Browsing by Author "Semoka, Johnson Mashambo"

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Effect of tillage methods, farmyard manure and potassium rates on some soil chemical properties and nutrient contents in cassava in Kagera, Tanzania
(Journal of Agriculture and Ecology Research International, 2023) Merumba, Mgeta Steven; Semoka, Johnson Mashambo; Semu, Ernest; Msanya, Balthazar Michael; Kibura, Jojianas Kokulamka
A study was conducted in Bukoba, Missenyi and Biharamulo districts, Tanzania for the objective of determining the effect of tillage methods, farmyard manure (FYM) and potassium rates on soil pH and the concentrations of N, P and K in the soils and cassava leaves. The treatments were arranged in the Randomized Complete Block Design (RCBD) using the split-plot design with three replications. Tillage methods (flat tillage, open ridging and tied ridging), were the main plots, and the fertilizer rates [farmyard manure (FYM) alone at 4 MT ha-1 alone or FYM alone at 8 MT ha-1, nitrogen (40 kg N ha-1) + phosphorus (30 kg P ha-1) + potassium at 40, 80 or 120 kg K ha-1 and the combination of FYM alone at 4 MT ha-1 or FYM alone 8 MT ha-1 + potassium at 40, 80 or 120 kg K ha-1] and the control, were the sub-plots. The inherent and post-harvest composite soil samples for determining soil pH and the concentration of N, P and K in each site were collected, processed and analysed. Post-harvest soil samples and cassava leaf samples were collected from the control plots and plots that received the combination of FYM at 8 MT ha-1 and potassium at 40 or 120 kg K ha-1 during the second cropping season. The leaf samples were oven dried at 70oC, grounded to pass through 0.5 mm sieve and analyzed. The results indicate that there was no a significant (P = .05) difference in the soil pH and the concentrations of N, P and K in the soils and cassava leaves among the tillage methods. There was a significant (P < .001) difference in the soil pH and the concentrations of N, P and K in the soils and cassava leaves between the control and the combined use of FYM and potassium rates. However, there was no a significant (P =.05) difference in the concentrations of N, P and K in the soils among the combined use of FYM and potassium rates, but there was a significant (P < .001) difference in the concentrations of N and K in cassava leaves among the combined use of FYM and potassium rates. The combined use of FYM at 8 MT ha-1 and potassium at 40 kg K ha-1, and the combined use of FYM at 8 MT ha-1 and potassium at 120 kg K ha-1 significantly (P < .01) increased the soil pH and the concentration of N and K in the soil. However, the combined use of farmyard manure at 8 MT ha-1 and potassium at 120 kg K ha-1 gave significantly (P < .001) higher concentrations of N and K in cassava leaves than the combined use of farmyard manure at 8 MT ha-1 and potassium at 40 kg K ha-1. Therefore, combined use of farmyard manure at 8 MT ha-1 and potassium at 120 kg K ha-1 is desirable for increasing the concentration of N and K in the soil and in cassava leaves. However, for the resource-poor farmers who cannot afford the high rate of K, the combined use of farmyard manure at 8 MT ha-1 and potassium at 40 kg K ha-1 could be used.
Pedological characterization and suitability assessment for cassava production in Bukoba, Missenyi and Biharamulo Districts, Tanzania
(Science Publishing Group, 2020) Merumba, Mgeta Steven; Msanya, Balthazar Michael; Semu, Ernest; Semoka, Johnson Mashambo
A study was conducted in Bukoba, Missenyi and Biharamulo Districts, Tanzania with the objectives of characterizing, classifying and assessing the suitability of the study area for cassava production. A reconnaissance field survey using transect walks and auger observations was done in the study sites, which were geo-referenced in terms of international coordinates using Global Positioning System. Soil profiles representative of the study sites were excavated and named as MARU-P1, MISSE-P1 and BIHA-P1 for Bukoba, Missenyi and Biharamulo Districts, respectively. Soil profile description and data on the morphological features of the representative soils were collected according to the FAO Guidelines for Soil Description. Disturbed and undisturbed soil samples were collected from genetic soil horizons, processed and analyzed in a soil laboratory. Data on site characteristics, climate, soil morphological features and soil physical and chemical properties were used to classify the soils to the family level of the USDA Soil Taxonomy and to tier-2 of the FAO World Reference Base for Soil Resources. Soil suitability assessment of the experimental sites was done using a simple limitation method based on the FAO Framework for Land Evaluation. The results reveal that Pedons MARU-P1 and BIHA-P1 have similar morphological properties, which are different from pedon MISSE-P1. However, the studied pedons differ in their physical and chemical properties, implying differences in their use and management. The climate of the study sites is semi-humid with Udic soil moisture regime, which is generally favourable for crop production. According to the USDA Soil Taxonomy, pedons MARU- P1 and BIHA-P1 were classified as “Typic Kandiudults”. In addition, according to FAO World Reference Base for Soil Resources, pedons MARU-P1 and BIHA-P1 were classified as “Haplic Ferralic Acrisols” and “Chromic Ferralic Acrisols”, respectively. Pedon MISSE-P1 was classified as “Typic Endoaquolls” according to USDA Soil Taxonomy and as “Fluvic Gleyic Phaeozems” according to FAO World Reference Base for Soil Resources. Pedons MISSE-P1 and BIHA-P1 were both evaluated as marginally suitable while MARU-P1 pedon was evaluated as moderately suitable for cassava production due to soil fertility constraints. We recommended specific soil fertility management strategies in each studied site for optimum cassava yields.
Profitability of using different rates of farmyard manure and potassium fertilizer for cassava production in Bukoba, Missenyi and Biharamulo districts, Tanzania
(ResearchGate, 2022-08-10) Merumba, Mgeta Steven; Semu, Ernest; Semoka, Johnson Mashambo; Msanya, Balthazar Michael; Kibura, Jojianas Kokulamka; Blandes, Joyce Siima
The resolution of using or not using a particular technology in crop production is governed by the profitability of that technology being used. A study was conducted in Bukoba, Missenyi and Biharamulo districts in the Kagera region during the 2018/19 and 2019/20 cropping seasons to determine the economic benefit of using different rates of farmyard manure (FYM) and potassium (K) fertilizer in cassava production. One village potential for cassava production was selected in each district for establishment of cassava trials. Three tillage methods [flat tillage, tied ridging and -1 -1 open ridging] and eleven fertilizer rates [FYM at 4 or 8 MT ha , N40P30 + K at 40, 80 or 120 kg ha , FYM at 4 or 8 MT ha-1 + K at 40, 80 or 120 kg ha-1] and the control, were arranged in a Randomized Complete Block Design (RCBD) with three replications using a split-plot design. Tillage methods were the main plots and fertilizer rates were the subplots. Cassava yields (MT ha-1) were collected at harvesting (12 months after planting). Partial budget analysis was carried out to estimate the gross values using the adjusted yields at market price for cassava and fertilizers. Costs and benefits -1 -1 were calculated on a hectare basis, in Tanzania Shillings (TShs) ha , and converted to USD ha based on the prevailing exchange rate of 1 USD, equivalent to 2 300 TShs. All variable costs were summed up to total variable cost (TVC). The net benefits (NB) [gross benefit (GB) - TVC] ha-1 of the tested treatments were calculated and used to assess the profitability of each treatment. Moreover, the benefit-cost ratios (BCR) [net benefit ÷ TVC] of the tested treatments were compared to the acceptable value of greater than 2 for the technology to be adopted by farmers. The results indicated that in both cropping seasons, and in all studied sites, all the tested fertilizer types and rates gave acceptable BCR of greater than 2, implying that all the fertilizer types and rates could be used for cassava production in the study area. The results on net benefit indicated that the combined use of FYM at 8 MT ha-1 and potassium fertilizer at 80 kg K ha-1 gave higher net benefit (3 020 500 – 9 168 000 TShs ha-1 (1 313.3 – 3 986.1 USD ha-1) than the other fertilizer types and rates (1 915 000 – 9 024 500 (832.6 – 3 923.7 USD ha-1) and is therefore, desirable for increasing cassava root yield and net benefit. However, for the resource-poor farmers, the combined use of farmyard manure at 8 MT ha-1 and potassium fertilizer at 40 kg K ha-1 can still be adopted because, for some reason, not all the famers can afford the best treatment.
Soil fertility status in Bukoba, Missenyi and Biharamulo Districts in Kagera Region, Tanzania
(Science Publishing Group, 2020) Merumba, Mgeta Steven; Semu, Ernest; Semoka, Johnson Mashambo; Msanya, Balthazar Michael
The study was conducted in three Districts of Kagera Region, Tanzania to assess the inherent soil fertility status of farmers' fields. Thirty-three fields, located three to five km apart, were selected and soil samples (0 – 20 cm depth) were taken, mixed thoroughly, air-dried, ground, sieved through 2 mm sieve, and analyzed in the soil laboratory based on standard laboratory analytical procedures. Correlation analyses among soil chemical properties were performed using IBM SPSS Statistic 20 and the mean values were calculated using Excel spreadsheet statistical package. Soil fertility index (SFI) and limiting nutrients were used to assess the fertility status of the fields. The results indicated that soil textures ranged from sandy clay loam to sandy clay, clay loam, clay to sandy. Soil pH ranged from strongly acid (5.1) to slightly acid (6.1) while EC levels were very low (0.03 - 0.17 dS m-1). Total TN ranged from very low to medium (0.04 - 0.41%), extractable P ranged from low to high (0.44 - 86.44 mg kg-1) and Exchangeable K ranged from very low to medium (0.08 - 0.98 cmol(+) kg-1). Exchangeable S ranged from low to medium (2.27 - 12.14 mg kg-1) while CEC ranged from very low to medium (5.20 - 23.00 cmol(+) kg-1), extractable Zn ranged from medium to high (0.85 - 18.41 mg kg-1), Cu from medium to high (0.47 - 2.81 mg kg-1), and Mn and Fe were medium (2.24 - 70.34 mg kg-1) and high (37.50 - 473.21 mg kg-1), respectively. The results also indicated both positive (r=+ve) and negative (r=-ve) and both significantly (p≤0.05) and highly significantly (p≤0.01) correlations among the soil chemical properties in each districts. Based on SFI, the soil fertility status of the studied fields ranged from poor fertility to good fertility. The results on the limiting nutrients across the studied fields indicated that N and K were the most limiting nutrients (67%) followed by P (52%), S (32%), Mg and OC (18%) and the least was Ca (15%). The results also indicated that N and P were the most limiting nutrients in Bukoba District while N and S were the most limiting nutrients in Missenyi District and N, P and K were the most limiting nutrients in Biharamulo District. Therefore, specific soil fertility management practices are recommended based on limiting nutrients in those fields having inadequate levels of plant nutrients together with training of farmers on proper use of the appropriate soil fertility management practices.
Tidal trends and magnitude of Chwaka and Uzi Bays as a proxy of seawater intrusion in Jozani Groundwater Forest, Zanzibar, Tanzania
(American Journal of Agriculture and Forestry, 2016) Said, Masoud Salum; Msanya, Balthazar Michael; Semoka, Johnson Mashambo; Maliondo, Salim Mohamed Salim
Tidal characteristics, land altitude, level of groundwater, and rainfall patterns are among the main factors determining seawater intrusions in coastal areas. As Jozani Groundwater Forest (JGWF) is a coastal forest of low altitude found between Chwaka and Uzi bays, it was assumed the forest is increasingly being intruded by seawater. This study was therefore intended to discern conditions of tidal trends and magnitude in relation to seawater intrusion into JGWF. Tidal data and rainfall patterns were collected from Tanzania Meteorological Agency, Kisauni Zanzibar. Two sets of three observation wells (OWs) were opened at two forest ends towards Chwaka and Uzi bays. The OWs were used as data collection points while Height of Instrument method with the help of SOKKIA C.3.2 level and benchmarks number 205 and 210 were used to determine elevation of ground surfaces of the OWs. GPS receiver model GARMIN etrex 10 was used for geo-referencing the OWs. Water level recorders were installed above the wells to record changes in water level (WL) around the wells. Total dissolved solids (TDS) in water samples from the OWs were measured in situ using Hanna Combo tester HI 98129. Results showed that WL in South-end OWs rises during rains and falls during dry seasons, and occasionally also rises during high water of spring tide (HWST) associated with South Easterly monsoon winds. Similar results were obtained at North-end OWs, but more frequently even during HWST that were not associated with Monsoon winds. Values of water TDS fell to a minimum of 0.7 x 103 and 4.9 x 103 ppm during rainfall and rose to a maximum of 25.5 x 103 and 34.1 x 103 ppm during dry season at South-end and North-end, respectively. It was concluded that intrusion takes place during dry seasons when seawater of HWST from Chwaka and Uzi bays through creeks reached the soil surfaces at North-end and South-end of JGWF. The water accumulated salts which were then diluted and drained off the areas by rain water.