Evaluation of CO2 emission from rice husk biochar and cowdung manure co-compost preparation

Composting of animal manure had been considered a sustainable alternative method for recycling organic waste. However the process involved had been associated with greenhouse gas emission (CO2, N2O and CH4) which play an active role in global warming. This study evaluated CO2 emissions from biochar-manure co-compost production. Biochar (from rice husk) and manure were mixed in a ratio of 3:1 v/v to achieve a range of different co-compost mixtures. The treatments and controls in triplicates of 18 units were arranged in a complete randomize design. All treatments were incubated at around 28 oC and turned every two days for 2 weeks, and later five days for 39 days. CO2 production in the compost bins was measured by trapping the evolved gas in 5M NaOH. Total CO2 emissions varied over time with higher rates at the beginning of the composting process. Within the first 7 days, total CO2 emissions (587 mg/m2) from cow dung alone was not significantly different from cow dung plus biochar (506 mg/m2). At the latter stages of the composting process, CO2 emission from cowdung and biochar mixture was less than from the other treatments

Virtual Visualization System for Growth of Tobacco Root

International audienceVisualization study on the growth of virtual plant roots is of great significance to enhance the overall level of research on virtual plant growth. In this study, with the tobacco root as the object, its growth was divided by systematic analysis into three stages: root emergence, root growth, and root branching. Through the quantitative analysis of the morphological data of the tobacco root and in combination with results of previous studies, the tobacco root growth, branching and other models were established, and parameter values of the models were extracted. On this basis, computer graphics technology was applied to establish a virtual visualization system for tobacco root growth that should be capable of simulating root growth and computing indicators of roots including the number, length, density, etc. Results indicated that this system can do a better job of simulating the morphological features for the tobacco root and virtually displaying the process of tobacco root growth in a more realistic way