Response Of Potato Growth And Yield To Drought Scenarios Based On APSIM-Potato In The Single-cropping Region In Northern China

Under the background of climate warming,due to the increase in the frequency and intensity of droughts,potato planting and production activities in the single-cropping region in Northern China were restricted,posing a threat to regional food security.Based on this,this paper took potatoes in the single-cropping region in Northern China as the research object,and combined the agricultural production system simulation model（APSIM）and mathematical statistics methods to complete the applicability evaluation of the APSIM model in the study area.The response of potato growth and yield to different drought scenarios was simulated and analyzed in the single-cropping region in Northern China.It provided a reference for better grasping the growth and development status of local potatoes,determining field management measures,improving water use efficiency in the region,and realizing the monitoring,early warning and impact assessment of potato drought in the single-cropping region in Northern China.The main conclusions were as follows:（1）We found that the APSIM-Potato could effectively simulate the phenology,LAI,above-ground biomass and yield of potato in different years in the single-cropping region in Northern China.The R²and D of the growth period were both above 0.75,and the RMSE were within 1.7～2.9 d;the R²and D of LAI,above-ground biomass and yield were all above0.8,and the NRMSE of the simulation results were all below 20%.The model had high simulation accuracy and was applicable in the study area.（2）The stage of drought stress in the study area would affect the growth and final yield of potato.Under the same drought stress,the highest response of potato LAI,above-ground biomass and yield to drought stress in a single developmental stage was the branch-flowering stage.Drought stress during this period could reduce potato LAI,biomass and yield by2.3%～35.3%,12.5%～38.6%and 2.0%～46.2%.Different study areas responded differently to drought stress at the sowing-emergence period,and mild drought stress（T₁）at the sowing-emergence period in individual sites increased potato yield.（3）The duration of drought stress in the study area would affect the growth and final yield of potato.Potato LAI,biomass and yield all decreased with increasing drought stress duration.Potato LAI,biomass and yield were most responsive to drought stress during the emergence-harvesting period.Drought stress at the emergence-harvesting period could reduce potato LAI,biomass and yield by 7.7%～50.6%,23.3%～62.8%and 3.6%～56.0%.The effects of persistent drought stress in three consecutive developmental stages on potato LAI,biomass and yield were greater than those in two consecutive developmental stages.（4）The intensity of drought stress in the study area would affect the growth and final yield of potato.Potato LAI,biomass and yield all decreased with increasing drought stress intensity..Under mild drought stress（T₁）,potato LAI,biomass and yield decreased by8.9%～15.2%,25.4%～31.7%and 4.1%～12.6%;Under moderate drought stress（T₂-T₃）,potato LAI,biomass and yield decreased by 17.9%～43.5%,30.5%～53.6%and 10.2%～49.1%;Under severe drought stress（T₄）,potato LAI,biomass and yield decreased by 59.7%,73.5%and70.5%.With the increase of drought stress time,the effects of drought stress on potato yield were persistent and additive.（5）The effects of water control simulations with different precipitation gradients on potato LAI,biomass and yield in a single developmental stage,successive developmental stage and whole growth stage were basically the same.The overall spatial distribution showed a trend of increasing gradually from the southeast to the northwest in the percentage reduction of each variable.Among them,the areas with larger losses of LAI,biomass and yield were mainly concentrated in the northwest.This was related to the topography,soil conditions,and the distribution of precipitation in the single-cropping region in Northern China.