Response Of Salt Tolerant Crop Growth And Salinity To Different Iirrigation Quota Uunder Subsurface Pipe Drainage

As an improvement measure of saline alkali soil,irrigation and salt pressing combined with subsurface drainage can improve the desalination effect,but at the same time,it will also cause the salt returning phenomenon of soil plough layer gradually with the growth period caused by the rise of groundwater.Different salt tolerant crops have different effects on the properties of saline alkali soil.In order to study the effect of increasing different irrigation amount in jointing period under subsurface drainage,different salt tolerant crops have different effects on saline alkali soil In response to soil water salt and soil pH,three treatments were designed,namely,no irrigation control treatment(“1”),water-saving irrigation treatment(“2”),traditional irrigation treatment(“3”).Oil sunflower(YK1?YK2?YK3),Pace Setter(GD1?GD2?GD3)and cyperus esculentus(YS1?YS2?YS3)were used as salt tolerant crops.Through monitoring soil EC,pH and water content,the effects of different salt tolerant crops in subsurface drainage combined with traditional irrigation were analyzed The correlation between water-saving irrigation and soil moisture,salinity and acid-base degree of severe saline alkali soil.The results showed that:(1)After YK2 and YK3 are irrigated,0-20 cm soil desalination is obvious,and the EC values are 30% and 45% of YK1 respectively.Under the condition of concealed drainage,the traditional irrigation amount during the growth period of Pace Setter is beneficial to the desalination effect of 0-60 cm soil,and the desalination effect reaches 18%.Planting cyperus esculentus under the condition of concealed drainage,the desalination effect of the soil in the 0-20 cm and 80-100 cm soil layer under water-saving irrigation is obviously27%?36%,and the desalination effect of traditional irrigation is obviously 60%?80%.(2)According to the analysis of the dynamic change of the average soil moisture content of 0-40 cm,the groundwater level decreases under the action of the concealed pipe drainage,and the soil moisture content is also lower.Because the oil sunflower control treatment has high soil salt content and low soil solute potential,the effective use of soil water is low,causing oil sunflowers to fail to grow normally and crop transpiration is small,so YK1 has a high water content.,resulting in failure to grow normally,and water-saving irrigation treatment will not be able to grow normally during the growth period.As crops require water,the soil has a certain amount of water stress,the traditional irrigation treatment is not subjected to water stress before the budding stage,and it is in a state of water stress from the flowering stage to the maturity stage.Pace Setter and cyperus esculentus are affected by salinity in water saving,and crops require the most water for traditional irrigation.(3)Compared with the water-saving irrigation in the early stage of the growth period,the oil sunflower finally reduced the 0-40 cm soil de-alkalization gradually by 2.55%,while the traditional irrigation will cause the phenomenon of soil alkalization to increase the pH by 7.66%.Planting Pace Setter irrigation is beneficial to reduce the pH of the 0-40 cm soil layer.The pH of water-saving irrigation treatmen is reduced by 0.62% to 5.63%,and traditional irrigation treatment is reduced by 0.74% to 5.97%.Compared with water-saving irrigation,traditional irrigation is more beneficial The pH of the soil at the early stage of heading.Compared with water-saving irrigation,the traditional irrigation of cyperus esculentus is more conducive to reducing the pH of the soil at 0-40 cm.The pH of the YS2 and YS3 treatments in the maturity period is reduced by 0.96% and 2.18%.(4)There is a negative correlation between the growth of oil sunflower and soil pH,which is greater than the effect of soil moisture and EC on pH,and this correlation can be significantly improved after irrigation at jointing stage.Pace Setter the effect of soil water content was greater than other factors.After irrigation at jointing stage,the effect of cyperus esculentus on soil salinity was greater than that of pH and water content,and the effect of water content on soil pH was positive correlation.