The diploma thesis deals with harrowing of spelt wheat (Triticum spelta L.) by the weeding harrows and its influence on weed frequency, yield and quality parameters of wheat. In the literature review there are described general cultivation principles for the growing of spelt (Triticum spelta L.) used in current agricultural practice. There is overview of the general principles of spelt wheat cultivation in the organic farming, available varieties in the Czech Republic and brief description of agricultural technology suitable for its cultivation. We also describe the types of weeds, their brief description and the possibility of reducing their frequency in the organic farming growing system. The literature review provides also information about the technology of harrowing cereal crops as a measure to control weeds and other positive aspects of harrowing on grain crops. In the practical part, data from a field trial were collected, where the effect of harrowing on the weed frequency, the influence of harrowing on spelt wheat tillering and other parameters were statistically evaluated and compared with results in the literature. At the end of the thesis, given the results evaluated in the practical part, it was determined whether it is appropriate to use harrowing as protection of spelt wheat (Triticum spelta L.), its number, influence on weed infestation and its influence on both the quantitative and qualitative properties of spelt wheat (Triticum spelta L.).

Soil scarification means lot to the regeneration of the forest because a good soil scarification boost the increment of the plants and it also makes the plants less attractive to dangerous insects. The surveys purpose was to investigate how different site factors influence the soil scarifications results. The goal was to see if any scarification method was better adapted to a certain site then the other. In order to see a result the survey investigated the bearing capacity of the stands, the surface structure and the slope of the terrain. The surveys material has been collected during august - October 2013 on SCA: s forest in Ångermanland in Sweden. Totally has 65 harrowed sites and 35 scalped sites been visited and material collected from. The survey result shows that the scarification quality after scalping was higher than after harrowed sites. The number of 5: s and 4: s was more frequent after scalping but the number of mineral 3: s was higher after harrowing. The analysis of the results shows that scalping was more sensitive to the site slope and surface structure then harrowed sites, but when used on the the right ground it will provide a better quality result. The conclusion of the survey was that harrowing is the better choice of the scarification methods because it showed a more stable result then scalping that is more depending on the terrain conditions. Harrowing should not be used on moist ground due to the risk of Hylobius abietis attacking the plants. Scalping on the other hand showed a better result of the scarification quality and on the right ground it is the optimal choice.

The agricultural industry is constantly evolving with automation as one of the current main focuses. This thesis involves the automation of a seedbed tine harrow, specifically the control of the tillage depth. The tillage depth is instrumental to farming as it determines the quality of the tilth, how well clods are broken up, and how well the soil aggregates are sorted. Poor control of the tillage depth could result in a bad harvest for the farmer. To control the tillage depth, several pulse radar sensors are installed on the harrow. The sensors measure the distance from the tines of the harrow to the ground. This distance is used in a control-loop that controls the hydraulic actuators that lifts and pushes down the frame of the harrow. Because of the rough working conditions of the tine harrow, the pulse radar sensors are in danger of being damaged or disturbed. A sensor not working as intended will lead to poor control of the tillage depth or even an unstable control system. The purpose of this thesis is to develop diagnosis systems to detect and generate an alarm if the output of a sensor is faulty. Four different systems are developed, three machine learning approaches and one model based approach. To be able to test and train models without having to go out on a field with a real harrow, a test rig is available. The test rig emulates a harrow driving on a field and the tests are designed to imitate plausible sensor errors. The models trained on and tuned to the test rig data are validated with data gathered from a real tine harrow.  The validation data from the harrow reveal that the main difference between the field data and test rig data are the vibrations and the sensor heights. The test rig produces negligible amounts of vibrations whereas the vibrations on a real harrow are immense. These differences affect the performances of the models and some tuning have to be done to the models to accommodate for the vibrations. The performance of the model based approach is good and no larger adjustments have to be made to it. The machine learning models created from the test rig data do not work in the field and new models are trained using field data. The new models are accurate and show great potential; albeit, it would be necessary to collect a lot more data for further training. Specifically, training the machine learning models on varying heights. In conclusion, the test rig data is similar to the field data but the vibrations in the system is missing and the heights differ. The missing vibrations results in that the models do not work as intended on field data. The conventional diagnostics approach works, but the generated alarms are binary meaning that the alarm only reveal if the signal is good or bad and does not provide any nuance. The machine learning models does provide nuance, meaning that the model can detect errors, what is causing the error, and warn if an error is about to occur. However, the machine learning models need a lot of data to train on to make this happen.

In recent years, the importance of sagebrush to shrub-steppe ecosystems and associated plant and animal species has been recognized. The historical removal of herbaceous species by excessive and uncontrolled livestock grazing on many of our sagebrush ecosystems has resulted in a stagnant state where dense, competitive stands of sagebrush prevent herbaceous species from recovering. Most early research on sagebrush control was directed toward eradication to increase herbaceous forage for livestock production, rather than sagebrush thinning to improve shrub vigor and understory production for wildlife habitat and community diversity. Mechanical treatments have the ability to retain shrub and herbaceous components, while improving diversity within degraded sagebrush communities. This study evaluated the effects of 6 mechanical treatments and revegetation of a Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) community in northern Utah that were treated in the fall of 2001 and spring of 2002 (aerator only). Disking and imprinting killed 98% of the sagebrush and significantly (p < 0.05) lowered cover and density of sagebrush more than any other treatment. Disking and imprinting was the only mechanical treatment to reduce cover and density of residual understory species, but also to successfully establish seeded grasses. One-way Ely chaining, 1-way and 2-way pipe harrowing, and aerating in the fall and spring reduced sagebrush cover from greater than 20% to less than 5% and reduced density by about half. Two years after mechanical treatment surviving sagebrush had greater leader and seed stalk growth than untreated sagebrush. Choice of a mechanical treatment to increase and diversify the perennial herbaceous component and retain the shrub component of sagebrush communities depends on the amount of residual herbaceous species, as well as economics. Chaining is potentially most economical for diversifying communities with a residual herbaceous perennial component. It is uncertain whether successful revegetation from disking and imprinting was a result of significant reduction in sagebrush, residual perennial herbaceous species, or both. Response of sagebrush communities with a very limited perennial herbaceous understory needs to be tested to determine how much and what kind of mechanical reduction in sagebrush is needed for successful revegetation.