Effect of tillage systems on soil properties, humus and water conservation

摘要

Human action upon soil by tillage determines important morphological, physical-chemical and biological changes, with different intensities and evaluative directions. Nowadays, it is internationally accepted the fact that global climatic changes are the results of human intervention in the bio-geo-chemical water and material cycle, and the sequestration of carbon in soil is considered an important intervention to limit these changes. Carbon sequestration in soil is net advantageous, improving the productivity and sustainability. The more the organic content in soil is higher the better soil aggregation is. The soil without organic content is compact. This reduces its capacity to infiltrate water, nutrients solubility and productivity, and that way it reduces the soil capacity for carbon sequestration. Organic matter is an extremely important constituent of soils and is vital to many of the hydrological, biological and chemical reactions required for sustaining plant life. We present the influence of conventional plough tillage system on soil, water and organic matter conservation in comparison with an alternative minimum tillage system (paraplow, chisel plow and rotary harrow). The application of minimum tillage systems increased the organic matter content 0.8% to 22.1% and water stabile aggregate content from 1.3% to 13.6%, in the 0 - 30 cm depth, as compared to the classical system. For the organic matter content and the wet aggregate stability, the statistical analysis of the data showed, increasing positive significance of minimum systems. While the soil fertility and the wet aggregate stability were initially low, the effect of conservation practices on the soil features resulted in a positive impact on the water permeability of the soil. Availability of soil moisture during the crop growth resulted in better plant water status. Subsequent release of conserved soil water regulated proper plant water status, soil structure, and lowered soil pene-trometer resistance.