Spatial distribution of winter wheat root in soil under field condition in North China plain

Development of wheat root system in soil under field condition is an indispensable parameter, which could quantify accurately the reaction between vegetation and climate and provide references for scientific management of wheat production and development of water saving agriculture. Using a large root monitoring system at Gucheng ecological environment and agriculturual observation station, roots of wheat species “NO.22Jimai” were observated, including root length, root length density, root dry-weight density and root diameter. Vertical distributions of roots were analyzed. The results indicate that the root length and root dry-weight decrease with increase of soil depth. There are four different treatments in this experiment, i.e. severe drought, light/middle drought, suitable moisture and heavy moisture. Correlation coefficients of root lengths between four treatments and a control experiment are 0.91, 0.29, 0.90 and 0.86 respectively. Root growth can be affected by soil moisture conditions. It is conducive to increase the amount of wheat root in upper layers and root biomass under sufficient soil water condition, while the inverse is true under water stress. Light drought is favorable to extend wheat roots in middle/lower layer soil. Root length density and root dry-weight density have a significant positive linear correlation in various soil depths. Root diameter decreases with increase of soil depth.