Legumes are becoming more popular in food and feed consumption. They are promoted by EU policy related to healthy lifestyle and environmental policy. Legumes can be grown in crop rotation as monocrop or in different kind of intercropping systems. It is a well-known fact that legumes play an important role in fixation of the atmospheric N, whereas their influence on other biological and chemical aspects of the soil ecosystem is only explored partially. The experimental trial was established at the Pūre Horticultural Research Centre with the aim of studying the influence of legumes on the soil properties in the intercrop with strawberries (Fragaria × ananassa Duch.). Different genotypes were included in the trial as intercrops: two local broad beans (Vicia faba var. major L.) genotypes, two pea (Pisum sativum L.) cultivars and clover (Trifolium hybridum L.). Two control treatments were included in the trial: with and without nitrogen fertilizer usage. Strawberries were planted in May of 2014 and maintained in the field for three years. Results showed that there were significant differences between treatments in soil respiration rate (SRR) and SRR dynamic throughout the experiment time. Dehydrogenase activity had similar results, though no significant differences between treatments were observed in the third year. No significant difference between treatments was found in the soil organic matter. Obtained data shows that legumes have a significant influence on the soil biological properties but not on biochemical properties. Further research needs to be carried out to determine legume influence on soil environment in more detail.

Aim of the paper is to identify low productivity lands distribution in Vidzeme region, identify enterprises that could use wood chips from willow plantations established on these lands as the main resource in electricity and heat production and calculate produced wood ash amount from these enterprises that could be used as fertilizer and could be recycled in SRC plantations. For better soil fertility evaluation and economic turn predictions all agricultural lands are evaluated in quality units, where one quality unit in money is equal to 5.38 EUR or 70 kg of rye. According to studies, traditional farming in lands, which are below 38 quality units, could be unproductive. In Vidzeme region are 501,880 ha of agriculture lands from which 206,574 ha (52%) are lands with quality assessment under 38 units. According to local farmers’ opinion, the real quality unit, below which economically profitable farming is impossible, are 25 quality units. There are 87,900 ha of agricultural lands under 25 quality units, which represent 18% from all agricultural lands in region. These lands could be used by growing SRC plantations in 2013; the region has 48 enterprises that used wood chips, with total amount of 170,500 oven-dried tonnes per year. Wood chips from SRC plantation could be used in these enterprises. To fulfil the wood chip demand in the region, about 17,000 – 34,000 ha of agricultural land should be planted with SRC plantations. To increase the yields from these lands, fertilization is recommended. In this region are more than 300 enterprises, which use wood as the main resource for electricity or heat production leading to 14,000 oven-dried tons of wood ash production every year.

After regaining independence the agricultural production in Estonia has undergone a drastic decline. Due to the inadequate application of fertilizers and pesticides, the yield of field crops and grasslands has decreased 1-7 % per year. The balance of nitrogen in the arable soils is negative, particularly respecting fodder crops. At present, in Estonia most of grasslands are practically not fertilized, or they are fertilized in the last order. The amount of nitrogen removed with the yield of fodder crops, cereals and potato are by 45, 20 and 17 kg ha*[-1) higher, respectively, compared with the amounts of N applied to the soil with organic and mineral fertilizers, available for those crops. The effectiveness of nitrogen fertilizers depends largely on weather conditions during the vegetation period and is the lower, the higher is soil humus content. On gleyic and gley soils, whose humus content is higher, the efficiency of nitrogen fertilizers is 2-3 times lower and the agroecological and economic fertilization risks are higher. On sown grasslands, the efficiency of nitrogen fertilizers depends not so much on soil fertility as on soil water supply, humus content and grass sward type. With proper application of fertilizers, use of suitable plant species and varieties, it is possible to increase significantly not only the yield per unit area but also its nutritive value.

Agriculture more than any other branch of production is influenced by various natural, anthropogenic and economic risk factors on which the profitability of production and preservation of the environment in rural areas depend. The prerequisite of prevention or alleviation of risks is their all-round knowledge and consideration. In order to understand the nature of risks, they will be dealt with in the present study on the example of the cultivation of the most common cereal in Estonia - barley. The difference in barley yields, resulting from the pedoclimatic coditions of Estonia, may be 2-4-fold in different regions and in different years. At the same time, differences in the profitability of barley cultivation, depending on economic factors and on the specificity of production, may be up to 6-fold.