Research On Regulation Of Soil Water-salt Transport Under Subsurface Drip Irrigation In Cotton Field In Xinjiang

Abstract: The regulation of water-salt transport under subsurface drip irrigation from both indoor and field experiments is researched in this paper. At lab, in the case of different flow and first primary moisture, variation penetrate interval, the subsurface drip line infiltration experiment which water constant is usual for 6.64L viewed in the homogenous soil under subsurface drip irrigation the area near trickle emitter soil moisture rate is highest, then reduce around wetting front, in vertical the soil moisture rate and salinity distributing is similar with a parabola, the salinity near trickle emitter is lowest and then increase surround wetting front gradually , the soil moisture rate and salinity distributing are minus correlation , the distance of wetting front transport is related drip time with a nonlinear correlation, the soil moisture rate and salinity distributing are related the distance away from trickle emitter with a nonlinear function correlation. The flow and irrigation frequency are more, draffy salt effect is better.In the field combine with Xinjiang Bingtuan cotton subsurface drip irrigation demonstration field, by the way of using tension meter, TDR and sampling 1m depth layer soil, moisture rate and electric conductivity, which in each section of cotton procreate, irrigation former or after and different distance away from drip tube are measured and viewed:1. Soil water-salt uprightness vertical movement occurs mostly in evaporation, infiltration and root system suction three cases, after irrigation the soil moisture rate near drip tube is higher, which is far from drip tube is lower; The moisture rate of soil above drip tube is higher than which under the drip tube, in vertical soil moisture is related soil depth with a nonlinear function. In horizontal salt of soil which near the line is in the case of draffy salt, and the one which is far from line is in the case of accumulate salt, it move to the middle of drip tubes in horizontal, and in vertical it move to both surface and deep layer.2. In the cotton all procreate period, the soil salt is higher in seedlings period, lower in boll period, and become higher in flower period. At last, the salt gather in the area between drip tubes, salinity of cultivation layer become lower, it moves to deep layer, and gather in the area under 80cm.3. Subsurface drip irrigation water-salt transport influent cotton biology character and yield, whether biology yield or economy yield is higher than drip under film.