Potato Yield Simulation And Planting Cost-benefit Analysis In Northeast China Based On DSSAT-SUBSTOR Model

The potato is a high-quality crop with high nutritional value,and demand for potatoes is increasing.Northeast China is a dominant potato production area,how to further improve yield by optimizing field management measures has become a hot issue in potato production management,and the pursuit of the highest yield is always the goal of farmers.For this reason,this study selects Yanshu 4 as the research object,and uses the DSSAT model to conduct interactive treatment experiments of different nitrogen application methods and different nitrogen application amounts on Yanshu 4 at 15 meteorological experiment sites in the northeast China from 2013 to 2017,to analyze the effect of nitrogen fertilizer on potato yield,to seek suitable nitrogen fertilizer application options,and to analyze the relationship between yield,cost,and net income by combining the cost-benefit method.To provide farmers with a reference for the most profitable potato planting management plan.The main findings are as follows.(1)Both phased and incremental applications of nitrogen fertilizer in potato cultivation can promote yield increase.The lowest yields were obtained by basal application of nitrogen fertilizer at sowing,and the highest yields were obtained by basal application of nitrogen fertilizer at sowing and topdressing at the end of tuber formation at a ratio of 1:1,respectively.Potato yields increased with increasing nitrogen application,but began to decrease with excessive nitrogen application,and the highest yields were obtained in the range of 275-330 kg/hm~2 at all sites in the northeast China.Potato yields within the northeast region were up to 26611 kg/hm~2 for the nitrogen fertilizer treatment,and the average of the highest yields was 22855 kg/hm~2.The highest potato yields in Heilongjiang,Jilin and Liaoning provinces were 25153 kg/hm~2,25216 kg/hm~2 and 26611 kg/hm~2 respectively.(2)The application of nitrogen fertilizer can increase the net income by promoting the increase of potato yield.In all experimental treatments,the net income was higher in nitrogen application treatments than in no nitrogen application treatments.The maximum net income among the sites in Northeast China from 2013 to 2017 was 52,030.41 yuan/hm~2,and the average of highest net income was 31,698.38 yuan/hm~2.The highest mean value of the highest net income of Yanshu 4 at all sites was37,527.89 yuan/hm~2 in Liaoning province,followed by Heilongjiang province with 32,953.02 yuan/hm~2,and the lowest mean value was 24,614.22 yuan/hm~2 in Jilin province.The experiment in Heilongjiang province had the highest mean net income increase of 241%for the nitrogen application treatment compared to the non-nitrogen application treatment,followed by Jilin province with 192%,and Liaoning province had the lowest mean net income increase of 164%.(3)The highest potato yields did not correspond to the highest net income in most of the nitrogen treatments.The net income of potatoes at each site gradually increased and then decreased with the increase in the amount of nitrogen applied,which is due to the fact that increased nitrogen fertilization increased yield and also increased input costs.For the nitrogen fertilizer management in potato planting in the future,it is recommended that potato farmers in Heilongjiang,Jilin and Liaoning provinces may consider phased application of N fertilizer at a ratio of 1:1 at the sowing and tuber last formation with recommended nitrogen application amounts of 220 kg/hm~2,220 kg/hm~2 and 275 kg/hm~2,respectively.