Soil Loss under Different Cropping Systems in Highlands of Uganda

Nabalegwa M Wambede,Asaba Joyfred,Turyahabwe Remigio

doi:10.13189/ujar.2016.040601

Abstract

This study assessed the influence of cropping systems on soil loss on agricultural slopes. The specific objectives were; to measure soil loss from different cropping systems and to compare the amount of soil loss from the different cropping systems. Soil loss was monitored for one growing season on experimental plots. Only dominant cropping systems were considered including; mixed cropping (maize and beans), onion on contours, and millet sole cropping system. One control treatment characterized by spear grass and short trees and other shrubs was considered. Data about cropping systems was obtained with the help of observation and questionnaires while that about soil and nutrient loss was obtained through experimentation and laboratory analysis. For experimental purposes, 3 slope sites at different slope ranges were considered as a representative sample for the whole sub county that is, lower slopes (080-160), middle slope (170-250) and upper slope (260-310.) At each of the slope sites, the above treatments were established from which data about run off, soil loss were measured after each erosive rain storm. The data obtained included: The most erosive system at all slope sites was mixed cropping, with7.98 t/ha, 19 t/ha and 25 t/ha at the lower, middle and upper slopes respectively, this was followed by contour with 5.68 t/ha, 12 t/ha and 16 t/ha at the lower, middle and upper slopes respectively while the sole cropping had the lowest i.e. 2.6 t/ha, 10.33 t/ha and 14.52 t/ha at the lower, middle and upper slopes respectively. The control plot had the lowest soil loss at all sites with 0.094 t/ha, 0.36 t/ha, and 0.54 t/ha at the lower, middle and upper slopes respectively. It was recommended that at the upper slopes, sole cropping system should be emphasized. This should be of pasture- like crops especially grain crops that grow close to the surface or/and have fibrous rooting system such as millet, sorghum and upland rice. At the middle slopes, millet (grain) sole cropping system is a better option just like at the upper slopes. However contour cropping system can also be applied, while at the lower slopes, all cropping systems can be applied including mixed, sole, inter cropping and ridging cropping systems.

Highlights

IntroductionThroughout the world, land productivity has declined due to human activity
Background to the StudyThroughout the world, land productivity has declined due to human activity
The results of the regressions run indicate that there is a significant relationship between crop growth stage and soil loss under the different cropping systems

Summary

Introduction

Throughout the world, land productivity has declined due to human activity. This has resulted into environmental degradation and food shortages. Once it occurs it is extremely difficult to reverse since it takes 500 years to form 25 mm depth of soil under agricultural conditions, Pimentel [1]. Soil is a thin layer of organic and inorganic materials on the earth’s surface that supports plant growth. It can be defined as a thin surface layer of the earth which is formed by the breakdown of rocks by weathering processes like, chemical, mechanical and biological weathering

Objectives

Methods

Results

Conclusion