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.

One of the main preconditions for an economical milk production is a balanced cow feeding that contains high quality grass forage. Chemical composition of cocksfoot forage during vegetation was investigated at the Research Centre "Sigra" in the Biochemical laboratory of the Latvia University of Agriculture. Changes in the content of crude protein, NEL MJ kg*[-1) of DM, NDF, ADF and DM digestibility were determined. The chemical composition of grass forage depends on many factors, the most significant of which is the harwesting time. The feeding value of the cocksfoot grass decreases during its growing stages as the content of fibre increases and becomes lignified.