Chapter 7 - Potential constraint of rainfall availability on the establishment and expansion of agroforestry in the Joe Gqabi, Alfred Nzo and OR Tambo Districts, Eastern Cape in South Africa

Abstract

Agroforestry is a land use system that includes the use of woody perennial and agricultural crops and animals in combination to achieve beneficial ecological and economical interactions for food, fiber and livestock production. South Africa is considered a semi-arid country vulnerable to water stress, particularly drought. The threshold for rainfall agriculture is averaged at 250mm annually and in terms of forestry, rainfall needs to be higher than 750mm per annum to sustain commercial forestry. OR Tambo district receives a median annual rainfall that ranges mostly between 800 and more than 1000mm. Climatically the area is thus well suited to rainfed arable agriculture where slopes and soils permit. A moderate summer peak in rainfall is evident. Summer rains start in September and the wettest months are November and December, and the driest, May to August. Similar to OR Tambo, the Alfred Nzo district receives a median annual rainfall that ranges mostly between 800 and more than 1000mm. Climatically the area is thus well suited to rainfed arable agriculture where slopes and soils permit. A moderately strong summer peak in rainfall is evident. Summer rains start in September. The wettest months are November and December, and the driest, May to August. Furthermore, Joe Gqabi district is vastly agricultural and it provides an ideal investment opportunity for agro-forestry, and its proximity to the ports of East London and Port Elizabeth, with links to major routes like the N6 and N10, is an advantage. Hence, the objective of the study was to determine the potential constraint of rainwater on the establishment and expansion of agroforestry in the Joe Gqabi, Alfred Nzo and OR Tambo Districts, Eastern Cape. A purposive sampling technique was used to select five agroforestry sites namely (1) Sinawo Forestry Enterprise (2) Mkambathi Forestry Enterprise (3) Izinini Forestry Enterprise (4) Gqukunqa Forestry Enterprise (5) Sixhotyeni Forestry Enterprise (6) Lusikisiki Forestry Enterprise. Coordinates were received from the Department of Environment, Forestry and Fisheries (DEFF) to plot the climate maps. The following approach was used to determine average monthly rainfall: Decadal (10-day period) 1km×1km surfaces were created from rainfall data (1920–99) downloaded from the AgroMet databank at the Agricultural Research Council-Soil, Climate and Water (ARC-SCW) (South African Weather Service and SCW weather stations) from stations with a recording period of 10years or more. Regression analysis and spatial modeling were utilized taking into account topographic indices such as altitude, aspect, slope and distance to the sea during the development of the surface. The September 2020 rainfall results indicated that there was generally good rainfall (75–100mm) in the agroforestry sites as compared to the agricultural open field areas. The October 2020 rainfall situation improved with an increase in rainfall (101–150mm). During November and December 2020, increasing rainfall was experienced at 125–175mm and 125–175mm, respectively. The last three rainfall status (33rd, median and 66th percentiles) indicated the estimates of rainfall in the future years. It estimated annual rainfalls at 801 to +1000mm; 901 to +1000mm and +1000mm across 33rd, 50th and 66th percentiles respectively. This rainfall situation is well above the Eastern Cape Districts annual average rainfall, agriculture and forestry thresholds. It can thus be concluded that rainwater is not a constraint in the study area for the establishment and expansion of agroforestry. Currently the profitable commodities were recommended to the Department of Environment, Fisheries and Forestry (DEFF) for agroforestry integration. The study recommends that the establishment and expansion of agroforestry be carried out in the identified suitable areas and in line with the Department of Agriculture, Forestry and Fisheries Agroforestry 2017 Implementation strategy.