丘陵山地水田旱地交错分布区耕地地力评价

Assessing the Soil Productivity of Paddy Field and Dry Land in Hilly Ecotone Area

在自然条件下,通过比较水田和旱地地块的肥力差异,选择合适的评价模式,以制定合理的耕地利用依据。结合研究区丘陵山地水田和旱地交错的分布特点,依据最小控制斑块面积确定评价单元数,重点分析了水田和旱地在实际耕作中的差异性,并结合操作实践合理分配水田和旱地在评价体系中各指标的权重系数。结果表明,评价单元数的多少对评价结果的影响比较明显,综合研究区耕地地力实际情况和节约计算耗时的实际,建议最小控制斑块面积在临界值(推荐值)的10%为佳;另外通过水旱分开评价和水旱统一评价两种评价模式的比较,发现水旱分开能使评价结果更加贴近实际情形,反映实际耕地地力状况,能够更加有效地指导农业生产实践。

Based on the topography of Daxian county, the spatial distribution about the whole cultivated land of the county was analyzed. The assessment unit by determined the minimum unit size was optimized. The weight coefficient about paddy field and the dry land in the assessment system with a focus on the differences between paddy field and dry land was reasonably allocated. The results showed that the numbers of the assessment units hardly had effect on the assessment results, The optimized minimum unit size should be limited as the 10% of the threshold proposed by the handbook soil productivity assessment, especially in some hilly agricultural area based on the consideration about the actual assessing time-consuming in the procedure and soil productivity. Based on the hypothesis proved to be true later, there was a significant productivity difference between paddy field and dry land. A separated assessment about these cultivated land was proposed because of the paddy field and the dry land having its soil productivity assessment respectively. The results of the separated assessment model showed that it was better to know the actual soil productivity compared with the integrated assessment model, which could provide the practical agriculture production.