Browsing by Author "Mrema, J. P."

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Contribution of legume rotations to the nitrogen requirements of a subsequent maize crop on a rhodic ferralsol in Tanga, Tanzania
Marandu, A. E. T.; Semu, E.; Mrema, J. P.; Nyaki, A. S.
Contribution of legume rotations to the nitrogen requirements of a subsequent maize crop on a rhodic ferralsol in Tanga, Tanzania
(2013) Marandu, A. E. T.; Semu, E.; Mrema, J. P.; Nyaki, A. S.
Industrial fertilizers are expensive for small-scale farmers who, as alternative, rely on legume crops for providing N for a subsequent maize crop. A legume-maize rotational experiment was carried out on a Rhodic Ferralsol at Mlingano Agricultural Research Institute in Muheza, Tanga, Tanzania, to evaluate the effects of legumes rotation in meeting the N fertilizer requirements of maize. The experimental site was located at 39o 52’E, 5o 10’S and 183 metres above sea level (m.a.s.l.). The experiment was conducted for two rotation cycles whereby cowpea, pigeonpea or greengram were grown during the short rains followed by maize during the long rains. The maize rotations were imposed on plots on which legumes had been grown during the previous legume rotation. Monoculture maize was grown with treatments of 0, 25, 50 and 100 kg N ha-1 imposed for purposes of plotting N fertilizer response curves. Based on the response curve lines, the effects of the legume rotation on maize yields were compared and translated as N fertilizer equivalency of the legumes in question. The grain and residue yields of the three legumes were significantly different (P<0.01), a fact which was attributed to the genetic differences of the legume species. The maize yields following rotation with each of the three legumes were significantly higher (P<0.05) than those under continuous maize. The effects of the rotations on increasing the maize yields were equivalent to application of 25, 19 and 16 kg N ha-1 for the cowpea, pigeonpea and greengram rotations, respectively. It was, however, concluded that the contributions of N by the legumes in the legume-maize rotations were not enough to satisfy the maize N requirements of 50 kg N/ha; hence supplementation with mineral N, in addition to the rotations, is necessary for increased yields.
Developing a coffee yield prediction and integrated soil fertility management recommendation model for Northern Tanzania
(International Journal of Plant & Soil Science) Maro, Godsteven, P.; Mrema, J. P.; Msanya, B. M.; Janssen, Bert, H.; Teri, James, M.
Exploring the nutrient release potential of organic materials as integrated soil fertility management components using SAFERNAC
(International Journal of Plant & Soil Science) Maro, Godsteven, P.; Mrema, J. P.; Msanya, B. M.; Janssen, Bert, H.; Teri, James, M.
Exploring the nutrient release potential of organic materials as integrated soil fertility management components using SAFERNAC
(International Journal of Plant & Soil Science, 2014-02-18) Maro, Godsteven, P.; Mrema, J. P.; Msanya, B. M.; Janssen, Bert, H.; Teri, James, M.
The aim of this study was to establish the nutrient release potential of different organic materials and assess their role in integrated soil fertility management for coffee using the new coffee yield model SAFERNAC. It involved an incubation experiment conducted at TaCRI Lyamungu Screenhouse for 180 days between April and September 2011. Cattle manure, coffee leaves, pulp and husks, Albizzia leaves and four green manure plants – Mucuna pruriens, Lupinus albus, Canavalia ensiformis and Crotalaria ochroleuca were mixed with two soil types – Eutric Nitisols from Lyamungu, Hai district and Humi-Umbric Acrisols from Yoghoi, Lushoto district. The mixing ratio was 5% organic to soil, the mixture was moistened to FC and incubated in 10 litre plastic containers arranged in RCBD (10 treatments and 3 replications) at room temperature. Duplicate soil samples + were taken at day 0, 3, 8, 15, 26, 45, 74, 112 and 180 and analyzed for NH 4 -N, NO 3 -N, available P and exchangeable K. The cumulative N min , P and K values resulting from the treatments were used to estimate their relative contribution to the soil nutrient pool and later exposed to the new model SAFERNAC for yield estimation under different nutrient management options (1 to 10 tons organics per ha alone on one hand and supplemented with 160 kg N, 60 kg P and 160 kg K). The tested organics differed significantly (P<0.001) in their N min, P and K release in the two soil types. They also differed in their substitution values and therefore the amounts of nutrients each one can contribute to the soil nutrient pools. Green manures showed about ten times higher potential as compared to cattle manure. Four of them (Crotalaria, Mucuna, Canavalia and Lupine) were picked as best bets for inclusion in the coffee ISFM programme. SAFERNAC recommended a number of nutrient management options involving the test organics and the two soil types under organic and conventional coffee farming.
Farmers’ perception of soil fertility problems and their attitudes towards integrated soil fertility management for coffee in Northern Tanzania
(Journal of Soil Science and Environmental Management) Maro, Godsteven P.; Mrema, J. P.; Msanya, B. M.; Teri, James M.
Pedological characterization of typical soil of Dakawa Irrigation Scheme, Mvomero District, Morogoro Region, Tanzania
(EXCELLENT PUBLISHERS) Mbaga, H. R.; Msanya, B. M.; Mrema, J. P.
Pedological characterization of typical soil of Dakawa Irrigation Scheme, Mvomero District, Morogoro Region, Tanzania
(EXCELLENT PUBLISHERS, 2017) Mbaga, H. R.; Msanya, B. M.; Mrema, J. P.
This study was conducted to characterize dominant soil type at Dakawa Irrigation Scheme (DIS), Tanzania. Typical soil at DIS was identified, excavated and described using FAO (2006) Guidelines. Six disturbed samples were taken from soil profile horizons together with three undisturbed core samples for laboratory analysis. The pedon developed from Neogene alluvial parent materials under ustic moisture and isohyperthermic temperature regimes. The pedon was very deep (> 150 cm), moderately well drained, with gray to very dark gray soil colours. CaCO3 concretions characteristic of calcic horizon were observed in subsoil. Soil texture was sandy clay loam throughout the pedon. pH was rated as medium (5.5 - 7.0) to very high (7.0 - 8.5) respectively for topsoil and subsoil. OC and N levels were very low; CEC and exchangeable bases were low to medium. Bulk densities were high (1.8 gcm-3) to very high (>1.9 gcm-3) for topsoil and subsoil, respectively. Study on moisture retention properties showed that subsurface (95 - 100 cm) and intermediate (45 - 50 cm) horizons retained more water than surface (0 - 5 cm) soil, congruent with increasing clay content with depth. According to Soil Taxonomy and World Reference Base for Soil Resources, pedon at DIS classified as Vertic Calciustepts and Haplic Vertic Cambisols, respectively. These taxa reflect properties that may guide use and management of soils at DIS including selection of crops and fertilizers and rates to use. Organic fertilizers were recommended to increase organic matter content in soil. Use of acidifying inorganic fertilizers and gypsum as soil amendments should also be taken onboard to correct emerging sodicity.
Phosphorus adsorption and its relation with soil properties in acid soils of Western Kenya
(Department of Soil Science Sokoine, University of Agriculture, Tanzania.) Muindi, E. M.; Mrema, J. P.; Semu, E.; Mtakwal, P. W.; Gachene, C. K.; Njogu, M. K
Phosphorus adsorption and its relation with soil properties in acid soils of Western Kenya
(Department of Soil Science Sokoine, University of Agriculture, Tanzania., 2014-10) Muindi, E. M.; Mrema, J. P.; Semu, E.; Mtakwal, P. W.; Gachene, C. K.; Njogu, M. K
Low available phosphorus (P) is one of the major hindrances to crop production in acid soils of western Kenya. Although considerable work has been done to establish P levels in the region, there is paucity of information on which to base fertilizer recommendations due to potential crop production differences caused by different soil types and climate. Phosphorus adsorption capacity and its relationship with some soil properties were evaluated in acid soils from nine locations of western Kenya. Adsorption data was obtained by equilibrating the nine soil samples with 30m1 of KH2PO4 in 0.01 M CaCl2, containing 0, 80, 150 and 300 pg m1-1 for 48 hours with shaking for 30 minutes at intervals of 8 hours. Langmuir, Freundlich and Tempkin adsorption models were fitted to the test results and relationship between P adsorption and soil properties determined by correlations. The result of this study showed that the soils were strongly to extremely acidic (pH 4.83 - 3.76), had high exchangeable Al3+ (>2 cmol Al kg-1), Al saturation of (> 20% Al) and calculated maximal phosphorous adsorption varied from 770.83 to 1795.83 mg kg' soil. Comparing the models, Freundlich linear model showed a better fit to the tested soils compared to Langmuir and Tempkin models. The regression coefficients (R2) for the fitted Freundlich P adsorption isotherms was highly significant ranging from (0.995- 1.000) for all tested soils. Analysis of relationship between adsorption maximum and soil attributes revealed that adsorption maximum positively correlated with clay content, exchangeable P, exchangeable acidity and Aluminium saturation and negatively correlation with organic matter and electrical conductivity. Due to differences in maximal P sorption capacities within the tested area, blanket P fertilizer recommendation may affect crop productivity in some sites. There is therefore need for further research to determine optimal Phosphorus requirements for soils in each research site.
Quantification of atmospheric n2 fixed by cowpea, pigeonpea and greengram grown on ferralsols in Muheza District, Tanzania
Marandu, A. E. T.; Semu, E.; Mrema, J. P.; Nyaki, A. S.
Quantification of atmospheric n2 fixed by cowpea, pigeonpea and greengram grown on ferralsols in Muheza District, Tanzania
(2010) Marandu, A. E. T.; Semu, E.; Mrema, J. P.; Nyaki, A. S.
Legume crops are usually intercropped with cereals in small-scale farming systems in Tanzania. This aims at taking advantage of legumes to replenish soil nitrogen (N due to legumes’ N2 fixation). Glasshouse pot experiments and field trials were carried out atMlingano Agricultural Research Institute in Tanga, Tanzania, with the objective to find out how much N2 can be fixed by cowpea, pigeonpea and greengram using native Rhizobia, thus substituting for the use of N-mineral fertilizers in maize production on Ferralsols. In the glasshouse pot experiment, the legumes were grown in 5L plastic pots for 40 days in soil sampled from 0 – 20 cm layer. The field experiment was maize – legumes intercropping whereby the N2 fixation assessment was done 35 days after planting. In both cases, maize (Katumani variety) was the non- N2- fixing reference crop. The legumes formed effective nodules with the native Rhizobia. Different quantities of N2 gas were fixed by the different legumes, the differences being attributed to the legumes’ differences in their genetic characteristics. In the field, monocropped cowpea, pigeonpea and greengram fixed 38, 21, and 49 kg N2, respectively. In the intercrop system cowpea, pigeonpea and greengram fixed 16, 4, and 24 kg N2, respectively. In both cases, the quantities of N2 fixed were less than 50% of their total N accumulation. It was concluded that in Muheza, maize grown in association with the legumes would continue to need supplementation of mineral N fertilizer to maximize its yields.
Response of rice to nitrogen and phosphorus applied on typical soils of Dakawa Irrigation Scheme, Morogoro, Tanzania
(Imperial Journal of Interdisciplinary Research (IJIR)) Mbaga, H. R.; Mrema, J. P.; Msanya, B. M.
Response of rice to nitrogen and phosphorus applied on typical soils of Dakawa Irrigation Scheme, Morogoro, Tanzania
(Imperial Journal of Interdisciplinary Research (IJIR), 2017) Mbaga, H. R.; Mrema, J. P.; Msanya, B. M.
A screen-house pot experiment was conducted at Sokoine University of Agriculture, Morogoro, Tanzania to assess response of rice variety TXD 306 growth parameters to nitrogen and phosphorus applied to the dominant soil type at Dakawa Irrigation Scheme (DIS) Morogoro, Tanzania. The study was prompted by low rice yields and the need to find out the soil constraints to high rice production at the scheme. Based on physical, chemical and biological properties of composite soil sample, the soil had low total N, OC, exchangeable Ca and Mg, hence rated as marginally to moderately suitable for rice production. N and P rates adopted were 0, 50,100, 150, 200 kg N ha-1 and 0, 40, 80, 120, 160 kg P ha-1, respectively. Sources of N and P were (NH4)2SO4 and Ca(H2PO4)2, respectively applied in a 52 factorial in CRBD. Number of tillers increased significantly (p < 0.05) with N and P levels from P0N0 kg ha-1 to P80N200 kg ha-1. Biomass weight (g) increased significantly (p<0.05) from 10.99 g pot-1 to 93.04 g pot-1 at P0N0 kg ha-1 and P160N200 kg ha-1, respectively. Grain yield (g) increased significantly (p<0.05) from 2.24 g pot-1 to 33.06 g pot-1 for the absolute control and P160N200 kg ha-1, respectively. Thus, for optimum grain yield of TXD 306 on Cambisols at DIS, 80 kg P ha-1 should be applied as basal and N in two splits i.e. 100 kg N ha-1 close to tillering and 100 kg N ha-1 at panicle initiation. For appropriate N and P recommendations, field studies should be conducted to take onboard integrated soil fertility management strategies, principles and practices in rice cultivation based on soil types to allow extrapolation of the results to other similar soils and areas.
Soil acidity management by farmers in the Kenya highlands
Muindil, E. M.; Semu, E.; Mrema, J. P.; Mtakwa, P. W.; Gachene, C. K.
Soil acidity management by farmers in the Kenya Highlands
(Sokoine University of Agriculture, Tanzania.) E. M. Muindi, E. M.; Semu, E.; Mrema, J. P.; Mtakwa, P. W.; Gachene, C. K.
Soil fertility evaluation for coffee (Coffea arabica) in Hai and Lushoto districts, Northern Tanzania
(International Journal of Plant & Soil Science) Maro, Godsteven, P; Msanya, B. M.; Mrema, J. P.