Application of Different Rates of Black Soldier Fly Frass and Cattle Dung Fertilizer on Maize Performance and Yield in Sudan Savanna Zone of Nigeria

A field experiment was conducted during the 2023 dry season (sown 3 February, harvested 23 April) at two sites in the Sudan savanna zone of Nigeria: the Centre for Dryland Agriculture (CDA) research farm, Bayero University Kano (BUK), and a farmer’s field at Dambatta, Kano State. The study evaluated the effects of different rates of black soldier fly (BSF) frass and cattle dung on the growth and yield of maize (EDVT). Five treatments were laid out in a randomized complete block design with three replications at each site: high frass (15 t ha⁻¹), medium frass (10 t ha⁻¹), low frass (5 t ha⁻¹), cattle dung (10 t ha⁻¹) and an unamended control. Plot size was 3 m × 3 m with 0.5 m between plots and 1.0 m between replications. Amendments were applied once, immediately after sowing, and plots were irrigated at 2-day intervals. Soils at both sites were sandy loam and low in organic carbon (4.5 to 4.6 g kg⁻¹), total nitrogen (0.5 to 0.6 g kg⁻¹) and available phosphorus (0.58 to 0.75 mg kg⁻¹). Frass contained more organic carbon, nitrogen, phosphorus, calcium and magnesium than cattle dung. Frass application significantly increased plant height (2 to 7 weeks after planting, WAP), leaf area (1 to 8 WAP) and chlorophyll content (1, 6 and 10 WAP) compared with the control and cattle dung. Grain yield differed significantly among treatments (P<0.001). High frass gave the highest yield (4035 kg ha⁻¹), about 121% above the control (1822 kg ha⁻¹) and 58% above cattle dung (2548 kg ha⁻¹). Medium and low frass also out-yielded the control, but only the high rate significantly outperformed cattle dung. The fertilizer × location interaction was not significant for yield. These results show that BSF frass, particularly at 15 t ha⁻¹, is an effective and sustainable organic fertilizer for improving maize production in the Sudan savanna.