Tropentag, September 10 - 12, 2025, Bonn "Reconciling land system changes with planetary health"

Agronomic and economic performance of fertiliser microdosing in the shea-maize agroforestry parklands of Benin

¹University of Kassel, OPATS, Germany
²University for Development Studies, Dept. of Soil Science, Ghana
³West African Science Service Center for Climate Change and Adopted Land Use (WASCAL), Burkina Faso

Abstract

Maize (Zea mays L.) is widely cultivated and plays an important role African people’s food security. Despite it importance, average yield of maize in West Africa has stagnated at 2 tons ha^-1 yr^-1 which is one-third of the global average. This stagnation is due to declining soil fertility since nutrients lost through harvest are not replaced through mineral fertilisers. Like other African countries, Benin tried to increase maize yield by reccommending blanket application of mineral nitrogen (N), phosphorus (P), and potassium (K) at rates of 76 kg N ha^-1, 13.1 kg P ha^-1, and 24.9 kg K ha^-1). However, due to often lacking cash availability for the purchase of inorganic fertilizers and often low and highly variable sowing rates, adoption of blanket fertilizer application at this rate is low. This led to the development of fertilizer microdosing which has been reported to enhance seedling establishment, plant growth, grain yield and fertiliser use efficiency (FUE). However, studies regarding its profitability, labor and time requirements under the typical agroforestry systems of the region are lacking. Therefore this study was carried out in Vitellaria paradoxa C.F. Gaertn. parklands to compare yield, profitability, and labour requirements of maize under no fertilizer (control), fertilizer microdosing (MD), and reccomended rate (RR) of broadcast mineral fertilizer application. Four V. paradoxa trees were selected and under each tree four distance areas from the tree were delineated: canopy area, 3 m from the canopy, 10 m from the canopy, and 20 m from the canopy, respectively zone A, B, C and D. In each zone, three fertilisation strategies were applied to maize. The treatments were (i) control, (ii) MD with NPK 15-15-15 applied in the planting hole alongside the seeds (17.8 kg N ha^-1, 3.1 kg P ha^-1, and 5.8 kg K ha^-1), and (iii) RR. The data showed no significant interaction between zone and fertiliser application. RR grain yields in zone D were 2.2 times higher than control yields in Zone A (p = 0.01). MD required 45% more time at sowing than control and RR (p < 0.01). Also, total labor time of RR was 12% higer than of MD (p < 0.01). MD and RR showed total costs that were 15% and 55% higher than for the control treatment, generating total revenues that exceeded the control by 1.22 and 1.85 times (p < 0.01) whereby the amount of fertiliser applied in RR was four times higher than in MD. Overall, maize in MD plots had a 50% higher FUE than in RR plots (p < 0.01). Fertilizer MD may thus be a viable entry pathway to intensified production of agroforestry systems for farmers with scarce cash availability.

Keywords: Fertiliser application, labour requirements, profitability, soil fertility, sustainable agriculture, tree crop interactions

Contact Address: Geronime Marlene Houeto, University of Kassel, Organic Plant Production and Agroecosystems Research in the Tropics and Subtropics, Witzenhausen, Germany, e-mail: hgeronimegmail.com