基于逐级递减法的洞庭湖区晚稻生产潜力模拟与预测

洞庭湖区是中国的重要商品粮基地,也是长江流域重要的农产品产业区。本文利用2003~2007年气象数据及全国第二次土壤普查相关资料,按照光、温、水、土逐级递减的过程,采用逐级递减法,对水稻生产力不同预测方法进行了对比研究。结果显示:2003~2007年实际产量均值为5904 kg/hm²,逐级计算光温潜力法所得的均值为7808.072 kg/hm²;而基于FAO-AEZ方法计算的晚稻生产力5年均值仅为5687.45 kg/hm²,小于实测产量。基于逐级计算光温潜力的预测模型比较适合洞庭湖区域的晚稻生产潜力预测。晚稻生产力空间分布研究结果表明,洞庭湖区晚稻生产潜力呈现由西北向东南递减的过渡趋势,中高产区主要集中于常德市所属的澧县、安乡、汉寿和临澧一带,低产区则多分布于长沙市、益阳市和岳阳市等几个区域所属县市;洞庭湖区整体的水稻生产潜力偏低,低产潜力区域达到45%,通过各种耕作措施进一步增产的空间较大。

Predictive analysis of late rice potential productivity in Dongting Lake Area(DLA)based on stepwise diminishing method

The Dongting Lake Area (DLA), a famous and important commodity grain production base in China, is one of nine industrial belts of the top agricultural products, and belongs to the top grain industrial belt of double-cropping paddy in the Yangtze River Basin. Therefore, the investigations based on the rice productivity of the DLA is vital for the optimization of the land resource allocation, assessment of the paddy field ecosystem, design of agricultural development plan and protection of agricultural eco-environment. According to the meteorological analysis data from 2003 to 2007 and the soil analysis data of the Second National Field Survey, utilizing the stepwise diminishing method of light, temperature, water and soil, a comparative research was carried out to build an appropriate rice potential productivity model for the DLA. Two rice potential productivity models (photosynthesis-temperature potential productivity calculation by step-by-step model and FAO-AEZ model) were investigated, followed by the analysis of the spatial distribution of late rice potential productivity with the assistance of Geographic Information System (GIS). The results showed that the mean simulation value of five years (2003-2007) predicted by a step-by-step model achieved 7808.072 kg/hm², higher than the observation value (5904 kg/hm²); while the simulation value obtained by FAO-AEZ model was only 5687.45 kg/hm², even lower than the mean observation value, which is unreasonable for the actuality of DLA. This disclosed that the model based on step-by-step calculation of photosynthesis-temperature potential productivity was appropriate to predict the late rice potential productivity in the study area. At the same time, the research also revealed that the late rice potential productivity in the DLA decreased gradually from northwest to southeast. The regions of Lixian, Anxiang, Hanshou and Linli counties in Changde city contributed high or medium yields, while the low yield areas were mainly distributed in Changsha, Yiyang and Yueyang cities. The late rice potential productivity of the DLA was inadequate, and the low yield area occupied 45% of the total DLA, which exhibited great potential for the improvement of the late rice yield by means of sound tillage control measures, including rational fertilization system and water management.