A SURVEY ON SOIL TESTING SERVICES AWARENESS (A CASE STUDY OF MIKANG L.G.A. PLATEAU STATE)
CHAPTER ONE
INTRODUCTION
BACKGROUND OF THE STUDY
Soil testing is a set of various chemical processes that determine the amount of available plant nutrients in the soil, but also the chemical, physical and biological soil properties important for plant nutrition, or “soil health”. Chemical soil testing determines the content of basic plant nutrients; nitrogen (N), phosphorus (P2O5), potassium (K 2 O), pH, humus content, total CaCO3, available lime, organic matter, total sulphur (S), trace elements, and other physical characteristics (capacity, permeability, density, pH – value). Soil testing processes involves: i. Taking soil samples, ii. Laboratory analysis of samples and iii.
The interpretation of the results by the issuance of fertilizer recommendation. The importance of this soil testing is to know the previous fertilizer and lime applied, the cropping history, nutrient contents of the parent materials, and losses of surface soil through erosion. Soil testing had its beginnings sometimes are the acceptance of the mineral theory of plant nutrition. In its broadest sense soil testing includes a thorough inventory of the soil properties including primary and secondary minerals, particle size, exchange capacity and adsorbed cat ions, organic; latter, etc. One cannot apply simple soil tests without at least a general knowledge of the range of the important parameters of the soils to which the soil test results are to apply. In the more restricted sense and the commonly understood one, soil testing consists of some biological or chemical test that can be used as an index of nutrient availability. This nutrient may be native or residual from past fertilizer or manure applications. This index of nutrient availability only indicates what is present or likely to become present
during the growing season. How much and what kind of fertilizer to apply involves judgment as to probable yields, effectiveness of the fertilizer and other variables mentioned earlier. Biological soil tests have included various kinds of pot or container tests using rye, sunflower, lettuce and other plants and fungi such as Asperzillus spp. or bacteria such as Azotobacter. The most complex of the biological tests was the Mitscherlich one from which inferences could be drawn not only as to nutrient availability; but the response of the soil and the crop to fertilization. Those from Western Europe know how many hundreds of thousands of such tests have been done. Most biological tests are slow and time consuming. They have fallen from favour because of the lower cost and
greater rapidity of chemical tests. A Chemical test is the measurement of ions in a solution extracted from the soil either without prior incubation of the sample as for P, K, etc. or are incubation as for nitrate production.
1.2 STATEMENT OF PROBLEM:
Although soil testing services is a powerful tool to support high productivity by way of rationalizing nutrient use, its current impact on farm practice is presently not visible. In order to make it an effective and farmer oriented service, it is important to expand the arena of soil fertility evaluation beyond NPK, the pH of the soil and fertilizer recommendations for high yield targets, involving all deficient nutrients and exploiting important positive nutrient interactions. Although, inorganic nutrient availability alone will not oer a complete assessment of soil fertility or soil biological influences on important soil properties and processes that aect crop yield and environmental quality. Soil testing could be elevated to a more holistic evaluation of soil fertility and health with the adoption of a test for soil biological activity.
