Municipal Household Solid Waste Compost: Effects on Carrot (<i>Daucus carrota</i>) Yield and Nutrient Content

Abstract

An experiment was conducted to evaluate the impact of municipal household solid waste compost on N, P and K uptake and yield of carrot (Daucus carrota), using a coastal savanna Haplic Acrisol. Bulked samples of fresh solid waste from 45 households within the Cape Coast Municipality in the Central Region of Ghana with 57 % total mass of organic components were composted using the pit method. Treatments applied were control, single supper phosphate (SSP) at 1.8g pot^-1 and sulphate of ammonia (SoA) at 2.0g pot^-1, compost at 7.0g pot^-1 and 14.0g pot^-1,  combined application of the 2 rates of compost and mineral fertilizer, and combined application of the 2 rates with 2.0g pot^-1 SoA. Each pot contained 7.0 kg of soil. A completely randomized design with four replicates was used. Carrot seeds were sown and nitrogen, phosphorus and potassium concentrations in carrot shoots were determined at six weeks after germination. Combined application of compost and inorganic fertilizer significantly increased N, P, K and ash concentration in the carrot shoot. Compost applied at 14.0g pot^-1 in combination with 1.8g pot^-1 SSP and 2.0g pot-1 SoA supplied 23 % N, 34 % K and 20 % ash to the carrot shoot, whereas sole application of compost at 14.0g pot-1 contributed 4.9 % N, 7.4 % K and 13.65 % ash respectively to the carrot shoots. Phosphorus content measured in the carrot shoots were however < 2.6 % in all treatments. Carrot yield positively correlated with shoot N, P and K contents (P < 0.01).

Keywords: Household solid waste, compost, biodegradable, Haplic Acrisol, Daucus carrota.