ABSTRACT
Historically, the study of soils has been largely centered on agricultural production. This chapter is devoted to that upper layer of soil which is responsible for the growth of plants and the preservation of life on earth as we know it. The agricultural properties of soil rely upon all of the individual scientific properties working in harmony to maintain the equilibriums that sustain the various “life cycles.” Essentially, raw materials provided by the soil (fertilizers, crop residues, and manure) are converted by the plants into complex chemical compounds. Several factors are especially important for the efficient growth of plants: moisture (water supply), energy from a light source, air—both above and below ground, temperature, a supply of nutrients, soil reaction (acidity or alkalinity), control of insects and predators, control of diseases, and genetic factors. The chapter presents a brief summary of the importance of each of these factors.
