Study On Temporal And Spatial Dynamic Distribution Of Cotton Root And Effectivity Of Root Exudates In The Cotton-wheat Inter-cropping System

Wheat-cotton double high yield complicated farming system, which realized the tight usage of light and quantity of heat, was an important productive mode in chief cotton planting regions of China. For the reason of competition between wheat and cotton, cotton seedlings grew weakly in the early stage that result in debase quality of cotton fiber. In this paper we used Meimian 33B and Yumai 34 as materials, for the sake of studying which make the weak growing of cotton seedling three aspects was determined, included effect of wheat root exudates on cotton seedling's growth, effect of cotton root exudates on fertilizer of soil, temporal and spatial dynamic distribution of cotton root.1. Study on temporal and spatial dynamic distribution of cotton root under condition of cotton-wheat cropping system.In the symbiotic period of wheat-cotton under the condition of high yielding cotton-wheat inter-cropping system, contrasting to the monoculture cotton (CK), three treatment i.e. wheat-cotton double cropping system in which the roots of wheat and cotton mixed naturally (PI), wheat-cotton inter-cropping system in which the roots of wheat and cotton separated with nylon net (PII), and wheat-cotton inter-cropping system in which the roots of wheat and cotton separated with plastic film (PHI), the temporal and spatial dynamic distribution of cotton root in cotton-wheat Composite root system was studied with drill and DTSCAN scanner. The results showed that the root length and root surface area and root average diameter of cotton in all treatment and single plant cotton had a single peak curve of changes during the whole growth stage, in the late period of growth stage the decline speed of the root length and root area in PI was lower than CK. The distance between wheat and cotton in wheat-cotton inter-cropping system had significant effect to cotton root, in detail, the growth of cotton root at the point of 12.5cm was better than the point at 21.25cm from cotton plant, PII was better than PHI also.2. Research of effect of root exudates in wheat-cotton inter-corpping system.(1) Effect of Bt cotton root exudates on available soil nutrition, microorganism...