Agroeko Žamberk (Czechia)

Organic matter balance in the farms located in Ústí nad Orlicí district has been investigated since 1979. As a result, so called need of organic fertilisation, has been determined and the supply of the organic fertilisers to soils, e.g. farmyard manure, slurries and also straw and green manure has been monitored over the whole time period. About 45 % of the arable land area in the district has been monitored.In addition to the organic matter balance, we determined several soil organic matter characteristics in soil samples (organic C, N and S contents, inert and decomposable C content, hot water soluble C content, hydrophobicity index calculated from the DRIFT spectrometry, available P, K, Ca and Mg contents and pH).The relationships between the organic matter supply with supplemental sources organic fertilisers and all the selected soil organic matter characteristics were statistically significant. Significant correlations were also found for the relationships between the organic matter need and all the selected soil organic matter characteristics.

Organic matter balance in soils is one of the important indicators of sustainability of the agricultural systems on the whole country level and the regional and farm level, as well. The annual organic matter (OM) turnover in arable soils is roughly estimated to amount 3.5 to 4.5t.ha m 1 in the Czech Republic. Input of OM in crop residues is estimated to 2.0 to 2.5t.ha m 1 OM annually. Resulting need of organic matter input by means of organic fertilisers is 1.5 to 2.0t.ha m 1 OM annually. However, the organic matter content in the farm fertilisers produced annually is estimated 0.8 to 0.9t.ha m 1 OM. The deficit in the organic matter input thus ranges between 0.7 to 1.1t.ha m 1 OM annually, over the whole country. Thanks to the programme of organic fertilisation initiated in the seventies in the Ústí nad Orlicí district (north-east Bohemia), several indicators of organic matter balance have been monitored up to now. Total area of agricultural land in the district is 75781 ha and 49784 of it is arable land (65.7%). Results of the detailed OM balances on the crop rotations level during the last decade are presented and discussed. Long-term monitoring of the organic matter balances reflected the transformation in agriculture in this country during the last decade.