Using DNDC model to study the potential of nitrogen fertilizer reduction in spring maize production under long-term straw return
[Objectives]This study focused on the potential of nitrogen fertilizer reduction as affected by straw return,aiming to provide a theoretical basis for efficient nutrient management in spring maize production of Northeast China.[Methods]A split plot experiment was carried out in Gongzhuling City,Jilin Province from 2017 to 2020.The treatments were under conditions of straw return and removal,nitrogen(N)fertilizer was applied at 6 rates,as:0,70,140,210,280 and 350 kg/hm2,respectively.The denitrification-decomposition model(DNDC)was calibrated and validated based on the field experimental measurements,then used to simulate the impact of straw return and removal on maize yield and N use efficiency,and predict the potential of N fertilizer reduction over a 30-year period(1991-2020).[Results]The calibrated DNDC model well simulated the spring maize yield,biomass,N uptake,and soil inorganic N content of the treatments,the normalized average relative errors(nARE)averaged-5.7％-7.6％and the normalized root mean square errors(nRMSE)averaged 10.0％-28.5％.According to the simulations,long-term straw return increased the maize yield,N recovery efficiency,agronomic efficiency,and partial productivity of N under the maximum yield N rate by 6.0％,5.5％,2.7 kg/kg,and 6.7 kg/kg,respectively,and decreased N surplus rate by 36.3％,relative to those of straw removal.Straw returns reduced N fertilizer requirement by 35.5 kg/hm2(18.4％)to reach the maximum yield under straw removal.Compared to the N input under straw removal from 1991 to 2020,the N fertilizer reduction potential by straw return first increased and then decreased to a plateau level.The average reduction potential was as high as 23.6％during 7th-15th years,and then declined to 15.8％during 19th-30th years of straw return.The annual precipitation influenced the reduction potential of straw return,the average reduction potential was 20.5％in wet years,18.7％in normal years,and 15.4％in dry years.[Conclusions]Long-term straw return increases the maize yield and N use efficiency,decreases the N fertilizer input and N surplus significantly.According to the DNDC model simulations,the relatively steady N fertilizer reduction rate by straw return is 10％-20％,depending on the annual precipitation in the spring maize area of Northeast China.
spring maizestraw returnnitrogen use efficiencynitrogen fertilizer reductionDNDC model
国家科技期刊平台
NSTL
万方数据
维普
