Soil Science Collection

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Soil classification, pedogenesis and land evaluation in Kapini area Lusaka, Zambia.
(Sokoine University of Agriculture, 1983) Kaltia,Cuulu
Back ground -information related to classification, pedogeneiis and laud evaluation is briefly given. It includes information on geology, geomorphology, topography, drainage, climate and vegetation. Literature on soil classification in relation to local and inter-■:n-3ti&2.yl classification systems is reviewed. Literature review on. pedogenesis critically focus on soil genesis work in Zambia in relation to important soil’ formng factors.International and local land evaluation systems are reviewed.together with concepts that are not used consistently and have often caused lots of confusion in land evaluation. The results of the study can briefly be summarised as follows: 1.The soils are classified, into four major orders:Ultisols, Alfisols and InceptIsols.Oxisols, (Soil Survey Staff 1975) or as Ferralsols, Luvisols, Acrisols, Hegosols and Lithosols (PJL.O./craESCO 1974). Classification is pursued up to the family level and sub-unit level respectively*. 2.The major processes which are important in pedogenesis are:Eluviation, illuviation, Cumilation, Pedoturbation, Desilication,Fertilization Decomposition and Synthesis.be the most important soil forming factor.Geology was found.to the most important soil forming factor. 3.Most of the soils in the area are moderately suitable to crop production (60^).- The major limitation to crop production are fertility (for the Oxisols), flooding, moisture availability, stoniness; and rooting depth« 4.Socio-economically the area is not suited to cash crop production at subsistence and intermediate management levels* 5.The area has a high potential for crop production especially with improved management.level'*
Soil survey amd land evaluation of a part of the university farm - Morogoro for rainfed agriculture
(Sokoine University of Agriculture, 1984) Mpepo,Haston Longwani James
Lack of a systematic and detailed soil survey and land evaluation report for guiding the utilization of the farm necessitated this study.About 1, 097 ha comprising the Northern part of trie farm was covered. It is possible to grow maize, sorghum, soyabeans, fieldbeans, ground- nuts and rice. J
Effects of spraying coffee with copper fungicides on the copper status of soils of Moshi district, Tanzania
(Sokoine University of Agriculture, 1990) Mkindi, Gerard Isaac
A 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.
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 Kinyamagoha
Pot 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.
Evaluation of Minjingu phosphate rock products as sources of phosphorus for maize and sorghum in some Morogoro and Hai soils
(Sokoine University of Agriculture, 1991) Kimbi, Gerald Gervas
Experiments effectiveness were partially of to evaluatethe acidulated phosphate rock conducted (PAPR) and non acidulated Minjingu phosphate rock (PR) as sources of for phosphorus maize and sorghum. Two studies was the test crop in the initial pot study and two field experiments were conducted.Maize in the field experiments while sorghum was used in the residual pot study.Five soils, namely Kwa Sadala, Mlama, Mafiga,Magadu and University Gate,varying widely in properties were used. Results of these experiments showed that all the P carriers increased yields in Mlama, Magadu and University Gate soils, indicating that the three soils were P deficient and thus required supplemental P. The KwaSadala and Mafiga soils, with high available P and nearly, neutral pH values, did not respond to either of the P sources.The initial PAPRs and results study indicated non ac i dulated PRs had the nearing that pot of University Gate that the fertilizer values TSPin soilsthe PAPRs and PRs were generally Mlama soil. In the Magadu and inferior to TSP. Results of the residual pot study showed that the PAPRs and PRs had superior residual effectiveness compared to TSP in Magadu, indicating that overMlama and time the P dissolved in the three soils.University Gate soils, carriers substantially
Assessment of copper and zinc status of some soils of Iringa district
(Sokoine University of Agriculture, 1992) Mkangwa, Chaboba Zaid
The 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.
Genotypic variation in phosphorus requirement and utilization in nodulated common beans (phaseolus vulgaris l.)
(Sokoine University of Agriculture, 1992) Ole-Meiludie, Dorothy John Simon
A 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.
Genotypic variation in phosphorus requirement and utilization in nodulated common beans (phaseolus vulgaris l.)
(Sokoine University of Agriculture, 1992) Ole-Meiludie, Dorothy John Simon
A 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.
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 Raphael
Experiments 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.
The effect of soil erosion on soil productivity under different management practices
(Sokoine University of Agriculture, 1996) Gebremedhin, Yemane Hallu
A study was conducted at Sokoine University of Agriculture, Morogoro, Tanzania, to evaluate the effect of erosion soil on soil productivity different under management practices using 10mx5m runoff plots with a 4 percent slope. (BF) ,permanent cropping(RO ,coarse mesh The treatments consisted of bare grass fine (GP) , flat mesh (FM) ,cropping medium fallow(CP) ,mesh ridge(MM) , and (CM). The CP and RC were planted with maize with a population density of 41 600 plants/ha. The FM, MM,and CM were simulated canopy covers with net shading rates of 80, 55, and 40 percent, respectively, stretched 40 cm above the surface.Runoff generated during every rainstorm was collected for determining amount of runoff, soil and nutrient losses from each treatment. Soil samples from the runoff plots taken at the beginning (initial) study were analyzed for and end (final) changes properties. Amount of nutrient loss and eroded sediments were in soil of the chemical in the runoff water determined. Grain yield and biomass were determined for the cultivated treatments. Runoff ranged from 143.9 m3/ha in the GP to 2398 m3/ha in the BF. The runoff from the BF, significantly different from all (p<0.05) other treatments. Soil GP, CP, and CM were amongst themselves and loss was between 0.09 Mg/ha in the GP and 12.49 Mg/ha in the CP. There was no significant difference in soil loss between the BF and CP treatments but they differed significantly from all other treatments.Organic carbon showed a significant decrease in the final soil samples in the BF, GP, RC, and FM treatments, while TN decreased significantly (P<0.05)in the CP,RC,and phosphorus CM treatments.Likewise, available was significantly lower in the final soil samples in the GP, CP, and FM. Surprisingly, both Na*and CEC were significantly higher in the final soil sample in some of the treatments. The BF and CP treatments lost significantly (P<0.05) more OM, nitrogen, and Ca2+ than all other treatments. The loss in AVP, K+, and significantly different Mg2+ the from (P<0.05) BF and CP were amongst themselves and from all other treatments.There was no significant difference in maize grain yield and biomass between the CP and RC. However, grain yield and biomass were higher in the RC treatment. Based on the results of this study, it has been shown that increasing canopy cover reduces nutrient losses. In addition, the runoff, ridges soil,were able and to effectively check soil erosion.
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.
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 Watiri
The 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.
Measurement of soil water evaporation using microlysimeters of different sizes: effect of shade and soil texture
(Sokoine University of Agriculture, 1996) Maseko, Stephen Phuz’ukuvela
The 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.
Measurement of soil water evaporation using microlysimeters of different sizes: effect of shade and soil texture
(Sokoine University of Agriculture, 1996) Maseko, Stephen Phuz’ukuvela
The 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.
Response of maize to phosphate released from Minjingu phosphate rock and farm yard manure applications in an oxic haplustult
(Sokoine University of Agriculture, 1997) Kitua, M.J.Y.
A glasshouse pot experiment was carried out to investigate the (Zea maize of response mays L combinations of MPR-Farm yard manure (FYM) applied to an Oxic Haplustult. were 0, .7.5,)to various (kraal manure),The rates of FYM applied 15 and 30 g/kg and the rates of MPR were 0, 50, 100, and 150 mg P/kg soil. The MPR-manure combinations were incubated seeds.The one for month showed results before an the sowing increase maize Bray-1-in an increase in dry extractable P by 8.3 mg P/kg soil, matter yields of 27.3 g/kg soil and phosphate uptake by 0.13%. The above increases were attributed to the P released from the solubilization of MPR and decomposition and mineralization of the farm yard manure.The small increases in Bray-lextractable phosphate increased with increasing indicate time of the gradual contact between solubilization, soil-MPR and FYM decomposition and mineralization of MPR and FYM, respectively. Response by crops to phosphate released from MPR-FYM-combinat ions' would be more pronounced when applied to the soil 6 to 12 months before planting, to ensure optimal solubilization and decomposition of the MPR and FYM, respectively.
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 Donat
A 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.
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.
Effects of selected insecticides on microbial numbers,leucaena decomposition and biological nitrogen fixation
(Sokoine university of Agriculture, 1997) Ng'ang'a, Josephine Nyambura
The 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.
Influence of shapes of the Ngoro on depression storage and crop performance.
(Sokoine University of Agriculture, 1999) Mogasa Pili Mogasa
A field experiment was conducted in the 1995/1996 growing season on a slope of 30% on the foothill of the Uluguru Mountains in Morogoro, Tanzania. The aim of the experiment was to evaluate the influence of various Shapes of the ngoro cultivation system on (i) soil moisture storage (ii) depression storage and (iii) maize growth parameters and yield. Three Shapes of the ngoro pits namely: Shape 1 (Rectangular with the longest side across the slope), Shape 2 (Rectangular with the longest side along the slope) and Shape 3 (Square) were compared with flat cultivation, a common practice in the study area. The various ngoro Shapes stored at least 1.36 times more soil moisture than flat cultivation (significant at the 5% level). The position of the ridge on the four sides of the pit had no significant effect on soil moisture storage (P < 0.05). Ngoro cultivation showed significantly higher amounts of soil organic matter (41% to 53%) than flat cultivation which had the lowest (about 6% organic matter, P < 0.05). Top soil (0 - 10 cm) had 15% organic matter (o.m.) compared to 7% and 6% o.m. at a depth of 10- 20 cm and 20-30 cm, respectively. Bulk density was significantly lower in the ngoro compared with flat cultivation (P < 0.05). Shapel had significantly (about 27%) lower depression storage compared to Shapes 2 and 3 (P < 0.05). Ngoro cultivation produced about 66% more grain than flat cultivation. This yield difference was significant (P < 0.05). The position of the ridge on the slope had no significant effect on maize growth and grain yield (p < 0.05). Therefore, if the aim is to improve maize performance in the study area any Shape of the ngoro can be employed as found out from this study.
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 Faraja
A 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.

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