耕作力学研究中的土壤结构表现与评价

Characteristics and Quantifications of Soil Structure for Soil Tillage Research

南京地区农地耕作层土壤显示2种土壤结构形态:机械耕作以及生物学特征的土壤结构表现。前者表现为可分离的较大尺度土垡,且土垡影响到作物根系的生长;后者表现为生物孔洞的存在。将涵盖所有尺度的土壤粒子构成的耕层土壤空间拓扑关系定义为土壤"广义结构",从而使耕作研究超出于土壤结构的农业与化学框架。耕作影响到土壤的广义结构,进而影响到不同尺度下生物系统的繁殖、生长与活动。

A field investigation on the tilled layer soil in Nanjing region revealed two distinctive types of soil structures, machinery-till related and biological related structures. The former was featured with relatively large-scale disintegrated soil clods, having a negative effect on corn root development, the later was characterized with the presence of bio-channels. The spatial topological relations among soil particles, encompassing different scales from primary soil particles to relatively large-scale soil clods as a result from tillage operations, were defined as soil macro-structures. Soil macro-structure brought forward a scope that was not to be coped with agricultural or chemical approaches. Soil tillage affects soil macro-structure, which further affects soil biological performances in different scales.