Collectable amounts and suitability evaluation of straw resource in China.

Objective The total production of straw in China ranks the first place in the world. It is of great significance to evaluate the collectable straw amount and suitability of comprehensive utilization ways correctly for fully recognizing the developing potential of straw resources and optimizing utilization structure on the basis of modern agricultural production. Method Combining with relevant survey information about straw residual amount in the field, the collectable coefficients of straw resources were estimated according to the investigation results of crop stubble height in the Huanghe-Huihe-Haihe regions. And then the collectable amount of straw resources in China in 2005 was calculated based on the data of the total straw yield and the collectable coefficients of straw resources. At last, the suitability of straw used as fuel, feed, fertilizer, industrial raw material and edible fungi and respective collectable straw amount were quantitatively and qualitatively evaluated. Result The calculated result showed that the collectable amount of straw resources in China in 2005 was 68 595×104 t with the average collectable coefficient of 0.81. The collectable amount of food crops straw, economic crops straw and other crops straw was 49 231×104 t, 16 261×104 t and 3 103×104 t accounting for 71.77%, 23.71% and 4.52% of the total collectable amount of straw resources in China in 2005, respectively. The straw amount suitable for processing to feed was 58 764×104 t, accounted for 85.67% of the total collectable amount of straw resources in China in 2005. The straw amount of crop-residue incorporation and suitable for returning to field directly, suitable for cultivating edible fungi and industrial processing was 61 600×104 t, 58 700×104 t and 58 700×104 t, accounted for 75.00%, 85.00% and 85.00% of the total collectable amount of straw resources in China in 2005, respectively. Conclusion It is concluded from analysis that the collectable amount of straw resources in China is so abundant that can be used in many ways.