Effects Of Ridge-furrow Plastic-film Mulching Planting And Nitrogen Application Rate On Lodging Resistance And Water And Nitrogen Use Efficiency Of Spring Maize

Spring maize is one of the most widely planted crops in the Loess Plateau,and water limitation and low nitrogen availability due to water scarcity are the key reasons for its low productivity.Ridge-furrow plastic-film mulching planting is an important planting method in the Loess Plateau.This planting method plays a significant role in rain collection,thermal insulation,and moisture preservation.Compared with traditional flat cropping,it significantly improves crop yield and water use efficiency.The application of nitrogen fertilizer is a common measure to improve soil nitrogen availability in this area.The improvement of soil water availability will promote the utilization of nitrogen by crops.Therefore,the combination of mulching and nitrogen fertilizer application in furrows will further improve crop productivity in this area.However,the water and fertilizer environment Improvement is often accompanied by a greater risk of lodging.Based on this,this study took the commonly used spring maize variety"Xianyu 335"in the Loess Plateau as the research object,adopted a two-factor randomized block design,and set up two planting methods:（P1（flat cropping）,P2（ridge-furrow plastic-film mulching planting））;two nitrogen fertilizer application rates:(N1(180 kg·ha^-1),(N2(300 kg·ha^-1)),to explore the effects of ridge-furrow plastic-film mulching planting and nitrogen application rates on soil water and heat,spring maize stalk and The effects of root lodging,yield and water and nitrogen use efficiency were analyzed,In-depth analysis of the response of maize lodging resistance to ridge-furrow plastic-film mulching planting and nitrogen application rates,which provided reference and theoretical support for the rationalization of field management practices for rainfed spring maize production on the Loess Plateau.The main conclusions are as follows:1.In 2020 and 2021,compared with flat planting,the soil temperature under ridge-furrow plastic-film mulching planting increased by 1.15°C and 0.82°C,respectively.The soil water content at 0-40 cm increased by 9.65%and 14.93%,respectively.Compared with 180 kg·ha^-1 nitrogen application,the soil water content at 0-40 cm under 300 kg·ha^-1 nitrogen application increased by 2.65%and 7.29%,respectively.2.In 2020 and 2021,compared with flat planting,the plant height of spring maize under ridge-furrow plastic-film mulching planting increased by 17.29%and 13.47%,the center of gravity increased by 9.87%and 10.41%,the ear height increased by 17.81%and 13.31%,the internode length of the third stem at the base increased by 51.63%and 52.25%,and the aboveground fresh weight increased by 44.36%and 39.38%,respectively.Compared with 180kg·ha^-1 nitrogen application rate,the plant height of spring maize under 300 kg·ha^-1 nitrogen application rate increased by 6.46%and 2.96%,the height of center of gravity increased by7.42%and 7.87%,the fresh weight of aboveground increased by 16.37% and 12.92%,the ear height increased by 7.25%and 3.10%,and the length of the third stem internode at the base increased by 12.02%and 12.68%.Correlation analysis showed that plant height,center of gravity height,basal internode length of the third stem and aboveground fresh weight were significantly positively correlated with the lodging rate of spring maize.Ridge-furrow plastic-film mulching planting and 300 kg·ha^-1 nitrogen application increased the lodging risk of spring maize.3.In 2020 and 2021,compared with flat planting,ridge-furrow plastic-film mulching planting increased the yield of spring maize by 2.76 t·ha^-1 and 2.9 t·ha^-1,respectively,by increasing the number of grains per ear,100-grain weight and the number of ears per unit area.Compared with flat planting,ridge-furrow plastic-film mulching planting significantly increased nitrogen accumulation by 18.62%and 33.89%,and increased grain nitrogen translocation to stem,water use efficiency by 33.53%and 28.42%.Compared with 180 kg·ha^-1 nitrogen application rate,total nitrogen accumulation increased by 9.51%and 11.63%under300 kg·ha^-1 nitrogen application rate,and water use efficiency increased by 10.07% and 5.91%.