No abstract

To assess the effect of different water application schedules on the growth and yield of lettuce (Lactuca sativa var. crispa), a field experiment was carried out at Golinga Irrigation Site. Four treatments were laid out in a Randomized Complete Block Design in four replications. The treatments were; TRT1 (adlib application by farmers), TRT2 (100% of the daily ETc applied only in the morning at each growth stage), TRT3 (100% of the daily ETc applied only in the evening at each growth stage) and TRT4 (100% ETc split: 50% of the daily ETc applied in the morning and the other 50% applied in the evening at each growth stage). The daily crop water requirement (ETc) of the crop was calculated for the four stages of growth using the CROPWAT software bearing in mind the area of each bed (16m 2). The data was analyzed using the Genstat Software. The results revealed that plants grown in the TRT4 grew healthier and recorded the highest plant height (23.3cm), number of leaves (9), leaf spread (25.03cm), leaf area index (5.25), and fresh matter weight of leaf (43.0g), yield (28.3t/ha) and water productivity (7.2kg/m). Plants grown in TRT3 recorded the least values for plant height (19.8cm), number of leaves (7), leaf spread (20.9cm), leaf area index (4.1), fresh matter weight of leaf (30.7g), yield (13.9t/ha) and water productivity (3.5kg/m 3). It is recommended that interested lettuce farmers could adopt TRT4 water application schedule since it gave the highest values in all the parameters used for data collection.

Effective management of reservoir sedimentation requires models which can predict sedimentation of the reservoirs. In this study, linear regression, non-linear exponential regression and artificial neural network models have been developed for the forecasting of annual storage capacity loss of reservoirs in the Guinea Savannah Ecological Zone (GSEZ) of Ghana. Annual rainfall, inflows, trap efficiency and reservoir age were input parameters for the models whilst the output parameter was the annual sediment volume in the reservoirs. Twenty (20) years of reservoirs data with 70% data used for model training and 30% used for validation. The ANN model, the feed-forward, back-propagation algorithm Multi-Layer Perceptron model structure which best captured the pattern in the annual sediment volumes retained in the reservoirs ranged from 4-6-1 at Karni to 4-12-1 at Tono. The linear and nonlinear exponential regression models revealed that annual sediment volume retention increased with all four (4) input parameters whilst the rate of sedimentation in the reservoirs is a decreasing function of time. All the three (3) models developed were noted to be efficient and suitable for forecasting annual sedimentation of the studied reservoirs with accuracies above 76%. Forecasted sedimentation up to year 2038 (2019–2038) using the developed models revealed the total storage capacities of the reservoirs to be lost ranged from 13.83 to 50.07%, with 50% of the small and medium reservoirs filled with sediment deposits if no sedimentation control measures are taken to curb the phenomenon.

Municipal waste management has been of major concern to many developing countries and is presently one of the subjects under discussion due to rapid industrialization and population growth. Most of these municipal wastes have the potential of being recycled and use in crop production. They are gradually becoming a problem in Ghana instead of being used for purposes to benefit human kind. In this study, dried faecal sludge and municipal waste co-compost was used as an organic fertilizer to cultivate cabbage and lettuce to assess its effects on their microbial load and yield. The yields of vegetables increased significantly with the application of recommended doses of the co-compost. The analysis of microbial load on the vegetables also showed significantly low microbial load on vegetables cultivated on co-compost plots followed by the chemical fertilizer and control. The presences of faecal coliforms such as Salmonella spp., Shigella spp., Escherichia coli, and Klebsiella spp. were confirmed in all. The performance of vegetable cultivated on plots treated with the co-compost makes it a good source of plant nutrients to be recommended to farmers. This could also serve as prudent strategy for managing municipal waste and faecal sludge to avoid impact of unscientific disposal on public health and quality of life.