Browsing by Author "Rwehumbiza, F. B."

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Determinants of farm-level adoption of water systems innovations in dryland areas: The case of Makanya watershed in Pangani river basin, Tanzania
(2005) Masuki, K.F. G.; Mutabazi, K. D; Tumbo, S. D.; Rwehumbiza, F. B.; Mattee, A. Z.; Hatibu, N.
Water system innovations such as rainwater harvesting involve abstraction of water in the upper catchments. Increasing adoption of rainwater harvesting in the riparian catchments could have hydrological impacts on downstream flows in the river basin, but it is assumed to have overall gains and synergies when efficient use of rainwater is optimized at farm-level. This paper examines the main determinants of adoption of water system innovations with specific emphasis on the intensity of adoption and adoption lag, using a cross-sectional sample of 234 farmers in the Makanya watershed. Censored Tobit models were used to estimate the coefficients of intensity of adoption and adoption lag of water system innovations. Group networking, years spent in formal education, age of respondent, location and agricultural information pathways were found to be major determinants of intensity of adoption at farm-level. It was also found that intensity of adoption and frequency of attendance to collective action are strong determinants of adoption lag of water system innovation in Makanya watershed. Empirical knowledge of the determinants of adoption of water system innovations is critical for an effective scaling out of best practices of water harvesting in the Basin.
Impact of projected climate change on agricultural production in semi-arid areas of Tanzania: A case of Same district
(2012) Tumbo, S. D.; Kahimba, F. C.; Mbilinyi, B. P.; Rwehumbiza, F. B.; Mahoo, H. F.; Mbungu, W. B.; Enfors, E.
Sub-Saharan Africa is one of the most vulnerable regions in the World to climate change because of widespread poverty and limited adaptive capacity. The future climate change is likely to present an additional challenge to the agricultural sector. Therefore, the effects of climate change on the current agronomic management practices were investigated using Same District, Tanzania as a case study area. APSIM software was used to investigate the response of maize (Zea mays L.) yield to different agronomic management practices using current and future (2046 - 2065) climate data. The climate change projections data from global climate models were downscaled using self-organising maps technique. Under the conventional practices, results show that during long rainy season (from March to May) there is yield decline of 13% for cultivar Situka, no change for cultivar Kito and increase of 10% and 15% for cultivars Sc401 and TMV1, respectively. Under the recommended practices, cultivars TMV1 and Sc401 are projected to register a 10% yield increase whereas cultivars Situka and Kito are projected to register a decrease of 10% and 45%, respectively. Also, under both conventional and recommended management practices, results showed that during short rainy season (from October to December/January) all cultivars are projected to register between 75% and 146% increase in maize yields. This implies that future climate change is going to have positive effects on current management practices during short rainy seasons and it will have negligible impact during long rainy seasons.
Pedological characterization and fertility evaluation of paddy soils of Mvumi Village, Kilosa District, Tanzania
(2017) Massawe, I. K.; Msanya, B. M.; Rwehumbiza, F. B.
This study was conducted to characterize, classify and evaluate fertility of soils of Mvumi Village, Kilosa District, Tanzania. Representative soil profile of the colluvio-alluvial plain covering Mvumi Village was identified, dug, described and sampled using FAO Guidelines. Four samples from genetic horizons and eight surface samples from eight farms were taken for pedological characterization and soil fertility evaluation respectively. Results on pedon morphology revealed very deep and moderately well drained to somewhat poorly drained profile with very dark grey clays and granular topsoil structure over weak coarse wedge-shaped subsoil structure. The pedon was classified as Ustic Endoaquerts and Haplic Vertisols respectively in USDA Soil Taxonomy and WRB for Soil Resources. Shrinking and swelling, and pedoturbation were typical pedogenic processes. Low pedon Ca/Mg ratios indicate nutrient imbalance likely to limit uptake of Mg by plants. Very high Mg/K ratios can also lead to nutrient imbalance and toxicity. All sampled farm sites had clayey texture and pH ranging from 5.2 to 7.4. OC (0.53 - 1.75 %) was low in all sites. N (0.06 - 0.19%), P (1.54 - 5.79 mg P kg-1) and K (0.12 - 0.40 cmol (+) kg-1) were deficient whereas micronutrients were adequate in all sites except for Zn (0.35 - 1.57 mg kg-1) which was low. CEC was rated as medium (15.2 to 21.6 cmol (+)/kg). Based on landform features and soil properties of both pedon and surface samples, soils of Mvumi were recommended for paddy rice as one of major crops. Prudent fertilizer use is deemed necessary to address possible deficiency and imbalance of some nutrient elements.
The Role of Response Farming Rainfall Forecasts in improving the performance of Agronomic Adaptation Strategies
(2016) Mahoo, H.F.; Tumbo, S. D.; Rwehumbiza, F. B.; Admassu, H.
Farming by resource-poor and inadequately informed farmers with fixed best-bet strategies under seasonal variability and changing climate in the semi-arid Central Rift Valley of Ethiopia has often proven to be of very low flexibility. While, struggling to survive in the face of high risks, farmers in semi arid-arid areas need flexible seasonal adaptation strategies. The “Response Farming” (RF) methodology, a system that derives forecast of seasonal rainfall from very early rain occurrences, and makes choices of crops and practices to conform to the forecasts was evaluated. The potential of RF in improving traditional adaptation measures employed to current rainfall variability and to observed and projected climate change was investigated. RF turned out superior to both research and farmers’ production strategies. Our evaluation of climate variability and change interventions (RF) show that adaptation strategies, based on RF modeling using long-term weather records, to be useful keys for improving traditional adaptation strategies and to make farming ecologically sustainable and economically feasible as climate change unfolds.
Using the PT model to determine appropriate water management for maize production: A case study of Fulwe village in Morogoro district
(2005) Pangapanga, C. P.; Marijani, B. J.; Tumbo, S. D.; Mpulila, T.; Rwehumbiza, F. B.
Fulwe village is located in Mikese ward, some 30 kilometres east of the Morogoro Municipality, along the Morogoro - Dar es Salaam highway. It is located at longitude 37º53’60’’ East, and the latitude is 6º46’ south. The annual rainfall ranges from 700mm to 1000 mm. The short rainy season (Vuli) starts in mid-October and ends in December while the long rains (Masika) start in February and ends in mid May. The dry season extends from June to October. The annual average maximum and minimum temperatures are 26ºC and 21ºC respectively. Soils are acidic lithosols and ferralitic latosols with deeper deposits of ferruginous sandy clay. Fulwe villagers depend mostly on rainfed agriculture and maize is the main staple food and also one of the major sources of income. Other crops cultivated include beans, soybeans and horticultural crops.