Parametric Land Suitability Assessment for Rainfed Agriculture: The Case of Bilate Alaba Sub-watershed, Southern Ethiopia

Abstract

The natural resources are becoming scanty in developing country like Ethiopia to support over increased human population without deprivation, scientific approach of land suitability is important to make a proper decision for sustainable agricultural development and maximizing the best use of the land resources. With the deliberation of Rainfed conditions of maize, sorghum and wheat, land suitability evaluation was carried out at Bilate Alaba Subwatershed. Uses of maximum limitation and parametric (Storie and Square root) were applied for the determination of land suitability categories of land characteristics. The result showed that climate is highly suitable (S1) for maize whereas moderately suitable (S2) for sorghum and wheat. From total sub-watershed, 2.45% is marginally suitable (S3) for wheat and 97.55% is moderately suitable (S2) for maize and sorghum production using FAO land evaluation method whereas offering Storie method, 14.75% of sub-watershed is marginally suitable (S3) for sorghum and wheat, 85.25% is moderately suitable (S2) for sorghum and wheat cultivation. Considering maize production under rain-fed conditions, all mapping units were moderately suitable (S2). Parametric Square root result revealed that four soil mapping units were moderately suitable (S2) for maize, wheat and sorghum crops in the sub-watershed. Soil fertility (phosphorus and nitrogen), moisture stress and erosion hazard were the most limiting factors in the sub-watershed. Soil management practices may recover soil fertility with the application of animal manures and household wastes for nitrogen and phosphorus limitations, proper natural resource protection practice to cut the effects of erosion due to topographic features.