Effects of Long-Term Ecological Management of Intensive Agricultural Systems On Soil Quality Indices.

Sustainability of intensive agriculture systems is crucial if we are to meet the demands of growing populations without compromising environmental integrity. To assess soil quality, indicators are usually linked to soil functions serving as a medium for plant growth, an environmental filter and buffer, a habitat of flora and fauna, and a living space for humans. To perform as good indicators, the selected soil properties should be sensitive, easy to measure and verifiable. The indicators should also be well related to land management and the effect of environmental transformation. Soil structural indices can provide an early indication of soil degradation and the need for remedial measures, and characterize changes in soil properties that would reflect the extent of rehabilitation or regeneration of degraded soils. A case study was done on the Kellogg Biological Station (KBS) Long term Ecological Research (LTER) project. The soils were managed for more than 20 years for different tillage, fertilizer and cropping systems. Soils were analyzed for a variety of physical, chemical and hydrological attributes at different intervals of time since inception of the project. Soils were also analyzed from uncultivated land in different successional stages as ‘bench mark soils’.  Observations suggested that the relative importance of tillage and fertilizer management in determining the behavior of various soil indices related to soil structure and stability could not be generalized, but should be assessed based on the need and the environmental benefits.