Study On The Effect Of Solar Subsurface Pipe Drainage On Saline-alkali Land Improvement And Crop Water Production Efficienty In Huinong District

There are more than 3000 mu of crops cultivated in the experimental area of Miaotai Village,Huinong District,Ningxia.The sunshine time is long,and the salinization phenomenon is serious in the experimental area.in view of the problem of small discharge and long drainage cycle of solar dark pipe in Miaotai Township,we should not only improve saline-alkali land,but also save water for irrigation,by contrast test,under the same conditions of cultivation,soil,fertilization,pest control and irrigation,set up solar electrical energy generation + subsurface pipe drainage + irrigation area for treatment,no subsurface pipe drainage + irrigation area as control,to observe the underground water table depth,soil total salt content,soil moisture content,groundwater salinity,crop photosynthesis,growth characteristics,crop yield,and so on,the variation law and relationship of these indexes were analyzed,and the suitable irrigation and drainage systems of maize and oil sunflower were established under the condition of sola:r power dark pipe drainage,it provides theoretical basis and technical support for comprehensive control of saline-alkali land and popularization of water-saving irrigation in Yinbei of Ningxia,the main findings are as follows:1.Through the analysis of the changes of the observed indexes in the treatment area and the control area,it was concluded that the desalination effect in the treatment area was better than that in the control area,the yield increased and the water use efficiency increased.(1)Through the analysis of groundwater table depth,it is concluded that:In the whole growth period of corn and oil sunflower,the buried depth of groundwater level in treatment area increased by 13.57%and 8.87%respectively,and the buried depth of groundwater level in the control area was reduced by 2.82%and 2.96%.,respectively.(2)Through the analysis of groundwater salinity,it was concluded that the salinity of groundwater decreased by 21.79%and 15.38%during the whole growth period of maize and oil sunflower,and the salinity of groundwater increased by 5.7%and 18.75%respectively in the control area.(3)Through the analysis of the total salt content of the soil,it is concluded that:During the whole growth period of maize and sunflower,the total salt content of soil decreased by 11.11%and 34.96%,respectively,and the total salt content of soil decreased by 3.60%and 7.46%in the control area,respectively.(4)The yield analysis showed that the yield of maize and oil sunflower increased by 17.46%and 55.21%respectively in the whole growth period of maize and oil sunflower.(5)Through the analysis of water use efficiency,it is concluded that:During the whole growth period of maize and oil sunflower,the productivity of irrigation water in the treated area increased by 17.48%and 61.67%than that in the control area,respectively.The water production efficiency in the treatment area was increased by 31.81%and 62.96%than that in the control area,respectively.Leaf Wue in the treatment area was 12.11%and 7.96%lower than that in the control area,respectively.2.Through the analysis of the observation indexes,it is concluded that the suitable local ones meet both irrigation and drainage requirements solar electrical enery generation + subsurface pipce drainage Irrigation and drainage system.In maize jointing and oil sunflower budding increased irrigation time and irrigation amount.In the year of high water,from April to September,winter irrigation for November 10 to December 10 for 7 months continuous drainage,drainage quota is controlled in 58.8m3/mu.In the normal and dry years,the drainage rate was controlled at 25.2m3/mu during the peak period of back salt drainage in April and June in spring,and the drainage rate was kept at 8.4m3/mu during the peak period of salt return in September in autumn.The winter irrigation lasted from November 10 to December 10.Drainage quota is controlled in 8.4m3/mu.3.By DPS fitting,the linear relationship between total salt content of soil and salinity of groundwater was obtained,that is,the linear relationship between maize and oil sunflower treatment area was y=0.13071x+0.52171 and y=0.151923x+0.472404.(where x represents salinity and y represents total salt content in the soil).