Effects of soil amendments on selected soil chemical properties and productivity of tef (Eragrostis tef [Zucc.] Trotter) in the highlands of northwest Ethiopia

Abstract

The lack of sustainable soil fertility management is a critical challenge for crop production in the world. The problem is more serious in the East Gojjam Zone highlands. Integrated use of lime, manure, and chemical fertilizers is considered as a good approach for sustainable crop production on acidic soils. In 2016 and 2017, a field experiment was conducted to determine the effect of soil amendments on soil fertility and tef productivity in the Gozamin district. Factorial combinations of two rates of lime (0 and 2 t ha-1), two rates of NP fertilizers (0/0 and 46/20 kg N/P ha-1), and three rates of cattle manure (0, 10, and 15 t ha-1) were laid out in randomized complete block design with three replications. The results showed that applying lime in combination with NP fertilizer and manure significantly improved soil chemical properties. Panicle length, effective tillers, and thousand seeds weight of tef increased from 25.1 to 44.4 cm, 2.8 to 11.3, and 0.23 to 0.37 g, respectively, when 10 t ha-1 manure and recommended NP fertilizer were applied together. The highest tef grain yield of 2.31 t ha-1 and net benefit of 2,252.91 USD ha-1 were obtained from the interaction of 10 t ha-1 cattle manure, 46/20 kg ha-1 N/P fertilizer, and 2 t ha-1 lime. This study recommends the combined application of 2 t ha-1 lime, 10 t ha-1 cattle manure, and 46/20 kg ha-1 N/P fertilizer as an effective amendment to improve soil chemical properties and yield of tef in acidic soils of northwest Ethiopian highlands.