Study On The Irrigation System And Soil Environmental Effects Of The Typical Crop Under Mulched Drip Irrigation W Ith Saline Water-Yellow Rive Supplementary Irrigation In Hetao Irrigation District Of Inner Mongolia

With the rapid development of economy and society,there is a shortage of water resources in Hetao district,contradictions of water for agricultural,industrial and ecological have become increasingly prominent,it has become a general trend to strive developing efficient water-saving agriculture and exploit new supply of irrigation.Based on the field experiment in Wulate irrigation area of Hetao irrigation district,I have studied the effects of soil environment after spring irrigation,water requirement of typical crops under mulched drip irrigation with saline water—Yellow River supplementary irrigation,water-soil environmental effect,growth and yield of typical crops,soil salt accumulation,economic and environmental benefits,a recommended irrigation system is put forward as a theoretical basis for vigorously expanding the technology of mulched drip irrigation with saline water.The main conclusions as follovw:(1)In order to improve the soil moisture contant and soil salt condition,it is suitable to irrigate moderate saline-alkali soil with the Yellow River's water every other year inthe next spring,the appropriate irrigation quota is 2250m3·hm-2.(2)The higher limit of mulched drip irrigation with saline water and the higher frequence of supplementary irrigation with Yellow River's water,the higher irrigation quota is,the higher consumption of typical crops,the bigger the crop coefficient is.(3)Changes of soil moisture and salinity are concentrated in 0?80cm and 0?100cm,wetted body's shape of mulched drip irrigation on sectional elevation of emitter which was perpendicular to the drip irrigation belt was approximated to semi-ellipsoidal.Affected by the infiltration of irrigation water,soil salt in 0?40cm inside of mulch move from inside to outside of the film and move from surface to the deep,affected by the evaporation of surface soil,soil salt inside of mulch in 20?100cm move to 0?20cm,The higher limit of mulched drip irrigation with saline water and the higher frequence of supplementary irrigation with Yellow River's water,the higher soil water content is,more fully the salt is leaching,the higher soil salt on surface outside of the mulch is.(4)The higher limit of mulched drip irrigation with saline water,the bigger stem diameter,height and leaf area is,the earlier the maximum value of sunflower leaf area appears,the slower the sunflower leaf died,maize yield under mulched drip irrigation drops less when compared with the traditional Yellow River's water irrigation.(5)Soil salt of maize and sunflower field accumulate mainly in 40?80cm and 40?100cm respectively,layers of maize and sunflower treatments which field is irrigated yearly with Yellow-River's water in spring is salt accumulating,surface 10cm of maize and sunflower treatments which field is irrigated every other year with Yellow-River's water in spring is salt desalting,The higher limit of mulched drip irrigation with saline water,the less of salt accumulate in layers of maize and sunflower field,the higher frequence of supplementary irrigation with Yellow River's water,the less salt accumulated in 0?100cm.Soil salt of sunflower field which irrigation limit is-30kPa accumulates least at the same frequence of spring irrigation.(6)Compared with the surface irrigation,maize and sunflower mulched drip irrigation with saline water—supplementary irrigation with water from Yellow River save fertilizer 51%and 48%resceptively,reduce the use of pesticides,it is beneficial to protect the ecological environment and improve the soil condition,The lower irrigation limit of mulched drip irrigation with saline water and the lower frequence of supplementary irrigation with Yellow River's water,the higher rate of water saving.Water saving rate of maize is higher than sunflower under the same irrigation system,income of maize and sunflower under spring irrigation every other year increased largest.Comprehensive consideration of water saving,profit increasing and salt controlling,the recommended irrigation system of maize and sunflower is:supplementary irrigation with water from Yellow River is conducted in noncrops growing season every other year in mid April,irrigation quota is 2250 m3·hm-2,saline water is irrigated 14 times in growing period of maize,the irrigation quota is 3300 m3·hm-2;saline water is irrigated 10 times in growing period of sunflower,the irrigation quota is 2745 m3·hm-2.