Study On The DSSAT Model To Develop The Winter Wheat Irrigation Scheme In North China Under Different Years

The suitable seasonal temperature mode and fertile soil tillage layers provide excellent background conditions for winter wheat production in North China Plain,and it is an important winter wheat production base in China.However,due to the typical temperate continental arid or semi-arid monsoon climate.Precipitation is mainly concentrated in the fact that for the winter wheat harvested in autumn and summer and with large water consumption,precipitation cannot meet the water requirement of the winter wheat growing season.Therefore it has been always relied on groundwater irrigation.In this paper,the Luancheng Agricultural Ecosystem Experimental Station of the Chinese Academy of Sciences was selected as the representative sample.Selecting"41851"winter wheat varieties,use the meteorological data of 1997-2016,field management data,etc.,Designed 16 different irrigation schedules?irrigation amount60mm/time?for different irrigation time?set optional irrigation for overwintering,jointing,heading and grouting for 4 development periods?and different irrigation times?0-4 times?.The DSSAT model was used to simulate the experiment,according to the simulation results of different types of production and water use efficiency,the optimal irrigation scheme for winter wheat in different types years of North China Plain was formulated.This article gets the following conclusions:?1?DSSAT crop growth model can better simulate the growth status of winter wheat in this area.DSSAT model can be applied to simulate the winter wheat in this area.?2?Based on the DSSAT model,the light-temperature potential productivity value of winter wheat in this area was mainly distributed between 7000 kg hm^-2 and9000kg hm^-2,and the mean value of light-temperature potential was 7526.6 kg hm^-2;The inter-annual variation of the photoperiodic potential productivity of winter wheat is significant.?3?The relationship between the yield of winter wheat under rain-fed conditions and the precipitation in the growing season is:Y_R=1780.487+14.752*PCP_G(Y_R:Yield under rain-fed conditions;PCP_G:Precipitation in the growing season)?4?Using DSSAT model to simulate different irrigation schemes,the average yield of winter wheat increased with the increase of irrigation times.The average yield of each irrigation program was ranked as follows:4-WJSF(6870.6 kg?hm^-2)>three3-WJS(at wintering+jointing+heading,6741.8 kg?hm^-2)>2-JS(at jointing+heading,6392.1 kg?hm^-2)>1-J(at jointing,5313.4kg?hm^-2)>R(precipitation,3720.3kg?hm^-2).The water use efficiency?WUE?of winter wheat obtained the highest value in the 2-JS?joint joint+heading water?program,and the average WUE order was:2-JS(15.79kg?hm^-2?mm^-1)>3-WJS(15.11 kg?hm^-2?mm^-1)>1-J(joining water,14.94kg?hm^-2?mm^-1)>4-WJSF(14.06 kg?hm^-2?mm^-1)>R(12.33 kg?hm^-2?mm^-1).Under the principle of the highest average yield and the best WUE average,it is suggested that the optimal irrigation scheme in this area is a 2-JS solution with two irrigation.The2-JS solution has the highest WUE and can also yield higher yields.In areas with more abundant water,3-WJS can be used to achieve higher and stable yields.?5?For some special years,through the analysis of DSSAT model simulation results,the selection method for the optimal irrigation scheme is determined.For example,in 1997-1998,in the winter wheat growing season with more precipitation but less precipitation from the early October to the late November in the early winter wheat planting period,after the simulation comparison,the 2-WJ scheme was selected as the optimal solution to consider the yield and WUE.?6?In 2012-2013 and 2015-2016,the precipitation from the early winter sowing stage of winter wheat to the wintering period from the early winter to the wintering period is significantly more than that from mid-October to early December,and the soil moisture is significantly reduced during the filling period.The optimal irrigation scheme is 3-JSF.