塔里木河流域不同作物化肥施用时空变化及贡献率分析

Contribution rate and change of fertilizer input in different planting structures in Tarim River Basin

化肥作为农业生产的重要物质投入,对农作物产出的影响较大,但如何评价化肥施用的增产效应及贡献率,目前还没有很多的研究,特别是对塔里木河流域农业生产中的化肥施用贡献率也没有看到相关研究报道。在分析塔里木河流域不同作物(小麦、玉米、棉花和苹果)化肥施用变动及各地州化肥施用结构变动的基础上,通过构建C-D生产函数,测算了塔河流域粮食、棉花和苹果3种作物的化肥、劳动力和机械投入的弹性系数,进一步估算了流域五地州农业生产的化肥贡献率,得出化肥施用对林果业和粮食的贡献较高;而且化肥施用增长幅度大的地区,化肥贡献率也高。表明塔里木河流域不同种植结构农作物产出对化肥施用的依赖程度还较高。

Fertilizers,an important material input in agricultural production,have tremendous influences on the growth of crops yield. A small number of researches on assessment of the contribution of fertilizer to the growth of crops output can be found at the moment,the covering research on the contribution ratios of fertilizer to agricultural production in the Tarim River Basin,however,has yet not reported till now. Firstly,this paper analyzes the change of fertilizers input in different planting structures in the Tarim River Basin from 2000 to 2010,and comes to the following conclusions：（1） The amount of fertilizer input in different crops （wheat,maize,cotton and apple） in the Tarim River Basin shows consistent and fast growth,albeit with turbulent trends,and is much higher than the average level of fertilizer usage in both Xinjiang and China as a whole. （2） The main types of fertilizers used in the Tarim River Basin are nitrogen and phosphorus,while potassium is employed with small percentage. （3） The fertilizer input in the region of Kashi and Aksu consists of large proportion of total five prefectures in the Tarim River Basin,and that in Bayingolin Prefecture presents the highest increase range. Also,this paper calculates input elasticity index of fertilizer,labor and machinery by constructing Cobb-Douglas（C-D） production function,and then estimates the contribution rates of fertilizer in the different agricultural production structures in five regions of the Tarim River basin. The empirical results can be summarized as follows：（1） During the period of 2000-2010,the contribution of fertilizer usage in Tarim River Basin to fruits and grain production is much higher with the percentage of 32.88 and 20.04 respectively,whereas the contribution ratio of fertilizer to cotton is relatively lower （7.77%）,which illustrates that the yield growth of grain and fruits in the Tarim River Basin highly depends on the increase of fertilizer input. （2） The contribution ratio of fertilizer to corps （grain,cotton and apple） yields in the five regions of the Tarim River Basin shows obvious differences,and the contribution ratio is also higher in these regions which appear to have fast increase in fertilizer input. More specifically,the contribution ratio of fertilizer input to both grain and cotton in Aksu Prefecture,compared with that in other four regions,is the highest,which again indicates that the output increase of different planting crops in the Tarim River Basin has a heavy reliance on the growth of fertilizer usage. Finally,based upon the research findings,the paper puts forward a series of suggestions,such as carrying out training on fertilizer usage to farmers and enhancing farmers’ education levels in order to raise the effective level of fertilizer usage and instructing individual farmers to properly input fertilizer.