不同施肥方式对坡耕地土壤水氮运移及玉米生长的影响OA

This study investigated the effects of different fertilizer application methods on soil water and nitrogen transport,and maize growth in sloping farmland.Soil water sensors and soil water sampling devices were set up in runoff plots to study the characteristics of soil water and nitrogen transport,maize uptake,and utilization of nitrogen on different slopes in sloping farmland under the treat-ments of no fertilizer application in bare soil(CK),uniform fertilization in maize field(UF),and non-uniform fertilization in maize field(NUF).The results showed that 1)the average soil moisture content at the toe of slope was the lowest at the same soil layer depth,except for the 40 cm soil depth of the CK treatment,and the degree of moisture fluctuation was the greatest at the 20 cm soil depth at the toe of slope under the combined effect of rainfall replenishment and evaporation.The coefficients of variation of the soil moisture content at most observation points under the NUF treatments were lower than those under the UF treatments.2)Under UF and NUF treatments,the nitrogen concentration at 20 cm soil depth was higher than that at 40 cm soil depth.Nitrate nitrogen and total nitrogen concentrations were lower under the CK treatment than those under UF and NUF treatments.However,ammoniacal nitro-gen concentration under the CK treatment was the highest,and the overall nitrogen change was the lowest.Total nitrogen concentra-tion increased from the top of slope to the toe of slope under the UF treatment,and there were relatively small differences in total ni-trogen concentrations among the top of slope,midslope,and toe of slope at 40 cm soil depth under the NUF treatment.3)Maize yield and partial factor productivity of nitrogen and nitrogen absorption rate under the UF treatment showed an increasing trend from top of slope to toe of slope.Total nitrogen accumulation at the midslope under the NUF treatment reached 31.51 kg·hm-2,which was higher than that at the toe of slope and top of slope,and the maize yield was also the highest at the midslope.The partial factor productivity of nitrogen and nitrogen absorption rate increased greatly from the top of slope to the toe of slope under the UNF treatment.In partic-ular,the partial factor productivity of nitrogen and nitrogen absorption rate of maize at the toe of slope in the first season increased by more than three times compared with that at the top of slope.4)Compared to the UF treatment,the UNF treatment ensured crop yield and substantially increased the partial factor productivity of nitrogen and nitrogen absorption rates(65.0％-69.0％and 43.8％-104.2％,respectively)based on a 28.6％reduction in fertilizer application.The non-uniform fertilizer application method in sloping farmland improves the crop uptake of nitrogen fertilizer by utilizing the downslope migration of nitrogen,reduces the amount of fertilizer applied while ensuring yield,and provides a scientific basis for scientifically formulating a fertilizer application system in sloping farmland and effectively controlling the loss of nutrients.