浙江省新垦耕地土壤熟化指标研究

土壤熟化是新垦耕地培肥的重要过程,是土壤肥力和生产力逐渐提高的表现,但如何设定指标来判断土壤是否熟化至今还存在较大的分歧。为此,在对耕地土壤熟化的本质、土壤熟化与土壤质量的关系、熟土与生土的区别、熟化指标的选择进行分析的基础上,以浙江省为例,探讨了水田与旱地土壤的熟化指标与熟化标准。提出设立初步熟化和高度熟化二级熟化标准,分别对应土壤熟化的“下限”与“上限”的观点。认为熟化指标应针对土地利用中存在的问题而设计,可考虑用耕作层厚度、土壤有机质、pH、容重和盐分作为鉴别指标。土壤熟化的“上限”值可参照当前耕地质量评价中的高等级耕地评价标准作为鉴定依据;土壤熟化的“下限”值的制定应平衡农作物生长需求与区域培肥现实2个方面的关系。最后,基于浙江省典型耕地熟化前后土壤肥力性状的变化,结合国内土壤定量分类中的某些标准,分别提出了浙江省旱地和水田土壤熟化的鉴定指标和标准。

Study on soil maturity index of newly cultivated land in Zhejiang Province

Soil ripening is an important process of newly cultivated land fertilization, which is the performance of the gradual improvement of soil fertility and productivity. However, there is no consensus in the judgement of soil ripening. Based on the analysis of the nature of soil ripening of cultivated land, the relationship between soil ripening and soil quality, the difference between mature soil and raw soil, and the selection of ripening indexes, the present study discussed the ripening indexes and standards of paddy field and upland soil with Zhejiang as an example. The viewpoint of establishing two sets of standards was put forward, namely, the primary ripening standard and high ripening standard, which corresponded to the “lower limit” and “upper limit” of soil ripening, respectively. It was considered that the ripening indexes should be designed according to the problems in land use, and the cultivated layer thickness, soil organic matter, pH, bulk density and salt content could be considered as the ripening indexes. The “upper limit” value of soil ripening could be identified by referring to the evaluation standard of high-grade cultivated land in current cultivated land quality evaluation method. Meanwhile, the “lower limit” value of soil ripening should balance the relationship between crop growth demand and regional fertilization reality. Based on the analysis of the changes in the soil fertility before and after the ripenig of typical cultivated land, and combined with some standards of soil quantitative classification in China, the identification indexes and standards of upland and paddy field soil ripening in Zhejiang Province were proposed.