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Nutrient release patterns and heavy metal contamination risks associated with animal manure and organic municipal wastes used as basal fertilisers are largely unknown in Zimbabwe. Carbon, nitrogen and phosphorus mineralisation patterns were determined in a 56-day incubation experiment of domestic sewage sludge (SS), pig (PG), poultry (PM) and cattle manures (CM). Maize biomass production, and nutrient and heavy metal (cadmium, copper, nickel and zinc) uptake were determined in a greenhouse experiment. Inorganic fertiliser, PG, PM, SS and CM were applied to the first maize crop and a second maize crop grown without addition of fertilisers. Aboveground biomass was harvested at four weeks after emergence. Fertiliser treatments had significant (p < 0.01) effects on mineralisation. Carbon, nitrogen and phosphorus mineralisation followed the order PG > PM > CM > SS. Maize grown in PM- and PG-amended soils had significantly (p < 0.01) higher biomass, nitrogen and phosphorus uptake than inorganic fertiliser-amended soil in the first crop. The second crop grown in organic fertiliser-amended soils had significantly (p < 0.01) higher biomass and nutrient uptake than inorganic fertiliser-amended soil. Heavy metal uptake was highest in SS-amended soils. Poultry and PG manures mineralised faster than SS and CM. Organic fertilisers had more residual fertility. Nickel toxicity is likely when SS is used as a fertiliser.Keywords: heavy metal uptake, mineralisation, nutrient uptake, organic fertiliser, urban agricultureSouth African Journal of Plant and Soil 2014, 31(2): 93–100

No-till planting basins are promoted using seed and fertiliser inputs as incentives for their widespread uptake in Zimbabwe. Notill planting basins are planting holes measuring 15 cm width x 15 cm length x 18-20 depth, spaced 60 cm within the row and 75- 90 cm between rows leaving up to 90% of the soil surface undisturbed. They are intended to conserve moisture and improve the targeting of nutrient application. We evaluated the effect of planting basins on crop yield and labour requirement in an on-farm experiment over two seasons in Murehwa district, Zimbabwe. The experiment was established in clay and sandy soils, in two fields types; degraded and better managed fields in 2009/2010 and 2010/2011 seasons. Two tillage treatments i.e mouldboard ploughing and no-till planting basins were tested. Tillage plots measured 1080 m2 (18 m x 60 m) and labour hours were derived by direct measurement in these plots. Due to grazing in the dry season, soil surface cover by crop residues in the experimental fields was less than 10% in both seasons. Previous field management, nutrient management in the experiment and season had a significant effect on crop yields (p