Evaluating effects of conventional practice and straw mulch applications on moisture conservation in semi arid Ethiopia.

Abstract

The dry land areas of Ethiopia account for more than 66.6% of total land area, and are substantial crop producing areas fall within the semi-arid parts. As a result, crops experience moisture stress at any time during their growth stage. The first action to improve agricultural production in the dry land areas is to apply moisture conservation techniques and then use the limited water efficiently for enhancing water productivity. A study was conducted at Holte kebelle of Dirashae district from April 1, 2016-July 31, 2016 to evaluate effects of conventional practice and straw mulch applications on soil moisture conservation and yield of sorghum under rainfed agriculture with six levels of sorghum straw mulch. The experiment was designed as a single factor experiment in randomized complete block design and replicated four times. Soil moisture has been taken for six times of 30 cm interval up to sorghum root depth (90 cm) in 3 weeks interval and analyzed volumetric moisture content. Physical and chemical properties, Field Capacity and Permanent Wilting Point in respective depths were analyzed. The analysis of variance indicated that there was highly significant difference (p ≤ 0.05) for soil moisture contents determined at 0-30 cm, 30-60 cm and 60-90 cm at different sorghum growth stages and straw applied. 2.2 and 3.0 ton/ha straw mulch prolonged the days to harvesting due to more moisture conservation in the soil profile and significant in growth and yield parameters. The maximum volumetric soil moisture content was recorded in 2.2 and 3.0 ton/ha straw mulch, which were between the Field Capacity and Permanent Wilting Point at different growth stages of sorghum however, grain yield was higher in 2.2 t/ha. Based on the experiment therefore, application of 2.2 ton/ha of sorghum straw mulch was found more effective in conserving soil moisture for maximum yield under rain-fed agricultural system better than other treatments.

Smallholders' Conservation Agriculture Adoption Decision in Arba Minch and Derashe Districts of Southwestern Ethiopia

“…Derashe is located in southwest Ethiopia with unpredictable and inadequate rainfall; hence, crop production was threatened by chronic soil moisture stress [18]. Short rainwater quickly evaporates due to soil-water evaporation exacerbated by the high temperature at low altitudes.…”

“…Derashe and Arba Minch Zuriya are neighboring districts with contrasting tillage and soil management practices; however, both dominantly cultivate maize (Zea mays) and sorghum (Sorghum bicolor) in common. In the early years, Derashe district residents sufered from soil erosion, rainwater shortages, and soil moisture stress [18]. As a result of erratic rainfall as well as smallholders' traditional tillage practices lacking appropriate soil management practices, the situation became critical.…”

“…Tese factors led to the invention of CA, using an indigenous moisture conservation technique known as Targa-na-Potayta. In this technique, own farm input is used for mulching and decomposed crop residue is used as a nutrient supplement [18][19][20]. In this land management system, only the cob of maize or the head of the sorghum harvest is taken and leaves the stalk in the feld to minimize nutrient mining from biomass removal.…”