In Sudan, loss of soil fertility and rainfall variability are among factors that contributed to low yields (Ayoub, 1999). Studies on the predominantly sandy soils have shown the complexity of soil fertility problems (Giller, 2001). There are slim chances of building soil organic matter in the tropics and hence nutrient stocks (Giller et al., 1997), rendering farmers to rely heavily on external nutrient inputs on a seasonal basis. However, most of the smallholder farmers use sub-optimal amounts of fertilizers due to cash limitations and poor access to fertilizer markets. Therefore, it is important to recycle both endogenous and exogenous nutrient pools.
Utilization of composted baggasse, water hyacinth and banana wastes in reclamation of desert soils
Inputs of organic materials play a central role in the productivity of many tropical farming systems by providing nutrients through decomposition and substrate for synthesis of soil organic matter. Organic inputs are currently of low quality and insufficient quantity to maintain soil fertility.
Objectives
In order to make use of organic wastes in agriculture there is a need to study their nutrient dynamics in the field, possibilities for modification of C/N ratio and their agronomic value.
The specific objectives of this project is:
To look at decomposition and nutrient release (N, P. K, Ca, Mg and trace elements) from baggasse wastes, banana wastes and water hyacinth.
To determine the effect of organic residues on the quality of sandy soils (OC, TN, P, K, water retention capacity, hydraulic conductivity, infiltration rate etc.)
To determine yield response of selected vegetables and fodder crops to recycled organic wastes of baggasse, banana and water haycinth.
Activites
Demonstration for farmers: The experimental site for the research will be prepared in the presence of farmers. They will be involved from the early stages of the project.
Compost preparation: At the beginning, there will be an analysis of the C and N content of the raw materials. Farmers will be informed that the starting material should have a certain C/N ratio. The following step is to calculate the ratios of the raw materials before mixing, in order toproduce a compost of good quality.
Monitoring decomposition and nutrients release: This is a field experiment set to monitor release of nutrients during decomposition.
Horticultural value, Agronomic values: These are field experiments to test the effects of compost on production of crops needed by farmers.
Expected Results
1. Improving the quality of sandy soils through practical management of organic wastes.
2. Solving the problem of N immobilization during recycling of baggasse compost.
3. Increasing the efficiency of residue nutrients through better synchrony.
4. Monitoring how nutrients are released and made available to crops in the dry tropics.