The effect of different management systems on the carbon balance, its sources and dry-matter yield | Vplyv rôznych systémov hospodárenia na bilanciu uhlíka, jeho zdroje a produkciu sušiny

In a period 1999-2004 a stationary field experiment was held on an experimental basis of RIPP (Research Institute of Plant Production) in Borovce [West Slovakia, Piešťany Distr.] in order to evaluate characteristics of the carbon balance and production of dry matter. We have compared two farming systems (organic and low-input system), six plots and two levels of fertilisation (N1 and N2). Carbon balance has been positive for both systems. The level of organic mater in soil has proved to be statistically significantly higher for low-input system (8.9%) compared to the organic system. In the LIS (Low Input System) we have found a higher rate as well as other attributes under examination, specfically the sources of carbon have been about 4.2% higher for carbon and about 6.9% for carbon from plant residues. There has been a highly significant difference for both attributes. The yield of dry mater has also been higher in the US (9.4%) and again with a highly significant difference. The difference between years has been highly significant for all attributes under examination. We have observed a significantly higher values of carbon balance and carbon sources at the level of fertilization N2 compared to N1 level. Differences in a constituent carbon from plant residues and a yield of dry matter between the levels of fertilisation were not significant. Harvest of dry matter per paticular plot has ranged from 8.72 t per ha ES (Ecological system) in (I. plot) to 10.22 t per ha (VI. plot) and in LIS has ranged from of 9.58 t per ha (I. plot) to 11.06 t per ha (V. plot). All differences were highly significant. Differences in yields of dry matter between plots are to be attributed to a different course of climatic conditions in particular years and their dissimilar influence on actual crops in a particular year. For the period of rotation in ES we found in average 51.7% of carbon from plant residues, 6.2% from compost, 26.9% from manure and 15.2% from green manuring and in LIS there was in average 53.0% of carbon from plant residues, 6.0% from compost, 25.8% from manure and 15.2% from green manuring.