertilization of the maize in Three Gorges Region.