One of the most important challenges to continuously maximize crop production on limited areas of agricultural land is to maintain or enhance soil fertility. Organic fertilizer application is needed to replace nutrient removed by crop from the fields in order to restore crop production potential of a soil. But application of organic fertilizer alone insufficiently increases crop yield per area because the nutrient content of organic fertilizer is unbalanced. A trial was conducted in the Lubumbashi region to investigate the combined effects of mineral fertilizer and chicken manure application on the balance of minerals and maize yield. Three mineral fertilizer doses (0 kg NPK+0 kg urea, 150 kg NPK+100 kg urea, 300 kg NPK+200 kg urea) and four chicken manure quantities (0, 1.75, 3.5, 7 t haG 1 ) have been tried. The combination of these factors gave a total of 12 treatments. According to obtained results nitrogen and phosphorus content before maize sowing is higher than those obtained after flowering. The present work confirms that integrated application of chicken manure and mineral fertilizers is more effective in increasing nutrient availability and maize performance than mineral or organic fertilizer applied alone. In contrast, applied doses of chicken manure have not improved soil nutriment balance sheet. Combined with the low dose of mineral fertilizers (150 kg NPK+100 kg urea), the amount of 7 t haG 1 of chicken manure resulted a better yield increase, which corresponds to 46% compared to the control, of which 16% only are due to mineral fertilizer application.

Improving soil fertility through organic fertilizers application has become a major factor that has enabled the world to feed billions of people. However, the required quantities of organic material are enormous, so it becomes necessary to combine different types of fertilizers to feed plants. The objective of this study was to evaluate the effects generated by the integration of human faeces to mineral fertilizers by bringing them to okra (Abelmoschus esculentus) crop. The trial was installed according to a 4×3 factorialdevice. Treatments in three repetitions, included four doses of human faeces (0, 1.75, 3.5 and 7 t haG 1 ) and three doses of inorganic fertilizers (0 and 150 kg NPK+100 kg urea as mineral fertilizer popularized and 75 kg NPK+50 kg urea as mineral fertilizer popularized halved). These fertilizers were applied alone or in combination and were compared to an unfertilized control. Obtained results showed that emergence rate increases when human faeces are made at low doses. As for the vegetative parameters, the results are similar regardless of the type or dose of made fertilizers. Without mineral fertilizers the different doses of human faeces generate low yields of okra. The application of 7 t haG 1 of human faeces combined with popularized mineral fertilizer dose halved (75 kg NPK+50 kg urea) afforded the highest yield (7.3 t haG 1 or an increase of 348% compared to unfertilized control treatment). In the present study, where access to chemical fertilizers is very limited, these results allow to save a half of usually made mineral fertilizer dose for the cultivation of okra.