Browsing by Author "Härkönen, Aino"

Biochars are soil amendment materials produced via pyrolysis of biomass. They are resistant to degradation and can be used as a way to sequester carbon from the atmosphere. Biochars can improve soil structure and water and nutrient retention capacity, and significant positive effects on soil aggregate stability, water retention capacity and nutrient availability have been observed in acidic soils with low carbon content. The positive effects of biochar on soil properties can also increase crop yields. However, most studies on the effects of biochar have been conducted in tropical or temperate climates, and currently very little is known on its effects on the yield formation of cereals, and more specifically, barley. The aim of this study was to determine the effects of softwood biochar on field soil moisture and nutrient contents, as well as its effects on yield components of barley (Hordeum vulgare L.) 8 years after its application (0, 5, 10, 20 and 30 t ha-1) to boreal soil. In addition, the effects of organic and mineral fertilizers, alone and together with biochar, on soil moisture, nutrient contents and barley yield components were studied. Biochar did not have significant effects on soil moisture or nutrient contents or on barley yield components. Fertilization had significant effects on contents of soil moisture and nutrients, electrical conductivity, pH and the biomass, leaf chlorophyll content, number and weight of seeds and the final yield of barley. The non-significant effects of biochar can be due to the high amount of carbon already present in the soil, and similar results have been observed on the research site in previous years. The added biochar may also have been misplaced by soil management or degraded by weathering. The growing season of 2018 was drier and warmer than the long-term average and drought during the beginning of the growing season combined with issues with weeds negatively affected crop development and yield components.