| The 2nd International Forum on Salinization Issues pointed out that the current threat of farmland soil salinization mainly comes from the overlapping effects of irrigation water and climate change,and it was especially necessary to strengthen research on climate change adaptation strategies in salinized areas.In order to further clarify and quantify the effects of climate warming and irrigation on the changes of water and salt in saline-alkali soil and the migration of salt ions at the soil-plant interface in the Ningxia Yellow River Irrigation District.In this experiment,the far-infrared radiator was used to increase the atmospheric temperature to simulate climate warming,and three warming levels(no warming,1.5℃ warming,and 2℃ warming)and three irrigation levels(irrigation volume did not increase,The irrigation amount was increased by 10%and the irrigation amount was increased by 20%),which were completely combined into 9 treatments.Through the analysis of soil water content,total salt,salt ion and spring wheat plant salt ion content in each soil layer,it provides a theoretical reference for coping with climate change and soil salinization prevention and control.The main findings of this paper are as follows:1.The influence of temperature increase and irrigation amount on soil water content is mainly in the 0～30cm soil layer.Warming led to a decrease in soil water content,and increased irrigation led to an increase in soil water content.Warming of 1.5 and 2℃ significantly decreased soil water content of 0-10,10-20,and 20-30 cm by 0.6%-67.6%,0.9%-38.9%,and 6.9%-10.3%,respectively;irrigation amount increased by 10%and 20%,respectively.%significantly increased the soil water content of 0～10,10～20,20～30cm by 1.2%～147.1%,1.5%～82.1%and 8.1%～14.1%,respectively.2.The influence of temperature increase and irrigation amount on soil pH value and total salt content is mainly in the 0～30cm soil layer.Warming led to an increase in soil pH and total salt content;increasing irrigation amount decreased soil pH and total salt content.The temperature increase of 1.5 and 2℃ increased the pH value of 0～30cm soil by 0.07～0.14,and the total salt content increased by 0.06～0.24g/kg;the increase of irrigation amount of 10%and 20%decreased the pH value of 0～30cm soil by 0.06～0.09,the total salt content decreased by 0.05～0.26g/kg.3.The influence of temperature increase and irrigation amount on soil salt ion content is mainly in 0～30cm soil layer.Warming led to the increase of soil Ca2+,Na+,SO42-,Mg2+,CI-content in different degrees,and the increase of irrigation amount decreased soil Ca2+,Na+,SO42-,CI" content to different degrees,but HC03-content did not change significantly.The contents of soil Ca2+,Na+,SO42-increased by 0.01～0.17,0.01～0.16,0.01～0.05g/kg with the temperature increase of 1.5 and 2℃,respectively;the increase of irrigation amount of 10%and 20%increased the contents of soil Ca2+,Na+,SO42Respectively decreased by 0.01～0.06,0.04～0.20,0.01～0.04 g/kg.The soil Mg2+ content increased when the temperature was increased by 1.5 and 2℃,and was less affected by the amount of irrigation.The contents of soil CI-and HCO3-did not show significant changes,and were basically not affected by warming and irrigation.4.Warming leads to a decrease in the absorption and accumulation of K+ and Mg2+ in wheat plants,and an increase in the absorption and accumulation of Na+,S,and Ca2+;increasing the amount of irrigation increases the absorption and accumulation of K+and Mg2+ in wheat plants,while the absorption and accumulation of Na+,S,and Ca2+ decreases.;CI-absorption and accumulation did not change significantly.The absorption and accumulation of K+and Mg2+ in plants decreased by 2.5%-17.5%and 2.3%-10.6%when the temperature was increased by 1.5 and 2℃,respectively,and increased by 1.8%-24.9%and 7.5%-13.5%when the irrigation amount increased by 10%and 20%,.Na+and S absorption and accumulation increased by 18.8%-54.9%and 10.6%-24.4%when the temperature increased by 1.5 and 2℃,respectively,and decreased by 5.6%～29.9%and 0.8%-15.5%when the irrigation amount was increased by 10%and 20%.The absorption and accumulation of Ca2+increased by 12.4%-28.8%when the temperature was increased by 1.5 and 2℃,which were not affected by the amount of irrigation;the absorption and accumulation of CI-did not change significantly,and were not affected by the increase.The effect of mild irrigation.5.The absorption and accumulation of K+and Mg2+ in plants were significantly negatively correlated with the content of soil total salt and Mg2+;the absorption and accumulation of Ca2+and CIin plants had no significant correlation with the content of total soil salt and other salt ionomers;the absorption and accumulation of Na+ and S in plants The amount of soil Salt,Na+,SO42-content was significantly positively correlated.In conclusion,the temperature increase of 1.5 and 2℃ decreased soil water content and increased salt content;an increase of 10%and 20%of irrigation amount increased soil water content and decreased salt content,and an increase of 10%of irrigation amount could basically eliminate temperature.The increase causes a decrease in soil moisture,an increase in salinity and pH,and adverse effects on crop growth. |
