Effects Of Different Modifiers And Tillage Practices On Improvement Of Saline-alkali Land And Crop Growth

soil salinization has become the main obstacle factor for the process of efficient utilization of land resources and improvement of ecological environment.It is an urgent problem to take effective measures to improve saline-alkali wasteland.Through field experiment with drip irrigation,the effects of different modifier on soil physical and chemical properties and crop growth under conventional ridge and smashing Ridge Tillage were studied.The suitable improvement measures in severe saline-alkali land were determined,which provide theoretical basis for the treatment of saline-alkali land,efficient utilization of water resources and land development in Hetao Irrigation area.The conclusions are as follows:(1)Different improvement measures have an impact on the soil physical and chemical properties,which can reduce the bulk density of soil and facilitate infiltration of water.Compared with CK,bulk density decreased by 2.33?4.61%in 2017 and 3.38?8.37%in 2018.The soil moisture holding capacity and surface temperature of the soil can be improved by applying modifiers,which provide good root water environment for crops;Meanwhile,Different improvement measures can reduce soil salinity,which decreased by 35.23?57.88%in 2017,decreased by 14.21?33.97%in 2018.The effect on pH was not significant.(2)Modifiers in soil have adsorbability,which make NH4+-N transform into NO3--N,the content of nitrate nitrogen in soil increased by 136%and 122%in biochar treatment and straw mulching,the efficiency of nitrogen was increased.The content of soil organic matter,alkali-hydrolyzed N,available P and available K were increased by modifiers.The soil nutrient in 2018 more than that in 2017,smashing ridge tillage had a significant positive effect on improving the fertility of saline soil.(3)Different improvement measures can promote the growth and development of sunflower and grain yield.Compared with CK,the yield was increased by 12.50%?78.75%.The crop yield as follows:biochar>desulphurization gypsum>straw deep mulching>desulfurization gypsum+organic fertilizer>straw surface mulching.(4)In a comprehensive consideration,applying modifier under smashing ridge tillage had significant positive effects on improving soil physical and chemical properties,enhancing soil fertility and increasing yield.Biochar treatment had the best effect on soil improvement,the next is desulphurization and straw deep mulching.