Kenya is considered to be a developing country. This means that basic needs such as nutrition are not met for an extended period of time (www, Sida 1, 2012). Approximately half of the population is living under the poverty line (www, CIA 1, 2012). Agriculture is the largest sector in the country, employing 75% of the population. These are thereby directly dependent on the sufficiency of outputs received.

Large amounts of phosphorus (P) are lost from the arable land due to water erosion. Both phosphorus attached to particles and dissolved phosphorus (mainly phosphate) are transported away with drainage-water and surface runoff. Good soil structure is important in minimizing these losses. In this study, soils from 50 fields were analysed with respect to aggregate stability as measured by dispersion of clay together with the content of total phosphorus (TotP), particulate phosphorus (PP) and phosphate phosphorus (PO4P) in the water phase. All soils were clay soils with clay content varying between 21 and 54%.

Complex Vertebral Malformation (CVM) is an autosomal recessive inherited defect in the Holstein breed. The defect has lead to structurally malformed calves and losses of pregnancies. To determine the effect of CVM on fertility in the Swedish Holstein Breed 375 Holstein bulls used in breeding by Svensk Avel and Skånesemin were assigned to this study. 228 bulls matched the criteria of birth year, 1995-1999, > 75 inseminations and a known CVM-status. Of the total 228 bulls 53 of them were CVM-carriers and 175 were non-carriers. The SAS-programme was used to determine the effects of CVM-status, the bull?s father and birth year on Non-return rates (NRR) for 28, 56 and 168 days.

AbstractThe research project Liberation, supported by the European Commission under the Environment and Sustainable Development Programme (Fifth RTD Framework Programme) aimed at developing a decision support system for ecological risk assessment of contaminated sites has proposed a tiered system including the triad method. This method integrates contaminant chemistry and bioavailability analyses with observed ecotoxicological effects in soil and groundwater. In this study the triad method was used to perform a risk characterization of a former surface treatment and metal industry, now used for the student union buildings of the Mälardalen University in Eskilstuna, Sweden. On the site, high concentrations of copper, zinc and nickel have been detected in the soil in a preliminary investigation of contaminant levels with XRF. For performing the risk assessment of the site according to the triad method, contaminant bioavailability, soil metal concentrations and soil toxicity were determined and an ecological assessment was carried out on four selected soil samples (one reference soil and three samples with low (B), medium (C) and high (D) contaminant levels). Contaminant bioavailability was measured through leaching (ISO TC 190/S7) and biouptake tests (DGT).

The margin in crop production is more and more less and it forces the producer to check out how to reduce the cost of establishment of new crop. One way to reduce the cost in establishment is to begin with plough less farming. It saves money and time compares to conventional soil preparation with plough and harrow. Not all soil types are god for plough less farming and should be continued with ploughing (mainly light soil), but other soil types working very well with plough free farming. If you want to success with plough less farming you have to think in new lanes. One of the things you have to think about is to not grow too much cereal after cereal. Low stubble is important when you harvest the crop and also to spread and chop the straw well. I have in this work interviewed some farmers and farm advisers in Östergötland to see which thoughts they have about plough less farming.

The decomposition of organic carbon in drained peat soils is a major source of carbon di-oxide in Sweden. A big part of these drained peat soils are used in agriculture and it is a big challenge to slow down their decomposition. It has earlier been thought that less tilling and higher water table levels would decrease the activity of soil microbes and thereby the decomposition, but recent experiments has showed that this has little or no effect. In this bachelor thesis a field experiment was made on drained peat soil with ley, outside Björklinge, Uppsala municipality, Sweden. The experiment was carried out in May 2011. The objective was to develop a method to examine how the net exchange of carbon diox-ide from plant covered peat soil is affected by temperature and photosynthetically active radiation (PAR).

The purpose of this report was to investigate how the abiotic factors (temperature, pH, nutrients, oxygen levels and water content) would affect the decomposition of oil-contaminated soil and how a variance in structured soil would affect the decomposition-rate. A minor field-study was made and soil where structured in five different ways (one was a default pile and was used as a reference). The study took place over 137 days and three samples were taken (start, middle, end) and analyzed for aromatic and aliphatic compounds. The result of this study shows that there is a significant difference between all methods for the aliphatic compounds and no significant difference for the aromatic compounds. The abiotic factors that affect decomposition vary from organism to organism, depending on what type of environment it will function the best.

It is important for today?s farmers to minimize the costs for crop establishment, because of decreased prices and support from the EU. Farmers, who plow in autumn on heavy clay soil, often do some kind of tillage in autumn to get better soil structure before spring seeding. This is especially important when growing small seed crop, e.g. sugar beet and oil plants.

The trend in milk production is similar in Sweden and across the world; the farms are getting fewer but increasingly bigger. The costs for hiring workers are increasing, which results in more cows per animal keeper. Sensors can then be a great tool for keeping track of animals which need special attention. With a reported decreasing fertility, sensors that can detect oestrus even at low levels can be especially helpful in bigger herds to pinpoint the cows that may be in oestrus. The number of farms with dairy cows that install AMS, Automatic Milking Systems, are increasing, and that also increases the need for sensors to control milk quality and composition when there is no visual control of the milk by a milker before milking starts.For the sensor data to be useful you have to have software designed to analyze and interpret the data to get relevant information that the farmer can use.

This study was made on former agricultural areas that had been planted with spruce or pine, in the county of Västerbotten. The goal of the project was to investigate suspected deficiency of boron in these areas. Several objects have been reported for possible deficiency and some of these have the characteristic symptoms of boron-deficiency. The hypotheses are that 1) Boron deficiency is present at several of the investigated objects. 2) Planting of forest on cultivated postglacial sediments leads to a successive podzolisation with a decreasing content of organic matter in the mineral soil, due to decomposition, and a decreasing pH in the soil, even on locations that have been added lime. To be able to confirm or reject the hypotheses a number of tests were performed.

Nitrogen deposition leads to environmental damage in areas where the nitrogen deposition is high. Southwest Sweden receives an annual nitrogen deposition of up to 20 kg N/ha. Nitrogen that is not assimilated by the vegetation is accumulated in the soil, which may lead to nitrogen saturation and an elevated risk of nitrogen leaching. Nitrogen leaching from forest areas in southern Sweden has proven to be higher than from agricultural areas, which have been thought to be the main contributors to elevated nitrogen levels in rivers and lakes. The amount of nitrogen that leaches depends on the fraction of the total nitrogen in the soil that consists of nitrate, since nitrate is easily transported through the soil.

Swedish agriculture has gone through big changes in the latest 60 years. The farm sizes have increased, which has led to raised tractor and machinery sizes and therefore increasing problems with soil compaction. A method to reduce these problems is to implement controlled traffic farming, CTF. All field operations are then concentrated to specific tracks by using GPS guidance. The aim of this work was to study how the tillage regime, with or without CTF, affects the soil, with the main focus on macroporosity. In Säby close to Uppsala, and Alnarp close to Malmö, randomized block trials has been carried out, and the data has mainly been taken from these trials.

Based on laboratory studies with lysimeters, the concentrations of dissolved reactive phosphorus(DRP) and particulate phosphorus, which is the main part of other P (OVRP), has been studied inpercolating water. The experiment was conducted through irrigation of small soil columnscontaining clay topsoil from an experimental field in Västergötland. Three rain simulations wereconsecutively performed. DRP concentrations in the percolating water ranged between 0.2 - 0.3mg·Lclearly related to the phosphorus concentration in the soil, measured in a soil extract ofammonium lactate (P-AL). Concentrations of OVRP were relatively low and ranged between0.12 and 0.16 mg·Lwas not proven and the experiment may reflect how a relatively slow percolation of water mayrelease DRP.

Buffer zones play an important role for the water quality in our watercourses. When harvesting a forest close to a watercourse a buffer zone should be left. When it's not left, it will lead to radical changes in the environment for the water organisms. The overall purpose of this thesis was to illuminate the production- and environmental thinking when establishing new buffer zones in south of Värmland. The partials goals were to determine choice of tree species, ways of regenerate, occurrence of soil scarification and the occurrence of machine tracks in newly established buffer zones.

This study was conducted in Kkingo district, west of Masaka, Uganda. It compared soil macrofauna abundance in non-agroforestry farms with that of agroforestry farms. The agroforestry farms had participated in the Vi Agroforestry´s program between 1995 and 2006, and continued on their own after 2006, when Vi Agroforestry left the area. The soil macrofauna is important for soil structure and processes that are contributing to soil organ-ic matter decomposition and nutrient mineralization. They are also predators of potential pests.