Effects of household composts on soil properties and productivity of vegetable crops: the case of tomato (Lycopersicon esculentum Mill)

Abstract

In Kolwezi, the soils are generally sandy in texture. Their chemical richness is at a very low level for all nutrients with a direct impact on crop yields. In order to assess the impact of household compost on restoring the fertility of market garden soils in Kolwezi, a split-plot trial with two tomato varieties (Tanya and Tengeru) and three doses (20, 25 and 30 t.ha-1) of household compost applied alone and/or combined with 250 kg ha-1 of NPK compared to a control without fertilizer was set up in two market garden sites (Musompo and Mwangeji). The waste collected from 100 households was sorted and weighed to determine the physical composition of a bin and the biodegradable part was composted. To inform the agronomic value of the compost, chemical analysis was carried out. From this study, it was revealed that on average, a bin in Kolwezi is composed of more than 50% degradable waste, from which the compost that is produced is a reservoir of N, P, K and other elements essential for cultivation. Applied on a soil perceived as poor and confirmed by chemical analyses, the compost doses improve soil fertility as a result of the tomato yield. 11.4 t.ha-1 against 11.7 t.ha-1 obtained respectively with the inputs of 30 t.ha-1 of compost and 30 t.ha-1 + 250 kg.ha-1 of NPK, supposes that the compost from household waste would be used in legume-cultivation without being combined with mineral fertilizers. The additional application of 250 kg NPK inevitably leads to a decrease in profitability, so 20 t.ha-1 of compost is recommended. Microbial analysis and the use of household compost on leafy vegetables would be a second phase of the study.