Studies On Productivity Of Spring Wheat In Northeast Region Based On WOFOST Model

This study rely on the Ministry of Agriculture’s public welfare industry scientific research special project subject (200903010)"the key technology of wheat’s digital remote monitoring and diagnostics management " project that was led by the Chinese academy of agricultural sciences institute of agricultural environment and sustainable development who provided the remote monitoring equipment.This topic research on northeast spring wheat’s diagnosis and set up monitoring stations in Harbin, SuiHua, nenjiang, Huma, Yakeshi, and other places to establish a wheat’s comprehensive monitoring network which has certain coverage and representative.This measure will implement the automatic acquisition of spring wheat producing’s various kinds of data information and get spring wheat’s dynamic diagnosis and decision which based on the field encironment and crop information.It also can quickly get information and feedback information timely.It has important significance in promoting the development of agricultural informatization, improving the management level of agricultural modernization, disaster prevention and mitigation, the realization of digital agriculture and the protection of food security in China.WOFOST model is developed by the world’s food research center (CWFS) and the Netherlands root rather agricultural university.Its purpose is to explore the developing countries growing food safety related agricultural production potential problems by use the simulation technology development.The model is a kind of simulation specific climate and soil conditions annual dynamic explanatory model of crop growth.This research has carried on the localization parameter calibration to WOFOST model, and carry the sensitivity analysis of the input relevant parameters.Then pick out several parameters which have big influence on result and make different adjustment scheme.Through the improvement of the model’s operation process, improvig the operation efficiency of the model.Setting up a corresponding model running database to simulation spring wheat growth and soil moisture content conditions which growth in Harbin, representative SuiHua, Nenjiang, Huma and Yakeshi area in2010,2011,2012,2011.Then compare the measured values and the simulation values, in order to understand the WOFOST model’s applicability for spring wheat area in the northeast of China.The specific research results are as follows:(1)Simulating the number of days required of spring wheat growth period by using WOFOST model, the simulated results and measured results had smaller error and the average error was1.52days, residual standard deviation was3.2days,R2=0.968.The seedling stage of simulation results is best.The average error is less than1day.Other growth period’s error was in three more days.It prove that model has good simulation effect. (2)After calibration of WOFOST model, the simulation of spring wheat aboveground biomass vriation tendency is more ideal, determination coefficient R2between0.9435to0.9935, the simulation results are more close to the measured results. The absolute average error was between0.34to0.87t/hm2, RMSE was between0.26to1.07, EF was between-0.246to-0.246, IoA was between0.975to0.997that in the confidence interval.On the whole, the simulation results of the model are higher than the measured values.(3)The absolute average error of the simulation value and the measured values which was simulated by WOFOST model for spring wheat’s economic yield was between0.05to0.53t/hm2, RMSE was between0.14to0.70t/hm2, EF was between-1.17-1.17.To Harbin, SuiHua, Yakeshi in2010and Nenjiang in2011, SuiHua, Nenjiang in2012and SuiHua in2013,the simulation values are lower, the rest of the simulation values are higher.It may be due to less consideration of plant diseases and insect pests, and the random errors exist in the process of random sampling, etc.The overall simulation effect is more ideal. IoA was between0.93to0.997that in the confidence interval.The points were less in the early stage of the grouting growth and the rate was higher.The late points was relatively dense and growth rate was small.It explain the main period of wheat grouting is in the early period of the grouting.(4)The simulation effect of WOFOST model on crop growth and development early dry matter accumulation quantity is good.The later period growth simulation value is higher than the measured values. It may be due to the random error of sampling and leaf falling below plant growth of later period,then lead to actual measured value is lower. The simulation value is significantly higher than the measured values of wheat growth later period in2013.It may be related to stick insect pests occurred.Wheat blade eat armyworm, cause the measured dry matter accumulation decreased, resulting in a decline in grouting rate. At the same time, it has influence on plant dry matter accumulation.Simulation of Harbin of dry matter accumulation of four years in R2values were0.9677,0.9299,0.9805,0.9677, both in the confidence interval.(5)To2012, and2013, the soil moisture content change simulated values of WOFOST model and the measured values absolute error was between2.43%to8.75%on average, RMSE was between6.75%to13.75%, EF was between-0.844to-0.844, CRM was between-0.272to-0.272, IoA was between0.457to0.789that in the confidence interval.On the whole, the model simulation of soil water content has a certain reference value.(6)Using the calibration model simulated the spring wheat soil evaporation and crop transpiration and crop water requirement in2012,2013.It can be achieved the purpose of using the fewer parameters for soil evaporation and crop transpiration separation.