Browsing by Subject "Agrotechnology (Agricultural and Environmental Engineering)"

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  • Petruneva, Ekaterina (Helsingin yliopisto, 2015)
    The present work was based on the analysis of glyphosate concentrations in six soil layers after continuous multiple applications of herbicide products and various sampling times during the study period of 2010?2012, and aimed to contribute to a better recognition of the glyphosate persistence in clay soil. Two tillage methods (conventional tillage and no-till) were carried out in two replicates on the experimental field located in Jokioinen, South-Western Finland. This experiment was important for the identification of glyphosate amounts in soil profile and for planning a better field management in the future on the larger scale. Results of the study demonstrated that glyphosate and its metabolite AMPA remained on the field a year after the spraying of the herbicide. Calculated reference degradation rate constants and half-lives were proved to be in a range with literature review. While the impact of tillage methods on the glyphosate retention in soil was not possible to assess by the present study due to the quite sparse nature of the data, the residuals of glyphosate and AMPA at deep layers were almost non-detectable. Study clearly showed that accumulation of glyphosate happens mostly in topsoil, and the leaching potential into deeper layers was quite limited.
  • Gustafsson, Markus (Helsingfors universitet, 2013)
    Soil compaction is a long known phenomenon in agriculture affecting several soil functions, crop yield and environment. Soil compaction is caused e.g. by natural processes and field traffic. In the agriculture soil compaction is often defined as reduced soil air porosity caused by field traffic in wet soil conditions. Ever increasing weight of agricultural machines can cause stress propagation in deep soil layers which increases the risk of subsoil compaction. Subsoil compaction can alter soil pore volume and continuity, deteriorate soil air conditions and air permeability and also increase water surface runoff and gaseous nitrous oxide emissions to the atmosphere due to denitrification. Effects of subsoil compaction on soil properties have been reported to be very long-term and to remain measurable for decades. This work was carried out as a part of the Nordic Poseidon project, investigating the arable soil compaction effects on soil functions and the environment. The objectives of this study were to design and implement a measurement program for soil sample gas diffusion coefficient measurements and secondly to analyze the continuous measurement data of soil moisture and temperature determined in situ (in the defined position) on a long term soil compaction experimental site in Southern Finland, Jokioinen. In the measurement program the accuracy of gas diffusion coefficient calculation process was confirmed by demonstration measurements. The measurement program eased the usage of gas diffusion measurement equipment and also enabled wider studies than in the past. In the Jokioinen experimental site soil temperature and moisture were found to vary from year to year depending on the weather conditions and the amount of rainfall. On the rainy summer 2011 the moisture level was higher in compacted soil than in uncompacted soil. The difference between the compacted and uncompacted soils was possibly caused by weakened hydraulic conductivity in the compacted subsoil. In addition the compaction treatment increased temperature variation during the day in the upper 15 cm layer possibly due to higher thermal diffusivity of the soil.
  • Jauhiainen, Samuli (Helsingin yliopisto, 2015)
    This study focuses on machinery and equipment failures in agriculture. For example, unreliable operations, or breakages and obstructions are common failures. Usually failures interrupt the work, either temporarily or for a longer period of time. Sometimes it is possible to continue working despite the failure. On the other hand failures can cause delaying or financial losses. Repairs can cause dangerous situations for farmers. Maintenance and repair works on farms are causing the most of the work-related accidents. The main targets of the study were to determine the most common failures on agricultural machinery and equip-ment, find the main reasons for the failures and find the ways to prevent failures and accidents caused by failures. The study was intended to serve as a basis of the newsletter to be made for farmers. The study was conducted 1.5 years lasting follow-up study. This study was finally included 21 farmers from all over the Finland. Farmers reported their machinery and equipment failures according to a pre-defined form. According to the results most machinery and equipment faults occurs with tractors. That is because tractors have a lot of places for failures and they are widely used on farms. Also harvesting machines seems to have a lot of failures. Machine failures were mainly on the frame and on the mechanical parts of power transmission. About one-fifth of all were electrical failures. Around two times out of three the failure interrupts working. According to farmers most of the failures were age-related and result from a "normal" wear. The remaining causes for failures were divided almost evenly between operating environment, machinery and equipment poor quality and factors resulting from the users. A significant result is that many failures can be prevented. For farmers it is almost impossible to avoid the machine and equipment failures. This study and the earlier stud-ies show that many of failures can be prevented and farmers should prepare better for failures. According to study the most important ways to prevent failures are proactive maintenance, careful reading of the operation manual, in-vesting to good quality machinery and equipment and by focusing to the work they are doing. Machinery mainte-nance and failure solving is safe when maintenance facilities are decent, using high quality tools and protective clothes, and when using the correct methods of work and not taking extra risks. It is also important to remember that the most demanding repair work should be left to professionals. The main goals of the study were achieved. TTS has published a newsletter for farmers, "Agricultural machinery and equipment failures - prevention methods and guidelines" based on the results of this study.
  • Alaspää, Aaro (Helsingfors universitet, 2013)
    This research was made in order to gather more information about lawn mowers' fuel consumption for the needs of LCA (Life Cycle Assestment). The lawn mowers' fuel consumption was measured in different circumstances in order to gather information on how different circumstances affect the lawn mowers' fuel consumption. When the fuel consumption was known, greenhouse gas emissions in three different mowing intensities could be calculated. These emissions were compared to emissions from liming and fertilizing lawns and the emissions from driving a car. Emissions from liming, fertilizing and the production of fuel needed in lawn mowing were calculated using information from literary research. The fuel consumption of the lawn mower varied between 2.9 kg/ha and 4.2 kg/ha when the height of the lawn before mowing varied between 11 and 19 cm measured with a measuring stick. The amount of biomass passed through the lawn mower varied between 398 kg/ha and 825 kg/ha. For the needs of emission calculations, it was judged from the results that if the lawn was mowed when its height was 11 cm (measured by stick), the fuel consumption was 2.7 kg/ha, if the height was 15 cm, the fuel consumption was 2.9 kg/ha, and if the height was 19 cm, the fuel consumption was 3.7 kg/ha. These heights correspond to timeframes of one, two and three weeks between each mowing day. In order to calculate the “loss drive” (area over which the mowing blades are driven two times), the distance that the mower drove was measured by GPS. Loss drive varied between 25 % and 88 %. Judging from these results, the loss drive caused by variation in the area and shape of the lawn can cause a rise up to 50 % in fuel consumption. Emissions from lawn mowing varied between 79 and 154 kg CO2-ekv/ha. The biggest emissions of lawn management were caused by liming (369 kg CO2-ekv/ha/year), when 3000 kg/ha of lime was used once in five years. The least emissions of lawn management were caused by mowing when it is done once in three weeks. Lawn mowing caused only a small amount of emissions compared to lawn management and driving a car. This research produced important information for the needs of LCA, for example about the fuel consumption of lawn mowers.
  • Jaakkola, Sauli (Helsingfors universitet, 2013)
    Assessing and avoiding environmental impact of agriculture and forestry has become more and more important during recent years. In Finland, half of the phosphorus load and nearly 40 % of the nitrogen load in the water system is caused by agriculture and forestry. Traditionally water quality monitoring has been carried out with manual water sampling and laboratory analyses. The problem with manual sampling is low amount of samples. Continuously working water quality sensors have been used for a relatively short time, which is why continuous water quality monitoring needs more research. The objective of the study is to clarify the feasibility of optical sensors in monitoring water quality and nutrient loading in an agricultural and forest management area. The study was carried out in three monitoring stations of the Savijoki catchment in Southwest Finland. Two of the stations were identically equipped and were located in forested subcatchments. A third station was located at the Savijoki catchment discharge point, making it possible to study how sensors work in different water qualities. According to the study, monitoring with continuously working sensors will result in more accurate nutrient loading estimates. With sensors used in the study it is also possible to draw conclusions about dynamics between run-off and nutrient concentrations in water. A prerequisite for successful monitoring is utilizing the appropriate sensors in the correct location. For example, low nitrate levels in water in forested areas have to be taken into consideration when choosing sensors. During the monitoring it is important to actively keep track of the quality of data and to check that sensors are working properly. Water quality sensors always need good calibration and control water samples from the entire concentration range. Sensors also have to be equipped with an automatic cleaning mechanism.