摘要
土壤宏观力学结构是土壤结构体概念的延伸,在尺度上高于土壤团聚体结构1-2个数量级,且具有更高的时空动态特征,其内容涉及土壤物理组构、力学评价指标、力学发生机理及力学应用4个方面,是精准耕作研究的理论依据。评价土壤宏观力学结构的指标包括抗剪强度、圆锥贯入阻力、平板下陷量和断裂强度等,而弹塑性力学、断裂与破碎力学和土壤流变学模型决定着结构动态的发生机理。土壤精准耕作通过对土壤宏观力学结构的测试、评价及模型描述,建立结构动态与外加机械力模式和强度指标之间的关系,运用精准技术手段实现土壤结构、作物秸秆、种子和水肥的精确调控与投放,改善土壤耕性、增强土壤结构力稳性、提高车辆通过性、增大土壤承载力、同时优化土壤-作物-水肥系统和土壤-机器系统。
Soil macro-structure, an extrapolation from soil structure, is 1-2 magnitudes higher in scale than soil aggregates and more spatially and temporally dynamic in nature. Soil physical composition, mechanical indices, mechanical governing mechanisms and potential mechanical applications in agricultural production comprised the key focus of soil macro-structure study, formulated a theoretical basis for precision tillage research. Indices for soil macro-structure quantification are comprised of shear strength, cone index, plate sinkage and fracture strength, which are governed by elasto-plastic, fracture and fragmentation, and rheological mechanics of soil macro-structural dynamics. Precision tillage is the effort of testing, evaluating and modeling the soil macro-structure. This quantification of the relationship between soil macro-structure dynamics and the mode and magnitude of the externally applied mechanical forces will finally lead to technical breakthroughs for precise placement or management of soil structure, crop residue, seed, water and fertilizer. The result of which will facilitate upgrading soil workability, enhancing soil structural stability, improving trafficability and soil bearing capacity, and optimizing soil-plant-environment or terra-machinery systems.
出处
《中国农业科学》
CAS
CSCD
北大核心
2012年第1期26-33,共8页
Scientia Agricultura Sinica
基金
国家自然科学基金项目(50875131)
中国博士后特别基金项目(200902521)
