Variability of soil physical and chemical properties across land productivity classes in banana plantations in Kabarole district

Abstract

Management practices such as mulching, intercropping, manuring/fertilizer application, water conservation, weeding, gap filling and so on affect the quality of soils and the crop productivity of farms. Assessing the soil physiochemical properties and subsequent implications on soil fertility is essential for understanding the influence of management practices on agricultural soil quality and the productivity on farms. This study, assessed the effect of management practices on selected soil properties and yield and the state of soil quality under banana plantations across sub-counties of Bukuku, Karangura and Kicwamba in Kabarole district - Uganda. The study site was stratified into land productivity classes based on tonnes of bananas per acre per farmer that is; increasing productivity, stable productivity, stable but stressed productivity, slightly declining productivity and declining productivity. Soil sampling and socio-economic analysis were conducted in each of banana land productivity classes. Basing on mean soil texture percentages, the soils across the study area can be classified as sandy clay loam, fine soils. The analysis of variance for selected soil properties under different productivity classes didn’t show statistical significance at P<0.05. There was a statistical significance (P<0.05) in yield of banana plantations under different productivity classes across the study area. The yield was highest in increasing and stable productivity classes averaging at 4.033 tonnes of bananas/acre compared to the rest of the productivity classes which averaged at 1.16 tonnes/acre. Nitrogen and Potassium were higher in increasing productivity and stable classes, moderate in stable but stressed productivity class and slightly declining productivity, and lowest in declining productivity class. The exchangeable cations, i.e., sodium was generally constant across the productivity classes. Magnesium was increasing across the productivity classes from increasing to stable to stable but stressed to declining productivity classes though it was lowest in slightly declining productivity class. Calcium followed the same trend like of magnesium. Soil pH was highest in slightly declining productivity class (pH=6.66) and lowest in increasing productivity class (pH=6.48). Soil organic matter (SOM) was highest in increasing, stable and stable but stressed productivity classes averaging at 6.2% and lowest in slightly declining and declining productivity classes averaging at 2.865%. In conclusion, the results showed soil that soils in increasing and stable productivity classes were generally superior to the rest of the productivity classes. The results from regression models and analysis of variance also showed that management practices significantly influenced the yield on the plantations.