Effects of Travertine in Improving Selected Soil Properties and Yield of Irish Potato ( Solumun tuberosum L.) in Acidic Soils

Abstract

The production of Irish potato is threatened by widespread acidity and nutrients deficiency in many parts of Rwanda. The aim of this study was to determine effects of travertine in improving selected soil properties an d yield of potato in acidic so ils of Burera District. In September 2011 rainy season, three sources of travertine (Musanze, Rusizi and Karongi) were evaluated in an randomized complete block design (RCBD ) experiment. Soil properties baselin e and lime materials quality (CaCO 3 , fineness, effective CaCO 3 , pH and moisture) were first analyzed. Soil pH, exchangeable Al and available P were monitored at 6, 12 and 16 weeks after limes application (WAP). However, nitrogen and base saturation were analyzed at 16 WAP. The results showed that 2.8 t ha -1 of Musanze travertine and burned lime increased 0.62 and 0. 61 units of soil pH, respectively. Lime rate of 2.8 t ha -1 of burned lime, Musanze and Rusizi travertines increased 1.72, 1.71 and 1.65 mg kg -1 of available P, respectively. On the other hand, burned lime and Musanze travertine improved soil nitrogen up to 0.24% in th e soils. The significant increase of available P after travertin e application was possibly induced by their ef fects in raising soil pH and reducing excha ngeable Al. The slight increase of N was due to the increase of soil pH which favors soil microbial activities fo r organic matter deco mposition. The similar effects of burned and travertine were attributed to their similar origin (travertine ro cks). Therefore, this study recommends the use of travertine i n acidic soils of Rwanda.