Predicting soil ECe based on values of EC1:2.5 as an indicator of soil salinity at Magozi Irrigation Scheme, Iringa, Tanzania

Soil salinity is one of the limitations to sustainable production of rice and other crops in many irrigation schemes in Tanzania. Soil salinity can be assessed from electrical conductivity (EC) measurements. Most soil laboratories in Tanzania appraise soil salinity from measurements of electrical conductivity of 1:2.5 soil:water suspensions (EC1:2.5) by virtue of their simplicity. However, the influence of soil salinity on plant growth is mainly based on electrical conductivity of saturated paste extract (ECe), so it is necessary to convert EC1:2.5 to ECe in order to assess plant response to salinity. This study was conducted at Magozi Irrigation Scheme in Iringa Region, Tanzania to establish regression model for predicting ECe from EC1:2.5 values. A total of 60 soil samples (45 samples for model training and 15 samples for model validation) were collected and analyzed for soil EC1:2.5, ECe and soil texture. Results showed that EC1:2.5 ranged from 0.1 to 4.2 dS m-1 with a mean value of 0.71 dS m-1. ECe obtained ranged from 0.3 (non-saline) to 12 dS m-1 (very saline) with a mean of 2.4 dS m-1 (slightly saline). In order of dominance, soil textural classes were sandy clay loam, clay, sandy clay, sandy loam and clay loam. Strong linear relationships between ECe and EC1:2.5 were observed in the developed linear regression equations. After validation, the study selected equation ECe = 3.4954*EC1:2.5 with R2 of 0.956 for combined soil textures to be used for prediction of ECe from EC1:2.5 at Magozi Irrigation Scheme. This model can be tested for its applicability to other similar soils in Tanzania in further studies

Pedological investigations of sites for slash and burn experiment in Lupilo village and soil erosion studies in Tukuzi village, Mbinga District, Tanzania

It is a report from Miombo Woodland Research Project (MWRP)The study area (Mbinga district) is under the Miombo Woodland zone of Tanzania which are areas that are or at one time were under Miombo Woodlands. Two villages namely Lupilo and Tukuzi were covered in the study at the request of other scientists interested to carry out experiments respectively on "slash and burn" type of agriculture and on soil erosion. Detailed characterization of two sites representative of the two villages was done including general ecological conditions, pedological measurements and soil clay mineralogy.Japan International Cooperation Agency (JICA

Economic Optimization of Nutrient Application to Coffee in Northern Tanzania Using SAFERNAC

The aim of this work, as an extension to SAFERNAC model, was to establish economically optimum combinations of N, P and K application to Arabica coffee in the Northern coffee zone of Tanzania. The study was conducted in Hai and Lushoto districts between 2010 and 2012. Prices of nutrient inputs and those of parchment coffee were introduced into the original SAFERNAC model, which was used to obtain yields from a soil of known properties receiving different levels of input N, P and K from both organic and inorganic sources (ISFM). The costs of these were derived from experience in Northern Tanzania, while coffee prices were estimated to range between 1250 and 2500 TZS kg-1. The result was economically optimum N:P:K ratios that give highest net returns and value : cost ratios in situations of low, medium and high soil fertility. It was also shown that farmers’ decision to deviate from the optimum and the allowable level of such deviation, depend much upon the prices of nutrient inputs in equivalent terms. In the medium-fertility situation (which applies in the study districts), the highest yield increment was noted with the maximum amount of N and P. The optimum application rate was 310 kg N and 200 kg P per ha, where the profit margin (the gap between gross returns and costs) is highest. This is an indication that soil-available K is likely to suffice the needs of the crop for optimum productivity, but this is largely dependent on the K fluxes in different soil types. The optimum rates were tested with actual soil data in the two study districts, against 5 tons of farmyard manure and a combination of the two. At both the coffee prices of 1250 and 2500 TZS kg-1, ISFM intervention (combination of organic and inorganic inputs) was more profitable than the other options, while coffee production showed to be more profitable in Hai than Lushoto

The potential of afromontane rain forests to mitigate carbon emissions in Tanzania

Journal of Tanzania Association of Foresters, 2004, 10:14-25One of the major ways of mitigating carbon emissions is by emission avoidance or conserving existing carbon (C) pools on the land through slowing deforestation or improved forest harvesting practices. Field measures of tree dimensions and chemical soil analysis for organic carbon were used to quantify the carbon (C) storage potential of three tropical montane rain forest ecosystems; one on the slopes of Mount Kilimanjaro and two (Usambara and Uluguru) in the Eastern Arc Mountains of Tanzania. The above ground and root carbon of trees ranged from 295±8 to 5/7 ± /7 o:'. The tree carbon storage was lowest in the Kilimanjaro forest (295±8 (SD) t h"), and highest in the Usambara forest (5/7 ± /7 (SD) t s'. The C storage in the Ulugurus was 388± /0 (SD) t «'. The soil carbon storage (/423.7 t h") in Kilimanjaro was significantly higher than that in tree biomass. On the other hand the soil carbon (4/8 ± /00 and 295 ± 53 t h") in the Usambara and Uluguru respectively) was significantly lower than the biomass carbon in both forests in the Eastern A rc forests. The potential of these ecosystems to act as carbon sink and mitigate greenhouse gas emissions is evident. This capacity for carbon storage. population pressure and the extensiveness of these forests in the region makes their conservation of global significance for carbon emission mitigation

Investigation of environmental factors for Land management in Litembo village, Mbinga District, Tanzania

It is a report from Miombo Woodland Research Project (MWRP)This report describes the natural resources study of Litembo village as part of the continuing project on the assessment of the natural resources of Mbinga district. The study covers measurements of terrain elements, soil physical and chemical properties, land use systems including farming and production systems and an appraisal of the ecological potential and constraints of the village natural resources.Japan International Cooperation Agency (JICA

Developing a Coffee Yield Prediction and Integrated Soil Fertility Management Recommendation Model for Northern Tanzania

The aim of this study was to develop a simple and quantitative system for coffee yield estimation and nutrient input advice, so as to address the problem of declining annual coffee production in Tanzania (particularly in its Northern coffee zone), which is related to declining soil fertility. The study was conducted between 2010 and 2013 at TaCRI Lyamungu, with source data taken from Hai and Lushoto districts, Northern Tanzania. An earlier model QUEFTS, developed for maize but under similar conditions as those of Arabica coffee (Coffea arabica) in the study areas was used as a benchmark. Secondary fertilizer trial data were used in model calibration for coffee, while adding two more steps related to balanced nutrition and the economics of integrated soil fertility management (ISFM). Primary soil analytical data and calculated yields on basis of tree number were used for model testing. The result was a new model which we hereby call SAFERNAC (Soil Analysis for Fertility Evaluation and Recommendation on Nutrient Application to Coffee). The model consists of three modules: SOIL (the soil properties of interest), PLANT (all the crop and crop management parameters such as physiological nutrient use efficiency, plant density, maximum yields per tree) and INPUT (nutrient inputs – organic and inorganic). It consists of two subsequent parts – a baseline approach (no input) for coffee land evaluation; and an integrated soil fertility management (ISFM) approach that involves application of nutrient inputs, for ISFM planning and design of fertilizer experiments. The model was checked for accuracy of the adjusted equations, and found to be capable of reproducing the actual yields by 80-100%. The new model is a useful tool for use in coffee farm

Exploring the Nutrient Release Potential of Organic Materials as Integrated Soil Fertility Management Components Using SAFERNAC

The aim of this study was to establish the nutrient release potential of different organic materials and assess their role in integrated soil fertility management for coffee using the new coffee yield model SAFERNAC. It involved an incubation experiment conducted at TaCRI Lyamungu Screenhouse for 180 days between April and September 2011. Cattle manure, coffee leaves, pulp and husks, Albizzia leaves and four green manure plants – Mucuna pruriens, Lupinus albus, Canavalia ensiformis and Crotalaria ochroleuca were mixed with two soil types – Eutric Nitisols from Lyamungu, Hai district and Humi-Umbric Acrisols from Yoghoi, Lushoto district. The mixing ratio was 5% organic to soil, the mixture was moistened to FC and incubated in 10 litre plastic containers arranged in RCBD (10 treatments and 3 replications) at room temperature. Duplicate soil samples were taken at day 0, 3, 8, 15, 26, 45, 74, 112 and 180 and analyzed for NH4+-N, NO3-N, available P and exchangeable K. The cumulative Nmin, P and K values resulting from the treatments were used to estimate their relative contribution to the soil nutrient pool and later exposed to the new model SAFERNAC for yield estimation under different nutrient management options (1 to 10 tons organics per ha alone on one hand and supplemented with 160 kg N, 60 kg P and 160 kg K). The tested organics differed significantly (

Investigation of the environmental attributes for agricultural development in kitanda village, Mbinga district, Tanzania

Project reportThis report describes the study of environmental attributes of Kitanda village as part of the continuing project on the assessment of the natural resources of Mbinga district. The study involved measurements of terrain elements, quantitative investigations of soil properties, inventory of land use systems and an assessment of the ecological potential and constraints as determined from a balance sheet analysis of resources and land use requirements.Japan International Cooperation Agency (JICA

Investigation of environmental factors for Land management in Litembo village, Mbinga District, Tanzania

It is a report from Miombo Woodland Research Project (MWRP)This report describes the natural resources study of Litembo village as part of the continuing project on the assessment of the natural resources of Mbinga district. The study covers measurements of terrain elements, soil physical and chemical properties, land use systems including farming and production systems and an appraisal of the ecological potential and constraints of the village natural resources.Japan International Cooperation Agency (JICA

Factors influencing soil distribution and their implication for agricultural land management in Morogoro urban District, Tanzania

Proceedings of tbe 1st University Wide Scientific Conference, 2000; Vol 2:161 - 171A standard soil and land resources survey was conducted in Morogoro Urban District, Tanzania to investigate the factors influencing characteristics and spatial distribution of soils and their implication for land management. Landforms, parent materials, climate, soil morphological, physicochemical and mineralogical properties were the main attributes studied. Soils were classified according to the FAO-World Reference Basefor Soil Resources. Six major landforms were identified namely; strongly dissected mountain ridges, mountain foothills, hills, piedmonts, peneplains and valleys. The strongly dissected mountain ridges comprise complex soils developed on pyroxene granulites. The soils include shallow, excessively drained sandy clay loams and deep well drained sandy clays and clays. The soils were classified as Lithic-Paralithic Leptosols, Hapli-Profondic Lixisols, Orthidystri-Episkeletic Cambisols and Hypereutri-Episkeletic Cambisols (Haplic). The hills are a complex of rock outcrops and shallow soils developed on muscovite-biotite migmatites. The soils are excessively drained, extremely gravely sandy loams and sandy clay loams. The soils were classified as Lithic Leptosols. The piedmonts and peneplains comprise largely associations of deep and very deep, well drained clays and sandy clays. These soils developed on colluvium derived from granulites and migmatites were classified as Chromi-Profondic Acrisols, Chromi-Profondic Lixisols, Rhodi-Profondic Luvisols and Cutani-Profondic Luvisols (Haplic). In the valleys, the soils are developed on alluvium of diverse mineralogical composition and are a complex of Calcari- and Stagni-Mollic Fluvisols and Calcari-Salic Vertisols. All the studied soils except those of the valleys have low soil fertility as shown by low organic carbon «1.0%), low levels of major nutrients (nitrogen <0.1%, phosphorus <5 mg/kg) and low CEC «12.0 cmol(+)lkg soil). Although the soils of the valleys are fertile, they are characterised by one or more of the following problems: poor drainage condition, high alkalinity and salinity (ESP >5%) and difficult workability. The results of this study show a close relationship between landforms, parent materials and soil types. The paper establishes some land qualities which are important for sustainable agricultural land management in the district