Effects of under mulch drip irrigation on water and salt transport and nitrate nitrogen leaching losses in spring-irrigated saline soils
To investigate the effects of different drip spring irrigation amounts on the transport and ecological effects of saline nitrogen in saline soils.A study on drip spring irrigation was carried out in Tiemenguan,Xinjiang in 2023.Cotton planting pattern was one film and three tapes in 6 rows with 66 cm+10 cm spacing.Five irrigation amounts were set up:75.0,112.5,150.0,187.5 mm and 225.0 mm(the local conventional spring irrigation amount),which were expressed as DW1,DW2,DW3,DW4 and DW5,respectively.Characteristic distribution of moisture,salinity and nitrate-nitrogen in different soil depths were analyzed.The results showed that compared with the pre-watering period,the soil water content of 0-40 cm increased significantly in all treatments after 30 d of watering,and the water was mainly distributed from the middle of the wide rows to the middle of the narrow rows.There was no significant difference in the ratio of incremental soil water storage from 0-100 cm as a percentage of irrigation between the DW3 and DW4 treatments,while the DW5 treatment was the lowest at 29.61%.Soil salinity distribution was similar in DW3,DW4 and DW5 treatments,with the DW4 treatment having the largest range of soil salinity desalination zones from 0-40 cm,and a significant reduction in soil salinity content from 80 to 100 cm.Soil salinity increased in the 40-60 cm soil layer of the DW3 and DW5 treatments in the range between the membranes to the middle of the narrow rows.DW4 treatment had the highest desalination rate from 0 to 40 cm,and the desalination rate from 0-20 cm was significantly increased by 148.9%,37.1%,27.5%,and 36.6%in the DW4 treatment compared with the DW1,DW2,DW3,and DW5 treatments,respectively.There was no significant difference in soil nitrate nitrogen leaching between the DW3 and DW4 treatments,which were significantly reduced by 35.5%and 26.6%,respectively,compared with the DW5 treatment.Cotton seedling emergence was not significantly different among DW3,DW4 and DW5 treatments,and was increased by 4.5%-8.8%compared with that of DW1 and DW2 treatments.DW4 treatment had the highest cotton yield,which was significantly increased by 29.2%,13.4%,6.1%and 5.8%compared with DW1,DW2,DW3 and DW5 treatments,respectively.The study showed that using spring irrigation by drip irrigation under the membrane,the 187.5 mm irrigation quota increased the moisture content of the soil till layer,improved the desalination rate of 0-40 cm soil,reduced the amount of soil nitrate nitrogen leaching,the cotton seedling emergence rate reached 90%,and the yield increased by 5.8%,which is a water-saving and high-efficiency,and the low risk of nitrogen leaching from the farmland to non-point source pollution in the spring irrigation quota.
drip spring irrigationsaline soilsoil water and salt transportsalt distributionnitrate nitrogen leaching loss
万方数据
维普
