基于潜力衰减模型的东北-华北平原旱作区耕地生产力评价

    Evaluation of cultivated land productivity based on potential attenuation model in the dryland farming regions of Northeast and North China Plain

    • 摘要: 在中国耕地资源日益紧缺、粮食安全问题愈发严峻的背景下,耕地生产力研究具有重要的现实意义。该研究以东北-华北平原旱作区为研究区域,以主要粮食作物玉米的光温生产潜力空间分布数据及相关县域统计数据为基础,结合土地利用、降水、土壤、社会经济等数据,运用潜力衰减模型,研究评价了东北-华北平原旱作区1995-2015年耕地生产力时空格局及其影响因素。结果表明:研究区光温-水生产力、光温-水-土生产力、光温-水-土-社会经济生产力均整体呈现东北平原旱作区高于华北平原旱作区的空间格局,且在东北平原旱作区和华北平原旱作区内部也均表现出南高北低的宏观趋势;通过分析各环境因子的订正系数发现,人为社会经济投入对当前耕地生产力的保障极为重要,特别是在耕地自然条件逐渐变差的华北平原旱作区表现的尤为显著;水分因子产量差在空间上整体呈现南低北高、东低西高的分布格局,土壤因子产量差明显呈现南高北低的空间格局,社会经济因子产量差呈现明显的北高南低空间格局,这与中国水热条件的地带性分布、东北平原地区优质的土壤条件及较高的自然禀赋等因素有关;研究区社会经济因子产量差>土壤因子产量差>水分因子产量差,且社会经济因子产量差在华北平原旱作区整体较小、土壤因子产量差在东北平原旱作区整体较小,进一步说明了社会经济投入是维系华北平原旱作区耕地生产力的最重要因素,而耕地本身的立地条件是保障东北平原旱作区耕地生产力的最主要原因。潜力衰减模型的应用对大尺度区域耕地生产力研究的方法创新方面有所裨益,评价结果可为不同农业区保持高产、稳产及耕地保育等方面提供科学参考。

       

      Abstract: With the cultivatable lands dwindling and concern over food security increasing in China, understanding the productivity of its croplands has become increasingly significant. Taking the drylands in the Northeast and North China Plains as examples, we estimated the production potential of maize based on spatial variation of light and temperature in these regions. Using data obtained from the national statistics bureau in a combination with land, precipitation, soil, social and economic data from 1995 to 2015, we calculated spatiotemporal variation of productivity of the cultivable lands and its determinants using the potential attenuation model. The results showed that: 1) The light-temperature-water production, light-temperature-water-soil production, light-temperature-water-soil-socio-economic production of the drylands in the Northeast China Plain were all higher than those in the North China Plain. Spatially, the productivity of the drylands in both plains increased from the north to the south. 2) Correction analysis between the determinants revealed that investments in social and economic development was extremely important for protecting production of the available cultivable lands, especially the drylands in the North China Plain that has been in degradation. 3) In both plains, the difference in water yield gap was lower in the south than in the north, and lower in the east than in the west, while the difference in soil yield gap was higher in the south than in the north; the difference in socio-economic yield gap was higher in the north than in the south; these spatial variations were closely related to the zonal geography in China, including soil quality, natural environment and other social and economic factors in the Northeast Plain. 4) The yield gaps caused by different factors in both plains were ranked in yield gap due to socio-economic condition > yield gap due to soil > yield gap due to water. The difference in social and economic output was small in the drylands in the north China Plain, and the difference in soil yield was small in the drylands in the Northeast China Plain. These further proved that investment in social and economic development was most important for maintaining productivity of the cultivatable dryland in the North China Plain while the inherent natural environment was most important for ensuring productivity of the drylands in the Northeast China Plain. The potential attenuation model is an effective to estimate productivity of large-scale farmland, and its results provide guidance for sustaining high and stable crop yield while in the meanwhile reducing land degradation in different agricultural regions.

       

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