Response of senescence characteristics for maize leaves under different plastic mulching and using patterns in oasis irrigation areas of northwestern China
In the conventional corn production system of the northwest oasis irrigation area,the extensive use of plastic mulching has resulted in severe environmental pollution,and maize leaves often experience premature senescence under extreme high tem-peratures.This study investigates the feasibility of delaying maize leaf senescence and increasing yield through the implementa-tion of no-tillage with plastic re-mulching technology.The goal is to offer theoretical support for developing efficient maize production techniques with reduced plastic mulching usage in the northwest oasis irrigation area.In 2013,we established three treatments:no-tillage with plastic re-mulching (NTP),no-tillage in autumn with new plastic mulching in spring (RTP),and con-ventional tillage with annual new plastic mulching (CTP,as the control).From 2021 to 2023,we examined the effects of these treatments on maize photosynthetic performance,stay-green characteristics,cellular antioxidant enzyme activities,and osmotic regulatory substance contents.The results demonstrated that NTP and RTP effectively regulated the dynamic balance between photosynthetic activity and leaf stay-green performance during the maize growing period.These treatments maintained higher leaf area index (LAI),photosynthetic potential (LAD),stay-green characteristics (SG),and relative chlorophyll content (SPAD) in the late growth stage,which contributed to delayed leaf senescence.Compared with CTP,NTP increased LAI,LAD,SG,and SPAD by 15.1％-16.1％,14.8％-15.5％,7.2％-9.2％,and 11.3％-11.7％,respectively,75-120 days after emergence.Similarly,RTP in-creased these parameters by 12.4％-13.0％,11.5％-12.4％,10.0％-17.6％,and 6.0％-6.7％,respectively.Additionally,fitting the green leaf area per plant revealed that NTP and RTP delayed leaf senescence by 5.8-7.0 days and 6.2-7.7 days,respectively,compared to CTP.This delay in senescence was attributed to enhanced antioxidant capacity and improved osmotic regulation in maize leaves during the bell stage and grain-filling stage.NTP exhibited superior effects,with increases in antioxidant enzyme activities (SOD,POD,CAT,and APX) of 17.6％-20.0％,28.4％-34.4％,6.7％-8.4％,and 8.3％-10.9％,respectively,compared to CTP.Likewise,RTP increased these enzyme activities by 11.3％-11.7％,16.9％-18.2％,4.4％-6.1％,and 5.8％-7.7％,respectively.Moreover,relative to CTP,soluble protein and proline contents in NTP and RTP increased by 35.9％-43.9％ and 29.5％-31.8％,and 20.7％-31.7％ and 17.4％-20.4％,respectively,while malondialdehyde content decreased by 26.0％-27.8％ and 17.5％-25.9％,respectively.Consequently,NTP increased maize grain yield by 5.2％-6.0％ in comparison to CTP.In conclusion,no-tillage with plastic re-mulching is a viable practice for delaying maize leaf senescence and increasing yield,while simultaneously reducing resource inputs in the northwestern oasis irrigation areas.
万方数据
维普
