Effects of Various Long-Term Tillage Systems on Some Chemical and Biological Properties of Soil

摘要

One of the directions of actions limiting the occurrence in soil environments of unfavorable phenomena accompanying conventional tillage is the introduction of reduced tillage, even total abandonment of cultivation operations. The objective of the performed investigation was to compare the impact of conventional tillage, reduced tillage, and no-tillage on some soil chemical (C_(org), total N, pH) and microbiological (total bacterial counts, numbers of oligotrophs, copiotrophs and fungi, activity of dehydrogenases and acid phosphatase) properties. Studies carried out in 2010-12 involved a static field experiment initiated in 1999 at Brody Research Station of Poznan University of Life Science, Poland, in temperate climate, on a soil classified as Albic Luvisols developed on loamy sands overlying loamy material. Analyses were performed on soil samples collected from under winter wheat from two horizons: 0-10 cm and 10-20 cm. In the 0-10 cm layer, the lowest values of almost all analyzed indices (C_(org), total N, total bacterial counts, numbers of oligotrophs, copiotrophs and fungi, as well as the activity of dehydrogenases and acid phosphatase) were determined in conditions of conventional tillage. In the 0-10 cm soil layer, in all years of study, the highest numbers of bacteria were found in conditions of reduced tillage and no-tillage. On the other hand, in the course of the remaining years of study, the most numerous bacterial counts in the 10-20 cm soil layer were determined in conditions of conventional tillage. More interesting conclusions were arrived at following the analysis of soil bacteria after splitting them into oligotrophic. Numbers of oligotrophs in individual experimental combinations were found to be distributed in a way similar to total bacteria counts.