Effects Of Various Climate Scenarios On Yield Of Rain-Fed Spring Maize In Liaoning Based On WOFOST Model

As the required climatic factors to guarantee the normal growth of crops,the magnitude,variation and spatial distribution of air temperature,precipitation and solar radiation potentially can determine the planting structure and grain yield of regional agriculture.The dependence of crops on “temperature-humidity-wind” climate condition elevates its sensitiveness on climate changes,as that exhibited by thermophiles and hydrophilic maize planted widely in China.Under the background of global climate change,the impact of climate elements and their interactions on maize production shows complexity and uncertainty.Thus,under modern climate situation with an increasing intensity of changes,it is essential to further the response relationship between main climatic factors and maize yield,in order to make the most of natural resources and reasonable adjustment of planting structure and optimize field management measures in serving the food and agriculture security.In the past,many related statistical studies have effectively improved our understanding of the importance of climatic elements in crop production.However,there is still insufficient analysis of crop growth mechanism and quantitative interpretation of the relationship between climatic factors and yield.This study first analyzed climatic characteristics of Liaoning’s meteorological stations based on the historical meteorological data over past 40 years,constructed different climate scenarios according to the required climate factors coupled with warming-drying trend of regional climate change,and adopted different ground data suits to calibrate WOFOST model and verify its performance.At the same time,the annual dryness is selected as the primary index of dry and wet area in Liaoning Province,and it is divided into humid,semi humid and semi-arid regions.The WOFOST model was localized using field-measured data from various agrometeorological stations and we used the localized WOFOST model to simulate grain yield trends of typical rain-fed spring maize in Liaoning under configured climate scenarios.The results show that:(1)Analysis of meteorological data for the past 40 a in Liaoning shows that the trends in temperature,precipitation and radiation are different.The average daily temperature increases differently in each region,but the overall trend is significantly higher(P < 0.01);the annual precipitation increases or decreases slightly but the trend is not significant;the trend of increase or decrease of total daily radiation varies in each region,but the trend of radiation at most stations passes the significance test(P < 0.05).(2)The model validation analysis shows that the calibrated WOFOST model simulates spring maize yields in Liaoning within the error tolerance range for all accuracy evaluation indicators,so the calibrated WOFOST model can achieve effective simulation of spring maize yields at the study site under different climate scenarios.(3)Simulations of rain-fed spring maize in different climate zones in Liaoning Province showed that spring maize yield was negatively correlated with temperature and positively correlated with precipitation within the range of climate factors set out in the study;the "increased radiation" scenario had a positive effect on spring maize yield in the humid zone and a negative effect in the semi-arid zone.The risk of drought stress in spring maize production under the "increasing temperature and decreasing precipitation" scenario is greatly increased,and its yield can reach the lowest value in all simulated climate scenarios in different wet and dry climatic zones,indicating that this climate scenario is a potential extreme climate and requires early warning and strengthening of macro-control and management of spring maize production to avoid significant The risk of yield loss and crop failure in spring maize is greatly increased.(4)The yield of Spring Maize in humid,semi humid(Wafangdian、Xiongyue and Suizhong)and semi-arid areas is significantly affected by temperature,precipitation is the main factor affecting spring maize yield in semi humid area(Changtu、Xinmin and Anshan).However,the radiation change only has a greater impact on the yield of spring maize than precipitation in the humid area,in other regions,the radiation increase or decrease of spring maize yield to a given proportion did not show obvious fluctuation.The paper has 20 pictures,9 tables,and 91 references.