Soil physical indicators of management systems in traditional agricultural areas under manure application

ABSTRACT Studies of the successive application of manure as fertilizer and its combined effect with long-term soil management systems are important to the identification of the interdependence of physical attributes. The aim of this study was to evaluate changes in the physical properties of a Rhodic Kandiudox under management systems employing successive applications of pig slurry and poultry litter, and select physical indicators that distinguish these systems using canonical discriminant analysis (CDA). The systems consisting of treatments including land use, management and the application time of organic fertilizers are described as follows: silage maize under no-tillage (NT-M7 years); silage maize under conventional tillage (CT-M20 years); annual pasture with chisel plowing (CP-P3 years); annual pasture with chisel plowing (CP-P15 years); perennial pasture without tillage (NT-PP20 years); and no-tillage yerba mate (NT-YM20 years) and were compared with native forest (NF) and native pasture (NP). Soil samples were collected from the layers at the following depths: 0.0-0.05, 0.05-0.10, and 0.10-0.20 m, and were analyzed for bulk density, porosity, aggregation, flocculation, penetration resistance, water availability and total clay content. Canonical discriminant analysis was an important tool in the study of physical indicators of soil quality. Organic fertilization, along with soil management, influences soil structure and its porosity. Total porosity was the most important physical property in the distinction of areas with management systems and application times of manure for the 0.0-0.05 and 0.10-0.20 m layers. Soil aeration and micropores differentiated areas in the 0.05-0.10 m layer. Animal trampling and machinery traffic were the main factors inducing compaction of this clayey soil.

摘要 连续施用粪肥作为肥料，并探究其与长期土壤管理体系的综合效应，对明确土壤物理属性间的相互依存关系具有重要意义。本研究旨在评估暗红湿润铁铝土 (Rhodic Kandiudox) 在连续施用猪粪浆与家禽垫料的不同管理体系下的物理属性变化，并通过典范判别分析 (canonical discriminant analysis, CDA) 筛选可区分各管理体系的物理指标。本研究涵盖的土地利用方式、耕作管理措施及有机肥施用时长的处理体系如下：免耕青贮玉米（NT-M，种植7年）；常规耕作青贮玉米（CT-M，种植20年）；凿形犁耕一年生牧草（CP-P，种植3年）；凿形犁耕一年生牧草（CP-P，种植15年）；免耕多年生牧草（NT-PP，种植20年）；免耕马黛茶（NT-YM，种植20年），并以原生林（NF）与原生草地（NP）作为对照。研究人员采集了0.0~0.05 m、0.05~0.10 m及0.10~0.20 m三层土壤样品，测定了容重、总孔隙度、团聚体稳定性、絮凝作用、抗穿透阻力、有效持水量及总黏粒含量。结果表明，典范判别分析是筛选土壤质量物理指标的有效工具；有机肥施用与土壤管理措施共同影响土壤结构及其孔隙状况。在0.0~0.05 m与0.10~0.20 m土层中，总孔隙度是区分不同管理体系与有机肥施用时长试验区域的核心物理属性；在0.05~0.10 m土层中，土壤通气性与微孔隙度可有效区分各试验区域。动物踩踏与农机通行是导致该黏质土壤板结的主要因素。