Effect Of Reducing Nitrogen And Increasing Yield Of Cucumber In Greenhouse Under Aerated Irrigation

Cucumber is one of the main vegetable crops grown in solar greenhouses.In recent years,the area of cucumber cultivation in facilities is getting larger and larger.However,in order to continuously increase the yield of crops cultivated in facilities,farmers often take measures such as excessive irrigation and excessive nitrogen application.Various economic and environmental problems have arisen,such as soil acidification or salinization,and inefficient waste and utilization of fertilizers.This severely limits the economic benefits and sustainable development capacity of facility agriculture.In addition,after excessive irrigation,soil moisture saturation in the root area will inevitably result in anoxic condition of the root system,which will further reduce the utilization efficiency of water and fertilizer of facility vegetables.Aerated irrigation can improve root ventilation and regulate soil microbial activity and nutrient availability.In order to reveal the effect of aerated irrigation on nitrogen utilization efficiency and vegetable yield,the experiment was carried out in Yangling greenhouse in shaanxi province,with cucumber?Qiande 777?as the experimental crop.Setting up two irrigation methods?AI and drip irrigation?and three N application rates(0,240,360 kg ha^-1).Measurement indicators include cucumber nitrogen use efficiency,dry matter accumulation,soil root zone environment and yield.The main findings are as follows:?1?Compared with non-aerated underground drip irrigation,soil O₂ content increased by2.0%under aerated irrigation,soil temperature and soil aeration porosity also slightly increased under AI,soil respiration increased by 25.2%significantly?P<0.05?.When the amount of nitrogen applied was 240 kg ha^-1,the effect of aerated irrigation on soil respiration,soil temperature,aerated porosity,and oxygen were all optimal.The soil environment in the cucumber root zone was optimal.?2?As compared to drip irrigation,the partial factor productivity of applied N?PFP?under AI increased 28.95%and 18.53%at 240 and 360 kg N ha^-1 nitrogen levels,cucumber yield under AI was 29.0%and 18.6%higher than that with drip irrigation condition.Aerated irrigation significantly improves the nitrogen use efficiency of cucumber?P<0.05?.?3?Compared with the non-aerated underground drip irrigation,the stomatal conductance of cucumber leaves increased by 19.1%and the net photosynthetic rate increased by 14.1%?P<0.05?.Aerated irrigation improves the photosynthetic capacity of cucumber leaves,and the dry matter accumulation and harvest index of cucumbers are improved.The cucumber with nitrogen application of 240 kg ha^-1?I1N2?had the highest yield,the highest cucumber yield was 72266 kg ha^-1,which was significantly higher than other treatments?P<0.05?.To further reduce the amount of nitrogen fertilizer application,while increase greenhouse cucumber yield and economic benefits,AI along with N application of 240 kg ha^-1 is recommended in Northwest China.