Effect of climate variability and change on land suitability for irish potato production in Kigezi Highlands of Uganda

Abstract

The impact of climate variability and change on land suitability for crop growing is not clearly understood. Glaring evidence exists in temperate world where rising global mean temperatures will, most likely, improve crop production. This contravenes the evidences in the tropical environments where gross crop yield decline is a clear manifestation of the rising temperatures. This lacuna jeopardizes standardization on the adoption of appropriate climate change mitigation measures. The Kigezi Highlands are highly vulnerable to climate change impacts; of which, it is quite challenging for small scale farmers to identify suitable areas for Irish potato growing. Our objective was to identify suitable areas for Irish potato production under different climatic scenarios and strengthen the small scale farmers' adaptability to climate variability and change impacts in Kigezi Highlands. Using Agricultural Production Systems Simulator (APSIM) model, we simulated historical and future time scenarios, and using Spatial Multi Criteria Evaluation (SMCE) coupled with remote sensing of a Sentinel 2 image, we generated suitable areas for Irish potato production. The results showed that 30.8% of the site was under agriculture, of which 71.5% was under Irish potato. Of this 71.5%, the most suitable area was only 1.95%, while 5.34% was completely not suitable, and the remaining areas were either moderately or marginally suitable. In the March-May (MAM) and September-November (SON) seasons, the trend of minimum and maximum temperatures was significantly (P < 0.05) increasing. However, rainfall was not significant (P > 0.05), and its trend was decreasing in the MAM and increasing in the SON seasons. The yield of Irish potato was not significant (P > 0.05) and its trend was decreasing in MAM and SON seasons. We concluded that climate variability and change will decrease land suitability for Irish potato; thus, appropriate soil and water conservation measures applicable to a highland environment need to be adopted.