Root-Water-Uptake Rate And Root Length Density Distributions Of Winter Wheat At Seedling Stage Under Subirrigation

Studying on root-water-uptake and developing of root-water-uptake model are challenging problem for soil physics and plant physiology scientists around the world. The accuracy of root-uptake-water model depends on the relationship of root-water-uptake rate and root length density to a certain extent. In order to study the relationship between the maximum root-water-uptake rate and the root length density, the distribution of root-water-uptake rate, and the distribution of root length density, Four winter wheat soil column cultivation experiments under different methods of water supply (traditional irrigation and subirrigation) and different water treatments (traditional irrigation A1. traditional irrigation A2. subirrigation B1, subirrigation B2) were conducted.In the first part of this thesis, the soil surface evaporation (E) under different water supply methods has been compared and analyzed. It indicates that E of subirrigation is far from lower than traditional irrigation.Secondly, the soil water content and root length density distribution under different water treatments have been analyzed. It shows that the distribution trend of root length density is independent of the water supply methods while the relative distribution in soil makes a difference with water supply method and soil water content.Root-water-uptake rate under different water supply methods and different water treatments has been calculated using the inverse method (Zuo and Zhang, 2002).The relationship between the maximum root-water-uptake rate (without water stress) and the root length density has been analyzed with statistics software. It approves the scientific hypothesis of Feddes etal (1978) and Prasad (1988) that the root length density is linear direct proportion to root-water-uptake rate.At last, we compare and analyze WUE under different water supply methods and different water treatments. It indicates WUE of subirrigation is higher than traditional irrigation, so subirrigation is a water-saving irrigation method.