Abstract

The impact of greenhouse gas mediated raised temperature and carbon dioxide on the manure driven carbon status and algal primary productivity was examined in managed aquatic system using six different treatments: (i) cattle manure + saw dust, (ii) poultry dropping + saw dust, (iii) vermi-compost + saw dust (iv) mixed combination with cattle manure, poultry droppings, vermi-compost and saw dust, (v) iso-carbonic states maintained with cattle manure using vermi-compost and (vi) poultry droppings as basal dose maintained under open and simulated greenhouse conditions. There was an opposite responses of the time scale variations of buffering mechanisms between the closed and open conditions. The maximal carbon burial rate, organic carbon but reduced algal productivity in the mixed treatment and the reverse response in the poultry dropping and saw dust combination regulated by the C/N ratio of input manure revealed that the carbon sink in the bottom soil was primarily due to allochthonous origin in the former, and from autochthonous source in the later. It may be concluded that substantial rise in carbon status in the sediment due to greenhouse effect was attributable to enhanced microalgae derived autochthonous carbon sink mediated through integrative functions of temperature induced microalgal productivity and microbial driven manure decomposition. The dead microalgae and residual manure that settled down in the bottom surface enhanced the carbon status of the system, in question.

Keywords: Carbon status; Microalgal productivity; Aquatic system; Polyhouse; Soil-carbon; Simulated green house