Effects Of Different Water And Nitrogen Application On The Grian Yield And Resource Utilization On Spring Maize Under Full Plastic Film Mulching Pattern With Double Ridges In Arid Area

The Loess Plateau is one of the most important spring maize production region in the Northwest China.The distribution of rainfall in this region is extremely uneven,which usually results in a substantial water shortage during crop growth,that severely limits the attainable grain yield of spring maize.Full plastic film mulching pattern with double ridges?FMDR?can maximize the storage of natural rainfall and significantly improve crop yield and water use efficiency?WUE?.Therefore,in this study,field experiments with two years were conducted in 2018 and 2019 at the Changwu Agricultural Research Centre in Shaanxi Province,with the conventional flat planting without mulching(CK:N application rate of 225 kg N ha^-1 but without irrigation)as a control and other three different FMDR treatments,including conventional FMDR treatment?the N and water management were the same as CK?,FMDR plus supplementary irrigation treatment?FMDR+SI?,FMDR plus supplementary irrigation and nitrogen?N?application rate?FMDR+SI+N?..The supplementary irrigation was executed at rate of approximately 60 mm per season under both FMDR+SI and FMDR+SI+N treatments.The additional N application rate was 45 kg N ha^-1 uner FMDR+SI+N treatment.Overall,this study was conducted to determine the effects of different FMDRs on soil microenvironment,crop growth and grain yield of spring maize and resource use efficiencies for water,N and solar radiation.The key results and conclusions in this study were as follows:?1?Full mulching double ridges cultivation can significantly improve the soil hydrothermal conditions of the plough layer in the early growth stage of spring maize,and make the crop emergence time one week earlier than the CK treatment.The effect of full mulching double ridges cultivation on soil temperature is mainly concentrated in the early stage of crop growth.Because the spring maize plants under full mulching double ridges cultivation have a large canopy,which causes a shielding effect on the soil and reduces the solar radiation reaching the ground,so the temperature-increasing benefit of plastic film mulch in the late growth stage of spring maize is weakened until to no significant difference from CK treatment.Full mulching double ridges cultivation can significantly increase the topsoil water content during the entire growth period,increasing the soil water content by 11.9%and 16.7%in the 2018 and 2019 growing seasons,respectively.Compared with CK treatment,full mulching double ridges treatment significantly increased the?-diversity of bacterial communities in rhizosphere soil,but had no significant effect on non-rhizosphere soil.?2?As the growth period progresses,the dry matter accumulation of spring maize ground under full mulching double ridges planting pattern is always significantly higher than that of CK treatment.When reaching the mature stage,the dry matter aboveground of FMDR treatment was 55.2%and 64.3%higher than that of CK treatment in 2018and 2019 respectively,but the difference between FMDR,FMDR+SI and FMDR+SI+N treatment was not significant,indicating additional nitrogen fertilizer and supplemental irrigation can not significantly affect the aboveground biomass of spring maize.Compared with CK treatment,the full mulching double ridges cultivation treatment can significantly increase the yield of spring maize,but the yield difference between the three full mulching double ridges cultivation treatments is not significant,indicating that additional nitrogen fertilizer and supplementary irrigation on the basis of FMDR treatment can not improve spring maize production.Compared with CK treatment,full mulching double ridges cultivation had no significant effect on the content of crude fat,crude starch and amino acids in spring corn.Compared with FMDR+SI treatment,the additional nitrogen fertilizer can significantly increase the crude protein,crude fiber and amino acid content of FMDR+SI+N treatment.?3?Compared with CK treatment,the full mulching double ridges planting treatment can significantly improve the spring maize WUE,which increased by 35.1%and 24.3%in the 2018 and 2019 growing seasons,respectively.Supplemental irrigation increased the water consumption of FMDR+SI and FMDR+SI+N treatments,and reduced FMDR+SI treatment by 7.0%compared to FMDR treatment of WUE.Full mulching double ridges planting cultivation can increase nitrogen accumulation in aboveground plants,especially after tasseling stage.There was no significant difference in nitrogen use efficiency?NUE?between the four different treatments.Compared with CK treatment,the full mulching double ridges planting treatments can significantly increase the radiation interception and radiation use efficiency?RUE?of spring maize.but the application of additional nitrogen fertilizer and supplementary irrigation can not improve the spring maize radiation interception and RUE under full mulching double ridges.Therefore,considering the comprehensive performance of the above three full-film double furrow cultivation modes and their comprehensive performance on resource utilization efficiency,FMDR treatment has low input and high grain yield,and has significantly improved water and nitrogen utilization efficiency and radiation use efficiency.It can be recommended as a water-saving cultivation model with high and stable yield and efficient use of resources in the spring maize planting area of the Loess Plateau or similar climate ecological area.