The aim of this study was to investigate the design and implementation of a Spatially Variable Fertilizer Application System (SVFAS) as an element of Spatially Variable Agricultural Production Systems (SVAPS). This entails the research and experimental testing of suitable systems, techniques and strategies with the aim of its possible implementation as a commercial venture.
There are two main motivations for developing agricultural systems that operate spatially within fields. The first is due to the expected increase in crop yield due to the more efficient use of agricultural chemicals. The major advantage however, is the environmental benefits due to the reduction of residual nitrogen and other harmful chemicals leaching into the ground water.
There is very little work that has been done locally. These systems have been justified and isolated topics implemented successfully overseas. A fair amount of success has been achieved within SVAPS in Germany, Britain, and the USA. The purpose of developing the system locally was to facilitate maintenance, equipment and personnel requirements and to develop a system that is locally understood and maintainable.
This document depicts the research into the design and the implementation of a SVFAS as an element of SVPAS. The comprehensive testing of a suitable positioning technique for a SVFAS and the experimental implementation of a typical phase of the SVFAS will also be described.
The document will begin with a more comprehensive description of a SVFAS and is followed by the literature review. The literature review is about the greater field of SVPAS and all the phases of a SVFAS. Inferences gleaned from this literature review will follow, outlining some elements of the design and strategy of a SVFAS. Both the literature review and the related references are discussed under the topics of: basic agronomic considerations, the theory and feasibility of positioning techniques, progress already made in relation to SVPAS systems and the constraints of the project in the local context.
The next chapter begins the description of the experimental work. The purpose and procedures required for the testing of a suitable positioning technique and for the implementation of a typical phase of the SVFAS is described. The findings and analyses of the field test data is discussed and conclusions are drawn. Finally, recommendations for future project developments are made.