Land Suitability Evaluation for Sorghum and Barley Crops in South Wollo Zone of Ethiopia

Abstract

This study was conducted to assess the physical land suitability of South Wollo Zone for sorghum and barley crops; and to produce land suitability maps for each crop. The study focuses on such an issue because land suitability analysis is a prerequisite to achieve optimum utilization of the available land resources. Lack of knowledge on best combination of factors that suit production of different agricultural crops has contributed to the low production. All criteria maps have been reclassified into five classes (S1, S2, S3, N1 and N2) values ranging from 1 to 5, where 1 represents S1 and 5 represents N2. Each of the criteria was separately reclassified and analyzed for their suitability for supporting barley and sorghum crops based on the FAO crop requirements specified for them. The land evaluation assessments of this study were conducted based on the methodology outlined in the FAO Guideline for Land Evaluation for Rain Fed Agriculture. The major data sources were climatic data, topographic data and length of growing period as well as crop requirements which have been considered to undertake suitability assessments of the study area. Moreover, both published and unpublished materials were used. The climatic data, topographic data and length of growing period were extracted from Ethio-GIS-2007 with the help of Arc Map 10 version. After clipping map of the study area with the help of the input data (mean annual rainfall, mean annual temperature, slope, elevation and length of growing period), it was reclassified and finally weighted overlayed with the Arc Map GIS software. This was done for sorghum and barley crops separately. Results of the study revealed that most of the lands in the study area are suitable for the cultivation of the two crops. Consequently, land suitability maps for both sorghum and barley crops were extracted using weighted overlay techniques. The suitability map of sorghum crop shows that 237.58 km² of the investigated area are highly suitable (S1), 14,492.57 km²moderately suitable (S2) and 2,208.87 km² marginally suitable (S3). On the other hand, the suitability map of barley crop shows that 649 km² of the investigated area are highly suitable (S1), 7,169 km² moderately suitable (S2), 9,171 km² marginally suitable (S3) and 122 km²unsuitable for economic reasons (N1). The total resulting areas for both crops reveal the importance of agriculture in the study area, and the suitability of the terrain.

Keywords: Land evaluation; Land suitability; Ethiopia.