The potential of anthill soils in smallholder maize production under conservation based agricultural systems in southern Zambia

Abstract

Soil fertility is one of the fundamental challenges faced by cash constrained smallholder farmers across sub-Saharan Africa. In an effort to ward off this hurdle, some smallholder farmers in southern Zambia opt to use anthill soil as alternative fertilizer to enhance soil fertility and mitigate against exorbitant fertilizer costs. This study investigated the potential of using anthill soil as fertilizer for enhancing crop productivity under conventional (CONV) and conservation agriculture (CA) tillage systems with two principals involving minimum tillage and soil cover. The study was conducted in Pemba and Choma districts of southern Zambia where the practice of anthill soil utilization is widespread. Qualitative and quantitative approaches were employed to gather data for the surveys using open data kit (ODK) tool. Pot and on-farm experiments were set in Complete Randomized and Randomized Complete Block Designs to assess growth parameters; plant height, girth, dry matter yield, plant uptake, leaflet length, width and area, grain, stover and core yield of test crop under anthill soil, mineral fertilizer, manure and their combinations. All data recorded were analyzed using Statistical Package for Social Sciences (SPSS) 22, STATISTICA 2010 Programme, GEN STAT 15 th edition and Origin Pro 9.0. Results from the survey revealed that key barriers to the application of anthill soils in agriculture production lay in biophysical, technological, land, institutional and agro-climatic issues. The study also found that elevated macro and micro nutrients were more pronounced in top segments of the anthills. Significant (p<0.05) growth parameter yields were observed in sole anthill soil (5 000 kg/ha) and in combination with manure (10 000 kg/ha) or half rate mineral fertilizer (100 kg/ha; 10% N: 20% P 2 0 5 : 10% K 2 O: 6% S and 46% NH 4 NO 3 ) under both pot and field conditions. Phosphatase enzyme activity across the study districts was lower in comparison to arylsulphatase. Moisture retention capacity was consistent in both CONV and CA plots and only in Pemba site. Financial benefits were accrued more in treatments involving sole anthill and in combination with manure. To attain optimal benefits from the practice of anthill soil utilization under CA systems, there is a need for capacity building amongst users on appropriate application techniques.