土壤湿度驱动WOFOST模型及其适应性

WOFOST Model Based on Soil Moisture Driven and Its Adaptability

WOFOST作物生长模型是以日降水量表征降水输入参数,通过推算土壤相对湿度实现作物生长模拟。由于日降水量随机性较大,很难通过控制日降水量实现不同土壤干旱等级情景设置,限制了WOFOST作物生长模型在不同水分胁迫下对作物生长的模拟,也影响了模拟试验的精度。本文提出以土壤相对湿度直接驱动WOFOST作物生长模型,并以Compaq Visual Fortran 6.5为开发平台,采用Fortran语言对WOFOST作物生长模型的源代码进行修改,将驱动模块中的日降水量文件替换为土壤相对湿度驱动文件。以2013年山东省夏津农业气象试验站玉米出苗-拔节期和抽雄-成熟期水分胁迫和整个生育期自然降水处理(对照)的试验数据为例,对修改后的WOFOST作物生长模型进行了模拟试验。结果显示,采用修订后的模型输出的实测鲜叶干重、鲜茎干重、营养器官干重、地上物质总重和叶面积指数等生物量指标均较原模型输出结果,不仅精度明显提高,而且,由于土壤湿度变化较平稳,较容易地实现了不同水分胁迫情景设置,进而实现不同土壤干旱等级条件下玉米生长的模拟,为分析不同程度干旱对玉米生长的影响及确定其生长发育指标提供了便利条件。

The crop growth model of WOFOST is used to simulate crop growth by estimation of soil relative humidity based on daily precipitation. It is difficult to set different scenarios of soil drought levels by changing daily precipitation,because of the randomness of daily precipitation. This weakness imposed restrictions on the simulation of crop growth under different water stress,and also had bad effects on the accuracy of the simulation. In the current study,a revised WOFOST crop growth model directly based on soil relative humidity was developed. The Compaq Visual Fortran 6. 5 was applied as the development platform,and the source code of WOFOST model was modified by Fortran language,which replacing the driving file of daily precipitation with soil relative humidity. The revised WOFOST crop growth model was used to simulate corn growth under the stages of seedling emergence-jointing and tasselingmature in the conditions of water stress. The results were compared with that under natural precipitation in Xiajin agricultural meteorological station in the Shandong Province in 2013. The results showed that the accuracy of model obviously improved by using the revised model in the output results of the fresh leaf dry weight,fresh stem dry weight,vegetative organs dry weight,total weight of the ground material and leaf area index. Furthermore,the corn growth under different soil drought levels was simulated by setting different water stress scenarios due to the stability of soil moisture.The revised WOFOST model is useful to evaluate the impact of different drought levels on corn growth,and to determine the indexes of corn growth and development.