EFFECT OF INTEGRATED SOIL FERTILITY MANAGEMENT ON SELECTED SOIL PROPERTIES AND YIELD OF BREAD WHEAT (Triticum aestivum L.) IN SINANA DISTRICT, ETHIOPIA

Abstract

Bread wheat is an important food security and cash crop in Ethiopia, particularly in the Bale and Arsi highlands. However, the yield of the crop is constrained by poor soil fertility management practices. Therefore, a field experiment was conducted during the 2015 main cropping season at Selka Kebele of Sinana District in Bale zone of Oromia Regional State, southeastern Ethiopian with the objective of investigating the influence of biochar, farmyard manure, and mineral nitrogen fertilizer on soil physico-chemical properties and yield, and yield components of bread wheat. The treatments consisted of two levels of farmyard manure (0 and 6 tons ha-1), three levels of biochar (0, 5, and 10 tons ha-1) and three levels of nitrogen (0, 23 and 46 kg N ha-1). The experiment was laid as a randomized complete block design (RCBD) with three replications using the improved bread wheat variety Sanete (14F/ HAR 1685) as a test crop. The results revealed that the interaction effects of biochar, farmyard manure, and mineral nitrogen fertilizer significantly (P<0.001) influenced the physico-chemical properties of major contents of soil available potassium, nitrate nitrogen and ammonium nitrogen after two months of treatments application. Similarly, the analysis of variance showed that the interaction effect of biochar and farmyard manure levels significantly (P<0.05) influenced soil reaction (pH) and CEC. Likewise, bulk density was also affected by the treatments at post-harvest. The yield and yield components of the crop as well as the net economic benefits obtained were also significantly influenced by the interaction effects of the treatments. The highest adjusted grain yield of 6324.90 kg ha-1 was recorded in response to the combined application of 10 t biochar ha-1 +6 t FYM ha-1 +46 kg N ha-1. However, the application of 5 t biochar ha-1 + 0 t FYM ha-1+46 kg N ha-1 remains profitable and recommended for farmers in Sinana district and other areas with similar agro ecological condition. It could, thus, be concluded that, applying biochar at the rate of 5.0 t ha-1combined with 46 kg N ha-1 resulted in optimum grain yield of the crop.