Effect of different manure application rates on nutrition content and distribution in maize

A consecutive 5-year (2002~2006) field trial in the lower reaches of Liaohe River was conducted. The study investigated the effect of manure application rates on nutrient content, distribution in plant and amount in each harvested unit grain of maize. The results show that manure is an important factor in stable and high maize yield. The content of N and P in grain and stalk increases with increasing rate of manure application. K content in stalk shows the same tendency, but in grain is unrelated to the amount of applied manure. The results also indicate that maize yield is directly correlated with the ratios of N and P content in grain to stalk, and not K. Increasing nutrient consumption to produce unit grains with increased manure application implies that N, P and K are lavishly absorbed by maize crops.