Effects of straw mulch and farmyard manure on runoff, erosion, in-situ water conservation, and yield and yield components of wheat at the highlands of Bale, south eastern Ethiopia

A field experiment was conducted under natural rainfall conditions to investigate the effects of farmyard manure and straw mulch on runoff, soil loss, in-situ water conservation, and the yield and yield components of an improved bread wheat variety (HAR-1480) grown on vertisol of Sinana area, south eastern Ethiopian highland. The experimental design used was randomized complete block design (RCBD) with seven treatments involving three levels of farmyard manure (2, 4 and 6 ton ha-1), three levels of barley straw mulch (2, 4 and 6 ton ha-1), and a control without manure and mulch that were replicated three times. The results revealed that there was a highly significant difference (P<0.0001) between the treatments regarding their effect on runoff depth, soil loss and in-situ water conservation. However, there was no significant difference in grain yield due to the treatments. Moreover, compared to straw mulch, manuring was found to be less effective in reducing runoff and soil loss in the first season of application. Additionally, the soil loss measured for all strawmulch rates were not significantly different, implying that the 2 ton ha-1 mulching rate can effectively check soil erosion under the existing slope and rainfall conditions of the study area.   Key words: Bale highland, runoff depth, soil conservation, grain yield, sediment concentration.