Soils and soil conditions of the Amatikulu project [KZN, South Africa]

Brouwers Marinus, Van den Berg M.. 2009. Soils and soil conditions of the Amatikulu project [KZN, South Africa]. Montpellier : CIRAD-SASRI, 31 p.

Résumé : This report describes a soil study which was carried out in the framework of SASRI project 06TT01, "Best management practices for small-scale sugarcane growers in the Amatikulu catchment (Zululand) including alternative crops" The soil study was carried out on the site selected between the three proposed by the community consulted for the project. This document reports the results of the field study taken into account the results of the soil analysis carried out (by SASRI) on the samples collected at three depths for nine soil pits in the selected area for the project. The geographic centre of the site is near 28°56'19" South and 31°13'56" East. The site is located 537 ±10 m above sea level near the village of Bongolwane. It covers ca 5 ha. The slope of the selected area is gentle when compared to other areas in the project region (but common in the sugarcane industry), and, as consequence, the soil depth is often greater then elsewhere in the region. The bedrock of the soils of the selected site, as well as for the main part of the project area, is of amphibolite type which is uncommon in the sugarcane industry and elsewhere in South African. But the soils developed on this rock type have a high agricultural potential, like for an important part of the soils of the sugarcane industry. In the upper part of the selected area the soils are humic, clayey, rich, and between 50 - 80cm depth underlain by a strongly weathered metamorphic rock, rich in amphibolite. Mid-slope the clayey humic surface horizon of about 50 cm depth is underlain by a deep reddish brown clayey layer and at the foot slope (i.e. near the geo-structural born wetland which borders the North of the site), by a red-brownish subsoil that shows at more than 1m depth the influence of a seasonal fluctuating water table. The topsoil - which has a depth of about 50cm - is throughout the area studied of a melanic type. The B horizon which underlies the melanic A horizon is thin in the top part of the site. This makes that the soils in this part of the site are of Mayo type according to the South African soil taxonomy and are Glossic Leptic Phaozems in the WRB (World Reference Base, edition 2007) Downslope, the depth of the B horizon increases quickly. According to the SA soil classification system the B horizon is of Yellow-Brown Apedal B or unspecified type. At the footslope of the site the influence of the seasonal fluctuating watertable makes that the B horizon is underlain by a gleyic horizon with distinct signs of oxidation. Soils of the mid- and down slope part of the site could not be classified according to SASRI¿s soil handbook "Identification and management of the soils of the South Africa sugar industry at soil form level. In the WRB systems they belong to the Cambic Gleyic Phaozem Soil chemical and physical characteristics are favourable for growing of sugarcane and other crops in all parts of the site: pH slightly to moderately acid, high CEC, low N requirement, parts of the area show deficiency in potassium and phosphorus is low throughout. The soils are easy to till, are very deep (except at the top) and have probably a high waterholding capacity. The possible influence on crop growth and husbandry operations of the fluctuating depth of the water table in the bottom part of the site has to be checked.

Mots-clés Agrovoc : sciences du sol, Saccharum

Mots-clés géographiques Agrovoc : Afrique du Sud

Classification Agris : P33 - Chimie et physique du sol
P35 - Fertilité du sol
F01 - Culture des plantes

Auteurs et affiliations

• Brouwers Marinus, CIRAD-PERSYST-UPR SCA (FRA)
• Van den Berg M., SASRI (ZAF)

Source : Cirad - Agritrop (https://agritrop.cirad.fr/550487/)

Métriques

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