Project
Effects of fertilization on productivity and nutritional quality of crops in Northern Ghana
The nutrient status of soils in northern Ghana is low. It is therefore expected that fertilizer application will lead to a substantial increase in yield. Yet, the yield increase in maize, and soybean when fertilizer is applied is lower than the expected. The low yield increase can be traced to in-season soil moisture variability. This study is therefore seeking to enhance the yield increase in maize and soybean under fertilizer application by using agronomic practices aimed at enhancing the effective uptake and utilization of soil moisture.
Background
Soils in northern Ghana are low in nitrogen (N), phosphorus (P) and potassium (K) (Antwi et al., 2016; Jayne et al., 2015) with levels below 0.1, 0.001 and 0.012 %, respectively, required for optimal crop yields (Tetteh et al., 2016). This has made the application of fertilizers containing these nutrients a prerequisite for optimal crop yields.
Nevertheless, maize and soybean farmers who apply fertilizers containing these nutrients get low yield increase per kg fertilizer applied under rainfed conditions. For instance, the yield increase per kg N (nutrient-use efficiency; NUE) has been found to be within the range of 5-13 kg for maize (Adzawla et al., 2021a). This is however 2-4 times lower compared to the yield response that has been reported for other African countries like Kenya (Sheahan et al., 2013). Among the factors that could contribute to the low yield increase, soil moisture variability due to insufficient rain has been found to be the most important (Adzawla et al., 2021a). This study is therefore seeking to enhance the yield increase in maize and soybean under fertilizer application by using agronomic practices aimed at enhancing the effective uptake and utilization of soil moisture. Changes in the nutritional quality of harvested produce will also be determined.
Project description
The study will be carried out in northern Ghana with maize and soybean. These two crops are among the staple crops grown in northern Ghana for food and feed (Adzawla et al., 2021b). Field experiments will be conducted at two locations varying in soil depth. Fertilizer containing nutrients including N, P and K will be applied in conjunction with practices such as ridging, mulching, increased planting density, different varieties and S application to ascertain the increase in yield and changes in nutritional quality that may result. The nutritional quality will be assessed using indicators such as Zn, Fe, and phytic acid concentrations and their ratios.