Influence of water and N fertilizer regulation on root growth characteristics of summer maize

Soil column simulated experiment was carried out to study the influence of different adjustment measures of water and nitrogen on root growth characteristics of summer maize,and the correlation between root parameters and grain yield,The results showed that water affected more significantly dry weight,activity and surface area of root than N fertilizer.The dry weight of root decreased with the increase of soil depth,especially in 0～10 cm soil layer.The root length density was large in 0～20 cm soil layer,and it firstly increased and then decreased with the increase of soil depth.With the increasing of N application rate,the root dry weight and root length density decreased,while the ratio of root to shoot tended to decrease.N fertilizer could improve the root activity of maize.According to the correlation analysis,the root dry weight,root length density,root surface area and root activity were correlated very significantly with the grain yield and the dry matter mass above the ground;the ratio of root to shoot was correlated only with the dry matter mass above the ground;the root surface area was correlated very significantly with the root activity;the root activity and nitrogen absorption ability played an important role in the growth and grain formation of maize,and there was a significant correlation between them.