Soil water competition in a temperate hedgerow agroforestry system in South Africa |
| |
Authors: | C S Everson T M Everson W van Niekerk |
| |
Institution: | (1) CSIR Natural Resources and the Environment, c/o School of Applied Environmental Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg, 3209, South Africa;(2) School of Biological and Conservation Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg, 3209, South Africa;(3) School of Applied Environmental Sciences, c/o Agrometeorology, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg, 3209, South Africa |
| |
Abstract: | An on-farm trial was conducted to determine dry matter production of four fodder tree species and their effect on soil water
and maize production. The trees were planted in rows intercropped with maize. The four tree species selected were Acacia karroo Hayne (indigenous fodder tree), Leucaena leucocephala (Lam.) De Wit (nitrogen fixing), Morus alba L. (fodder and fruit), and Gleditsia triacanthos L. (fodder and fuel). Volumetric soil water was measured in the upper 0.3 m of soil in each row of the trial using the time
domain reflectometry technique. The neutron probe technique was used for monitoring the water content deeper in the soil.
Geostatistical methods were used to analyse treatment differences in the upper 0.3 m of soil. The soil water content did not
differ significantly between the maize and tree rows indicating that competition for water in the upper horizon was not the
reason for lower maize yields. However, at greater soil depths (75–125 cm) trees in the wide spacing used less water than
those in the narrow spacing. Light interception was an important factor in reducing maize yields in the row nearest to the
trees. High soil water values recorded during summer indicated that in the current cycle of good rainfall the plants in the
agroforestry trial were not stressed. Thus the trees do not compete with the crops for soil moisture in good rainfall seasons.
However, this study would need further evaluation for the competition for water for the low rainfall years. Since the trees
have access to water at greater depths, they are likely to be more productive into the dry season than shallow rooted crops. |
| |
Keywords: | Competition Intercropping Hedgerow intercropping Light interception Soil water |
本文献已被 SpringerLink 等数据库收录! |
|