The Effect of Black Soldier Fly Frass, NPK, and Azolla on the Vegetative Growth of Spinach

Abstract

The study was carried out in a screen house at Makerere University. The xperimental materials included marrum soil, Black soldier fly (BSF) frass, Azolla, and NPK fertilizer. The soil used was excavated from an open field and sieved before use in the experiment. The BSF frass was obtained from Ento-organic farm, while Azolla and NPK (10:10:10) was procured locally. Different concetrations of BSF frass, Azolla, and NPK) were used that is to say high(45g), medium(30g), and low (15g) and applied in pots containing spinach plants in replicates and experiment monitored weekly for 10 weeks. A control setup was also included. The leaf area and other growth parameters of the plants were recorded for the different sets of fertilizers and data was analyzed using a multi-way ANOVA to determine the effects of fertilizer type, concentration, and fertilizer: concentration on leaf area index, fresh weight, and maximum height. Post-hoc tests were conducted to compare means and determine significant differences. It was found out that the effect of concentration and fertilizer type on fresh weight and maximum height for BSF frass was significant compared to NPK and Azolla while the effect on leaf area index of the same fertilizers was not significant. (p<0.05) It was also discovered that the high concentration of potassium in NPK hindered normal plant growth and hence resulted in a reduced increase in fresh weight and maximum height. Therefore BSF frass can be adopted as a fertilizer for growth of leafy vegetables.