Soil Science Collection
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Item Genotypic variation in phosphorus requirement and utilization in nodulated common beans (phaseolus vulgaris l.)(Sokoine University of Agriculture, 1992) Ole-Meiludie, Dorothy John SimonA study to investigate the genotypic variations in phosphorus requirement and utilization by four common bean genotypes AA/2/5/6xK-2; 86EP 5091-B-2; EP 3-2 and Selian wonder, referred to as C2' C4' C5 and C8 respectively, inoculated with a locally produced Rhizobium strain, PV1, was carried out at the Sokoine University of Agriculture, Morogoro, Tanzania in a glasshouse pot experiment. The soil used as the growth medium was an Oxic Haplustult with low levels of total nitrogen and Bray-1 phosphorus with a slight acid reaction. phosphorus applied were 0, The 5, 10, 20, 40, 160mgP/kg soil as kh,poa Z 4 extractable levels of 80, 120 and and these rates were each replicated six times for each common bean genotype. The increases in the number of nodules, (hence nodulation), nodule weights, shoot dry weights, root dry weights, pod production, seed production, percent N in the shoots and percent P in the shoots with increasing rates of applied phosphorus were significant and these plant parameters were positively and significantly correlated to one another, suggesting the vital role of phosphorus in symbiotic nitrogen fixation. The variations in phosphorus requirement and utilization based on the above plant parameters were attributed to the inherent genetic characteristics of the four common bean genotypes. The genotypes most tolerant to low levels of Bray-1 extractable phosphorus fixed more nitrogen symbiotically and accumulated more dry matter. The genotypes' tolerance phosphorus followed to low levels of the order different phosphorus rates C5 > C4 > for optimum symbiotic nitrogen fixation for each C2 extractable > C8‘yields individual. The and common bean genotype should be established in a similar investigation under field conditions. The ability of the genotypes to form nodules hence fix inoculated with the Rhizobium nitrogen, strain PV1 indicate when the ability of the Rhizobium strain PV1 to tolerate low levels of Bray-1 extractable phosphorus. Based on the results and C4 inoculated obtained in this study, the genotypes C5 with Rhizobium strain PV1 can be grown in soils deficient in available phosphorus without any effect on reducing seed yield.Item Genotypic variation in phosphorus requirement and utilization in nodulated common beans (phaseolus vulgaris l.)(Sokoine University of Agriculture, 1992) Ole-Meiludie, Dorothy John SimonA study to investigate the genotypic variations in phosphorus requirement and utilization by four common bean genotypes AA/2/5/6xK-2; 86EP 5091-B-2; EP 3-2 and Selian wonder, referred to as C2' C4' C5 and C8 respectively, inoculated with a locally produced Rhizobium strain, PV1, was carried out at the Sokoine University of Agriculture, Morogoro, Tanzania in a glasshouse pot experiment. The soil used as the growth medium was an Oxic Haplustult with low levels of total nitrogen and Bray-1 phosphorus with a slight acid reaction. phosphorus applied were 0, The 5, 10, 20, 40, 160mgP/kg soil as kh,poa Z 4 extractable levels of 80, 120 and and these rates were each replicated six times for each common bean genotype. The increases in the number of nodules, (hence nodulation), nodule weights, shoot dry weights, root dry weights, pod production, seed production, percent N in the shoots and percent P in the shoots with increasing rates of applied phosphorus were significant and these plant parameters were positively and significantly correlated to one another, suggesting the vital role of phosphorus in symbiotic nitrogen fixation. The variations in phosphorus requirement and utilization based on the above plant parameters were attributed to the inherent genetic characteristics of the four common bean genotypes. The genotypes most tolerant to low levels of Bray-1 extractable phosphorus fixed more nitrogen symbiotically and accumulated more dry matter. The genotypes' tolerance phosphorus followed to low levels of the order different phosphorus rates C5 > C4 > for optimum symbiotic nitrogen fixation for each C2 extractable > C8‘yields individual. The and common bean genotype should be established in a similar investigation under field conditions. The ability of the genotypes to form nodules hence fix inoculated with the Rhizobium nitrogen, strain PV1 indicate when the ability of the Rhizobium strain PV1 to tolerate low levels of Bray-1 extractable phosphorus. Based on the results and C4 inoculated obtained in this study, the genotypes C5 with Rhizobium strain PV1 can be grown in soils deficient in available phosphorus without any effect on reducing seed yield.Item Effects of nitrogen sources and rates on soil tissue nutrient concentration and properties, yield of cotton (gossypium hirsutum l.) In soils of the university farm, Morogoro(Sokoine University of Agriculture, 1990) Mwaganicha, Thobias KinyamagohaPot and field experiments were carried out to investigate the effects of different rates and sources of N in soils with different initial pH on soil chemical properties, tissue nutrient concentration, growth and yield of cotton at the University Farm, Morogoro. Nitrogen rates applied were 0,150 kg N/ha and the N sources were SA, 50, 100 and urea and CAN. The soils used had initial pH values of 4.8, 6. 1 and 6.9 and were designated as strongly acid soil (SAS), moderately acid soil (MAS) and almost neutral soil (ANS), respectively. The experimental design was a split-plot with N rates as N sources as main plot and N source plots. Soil chemical properties assessed were pH, exchange able acidity, Al, bases and Mn. Concentration of N, P, Mn were determined in Ca and leaf tissues at flowering in the pot study and at flowering and boll stages of cotton development in the field experiment. Shoot dry weight, plant heights, number of fruiting branches, number of flowers, number of bolls, number of early maturing bolls, as well as seedcotton yield and one thousand seeds weight were also determined Nitrogen application above the control significantly increased exchangeable acidity and aluminium in the SAS, the effects being mainly due to different rates of SA. Other soil chemical properties in SAS and all measured properties in MAS and ANS were not significantly affected by the rates and sources of N. Nitrogen application significantly increased N concentration in leaf tissues except that of leaf blades at flowering in SAS and in both petioles and leaf blades at boll development stage in ANS. The N concentration at flowering associated with maximum seedcotton yield was 2.0% for petiole N and 4.4% for leaf blades N. While P and Ca concentrations in leaf tissues at flowering were significantly increased due to different rates of CAN, Ca concentration was significantly decreased at 150 kg N/ha applied as SA and urea in the SAS. in leaf tissues at Manganese concentration flowering was significantly increased due to various rates of SA in the SAS, and in leaf blades at flowering and boll stages of cotton development in the ANS. Shoot dry weight, branches, plant heights, number of fruiting number of flowers and number of bolls were significantly increased by N application. Were early maturing bolls not significantly affected by N application. Nitrogen sources did not significantly affect the growth and reproductive characters of cotton, except shoot dry weight in the field experiment at flowering which was significantly increased by SA. Seedcotton yield and one thousand seeds weight were significantly increased by N application, with maximum responses being at 100 kg N/ha. Nitrogen sources had no significant effects on the yield components of cotton in the ANS. Nitrogen concentration in leaf tissues was significantly correlated with shoot dry weight and yield of seedcotton. It was therefore concluded that (i) consideration of N sources was necessary in the SAS but was appearing irrelevant in the MAS and ANS, (ii) the agronomic optimum N rate was close to 100 kg/ha for these soils and (iii) concentration of N in petioles and leaf blades at flowering could be used to assess the N I status of cotton plants with values of 2.0% and 4.1l% respectively, being tentatively suggested as optimum.Item Assessment of suitability of the soils of madura research institute, Arusha, Tanzania, for the production of soybeans and mungbeans(Sokoine University of Agriculture, 2001) Mlahagwa, Moses RaphaelA field study was conducted to assess the suitability of the soils of Madiira Research Institute farm for the introduction of growing and production of vegetable soybeans and mungbeans in Tanzania. The specific intention was to assess the fertility status of the soils, determine the plant uptake of the essential nutrient elements from the soils, and try to suggest measures and soil fertility management strategies for the sustainable and optimal production of vegetable soybean and mungbean production. Composite soil samples for the determination of the physical and chemical properties were sampled from two sites selected on the farm. About 400 m2 of land for each site was plowed and then harrowed and each site was divided into three 8 m x 6 m plots/blocks for four soybeans and for five mungbeans, grown at a spacing of 30 cm x 10 cm and replicated three times respectively. Just before flowering nine plants of each line and from each block were harvested for dry matter yield determinations and total plant nutrient analysis. The other plants were left on the field to grow to maturity for grain yield determinations. The soils were found to be medium acidic, with medium CEC, OC, exchangeable Ca, and Mg, low levels of total N, and high levels of exchangeable K and Bray-1 P. The DTPA extractable Fe and Cu were above the critical limit, while Zn and Mn were medium. The plant analysis for soybeans showed that P and Zn correlated positively with the dry matter yields while total N, Ca, Mg, K, Fe, Cu and Mn correlated negatively with the same. Nitrogen, Mg, K, Fe, Cu and Mn correlated positively with grain yields while Ca, Zn and P correlated negatively with the same. The plant analysis for mungbeans showed that N, Mg, K, Zn and Cu correlated positively with dry matter yields while P, Ca, Fe and Mn correlated negatively with the same. Nitrogen, Mg, K, Zn, Cu and Mn correlated positively with grain yields while Ca, Fe and P correlated negatively with the same. The soybean performances based on fresh grain yields were in the following order: GC 84051-32-1 AGS 338 > AGS 329 > AGS 292 corresponding to 14730.0, 8861.6, 6447.0, and 6364.3 kg/ha respectively, while mungbean performances were: VC 6173(b-10) VC 6148(50-12) > VC 6372(45-8) > VC 6379(232-1) > KANTI corresponding to 11178.0, 10549.3, 9167.6, 8547.0 and 6553.3 kg/ha respectively. The soils analytical data indicate that the soils are of medium fertility status, that is medium levels of CEC (16.2-16.8 cmol (+)/kg soil), OC (1.3-1.5%), Ca (8.0-8.1 cmol (+)/kg soil), Mg (2.7-3.0 cmol (+)/kg soil) and low levels of total N (0.190.22%), hence can support the growth of soybeans and mungbeans in the short-term period. Recommendations are made to publicise the production of the best two high yielding soybean lines (i.e. GC 84051-32-1 and AGS 338) and mungbean lines (i.e. VC 6173(b-10) and VC 6148(50-12). Seed inoculation for effective Ni-fixation is recommended. On-site incorporation of the legume vegetable crop residues into the soils and further experiments and use of fertilizer rates are recommended for the sustainable soybean and mungbean production.Item Effects of spraying coffee with copper fungicides on the copper status of soils of Moshi district, Tanzania(Sokoine University of Agriculture, 1990) Mkindi, Gerard IsaacA series of investigations assess the were conducted to effects of spraying coffee with copper (Cu) fungicides on the Cu status of some soils of Moshi district, Tanzania. The studies involved analysis of soil samples taken from coffee fields sprayed with Cu fungicides for durations of 10 years, 10 30 years, >30 years and from fields which have not been sprayed. Copper from the soils was extracted using 0.005M DTPA. Then three glasshouse experiments were set the effects of different Cu levels in soils pH on up to assess and soil the growth of beans and Cu concentration in shoots. In addition, coffee from selected coffee leaves were collected the fields and analysed for Cu content. The results indicated that DTPA extractable Cu in the topsoil (0-5cm) of 5.6 ppm in farms increased from an average that had never been sprayed with copper fungicides to more gave than 30 years. 186.2 ppm in farms sprayed for shorter durations of spraying intermediate values of extractable ctable Cu Cu. decreased sharply with depth. The extra Beans grown in soils ranging in DTPA Cu contents from 3.7 to 368 PPm had a shoot of 23.2 ppm and in any no of the treatments. average Cu content in the toxicity symptoms was observed. Application of 200pg Cu/kg soil increased the average Cu content of shoots to 25.6 ppm but again the plants were free from any Cu toxicity. Coffee leaves from sprayed fields contained higher levels of copper (up toGOppm) but were also free from Cu toxicity symptoms. 5.1 However, when pH was lowered to or less, copper concentration in bean shoots increased to 35 ppm or greater and caused copper toxicity to bean plants. It was concluded that spraying coffee with copper fungicides increased the amount of copper in the soil and that the largest increase occurred in the 0-5 cm layer of soil. Not the copper accumulated in the soil was toxic to either coffee or bean plants but could become toxic if the pH of the soils decreased below 5.2.Item Measurement of soil water evaporation using microlysimeters of different sizes: effect of shade and soil texture(Sokoine University of Agriculture, 1996) Maseko, Stephen Phuz’ukuvelaThe effect of soil texture and shade on soil water evaporation using microlysimeters of different sizes was investigated. The rate of evaporation from the different sized microlysimeters was studied to see which evaporates the most. The days after irrigation were monitored to see if evaporation would increase or decrease. The effect of the depth of the microlysimeters was also studied to find out which depth evaporates more between the shallow depth microlysimeters (SDM) (10 cm), and the deeper depth microlysimeters (DDM) (20 cm). Two periods of the day, morning period (MP) and afternoon period (AP) were also studied to determine which one had more evaporation. The study, which was conducted from October to December 1994, was carried out in two sites with contrasting soils viz; (a) Ismani, in Iringa region selected for its clayey soils, and (b) Hombolo, in Dodoma region which had sandy soils. For the experiment, two plots were used, one shaded and the other unshaded. Shading was obtained by using a shade screen (a black net) which provided a shade of about 50 per cent. Sixty mm of irrigation water was applied on both plots at the same time. Results show that sandy soils evaporated significantly (P<0.05) more water, up to about 20 per cent, than clayey soils. Shading significantly (P<0.05) reduced evaporation by 5 to 10 per cent. The 10 cm diameter microlysimeters lost more water than the 5 cm diameter ones. This was prominent in clayey soils (P<0.05) than in the sandy soils, at the initiation of the experiment. However, towards the end of the study the difference was reduced. It was also observed that evaporation significantly decreased as the soil progressively dried after irrigation. The second day’s evaporation was reduced by almost 50 per cent. The rest of the days’ evaporation was steady at about 10 to 20 percent of the first day. There was no significant difference between the SDM and DDM. It seems depth (10-20 cm) does not significantly affect evaporation. The periods of the day showed some significant difference. In clayey soils significantly (P<0.05) more water was lost in the MP than in the AP. However, the reverse was true for the sandy soils.Item Measurement of soil water evaporation using microlysimeters of different sizes: effect of shade and soil texture(Sokoine University of Agriculture, 1996) Maseko, Stephen Phuz’ukuvelaThe effect of soil texture and shade on soil water evaporation using microlysimeters of different sizes was investigated. The rate of evaporation from the different sized microlysimeters was studied to see which evaporates the most. The days after irrigation were monitored to see if evaporation would increase or decrease. The effect of the depth of the microlysimeters was also studied to find out which depth evaporates more between the shallow depth microlysimeters (SDM) (10 cm), and the deeper depth microlysimeters (DDM) (20 cm). Two periods of the day, morning period (MP) and afternoon period (AP) were also studied to determine which one had more evaporation. The study, which was conducted from October to December 1994, was carried out in two sites with contrasting soils viz; (a) Ismani, in Iringa region selected for its clayey soils, and (b) Hombolo, in Dodoma region which had sandy soils. For the experiment, two plots were used, one shaded and the other unshaded. Shading was obtained by using a shade screen (a black net) which provided a shade of about 50 per cent. Sixty mm of irrigation water was applied on both plots at the same time. Results show that sandy soils evaporated significantly (P<0.05) more water, up to about 20 per cent, than clayey soils. Shading significantly (P<0.05) reduced evaporation by 5 to 10 per cent. The 10 cm diameter microlysimeters lost more water than the 5 cm diameter ones. This was prominent in clayey soils (P<0.05) than in the sandy soils, at the initiation of the experiment. However, towards the end of the study the difference was reduced. It was also observed that evaporation significantly decreased as the soil progressively dried after irrigation. The second day’s evaporation was reduced by almost 50 per cent. The rest of the days’ evaporation was steady at about 10 to 20 percent of the first day. There was no significant difference between the SDM and DDM. It seems depth (10-20 cm) does not significantly affect evaporation. The periods of the day showed some significant difference. In clayey soils significantly (P<0.05) more water was lost in the MP than in the AP. However, the reverse was true for the sandy soils.Item Assessment of uranium levels in selected soils and its uptake by rice, maize and millet in Bahi district, Tanzania(Sokoine University of Agriculture, 2014) Makoti, Clavery AtiianasThis research aimed to determine levels of uranium (U) contamination in selected agricultural soils of Bahi District and its uptake by food crops in order to enhance public awareness and safety. The research involved determination of spatial distribution of U in agricultural soils, its uptake and translocation in plant/crop tissues. Soil, plant and water samples were collected randomly from farmers' fields and water sources, respectively. Laboratory sample analysis was done at the Government Chief Chemist Laboratory in Dar es Salaam and Soil Science Laboratory at the Sokoine University of Agriculture. Substantial differences of U concentrations in soils, plants and water were determined. The highest U level in soil profiles was 74.8 pg kg’1 at Mpamantwa and the lowest was18.3 pg kg’1 at Hindi. Along the studied transects, the highest U level was 743 pg kg’1 at Bahi and lowest was 13.6 pg kg’1 at Hindi. Uranium concentrations in maize and rice were below detectable limit (<10 pg L"1) except for finger millet where U accumulation levels ranged from 10.4 to 32.0 pg kg‘l. The concentration of U in water differed from village tovillage. The highest U level of 1233 pg L’1 was found in Hindi village at Hindi Playa Lake whereas in Bahi the highest U concentration was 62.9 pg L’1 found in one of the Bubu tributaries under the bridge. The concentrations of U in water in Hindi and Bahi villages were more than 30 pg L’1 the tolerable limit set by WHO for human and animal consumption. The levels of U in soils and crops were within the tolerable limit for agricultural use and the environment. Further studies should be carried out for other types of crops that are grown in the Bahi District villages to assess their safety for human consumption.Item Response of maize to nitrogen, phosphorus and filtermud applied to a dystric nitosols(Sokoine University of Agriculture, 2003) Luambano, NessieA glasshouse pot experiment to study the response of maize (Zea mays') to nitrogen, phosphorus and filtermud applied to a Dystric nitosols was carried out at the Sokoine University of Agriculture (SUA) Morogoro, Tanzania. The Dystric nitosols was collected from the central part of SUA farm while the filtermud was obtained from Mtibwa Sugar Factory, Turiani Morogoro, Tanzania. The Dystric nitosols was characterized by low total organic carbon, nitrogen, exchangeable Ca and Mg, CEC, plant available P and a very strongly acid reaction. The filtermud contained low amounts of the essential nutrients elements and had a very mild alkaline reaction. Fifty four, 12 kg soil sample portions of the Dystric nitosols were weighed into 10 litre capacity plastic buckets and thoroughly mixed with nitrogen as (NH^SCXi at the rates of 0, 50 and 100 kgNha'1, P as KH2PO4 at the rates of 0, 75 and 150 kg P ha’1 and filtermud at the rates of 0, 15 and 30 tonsfiltermudha’1 in a 3° factorial experiment in a completely randomized block design with two replicates. The soil-N-P-filtermud treatments were incubated at field capacity for 3 weeks after which five maize seeds were planted in each pot and allowed to grow for 6 weeks. The whole maize plants above the soil levels in the plastic buckets were harvested according to treatments at the end of the 6th week of growth and dried at 70 °C to constant weights for dry matter determination. The oven dried maize plants were chopped into small pieces and ground into fine powder for the determination of N, P and K contents. The application of N, P alone and in combination and N-P-filtermud combinations significantly increased the dry matter yields and percent N, P and K in the maize plants. The increases in the N, P and K contents in the maize plants were attributed to increased availability of N, P and K added to the soil as N and P fertilizers and the N, P and K released from the filtermud through decomposition and mineralization. Further, improvement of the physical, chemical and biological properties of the soil by the filtemud could have contributed to increased uptake of N, P and K. However, application of filtermud alone decreased the N, P and K contents of the maize plants and this was attributed to the immobilization of these nutrients in the soil. Filtermud could be used as an organic soil amendment when applied together with inorganic fertilizers for the enhancement and sustainability of soil fertility. Application of inorganic fertilizers and filtermud would improve soil productivity without detrimental effect to the environment.Item Assessment of copper and zinc status of some soils of Iringa district(Sokoine University of Agriculture, 1992) Mkangwa, Chaboba ZaidThe objectives of this study were to select suitable extractants for determining available copper and zinc in soils of Iringa district and to assess the fertility status of the two nutrients in the district. Two sets, each of ten soils for one element, were selected for glasshouse studies using maize as a test crop. The soils were treated with 0 and 5 kg ha' of either copper or zinc in their respective trials. Three extractants, viz: 0.1M EDTA-(NH.)jCO;, 0.005M DTPA and 0.1NHC1 were tested for their suitability to extract these elements. The concentrations of these elements in maize shoots were also determined. A total of 61 samples were collected from the district and analyzed for copper and zinc using the methods found to be suitable. Copper and zinc application slightly increased dry matter in four and eight soils, respectively, out of the ten soils tested. However, the increase was not statistically significant. The 0.1N HC1 extractant was superior to the other two in extracting zinc but none of the methods was suitable for copper. The tentative critical concentration for zinc was found to be 0.28ppm. Application of either of these elements in the soils, significantly increased their concentration in the plants. The tentative critical 6.30ppm. copper concentration in maize shoots was For zinc, the critical concentration in shoots was not determined because all the values obtained were above critical concentration extractant, range reported elsewhere. zinc concentration Using the 0.1N HC1 in the soil ranged from 0.14 to 27.30 ppm. For zinc, two fertility classes: medium and high were obtained. The proportions of soils which fell in the medium and high zinc fertility classes were 8.20 and 51.80%, respectively.Item Evaluation of minjingu phosphate rock as a source of phosphorus for grapevine production in Dodoma district Tanzania(Sokoine University of Agriculture, 1995) Budotela, George Masanja RaphaelExperiments were conducted to assess the P status of selected soils of Dodoma district, Tanzania and the response of grapevine to P application. The experimental sites were Msalato A, Msalato-Manispaa and Veyula Makutupora. The studies included (i) the initial fertility characterization of the incubation study and (iii) experimental soils (ii) an a field trial which compared MPR and TSP as sources of P. Results from the characterization study showed that fertility status decreased with increasing distance from the tree trunk congruent to the location of the fertilizer band. In the incubation experiment, solubility of MPR was found to increase steadily with time until equilibrium was reached at about 45 days. At this time 52% of the applied MPR, equivalent to 260 mg P/kg had dissolved. Soil samples incubated with TSP at this time released 64% of soluble P. Calcium and Phosphorus sinks were demonstrated as important parameters which influenced P dissolution in the test soils. In the field trial, both TSP and MPR application increased grape yield significantly over the control with TSP giving higher yield than MPR. The relative agronomic effectiveness (RAE) value for MPR averaged 67%, suggesting that TSP had a higher fertilizer value. The study further demonstrated that P rates above 168 kg P/ha decreased grape yields at Veyula-Makutupora site while at Msalato A and Msalato-Manispaa sites yields continued to increase. From these findings, it was concluded that: in addition to N, P application was needed in order to optimize grape yield in Dodoma district and a tentative rate of 168 kg P/ha is recommended. Minjingu PR was found to be a promising substitute for TSP but assessment of residual effects should be made before a definite recommendation can be made. Further research should be conducted to increase P use efficiency.Item Effect of gliricidia sepium green manure placement on solubility of minjingu rock phosphate, growth and yield of maize at SUA farm, Morogoro, Tanzania(Sokoine University of Agriculture, 2000) Kimaro, Anthony AndersonThis study was carried out at Sokoine University of Agriculture (SUA) Farm, Morogoro, Tanzania to assess the effect of Gliricidia sepiutn green manure (GM) placement method on solubility of Minjingu rock phosphate (MRP), growth and yield of maize. The study involved pot and field factorial experiments with treatments arranged in a complete randomized block design in three replications. For the pot experiment, the experimental factors were G. septum. GM placement method (5 t ha’1) at three levels (i.e. No GM, Incorporation and Mulching) and P- fertilizer application rates at seven levels (i.e. 0, 12.5, 25, 50, 100, 150 mg P kg soil’1 as MRP and 50 mg P as TSP). Air dried soil (2 kg) was filled in each of the 63 pots representing the 21 treatment combinations. The various treatments were then incubated at 70% field capacity (FC) at ambient temperature for three months. Within this period soil sub samples were collected at two weeks intervals for available phosphorus (AVP) deter mination in the laboratory. For the field experiment, the experimental factors remained the same as for the pot experiment except that the P-fertilizer application rates were 0, 10, 20, 40, 80 kg P ha’1 as MRP and 30 kg P ha’1 as TSP. Soil samples were collected at two weeks intervals for the determination of AVP in the laboratory. Additionally, maize height (m) at tasseling stage was recorded and maize samples were collected for the determination of P and N in the leaf, grain and stover. Grain and stover yields were also determined at maturity. The results indicated that GM placement method significantly improved AVP in both pot and field experiments, with the highest AVP obtained by the incorporation treatment. In most of the sampling dates AVP values for incorporation and mulching treatments were not significantly different in both the pot and field experiments. The AVP increased with increase in MRP application rates for both experiments and for all sampling dates. Except for stover N, GM placement method significantly increased concentration and content of P and N in maize leaf. For the incorporation treatment, the values were leaf concentra- tion (0.2005% P; 2.298% N) and leaf content (5.835mg P; 66.19 mg N). The corresponding values for the mulching treatment were leaf concentration (0.1908% P; 2.252% N) and leaf content (5.426 mg P; 63.43 mg N). Similarly, P and N uptake were significantly increased by GM placement method. The uptake values for incorporation treatment were as follows: grain (6.22 kg ha"1 P;37.82 kg ha"1 N), stover (2.18 kg ha"1 P; 10.98kg ha"1). Whereas corresponding values for the mulching treatment were grain (5.40 kg ha"1 P; 33.77 kg ha"1 N), and stover (1.76 kg ha"1 P; 9.59kg ha"1). Total P and N and maize height as affected by GM placement method followed a pattern similar to that of P and N for grain and stover. Maize yield was (2.07 kg ha"1 grain; 2.57 kg ha"1 stover) for control, (2.60 kg ha"1 grain; 3.33 kg ha'1 stover) for incorporation and (2.34 kg ha"1 grain; 2.98 kg ha"1 stover) for mulching. P and N uptake by maize significantly increased with increase in MRP application rate. However, at higher rates (i.e. 40, 80 kg P ha"1 as MRP), the increase of maize leaf P and P uptake was not significant. Generally, most of the parameters studied showed a linear and quadratic relationship with MRP application rates. Furthermore, the interactions between GM placement method and MRP application rates for most of the parameters studied were not significant. Based on the results of this study, it was concluded that incorporation and mulching of GM has the potential to improve solubility as well as growth and yield of maize. However, adoption of the practice may be limited because of the labour required in cutting, transporting and incorporating the GM into the soil. Getting a source that will provide sufficient amount of GM to cater for the needs of most of small holder farmers at the appropriate time may also be a problem. Furthermore, GM in this study was used as a source of N for maize and this is merely transferring nutrients within the farm and not actually redressing the nutrient depletion in the soil, therefore it may not be sustainable in the long run.Item Influence of legume biomass on soil fertility status and maize performance in striga infested soils of Iringa, Tanzania(Sokoine University of Agriculture, 2013) Hepelwa, RebecaThe effect of incorporation of legume biomass residues on Striga infested soils was evaluated at Mangalali and Kiwere villages in Iringa district, Tanzania. Six legumes: [cow pea (Vigna unguiculata). green gram (Vigna radiatci), mucuna (Mucuna puriens). jack beans (Canavalia ensiformis), sunhemp (Crotaliria ochroleuca) and chick pea (Cicer arielinum)] plus two controls (no fertilizer added and one level of fertilizer 80 kg N ha-1 as urea) as nitrogen source were evaluated in randomized complete block design experiment. The legumes and their biomass quantities were incorporated into the soil four weeks prior to planting maize during 2011/12 growing season in the field. Significant differences (P<0.05) were recorded for soil chemical properties. Soil pH increased from (6.33 to 6.39) and (4.88 to 5.31) at Mangalali and Kiwere villages respectively. The highest organic carbon increase was recorded in plots incorporated with cowpea and mucuna with increases of 14% and 5% compared to chickpea (1%) at Mangalali village. At Kiwere village the highest organic carbon increase were recorded in plots incorporated with sun hemp (38%) and cow'pea (36%) compared to chickpea (1%). The highest N increase was observed in sun hemp (101.8%) followed by cowpea with an increase of (90.2%) compared to chickpea (12%) at Mangalali village, while at Kiwere village the highest N increases were recorded in sun hemp and cow-pea with increases of 553.84% and 541.67%, respectively compared to green gram (169.23%). Mucuna, sun hemp and cowpea also improved soil pH, organic carbon, total nitrogen and available P. Hence there were significant differences (P sun hemp (3.5 t ha'1) > mucuna (3.4 t ha'1) > green gram (2.3 t ha'1) > canavalia (2.1 t ha'1) > chick pea and control (1.6 t ha'1). Among legumes, cowpea incorporation was observed to produce higher yield compared to the other studied legumes. The incorporation of cowpea, mucuna and sunhemp legume residues are recommended to be used by poor resource farmers to improve soil fertility, reduce Striga infestation and increase maize yield in Striga infested areas with low soil fertility.Item The effect of soil type, manure application rate and placement method on the decomposition of, and nitrogen release from, senna siamea green manure(Sokoine University of Agriculture, 1996) Haru, Ruth WatiriThe decomposition and nitrogen release of Senna siamea green manure was studied under glasshouse and field conditions. The effects of two soil types, two manure application rates and two methods of manure placement on the decomposition rate were monitored by use of three parameters, namely residual dry matter, organic carbon and total nitrogen. These parameters were measured at the 1st, 3 rd 6ch 9 th and 12th week of manure incubation in the glasshouse while in the field, measurements were made at the 3rd 6 th and 9ch week. The glasshouse study revealed that there was no significant (p=0.05) difference between the decomposition rates, at 10 cm depth, in a Rhodustult (soil 1) and Dystropept (soil 2) as indicated by the three parameters. The manure decomposed faster at a lower application rate (60 kg manure-N/ha) than at a higher rate (150 kg manure N/ha) . Under field conditions, buried manure decomposed faster in soil 2 than in soil 1 while for the surface placed manure the opposite was observed. In soil 1, where termite activity was appreciable, the surface-applied manure decomposed faster than the buried material while in soil 2 manure. the decomposition rate was faster for the buried. The trends of manure decomposition were similar under the two incubation conditions but the decomposition rate after the third week was significantly higher in the field than in the glasshouse. The results of the present study indicated that in the glasshouse, the decomposition rate of green manure was not affected by the soil types used. But the decomposition varied with soil type, manure application rate as well as the mode of placement in the field. Therefore these factors should be considered when conclusions are to be made with respect to nutrient release from this manure.Item Assessment of zinc and copper status in soils of the central part of Sokoine University of Agriculture farm, Morogoro, Tanzania(Sokoine University of Agriculture, 1999) Gideon, Ngerageza FarajaA study was conducted to assess the zinc and copper status in the soils of the central part of Sokoine University of Agriculture (SUA) farm. Twelve soil samples were collected from selected areas in the farm. Zinc and copper in these soils was extracted with four extractants namely 0.005M DTPA-TEA (pH 7.3), 0.005 DTPA-AB (pH 7.3), double acid (0.05M HC1 + 0.0125M H2SO4) . 0.1M HC1 and Two soils (Oxic Haplustult and Typic Rhodustult) out of the twelve soils were used for glasshouse experiment determine to response of beans (Phaseolus vulgaris) to zinc and copper zinc and application. The soils were each treated with copper at the rates of 0, 2.5, 5 and 10 Kg/ha. the Zinc application generally increased the dry matter yield plants in dry matter yield) was both soils. The increases of bean significant when compared to the dry matter yields of the controls. Copper application increased dry matter yield in the Oxic Haplustult where there were positive response to copper application. However negative response (decrease in observed in the Typic Rhodustult. Zinc and copper tissue- concentrations in bean shoots and were their uptake were significantly increased in both soils by the application of zinc and copper. However, the tissue zinc and copper concentrations observed were rather high and above the critical concentrations reported in the literature. Of the four extractants tested, 0.005M DTPA TEA was found most suitable for assessing the available zinc in the soils since it gave significant correlations with plant parameters (dry matter yield, tissue zinc concentrations and zinc plant uptake). The 0. IM HC1 was the second in suitability. However, none of the methods was found to be suitable for the extraction of copper in these soils.Item Origin and characteristics of salt affected soils in Mafiga - Chamwino lowland area Morogoro - Tanzania(Sokoine University of Agriculture, 1996) Kaboni, Elmens L.Salt affected soils is a major problem limiting crop growth in majority of the flood plains in Tanzania, the Mafiga-Chamwino lowland in Morogoro district being one of them. A detailed study was conducted to investigate the distribution and characteristics of salt affected soils in the Mafiga-Chamwino lowland in Morogoro district. The objectives were characterisation, classification and mapping the extent of distribution of salts; determination of spatial distribution of salts and corresponding crop performance; and investigation of the sources of salt accumulation. Distribution of different types of soils was studied by carrying out grid survey at 50 m spacing while the spatial distribution of salts and the corresponding crop performance was done at 10 m spacing. The corresponding maps were drawn at a scale of 1:10 000 and 1:1 000 respectively. Detailed laboratory characterization was done on the salt affected soils, surface and ground waters as well as rocks from the weathering front. Four- types of soils: Gleyic Solonchak, Chromic Luvisols, Gleyic Luvisols and Sodic Solonchak exist in the studied area. These were categorized as saline soil, intergrade between sodic and normal soil, sodic soil and saline-sodic soil respectively. The calcium-magnesiumand sodium-calcium types of cation salinization, and sodium carbonate-chloride anion types of salinization dominated in the soils. Large variations of salinity and alkalinity accompanied by corresponding rice crop performance occurred at a short distance in the area studied. Leaching from the weathering of the dominating basic rocks in the vicinity of the study area accounts for the salinization of both surface and ground waters. These waters are the primary source of salts in the soils. Fluctuation of the ground water determines salt distribution in the soil solum. Each of the four soils requires a different approach in order to control salt problems.Item The effect of seed factors and the duration seed remains in soil before the onset of rains on establishment of maize and sorghum(Sokoine University of Agriculture, 1997) Tarimo,Bartholomew DonatA study was undertaken to: (a) assess the seed quality in commercial and farmers planting seed,(b) extent of seed ageing in storage and (c)investigate the monitor the effect of length of time seed remain in soil before onset of rains on establishment of maize (Zea mays (L) and sorghum (Sorghum bi color (L). Seed of three cultivars of maize (Staha, TMV-1, and Kito) and one sorghum cultivar(Tegemeo) were from bought Tanzania Seed Company (TANSEED), Morogoro branchz and from farmers around Morogoro Municipality. The bought seed was stored alongside TANSEED and farmer's seed. Initially, seed samples from each lot and each farmerz were taken to the laboratory for refrigeration to minimize ageing and hence to serve as control. Acquired seed was initially subjected to a germination test to assess its quality as a planting material.Germination test were conducted in a sandbox set at a matric suction of IkPa. The study on the effect of length of time seeds remain in soil before the onset of rains on establishment was conducted both in glasshouse and in the field using high,medium and low vigour seeds.High vigour seeds were the fresh / imaged seed samples from the seed lots.Medium and low vigour seeds were obtained by artificial ageing of fresh seed for 2 and 3 days respectively.Planting, both in the glasshouse and in the field was done at an interval of 3 days z that is 0 r 3, 6, 9, 121 15 days.Watering was on the 15th day with an equivalent of 20mm of rainfall. Seeds from TANSEED had ranging from 93 to 100%, initial germination percentage (maize) and 92 to 96% (sorghum)・Seeds from farmers had gemination percentage varying from 64 to 99% (maize) and 8 to 65% (sorghum)・seeds from TANSEED had relatively capacity than those from farmers. Higher germination Seeds from farmers had high initial seed moisture content (SMC) seed. Overall sorghum than commercial Sorghum had higher SMC than maize irrespective of the source ・Initial SMC was about 10 and 11% for maize and sorghum respectively.At the end of the studyz SMC had increased to an average of 12 and 14% for maize and sorghum respectively. Time to 50% germination (T50) increased with storage time for seeds obtained from TANSEED. maize cv St aha lot A were 2.2,T50 values (in days) for (initially) , 2.4 one month) and 2.7 after two months)・(after Seeds from farmers showed no consistent trend.In both field and glasshouse emerged earlier than maize seeds.studies,sorghum seeds Sorghum seeds started emerging 3 days after watering whereas for maize emergence started on the 4th day.The length of time seed remained in the soil(dry planting)had no effect on percentage emergence in the glasshouse experiment. Under field conditions percentage emergence decreased with the length of time seed remained in soil before watering.High vigour maize seeds had relatively higher proportion of seeds categories.which emerged than Insorghum,medium and low vigour the other two vigour seeds performed better in terms of emergence than high vigour seeds.The average shoot length for maize 10 days after watering varied from 157mm to 238mm and 90.7mm to 248mm for the glasshouse and field experiments respectively.Sorghum seedlings grown in the glasshouse had mean shoot lengths varying from 121mm to 172mm and the mean values recorded in the field varied from 63mm to 101mm.Item Assessment of in-situ rainwater harvesting techniques for improving smallholder maize production in semi arid areas of Morogoro, Tanzania(Sokoine University of Agriculture, 2003) Bwana,Thomas NestoryA study was conducted at Morogoro, Tanzania during long rains ('Masika') to evaluate the effect of in~situ rainwater harvesting (RWH) techniques in improving maize yield. Three commonly used techniques, ridging after planting (RA), ridging before planting (RJB), and tied ridging (TR) were tested against a no tillage practice locally known as "kuberega" (K) on an Oxic Paleustalf soil with maize (Zea maize L.) variety TMV1 as the test crop. Daily rainfall was recorded and the total rainfall received during the 2001/02 growing season was 562 mm with a series of dry spells. Moisture content at 0-15 and 15-30 cm depth was measured twice weekly. Significantly (p<0.05) higher soil moisture variation and lower moisture content were noted in treatment K than in the other treatments. Treatments RB and TR had lower moisture variations and higher moisture content throughout the season. Grain yield, biomass, plant height, bulk density, infiltration rates (on the ridge and in the furrow), runoff and soil loss were also measured. Significant differences were observed among the treatments (p<0.05) in runoff, soil loss, on ridge infiltration, grain yield, and biomass. The maize yield ranged between 2.97 Mg/ha and 3.89 Mg/ha for treatments K and RB, respectively. The runoff loss was highest for K and least for TR. Treatments K and RA did not differ significantly from each other but differed significantly from RB and TR (p<0.05). Soil loss had a similar trend as that of runoff. More runoff loss was recorded early than late in the season. On ridge infiltration was not significantly different for treatments TR, RA, and RB but was significantly higher than the control (K) at (p<0.05). On furrow infiltration, however, had a reverse order with K having higher rates. Bulk density in both depths (0-15 and higher bulk density. The results show that ridges are effective in-situ rainwater harvesting technique that conserves water and soil and improves productivity.However, ridging after planting is inferior to both ridging before planting and tied ridging.15-30 cm) was not statistically different (p<0.05), however treatment K had slightlItem Effects of selected insecticides on microbial numbers,leucaena decomposition and biological nitrogen fixation(Sokoine university of Agriculture, 1997) Ng'ang'a, Josephine NyamburaThe effects of Lannate and Karate on the decomposition of leucaena green manure and nitrogen fixation by cowpea were evaluated, after establishing their inhibitory effects on the decomposer microorganisms and their toxic effects on the bradyrhizobia in vitro.In the decomposition experiment,manure the in in the perforated plastic litter bags was buried (10 cm) soil contained in wooden troughs and the insecticides were applied on the soil at final concentrations of 0.5 and 1.5 ppm for lannate or and 0.51.0 ppm for decomposition process was monitored at 0, after weeks matter, and incubation by measuring residual organic carbon,inorganic-N heterotrophic content microbial of count karate.1, the 5 and 73,residual dry residual total nitrogen was the soil.The determined total at each sampling time.The effects of these insecticides each at 0.5 and 1.5 ppm on the covrpea-Bradyrhizobium symbiotic relationship were assessed in potted soil. Cowpeas were grown and harvested after 35 days. Nodule numbers and dry weight,shoot dry weight and nitrogen content were assessed.Results of these studies indicated that lannate and karate had an apparent depressive effect on the growth of the heterotrophs at the 0.5 ppm concentration but not at higher concentrations. The bradyrhizobial proliferation invitro was more affected by lannate than karate. However, nodulation and nitrogen fixation was not affected by any of the insecticides at significantly any of the the two concentrations tested.It was concluded from this study that insecticides, when applied even up to ten times the field recommended rate have no profound effects heterotrophic microorganisms, their ability to on the decompose leucaena green manure and on biological nitrogen fixationin cowpeas. However, the very severe depressive effect of lannate on the cowpea-bradyrhizobia in vitro, may warrant further studies in soils.Item Pedological investigation and characterization in Litembo village, Mbinga district, Tanzania(Sokoine University of Agriculture, 1997) Meliyo, Joel L.A pedological investigation was carried out in Litembo village, Mbinga district (Tanzania) to identify the various soil types and characterize them in terms of their physical, chemical and mineralogical properties. The soils were classified according to FAO-Unesco and USDA Soil Taxonomy systems. On the basis of soil and other ecological parameters the potentials and constraints of the land resources were assessed. Standard soil survey methods and laboratory procedures were utilised to generate both field and laboratory data. Results indicate that Litembo village has four major landforms i.e. plateaux, hills, piedmonts and valleys Most piedmont soils are deep to very deep having dark brown to dark reddish brown sandy clay topsoils and dark red to red clayey subsoils. The hills and plateaux have shallow sandy clay loam soils. All the studied soils are well drained to excessively well drained except those of the valley bottoms which are poorly drained. Topsoil bulk densities range from 0.99 to 1.2 Mg m'3 whereas subsoil values are slightly higher. Total porosity ranges from 56 to 72% in the topsoils and from 40 to 53% in the subsoils. Topsoils have lower penetrometer resistance (PR values 0.1 to 0.28 MPa) than subsoil (PR values 3.97 - 5.52 MPa). Available water capacity (AWC) of most topsoils ranges from 15 to 25% by volume and the values decrease slightly with depth. AWC per meter range from 125 to 177 mm which is medium to high. General soil fertility status is poor. Soil reaction is very strongly acid to strong acid with pH values between 4.4 and 5.4 in topsoils and 4.4 and 6.0 in subsoils. Total nitrogen ranges from very low to medium (< 0.03 - 0.3); phosphorus, bases, CEC and base saturation are low. OC ranges from low to very high in topsoils and very low in subsoils. The clay mineralogy is dominantly kaolinitic with accessory amounts of gibbsite and goethite. The piedmont soils classified as Ferric Acrisols, Haplic Acrisols and Humic Acrisols, plateau soils classified as Humic Acrisols; soils of the as Dystnc Leptosols and Haplic Acrisols and valley bottom soils as Umbric Fluvisols. From the results of this study it is concluded that Litembo soils developed under intensive leaching environment, facilitated by a mountainous/hilly topography. Fertility status is poor, and due to steep slopes and weak soil structure Litembo soils are prone to erosion. The traditional farming system (ngoro) seems to control soil erosion on steep slopes. It is recommended that steep slopes should be planted with trees that will protect soil from erosion. Use of the traditional farming system (ngoro) should be encouraged. Due to low soil fertility status, use of fertilizers both artificial and organic manures is recommended Non-acidifying fertilizers should be preferable because of the low soil pH values. The study area lacks climatic data. More research in this line is recommended. Research on different land use alternatives which can sustainably be applicable in the village should be carried out.