[Definition and assessment of coefficients for the calculation of forestry residues].

Organic waste is an important biomass resource. In this study the definition of coefficients for the calculation of all the secondary 10 forestry residue categories was improved and established according to literature reviewing of previous reports between 1982 and 2017. The rationality of value-taking for each coefficient in previous literature was examined by tracing to its citation sources. The irrational, or unstudied coefficients were assessed using the data in previous reports or questionnaire surveys. Lastly, values of the coefficient for the calculation of woody nursery residue, forest woody pruning residue, wood logging residue, firewood, wood bucking residue, wood handling residue, waste wood, banana and pineapple plant residue, bamboo processing residue and waste bamboo were reasonably assessed in this study.

[Methods for assessing resources of forestry residues].

In this study, models for assessing resources of forestry residues were improved based on analysis of previous studies and current forest production in China. And novelties are highlighted: this study covered the models for the calculation of 10 secondary forestry residues from woody nursery, forest woody pruning, wood logging, firewood, wood bucking, wood handling, waste wood, banana and pineapple plants, bamboo processing and waste bamboo; the residues produced from fast-growing forest for logging and processing of imported wood were taken into consideration to calculate woody residue potential; the calculation of pruning residue included woody fruit trees, and herbaceous fruit plants from the management of orchard and other economic forest; the consistency of parameter terminology and definition which referred from their literature resources have been ensured; more studies focused on the coefficient values, industrial standard, forestry residue amount and spatial distribution are recommended for future researches.

[China's crop residues resources evaluation].

The availability of crop residues in China is reviewed in this article. The definition of crop residues is clarified as the total byproducts of field production and processing industry thereafter, and methodology for evaluating crop residues is discussed. Based on literature, the progress on the crop residue assessment is addressed. The annual field crops residues in China from 1991 to 1999 were estimated between 6.0-6.8 hundred million tons, while the data for the process residues were not available. From 2000 to 2007, the annual crop residues were estimated between 5.9-7.3 hundred million tons, while the processing residues at the range of 0.9-1.1 hundred million tons. The reasons for the significant variations are due to the disagreement on crop residue definition, different, even inaccurate residue to grain ratio data used in the estimations, and the lacking of clear understanding on the statistical analysis and grain outputs related to the crop residue evaluation. With the complete statistic analysis method, the author's group evaluated the residues in 2006 and 2007 to be 7.4 hundred million tones in total, including 6.5 hundred million tons for field crop residues and 0.9 hundred million tons for process residues. Moreover, the geographic distribution of the field crop residues was analyzed based on the harvest indices (HI) tested within the near five years.