FROM EXPERIMENTAL TRIAL DATA TO FARM LEVEL RECOMMENDATIONS: A CASE STUDY ON THE VALUE OF SOYA BEANS IN CROP ROTATION SYSTEMS

Abstract

Trial data obtained by research institutes such as the Agricultural Research Council's (ARC) Small Grains Institute (SGI) & Grain Crops Institute (GCI) are often criticised as being obtained under very controlled environments and under conditions not representative of farm-level scale and climatic variation, often ignoring labour and mechanisation inputs, so critical in today's farming production decisions. As conducting trial experiments under controlled and easily quantifiable conditions at farm level is almost impossible, the true value of trial data lies in the realistic extrapolation to farm level. The purpose of this paper is to present a methodology used in deriving the financial effects at representative farm level in the Viljoenskroon region from a 9-year crop rotation trial incorporating soya beans, conducted by the ARC-GCI at Potchefstroom. The bio-physical trial results indicated a definite improvement in maize crops fallowing soya beans and groundnuts. The application of the resultant production functions to realistic farm-level rotation systems and the incorporation of costs and returns in a multi-year spreadsheet simulation model show definite financial benefits at the farm level as well.