One of the major constraints associated with Sorghum [Sorghum bicolor (L.) Moench] cultivation is striga weed and improper nutrient management. Therefore, a field experiment was conducted during the 2013 cropping season to study the influences of different levels of nitrogen (N) and vermicompost (VC) application on Striga infestation and soil fertility status at Fedis Agricultural Research Center, eastern Ethiopia. The treatments consisted of three rates of N (0, 46, 92 kg/ha) and five rates of vermicompost (VC) (0, 0.5, 1, 1.5, 2 t/ha). The experiment was laid out as a randomized complete block design in a factorial arrangement and replicated three times. The analysis of variance revealed significant differences in the parameters studied. The results of this study revealed that application of vermicompost significantly increased soil organic carbon, total nitrogen, available phosphorus, and exchangeable potassium contents. At sorghum flowering, the interaction effect of vermicompost and nitrogen significantly (P < 0.05) influenced soil moisture content. Moreover, vermicompost had a much more profound effect on enhancing moisture content of soil than nitrogen. Nitrogen and vermicompost interacted to significantly (P < 0.01) influence the number of Striga per hectare. Number of Striga in the control plot was about 4.6-fold higher than in the plots treated with the highest rates of the two fertilizers. However, increasing the rate of nitrogen from nil to 46 kg N/ha resulted in a 57% increase in grain yield, with no further increases noted beyond this level. Similarly, increasing the rate of vermicompost from nil to 1.0 t/ha increased grain yield of sorghum by about 17%. In conclusion, the findings of this study have demonstrated that application of 46 kg/ha nitrogen and 1.0 t/ha vermicompost significantly reduced infestation of Striga in sorghum, improved soil moisture and nutrient contents, and enhanced yield of the crop.
Soil properties, Striga hermonthica,vermicompost.