SOIL CHARACTERIZATION AND LAND SUITABILITY EVALUATION

CHAPTER ONE

INTRODUCTION

It is important that the land that will be used for agricultural production should be used according to its capacity for optimization and sustainability of soil productivity (Adeboye, 1994). This becomes very vital at this time when precision farming is gaining wider acceptance and the relevance is particularly more now in the developing world where the use to which a land is put is very often not related to its capacity (Senjobi, 2001).

A major problem of agricultural development in Nigeria is poor knowledge and appraisal of suitability of parcels of land for agricultural production. The result is poor farm management practices, low yield and an unnecessary high cost of production (Aderonke and Gbadegesin, 2013). Land evaluation using a scientific procedure is essential to assess the potentials and constraints of a given land parcel for agricultural purposes (Rossiter, 1996). The knowledge of soil limitations arising from land evaluation reports aims at ameliorating such limitations before, or during cropping period (Lin et al., 2005). Therefore, soil as a main medium for cultivation needs to be assessed (surveyed / characterized) scientifically. The performance assessment is based on matching qualities of different land units in specific area with the requirements of actual or potential land utilization types. This assessment results in classification of lands as to their suitability to produce specific crops or combination of crops (Ezeaku, 2011).

Soil suitability evaluation involves characterizing the soils in a given area for specific land use type. The suitability of a given piece of land is its natural ability to support a specified land use such as rain-fed agriculture, livestock production, forestry, etc. The main objective of land evaluation is to predict the inherent capability of a land unit to support a specific land use for a long period of time without deterioration. Ozcan (2006) observed that all lands can be used for utmost purpose if sufficient inputs are supplied. In the tropics, many different soil types occur as a result of combination of pedogenic factors such as climate, topography, parent materials and soil forming processes. Every land use has specific biophysical requirements with respect to land conditions, and in the matching process of land evaluation, these biophysical requirements are compared with the relevant combination of soil characteristics (measureable attributes like slope percentage, drainage, soil texture, base saturation, etc) of a land resource; which are related to the agricultural use of the soil and more specifically to specific crop requirements and tolerance (Fischer et al., 2008).

Anuka is an agrarian community. Its dwellers are mainly commercial farmers of both small scale and large scale production of several staple crops such as cassava, yam, maize and tree crops like oil palm among others. The soils have been under intensive cropping by inhabitants of the community. Despite the high agricultural development potential of the soils, the soils have not been classified taxonomically to make for easy transfer of knowledge carried out on similar soils elsewhere. Due to lack of guidance, many farmers cultivate crops on soils that may not be suitable for their cultivation. Thus, the main objective of this study was to evaluate the suitability of the soils of Anuka farmland, for both arable and plantation crops. The specific objectives included to:

a)      characterize the soils of the farm land, and classify them according to USDA Soil Taxonomy and FAO/UNESCO;

b)      determine the crop nutrient spread in the farm; and

c)      evaluate the sampling units according to their suitability for maize, yams, cassava and oil palm production.