Hydrological and Physical Responses of a Semi-arid Sandy Soil to Tillage

• Published in: Journal of agricultural engineering research Vol. 72; no. 4; pp. 385 - 391
• Main Authors: Bruneau, P.M.C., Twomlow, S.J.
• Format: Journal Article
• Language: English
• Published: London Elsevier Science Ltd 01.04.1999; Academic Press
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Cropping systems. Cultivation. Soil tillage; Earth sciences; Earth, ocean, space; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Physical properties; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Soil erosion, conservation, land management and development; Soil science; Soil tillage; Soils; Surficial geology; Tillage. Tending. Growth control; Water and solute dynamics; Zimbabwe; Southern Africa; Africa; Crust; Tropical zone; Cultivated soil; Water conservation; Fersiallitic soil; Sandy soil; Soil conservation; Tropical soil; Rain; Ground surface; Semi arid zone; Surface conditions; Hydraulic properties; Water infiltration; Soil tillage; Soil moisture; Property of soil; Experimental study; Physical properties; Soil management; Microrelief; Soil water properties; Runoff; Conservation tillage; Structure modification
• ISSN: 0021-8634; 1095-9246
• DOI: 10.1006/jaer.1998.0384

For sustainable crop production in semi-arid environments with low and erratic rainfall (<800 mm), runoff must be minimized and water conserved. However, little is known about how soils in semi-arid southern Africa respond to cultivation. This study investigated the hydrological and physical responses of a fersiallitic soil to conventional (flat) and improved (tied ridge) tillage practices over four seasons under natural and simulated rainfall conditions in Zimbabwe. Changes in soil surface roughness and the development of crusts were investigated and related to variation in the runoff ratio (total volume of runoff/total volume of rain). Relationships between runoff, rainfall intensity and antecedent precipitation index (API is an indicator of soil moisture content based on daily rainfall) were established for both systems. For the tied ridge system, API showed no significant contribution to runoff prediction. This reflects the greater and more stable depression storage capacity of the furrow in the tied ridge system. By comparison, the depression storage capacity of the flat system is temporary in nature and, as the micro relief of the soil surface weathers and crusts develop, its capacity declines, as does the time to ponding and runoff generation.