Soil organic carbon and nutrients in smallholding land uses in southern Ethiopia

Abstract

This study assessed the soil organic C (SOC) and soil nutrients in smallholding home garden, woodlot, grazing land, and cropland at two soil depths and two sites in Wolaita Zone, southern Ethiopia. The results showed that soil properties were significantly influenced by land use. The home garden had significantly higher (p < 0.05) SOC and soil nutrients when compared to the cropland. When the home garden was compared to the woodlot and grazing land uses, it had significantly higher (p < 0.05) values except in SOC, total N (TN), cation exchange capacity (CEC), and exchangeable Ca. Cropland, in comparison with grazing land and woodlot, had a non-significant difference except TN. The SOC stock (0-40 cm) in the home garden, woodlot, grazing land and cropland was 79.5, 68.0, 65.0, and 58.1 Mg ha -1 , respectively. Home garden significantly differed (p 0.05) in SOC only from cropland, and this was attributed not only to the relatively higher organic input in the home garden but also to the little organic matter input and frequently tillage of the cropland. The similar SOC among the home garden, woodlot and grazing lands may imply that the balance between inputs and outputs could be nearly similar for the land uses. Soil TN and CEC had a nearly similar pattern of difference as in SOC among the land uses because of their close relationship with SOC. In general, the land use influence on soil nutrients can be in the order: home garden > wood land grazing land cropland, with home garden showing the least difference from the woodlot and the greatest from the cropland. In the agroecosystem, in general, the influence of smallholding home garden on SOC and soil nutrient was marginally different from Eucalyptus woodlot and grazing lands but evidently different from cropland.

Phosphorous Sorption Characteristics of Soils in Smallholding Land Use in Southern Ethiopia

“…However, the lowest MBC in the grazing land and home garden suggests the lower P sorption capacity with increasing P concentrations in the soil. e organic matter input in the home garden and manure from grazing livestock in grazing land could contribute to the higher SOC [17]. us, less buffered soil can supply high P to soil solution due to higher SOC, of the mineralization as well as interference with sorption, supplies a relatively higher P to the soil solution [33].…”

“…e soil sample was air-dried, ground with mortar and pestle, and passed through a 2 mm sieve. e soil parameters: pH, OC (organic carbon), clay, AP (available phosphorous), and CEC (cation exchange capacity) were determined as presented in Lulu et al [17]. Dithionate-citrate-bicarbonate (DCB) extractable Fe, Al, and Mn oxides (Fe d , Al d , and Mn d ) were determined by the method described by Mehra and Jackson [18].…”

Estimating acid soil effects on selected cereal crop productivities in Ethiopia: Comparing economic cost-effectiveness of lime and fertilizer applications

“…In all it is estimated that 40% of Ethiopia’s arable lands are acidic [ 11 ]. More recent assessments have indicated that soil acidity is expanding in scope and magnitude in Ethiopia, seriously affecting crop production [ 15 ]. For example, in some barley, wheat and fava bean growing areas of central and southern Ethiopian highlands, farmers have shifted to producing oats that are more tolerant to soil acidity [ 16 , 17 ].…”