Characterisation of soil physico-chemical properties under furrow irrigated maize in Mubuku 1 irrigation scheme.
Abstract
There are limited reports about the characterisation of soil physico-chemical properties under furrow irrigated maize (Zea mays L.) in Mubuku irrigation scheme. Irrigation practices have been observed to impact scheme soil properties and other parameters negatively. These could be as a result of irrigation water quality, method of application and nature of scheme soil. This study was therefore conducted to study the relationship of soil physio-chemical properties and furrow irrigation practices of maize on the physico-chemical properties of soils at Mubuku Irrigation Scheme, Kasese district, mid-western Uganda. Soil samples were taken at depths 0 – 15 cm, from the maize garden at the study area and were analysed for chemical parameters (pH, Available P, TN, SOC, SOM, Ca, Na, and K) and physical property (texture). Slope position had no significant (P>0.05) effect of on soil pH in a maize field at Mubuku I Irrigation Scheme. The soil pH is the moderately acid making pH is not a key problem for maize production. The pH ranges (6.6±0.17 to 6.8±0.17) of the soils studied explains the high amount of Available P in the furrow irrigated maize in Mubuku 1 irrigation scheme. Slope position had significant (P<0.05) effect on SOC and SOM. The content of SOM was highest at the upper slope position and lowest in the lower slope position. The poor drainage of soils at the upper slope position causing a decline in soil oxygen concentrations due to poor aeration has led to typical accumulation higher levels of SOM than well-drained soils at the lower slope position. The mean value of total N was 0.20% which is ≥0.2 considered the lower threshold limit, implying that N is adequate in the soil. The mean available P was 90.5 ppm which is above the critical limit of 15ppm and the concentration of available P gradually increased down the slope position. The overall average K was 0.08 cmol/kg which is below critical (0.4 cmol/kg) limit for a soil which indicates the requirement for K fertilizer application. The general mean (cmol/kg) of Na was found to be 0.032 which is below the cut-off point for medium rate (0.7 cmol/kg) which is regarded as not potentially sodic.