Long-term effects of tillage, sub-soiling, and profile strata on properties of a Vitric Andosol in the Kenyan highlands
Keywords:
Bulk density, Hydraulic conductivity, Infiltration rate, Soil organic carbonAbstract
Tillage alters the structure and composition of soil aggregates affecting infiltration rate (IR) and hydraulic conductivity (K). This study investigated the long-term effects of conventional, minimum, and no-tillage with or without subsoiling on aggregate stability, soil organic carbon (SOC), bulk density, IR, and K of a stratified Vitric Andosol in Kenyan highlands. The experiment was laid out in a spilt-split plot design with three replicates. Stepwise profiles were dug in order to expose the soil layers at 0 to 30, 30 to 60, and 60 to 90 cm depths. Soil bulk density was 6% lower in the minimum tilled and 12% lower in the conventionally tilled plots that were subsoiled compared to treatments with no subsoiling and tillage. Subsoiled treatments also increased sequestration of SOC by 20% in the 30 to 60 cm layer. Conventional tillage, however, decreased aggregate stability by 32% compared to no-tillage treatments. Subsoiling in combination with minimum tillage decreased IR by 25% but increased IR about three-fold in conventionally tilled plots. Hydraulic conductivity in the 60 to 90 cm layer was lowest, which constrained water movement in this stratified soil.Downloads
Published
How to Cite
Issue
Section
License
Copyright © 2001-11 Kerala Agricultural University. Some rights reserved. This journal and the individual contributions contained in it are protected under copyright by the Kerala Agricultural University and the following terms and conditions apply to their use; Photocopying Single photocopies of single articles may be made for personal use as allowed by national copyright laws. Permission of the publisher and payment of a fee is required for all other photocopying including multiple or systematic copying, copying for advertising or promotional purposes, resale, and all forms of document delivery. Permission may be sought directly from the Editor, Journal of Tropical Agriculture, Department of Agronomy, College of Horticulture,, Kerala Agricultural University, KAU PO, Thrissur 680 656, Kerala, India. (Phone: +91-487-2438325; Fax +91-487-2371040; E-mail: editor.jta@kau.in. Derivative works Subscribers may reproduce tables of contents or prepare lists of articles including abstracts for internal circulation within their institution. Permission of the Publisher is required for resale or distribution outside the institution. Permission of the Publisher is required for all other derivative works, including compilations and translations. Notice No responsibility is assumed by the Publisher for any injury and/or damage to persons or property as a matter of products, liability, negligence, or otherwise, or from any use of any methods, products, instructions or ideas contained in the material herein.