The influence of farmyard manure utilization on the pedogenesis of carbonate rocks

The influence of farmyard manure utilization on carbonate rock weathering has in turn impact on the pedogenesis of carbonate rocks and source/sink of atmospheric CO₂. To ascertain the influence of farmyard manure utilization on pedogenesis of carbonate rock, dolomite and limestone tablets were buried in different depth of soil profiles in Guiyang, Guizhou province, the dissolution amount of tablets, soil carbon dioxide, pH, water content, mineral and chemical composition, and water chemistry of soil were observed. The results showed that the dissolution amount of carbonate rock was remarkably decreased by farmyard manure utilization, the decrease of limestone dissolution was 11.7%-116.9%, and 34.23% in average, the decrease of dolomite dissolution was 25.0%-65.69%, and 39.45% in average. Moreover, the dissolution of limestone was stronger than that of dolomite in same condition. This suggested that soil forming speed of carbonate rock was slowed by farmyard manure utilization for 35.77%-59.41%.