Conservation Tillage and Crop Rotation: Concomitant Systems to Incorporate Tef [Eragrostis tef (Zucc.) Trotter] Production with Sustainability in the Dryland Oromia

Abstract

The encorpration of tef production with sustainability in field experiments was conducted in 2003 and 2004 at two locations using different tillage options as the main plot and two cropping systems as sub plots under a randomized complete block design with three replications. Significantly higher mean grain yield of 1231 kg/ha was obtained from rotation plots as compared to the grain yield obtained from continuous tef monoculture (851 kg/ha). The same trend as grain yield was observed for straw and aboveground biomass yields. The increment of soil organic matter content for no-tillage over conventional tillage were 0.30 and 0.28% at 0-15 cm and 15-30 cm soil depths, respectively. Total soil nitrogen was increased by 0.03% in no-tillage over conventional tillage. The bulk density of no tillage at 0-15 cm (1.16 g cm^–3) and 15-30 cm (1.20 g cm^–3) was remarkably higher than that of conventional tillage (1.09 g cm^–3 and 1.10 g cm^–3, respectively). Both soil organic matter and total soil nitrogen concentrations
were higher for rotational cropping than monoculture. In the dryland Oromia, increasing soil organic matter is especially important, since many soils are naturally low in organic matter and high temperature leads to its rapid breakdown. Hence, the implementation of conservation tillage and crop rotation can be an effective concomitant strategy in improving soil properties and increasing yield of tef without an adverse impact on the environment.