Effect of Cyanobacterial Biofertilizer on Soil Quality in Kale (Brassica Oleracea L) Crop Growing Field at Ziway Area, Ethiopia

Abstract

The agricultural soil of Ethiopia is generally low in nitrogen (N) and phosphorus (P) which can affect crop production. Basically, commercial fertilizers could improve the soil fertility and crop yield. However, farmers are unwilling to use sources of inorganic fertilizers because of higher costs, accessibility and also in the long run, they affect the soil biota. This experiment was conducted to evaluate the effect of cyanobacterial biofertilizer on soil quality on kale (Brassica Oleracea L.) crop growing soil in Ziway. Five treatments: liquid cyanobacterial, dry cyanobacteria, urea, cattle manure and control were laid out in RCBD with three replications. Soil data were collected before and after harvesting the kale crop for selected soil physicochemical properties laboratory analysis and the data subjected to analysis of variance (ANOVA). The results showed that, soil total N, Organic Carbon (OC), available P, available Fe, and available Zn contents have increased by 1.2%, 0.49%, 21.1mg kg-¹, 3.54 mg kg-¹, and 5.31mg kg-¹, respectively over the control when dry Cyanobacteria biofertilizer was applied. Similarly, the incorporation of dry and liquid cyanobacteria biofertilizer was significantly decreased the soil pH to 6.6 and 6.9 over the control 7.75, respectively. Therefore, the use of cyanobacteria as a biofertilizer should be recommended as an alternative source of inorganic N fertilizer to improve the soil quality and reclaim alkaline soil for kale crop yield improvement for medium and small-sized farms in the study area.

Keywords: Anabaena species, Biofertilizer, Cyanobacteria, Soil Quality, Kale crop and N-fixing