The 2017 research series presents the current WPRD projects carried out in collaboration between SAT and Sokoine University of Agriculture (SUA). This first issue focuses on the four research projects focused on soil fertility. Currently, the student researchers are busy with harvesting and data collection. Soon their first results will be available – we are excited and will keep you up to date!
Soil nutrient depletion is an important concern directly linked to food insecurity. It is caused by both natural and human-induced processes such as continuous nutrient mining without sufficient replenishment of nutrients harvested in agricultural products and soil erosion. The purpose of this study is to determine the soil nutrient status and the appropriate application rate of organic manures. To this, the yield response of farmyard and poultry manure as well as intercropping is investigated with the aim to enhance the soil fertility status and thereby increase maize yield.
Hankungwe Zaward carried out his field research in Mkuyuni area. To evaluate the response of the maize plants to the different manure treatments (farmyard, poultry and intercropping), a Randomized Complete Block Design experiment was set up. Growth parameters such as percentage seed germination, plant height, dry matter weight and grain yield are collected and the nutrient content of different plant parts determined. Soil analysis was carried out to determine various soil characteristics, such as pH and electric conductivity, organic carbon, nitrogen content, available phosphorus, exchangeable base, cation exchange capacity as well as soil texture.
At the mid-term farmer visit in June (photo), Hankungwe Zaward presented his research to the farmers at Tushikamane centre. He is looking back to a successful field and lab period since he could carry out his experiment successfully in collaboration with farmers and achieved the main objective of his study. To this, he was able to manage the challenges of accessibility to the field site due to the location and with regard to the university timetable as well as to deal with monkeys and birds threatening germination.
In Tanzania, the demand for leafy vegetables has increased considerably recently but it’s production is limited by, among other factors, low soil fertility. Chard has a high nutrient demand particularly in that of nitrogen. For that reason, there is a need to find a way to meet the high demand of nutrients by organic nutrient sources. The overall objective of this study is to investigate the effect of different combinations of organic nitrogen sources on the above ground biomass yield of chard in a Randomized Complete Block Design experiment and to relate the later with plant nitrogen uptake. As source of organic nitrogen, Kihwili Ottu planned to use animal manure, glyricidia powder as well as plant tea. Since the germination of the plants was challenging due to unusual heavy rainfalls this year, the student was not able yet to start with the intended data collection of above ground biomass, plant growth parameters, plant nitrogen uptake, chlorophyll content as well as soil characteristics. When visiting his plot at SUA in June, Prisca Kimaro from SAT and Kihwili Ottu discussed the challenges faced as well as possible solutions.
Declining maize yield is a major problem facing smallholder farmers in Mikese ward and consequently food insecurity and decrease in income are a serious problem. Therefore, the objective of this study is first to identify the main causes of low maize productivity using a questionnaire survey as well as soil fertility evaluation, second to investigate the effect of local and improved maize cultivars, timing of weeding and soil amendment practices on maize productivity through a Randomized Complete Block Design field experiment and third to verify the costs and benefits of maize crop production.
The questionnaire survey as well as the soil collection for the consequent soil fertility analysis in the lab (pH, organic carbon, nitrogen, phosphorus, soil texture) was conducted in Mikese ward aiming to get information about farmers’ practices and the state of the farmers’ fields. First results show that the soil of Mikese ward is nutrient-exhausted, hence amendment practices need to be improved to increase maize yield in the future. The field experiment was carried out at SUA and consists of three factors, namely: maize cultivars (farmer saved and improved), soil amendment practices (farmyard manure, compost and cowpea) and weeding time (early and late). At the mid-term farmer visit of his plot, Shango and his supervisor Dr. Ramadhani Majubwa presented the experimental setup to the farmers (photo). Very soon Shango Abdul will start harvesting and complete data collection. The parameters he will measure include maize leaves length, stem girth, plant height as well as yield (number of ears per plant, ear length, ear weight, number of kernel per ear, average weight of kernels per cob and total weight of kernels).
According to Shango, the collaboration with the farmers was of great value for his project and he appreciates the cooperation at different stages of his project, especially at the WPRD workshop in November when the farmers conveyed their problems to the researchers, at the questionnaire survey and while collecting soil samples at Mikese ward, as well as at the mid-term farmer visit workshop in June.
Low soil fertility is a major limiting factor in crop production in most parts of Tanzania. Therefore, the aim of this study is to develop sustainable soil fertility management strategies through participatory soil fertility evaluation. Someke Buhwahwa investigated problems associated with soil fertility management through focus group discussions and quantified the soil fertility status in the target farmer’s field as well as assessed the performance of different nutrient management strategies. Someke analysed the soil in the lab for pH, electrolytic conductivity, organic carbon, nitrogen, phosphorus, potassium, calcium and magnesium. To this, the soil samples were analysed for micronutrients such as iron and zinc and physical parameters such as soil texture and colour were included. In a next step, Someke will discuss the results with farmers to come up with strategies for soil fertility improvements. A first exchange took place already in June, when farmers and researchers discussed the findings of the study at the mid-term farmer visit workshop at Tushikamane Centre.