Impact of Zero-tillage on Soil Quality Changes Under Crop Rotations and Fertilizer Treatments in a Black Soil

Assess whether or there has been a significant change in soil quality and/or yield trends in the 6 years since the field soil in this study were converted to no-tillage from conventional tillage.

IPNI-1997-CAN-SK19

12 Sep 2001

Methodology

    On the thin Black chernozem at Indian Head Experimental Farm a crop rotation was initiated in 1957 and conducted until 1990 using conventional tillage management. Since then all treatments were changed to zero tillage. Campbell et at. sampled all treatments in spring 1987 and twice thereafter to determine the influence of these treatments on soil quality attributes.

    The treatments in the experiment are: Fallow-wheat (F-W), F-W-W, and continuous wheat, each either fertilized (N + P) or unfertilized; sweetclover green manure (GM)-W-W, and F-W-W-hay (H)-H-H, both unfertilized. As well, there is a fertilized F-W-W treatment in which straw is baled and removed each crop year. All rotation-phases are present each year and there are 4 replicates (i.e., a total of 96 plots).

    In spring 1997, soil from the 0-7.5 and 7.5-15 cm depths of a phase cropped in 1996 will be sampled from each rotation (i.e., 9 treatments). They will be used to measure organic C & N, bulk density, microbial biomass, light fraction organic matter, C and N mineralization, and water soluble C, bicarb P and NO3-N. Separate samples will be taken (0-5 cm depth) for determination of soil aggregation by dry sieving and also by wet sieving techniques.

    The results will be compared to values obtained in 1987-1990 by Campbell et al. It is assumed that all systems would have remained at equilibrium between 1987 and 1990 (changed to zero till in 1991) because, after 30 years of conventional tillage, this should be the case.