Agriculture is the foundation of human live. As the majorcomponent of agriculture, the crops are both as sources of "carbon emissions" and"carbon sinks".Reason is that crop can not only increase carbon emissions byrespiration but also absorb and fix carbon through photosynthesis. Farmland vegetationis one of the important component parts of the carbon pool in the farmland ecosystem.In addition, crop straw is the main part of the farmland vegetation which utilization hasan important influence on farmland vegetation carbon sequestration and emissions offarmland vegetation. Researching crop resources, carbon storage and usage has greatsignificance for the development of Low-carbon agricultural and environmentalprotection whose purpose is to rationally use straw resources, accurately estimatecarbon storage in vegetation carbon pool of farmland ecosystem, promote regionalsustainable development of agriculture and achieve lower energy consumption, lowerpollution and lower emission".Based on field visits, farmland observation, experimental analysis and thestatistical yearbook data (2009~2013)of Dingxi City, etc, the author put forwardcorresponding measures for efficient and reasonable utilization of straw resources anddevelopment of Low-carbon agricultural. This was realized by the estimations of strawresources and carbon storages of the three major crops wheat, corn and potato in DingxiCity through the straw storage estimation model and carbon resource estimation model.And the conclusions are as follows: (1)In the latest5years(2008~2012),there was a large-scale fluctuation in totaloutput of the straw resources of three main crops wheat, corn and potato in Dingxi City,and the amount of crops residue’s regional differences and various crops constitutionsetc of the City is quite different. The straw resources of main crops in Dingxi City wereabundant, especially for corn straw (account54%), and wheat straw (account34%)wasfollowed behind. However, the potato straw only account12%, was relatively deficient;the amount of crop residues in whole6Counties and one District of Dingxi City wereordered as follow: Tongwei County (29.87%)> Anding District (23.72%)> LintaoCounty (18.87%)> Longxi County (14.41%)> Weiyuan County (6.72%)> Zhang County(3.88%)> Mingxian County (2.54%).(2) In the latest5years(2008~2012), there was a large-scale fluctuation in totalstraw resources output of three main crops wheat, corn, and potato in Dingxi City. Oneof the biggest fluctuation is potato straw(the highest straw resources was20times thanthe lowest), followed by corn straw(the highest straw resources was10times than thelowest), and wheat straw was minimal (the highest straw resources was about2timesthan the lowest); In terms of crops regional differences in whole6Counties and oneDistrict of Dingxi City, the amount of wheat stalks order is Lintao County (20%)>Zhang County (19%)> Ming County(16%), Anding District(16%)> Weiyuan County(15%)>Tongwei County(8%)> Longxi County(6%); the amount of corn stalks order isTongwei County(26%)> Longxi County(25%)> Anding District(14%)> LintaoCounty(12%), Zhang County(12%)> Weiyuan(11%)> Ming County; the amount ofpotato stalks order is Ming County(40%)> Weiyuan County(21%)> Anding District(11%)> Zhang County(10%)> Lintao County(9%)> Longxi County(6%)> tongweiCounty (3%).(3) The main utilization measures of Dingxi City about crop straw resourcesinclude straw for field and feed, the main straw has been for farmland by directed tofield, by livestock stomach to field and burned to field more then composed and coveredto field. other methods like straw has been used for energy substances, straw has beenused for industrial condiments and straw has been used for mushroom cultivation arefewer, which utilization only in partial local.(4) In the latest5years(2008~2012), there was a significant fluctuation in the totalcarbon storage of the straw resources of three main crops wheat, corn, and potato inDingxi City. And all kinds of crop straws carbon storage’s regional differences and cropconstitution differences are significant. According to the amount of straw resources changes, the straw carbon storage also changes. Among the three main crop strawscarbon storage of Dingxi City, the highest carbon storage’s crop is corn straws, whichhas81.81104t, wheat straws carbon storage fall behind, which has52.06104t,however, the potato straws carbon storage only has21.65104t; the main crop strawscarbon storage in whole6counties and one district of Dingxi City were ordered thatTongwei County (9.12104t)> Anding District (7.20104t)> Lintao County(5.73104t)> Longxi County (4.39104t)> Weiyuan County (2.03104t)> ZhangCounty (1.18104t)> Ming County(0.75104t).(5) For the using methods of crop straw resources is single, industry associateddegrees is not high, straw resources’ waste is very serious and peoples’ awareness aboutlow carbon agricultural is insufficient, and so on. Dingxi City’s command should takefollowing measures to increase reasonable utilization of crop straw resources anddevelop low carbon agricultural: strengthening education and advocacy; developingrelated of award and punishment system; Combining livestock’s and crop production’sdevelopment, improving straw resources utilization level, reducing carbon emissions;achieving straw resources’ industrialization development; stabilizing sown area of cornand wheat, and Increasing their carbon sequestration potential in the future. |