长期有机无机配施对中国典型农田土壤活性有机碳组分的影响
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摘要
农业土壤的物理、化学和生物过程决定了其生产力,而土壤有机碳(SOC)在其中起到了关键的作用。但是,以往SOC方面的研究多集中在SOC的动态变化、与土壤总碳的关系及其颗粒组成的变化上,很少涉及不同土壤类型中活性与非活性组分的变化,对这些组分在土壤剖面的分布以及施肥对它们的影响的研究就更少。本研究针对这一问题,通过分析SOC的变化、不同土壤深度的活性SOC、惰性SOC含量和比例的变化、活性SOC与总SOC的关系,揭示长期施用有机肥和化肥如何影响1)活性与惰性SOC的增加过程2)活性SOC在土壤剖而的分布。
本研究选取中国典型耕作地区不同土壤类型、种植制度和农业气象条件下的5个长期肥料试验(公主岭、郑州、重庆、进贤和祁阳)。施肥处理包括：(1)对照(种植作物但不施肥);(2)撂荒(自试验之初就不种植作物也不施肥)；(3)氮磷钾化肥配合施用(NPK);(4)氮磷钾化肥配施秸秆(NPKS)；(5)氮磷钾化肥配施有机肥(NPKM);(6)高倍的氮磷钾化肥配施有机肥(1.5NPKM)。采集各处理0～20cm、20～40cm和40～60cm土层样品,测定了总碳(TC)、土壤总有机碳(SOC)、土壤易及土壤有机碳的四种组分：高活性有机碳(Cfrac1=12N H2SO4)、活性有机碳NH2SO4)、低活性有机碳(Cfrac3＝24N-18N H2SO4)和非活性有机碳(Cfrac4=SOC-24N H2SO4)的含量(其中,Cfrac1和Cfrac2代表活性SOC,Cfrac3和Cfrac4代表惰性SOC),分析了它们的变化量及相互关系。试验的主要结果如下：
1.与1990年起始值相比,施用有机肥和化肥增加了SOC含量。在公主岭试验点,NPK、 NPKS、NPKM和1.5NPKM处理0～20cm土层的SOC含量分别增加了14%、17%、54%和69%,20～40cm土层的SOC含量分别增加了15%、28%、52%和80%。在祁阳点,NPK、M、 NPKM和1.5NPKM处理0～20cm土壤有机碳含量增加了28%、90%、82%和121%。郑州点1.5NPKM处理的SOC增加幅度最高,达到115%。在5个试验点中,M和1.5NPKM处理都是SOC含量最高的处理。
2.与1990年起始值相比,施肥增加了土壤有机碳不同组分的含量。在公主岭点,NPK、NPKS、NPKM和1.5NPKM处理0～20cm的土壤Cfrac1含量增加了6%、14%、39%和48%;Cfrac2含量增加了12%、27%、49%和50%；1.5NPKM处理中Cfrac4含量在0～20cm和20～40cm土层分别增加了120%和102%,其次是NPKM处理,分别增加了83%和61%。在祁阳点,0～20cm土层增加最大的是M, NPKM和1.5NPKM处理的Cfrac4含量,分别为126%、113%和158%。而在郑州点,0～20cm土层,NPK、NPKS、NPKM和1.5NPKM处理的Cfrac4含量分别增加了63%、71%、141%和179%,在各个点中为最高。在5个试验点中,相比于不施肥的对照,施用化肥和有机肥都增加了土壤活性和惰性SOC库。SOC各组分之间存在显著的相关性,这说明这些不同组分之间处于动态平衡中,一个组分的增加或降低会改变这种平衡而影响其它组分的数量。
3.长期有机肥配施化肥(NPKM)(?)目比不施肥或单施化肥更多地增加了惰性碳库(Cfrac3和Cfrac4)。在公主岭和重庆试验点,1.5NPKM处理的惰性碳库在各处理中最高,达到66.1Mg ha-1和56.6Mgha-1。在进贤试验点,NPKM处理的惰性碳库最高,为39.6Mgha-1。与不施肥的对照相比,长期施用有机肥和化肥降低了活性炭库和惰性碳库的比例,且对SOC有更好的保持能力。在5个试验点中,活性库(Cfrac1和Cfrac2)占到SOC的52-56%,惰性库占44-48%。
4.有机肥和化肥在土壤剖面中对增加SOC组分的作用不同。有机肥增加了土壤深层惰性库的含量。在祁阳点,M处理20-40cm土层的惰性SOC占总SOC的55%,而表层为51%。化肥则更多地增加了表层的活性SOC,以公主岭为例,NPK处理土壤表层的活性组分含量占到总SOC的55%,而在20-40cm为50%。在所有处理中,20-40cm土层活性SOC与惰性SOC的比例低于表层。表层土壤具有大量的易分解的碳,随着土层的加厚,稳定的碳含量增加。
5.本文采用不同浓度的硫酸来分离SOC的组分。但是,在测定极易分解组分的时候,12NH2SO4法测定的数值比传统的KMnO4法测定的数值高。因此,我修正了这种方法,降低了硫酸浓度到6N。结果显示,在4个试验点上,KMnO4和6N H2SO4两种方法测得的极易分解组分数值间存在着显著的线性正相关关系。因此,可以采用6N H2SO4法代替KMnO4法来表征土壤极易分解组分的数量。
根据以上结果可以得出结论：中国农业十壤上有机无机配施可显著增加土壤有机碳含量及其各组分的碳库容量。化肥配施有机肥相比不施肥和单施化肥更多地增加了的惰性SOC组分所占的比例,说明有机肥的施用有助于提高惰性组分的形成从而减少土壤有机碳的分解和损失。而化肥提高了表层土壤活性SOC的比例,说明化肥的施用有助于提高土壤表层SOC的活性。深层土壤相比表层十壤有更低的活性与惰性有机碳比例,表明改善深度分布对实现碳同定具有实际意义。
Soil organic carbon (SOC) plays a key role in several physical, chemical and biological soil processes that contribute productivity of agricultural soils. More researches are mainly focused on the dynamics of total SOC, its relationship to the total carbon, and particle fractions of SOC in the upper surface (0-20cm) layer of soil. A few studies were conducted to examine the active and passive fractions of SOC in different soils, much less along further soil profile or under long-term application of manure and fertilizers. Thus, in the present study, an attempt has been made to evaluate the effects of long-term manure and fertilizers on active organic carbon fractions in0-20,20-40and40-60cm soil layers. I analyzed the changes of SOC, the amount and relative proportions of active SOC fractions in different depths, and relationships between active fractions and the total SOC to explore how the long-term application of manure with fertilizers affect (ⅰ) the increment of active fractions of SOC (ⅱ) and the distribution of active fractions in the soil depth.
This study was carried out in five long-term fertility experiments (Gongzhuling, Zhengzhou, Chongqing, Jinxian and Qiyang) varying in soil type, cropping patterns and agro-climatic conditions in the arable cropping regions of China. The treatments examined were:(1) No-fertilization (control);(2) Fallow, where no crop was grown since the initiation of the experiment;(3) NPK;(4) NPK combined with crop straw (NPKS);(5) NPK with livestock manure (NPKM); and (6) higher application rate of NPKM (1.5NPKM). Soil samples were collected at0-20,20-40and40-60cm depths and analyzed for total C, total SOC, and four fractions of SOC:very labile (Cfrac1=12N H2SO4), labile (Cfrac=18N-12N H2SO4), less labile (Cftac3=24N-18N H2SO4) and non-labile (Cfrac4=Total SOC-24N H2SO4). The main results are summarized as follows:
1. The application of manure and fertilizers increased the SOC when compared with the initial C content of1990. At Gongzhuling site, the NPK, NPKS, NPKM and1.5NPKM treatments increased the SOC content by14,17,54and69%in0-20cm and15,28,52and80%, respectively in20-40cm soil layers. The NPK, M, NPKM and1.5NPKM treatments increased the SOC content by28,90,82and121%, respectively in0-20cm soil layer at Qiyang. The highest increase of SOC was179%observed in1.5NPKM treatment at Zhengzhou. The1.5NPKM and M had the highest SOC in all five sites.
2. The fertilization increased the different fractions of SOC compared with the initial C content of1990. At Gongzhuling, the NPK, NPKS, NPKM and1.5NPKM treatments increased the Cfrac, and Cfrac2content by6,14,39and48%, and12,27,49and50%, respectively in0-20cm soil layer. The Cfrac4was increased by120and102%in1.5NPKM treatment followed by83and61%in NPKM at0-20cm and20-40cm soil layers. At Qiyang, the highest increase of126,113and158%was recorded in M, NPKM and1.5NPKM treatments in Cfrac4at0-20cm soil layer. While, at Zhengzhou, the highest increase of63,71,141and179%was observed in Cfrac4in NPK, NPKS, NPKM and1.5NPKM treatments. In all5sites, the inorganic and manure fertilization treatments increased the both labile and recalcitrant C pools compared to control treatment. Significant correlations were found among different fractions of SOC. This suggests that these C fractions are in dynamic equilibrium with each other. The increase or decrease in one fraction may shift this equilibrium and also affect the size of the other fractions.
3. Manure and fertilizer application increased the recalcitrant C fraction (Cfrac3and Cfrac4) of total SOC compared with control and fertilizer only treatments. At Gongzhuling and Chongqing, the significantly highest recalcitrant C pool of66.1and56.6Mg ha-1was observed in1.5NPKM treatment. While, at Jinxian the significantly highest recalcitrant C pool of39.6Mg ha-1was found in NPK+M treatment. The long-term manure and fertilizers application decreased the labile:recalcitrant ratio of SOC compared with the no-fertilization control. The SOC retention was higher in the NPK and manure treated plots compared to control plots. The active C pool (Cfrac1and Cfrac2) constituted52-56%and recalcitrant C pool (Cfrac3and Cfrac4) constituted44-48%of total SOC at all five sites.
4. Manure and fertilizers showed the different roles in increasing the fraction contents with the soil depth. Manure increases the recalcitrant fraction (Cfrac3and Cfrac4) in deep layer. For Qiyang, the recalcitrant C fraction was55%of total SOC at20-40cm in M treatment compared with the surface layer (51%). Fertilizers showed to increase the active fractions (Cfrac1and Cfrac2) in the surface layer much. For Gongzhuling, the labile fraction was55%of total SOC in0-20cm soil layer compared with50%at20-40cm in NPK treatment. The labile:recalcitrant ratio of SOC was lower in20-40cm soil layer compared with the surface layer in all the treatments. A larger proportion of more oxidizable C was recorded in upper layer. With the increase in depth the proportion of resistant C fractions was increased.
5. Serial H2SO4concentrations were used to divide SOC into different fractions. But, the very labile fraction measured by12N H2SO4was higher than the active carbon measured by traditional KMnO4method. So, I modified this method and decreased the concentration of H2SO4to6N, The results revealed that labile fractions determined by the KMnO4and6N H2SO4methods showed a significantly positive correlation in four sites. Therefore, it is suggested that6N H2SO4method may be used for determination of labile fraction of SOC.
I concluded that the combined application of manure and fertilizers has the potential to significantly increase the SOC and its fractions in agricultural soils of China. The inorganic plus manure fertilizer treatments contained a larger proportion of total SOC in recalcitrant fraction compared with NPK and no-fertilizer treatments indicating that manure application helped in promoting the formation of SOC in the recalcitrant fraction and thus protecting SOC from decomposition losses. Fertilizer treatment had the higher labile:recalcitrant ratio in surface layer than the sub-surface layer implied that fertilizer helped to increase the surface SOC activity. The higher labile:recalcitrant SOC ratio in surface layer than deeper soil layer indicating that improving the depth distribution may be practical suggestion to achieve C retention.
本研究选取中国典型耕作地区不同土壤类型、种植制度和农业气象条件下的5个长期肥料试验(公主岭、郑州、重庆、进贤和祁阳)。施肥处理包括：(1)对照(种植作物但不施肥);(2)撂荒(自试验之初就不种植作物也不施肥)；(3)氮磷钾化肥配合施用(NPK);(4)氮磷钾化肥配施秸秆(NPKS)；(5)氮磷钾化肥配施有机肥(NPKM);(6)高倍的氮磷钾化肥配施有机肥(1.5NPKM)。采集各处理0～20cm、20～40cm和40～60cm土层样品,测定了总碳(TC)、土壤总有机碳(SOC)、土壤易及土壤有机碳的四种组分：高活性有机碳(Cfrac1=12N H2SO4)、活性有机碳NH2SO4)、低活性有机碳(Cfrac3＝24N-18N H2SO4)和非活性有机碳(Cfrac4=SOC-24N H2SO4)的含量(其中,Cfrac1和Cfrac2代表活性SOC,Cfrac3和Cfrac4代表惰性SOC),分析了它们的变化量及相互关系。试验的主要结果如下：
1.与1990年起始值相比,施用有机肥和化肥增加了SOC含量。在公主岭试验点,NPK、 NPKS、NPKM和1.5NPKM处理0～20cm土层的SOC含量分别增加了14%、17%、54%和69%,20～40cm土层的SOC含量分别增加了15%、28%、52%和80%。在祁阳点,NPK、M、 NPKM和1.5NPKM处理0～20cm土壤有机碳含量增加了28%、90%、82%和121%。郑州点1.5NPKM处理的SOC增加幅度最高,达到115%。在5个试验点中,M和1.5NPKM处理都是SOC含量最高的处理。
2.与1990年起始值相比,施肥增加了土壤有机碳不同组分的含量。在公主岭点,NPK、NPKS、NPKM和1.5NPKM处理0～20cm的土壤Cfrac1含量增加了6%、14%、39%和48%;Cfrac2含量增加了12%、27%、49%和50%；1.5NPKM处理中Cfrac4含量在0～20cm和20～40cm土层分别增加了120%和102%,其次是NPKM处理,分别增加了83%和61%。在祁阳点,0～20cm土层增加最大的是M, NPKM和1.5NPKM处理的Cfrac4含量,分别为126%、113%和158%。而在郑州点,0～20cm土层,NPK、NPKS、NPKM和1.5NPKM处理的Cfrac4含量分别增加了63%、71%、141%和179%,在各个点中为最高。在5个试验点中,相比于不施肥的对照,施用化肥和有机肥都增加了土壤活性和惰性SOC库。SOC各组分之间存在显著的相关性,这说明这些不同组分之间处于动态平衡中,一个组分的增加或降低会改变这种平衡而影响其它组分的数量。
3.长期有机肥配施化肥(NPKM)(?)目比不施肥或单施化肥更多地增加了惰性碳库(Cfrac3和Cfrac4)。在公主岭和重庆试验点,1.5NPKM处理的惰性碳库在各处理中最高,达到66.1Mg ha-1和56.6Mgha-1。在进贤试验点,NPKM处理的惰性碳库最高,为39.6Mgha-1。与不施肥的对照相比,长期施用有机肥和化肥降低了活性炭库和惰性碳库的比例,且对SOC有更好的保持能力。在5个试验点中,活性库(Cfrac1和Cfrac2)占到SOC的52-56%,惰性库占44-48%。
4.有机肥和化肥在土壤剖面中对增加SOC组分的作用不同。有机肥增加了土壤深层惰性库的含量。在祁阳点,M处理20-40cm土层的惰性SOC占总SOC的55%,而表层为51%。化肥则更多地增加了表层的活性SOC,以公主岭为例,NPK处理土壤表层的活性组分含量占到总SOC的55%,而在20-40cm为50%。在所有处理中,20-40cm土层活性SOC与惰性SOC的比例低于表层。表层土壤具有大量的易分解的碳,随着土层的加厚,稳定的碳含量增加。
5.本文采用不同浓度的硫酸来分离SOC的组分。但是,在测定极易分解组分的时候,12NH2SO4法测定的数值比传统的KMnO4法测定的数值高。因此,我修正了这种方法,降低了硫酸浓度到6N。结果显示,在4个试验点上,KMnO4和6N H2SO4两种方法测得的极易分解组分数值间存在着显著的线性正相关关系。因此,可以采用6N H2SO4法代替KMnO4法来表征土壤极易分解组分的数量。
根据以上结果可以得出结论：中国农业十壤上有机无机配施可显著增加土壤有机碳含量及其各组分的碳库容量。化肥配施有机肥相比不施肥和单施化肥更多地增加了的惰性SOC组分所占的比例,说明有机肥的施用有助于提高惰性组分的形成从而减少土壤有机碳的分解和损失。而化肥提高了表层土壤活性SOC的比例,说明化肥的施用有助于提高土壤表层SOC的活性。深层土壤相比表层十壤有更低的活性与惰性有机碳比例,表明改善深度分布对实现碳同定具有实际意义。
Soil organic carbon (SOC) plays a key role in several physical, chemical and biological soil processes that contribute productivity of agricultural soils. More researches are mainly focused on the dynamics of total SOC, its relationship to the total carbon, and particle fractions of SOC in the upper surface (0-20cm) layer of soil. A few studies were conducted to examine the active and passive fractions of SOC in different soils, much less along further soil profile or under long-term application of manure and fertilizers. Thus, in the present study, an attempt has been made to evaluate the effects of long-term manure and fertilizers on active organic carbon fractions in0-20,20-40and40-60cm soil layers. I analyzed the changes of SOC, the amount and relative proportions of active SOC fractions in different depths, and relationships between active fractions and the total SOC to explore how the long-term application of manure with fertilizers affect (ⅰ) the increment of active fractions of SOC (ⅱ) and the distribution of active fractions in the soil depth.
This study was carried out in five long-term fertility experiments (Gongzhuling, Zhengzhou, Chongqing, Jinxian and Qiyang) varying in soil type, cropping patterns and agro-climatic conditions in the arable cropping regions of China. The treatments examined were:(1) No-fertilization (control);(2) Fallow, where no crop was grown since the initiation of the experiment;(3) NPK;(4) NPK combined with crop straw (NPKS);(5) NPK with livestock manure (NPKM); and (6) higher application rate of NPKM (1.5NPKM). Soil samples were collected at0-20,20-40and40-60cm depths and analyzed for total C, total SOC, and four fractions of SOC:very labile (Cfrac1=12N H2SO4), labile (Cfrac=18N-12N H2SO4), less labile (Cftac3=24N-18N H2SO4) and non-labile (Cfrac4=Total SOC-24N H2SO4). The main results are summarized as follows:
1. The application of manure and fertilizers increased the SOC when compared with the initial C content of1990. At Gongzhuling site, the NPK, NPKS, NPKM and1.5NPKM treatments increased the SOC content by14,17,54and69%in0-20cm and15,28,52and80%, respectively in20-40cm soil layers. The NPK, M, NPKM and1.5NPKM treatments increased the SOC content by28,90,82and121%, respectively in0-20cm soil layer at Qiyang. The highest increase of SOC was179%observed in1.5NPKM treatment at Zhengzhou. The1.5NPKM and M had the highest SOC in all five sites.
2. The fertilization increased the different fractions of SOC compared with the initial C content of1990. At Gongzhuling, the NPK, NPKS, NPKM and1.5NPKM treatments increased the Cfrac, and Cfrac2content by6,14,39and48%, and12,27,49and50%, respectively in0-20cm soil layer. The Cfrac4was increased by120and102%in1.5NPKM treatment followed by83and61%in NPKM at0-20cm and20-40cm soil layers. At Qiyang, the highest increase of126,113and158%was recorded in M, NPKM and1.5NPKM treatments in Cfrac4at0-20cm soil layer. While, at Zhengzhou, the highest increase of63,71,141and179%was observed in Cfrac4in NPK, NPKS, NPKM and1.5NPKM treatments. In all5sites, the inorganic and manure fertilization treatments increased the both labile and recalcitrant C pools compared to control treatment. Significant correlations were found among different fractions of SOC. This suggests that these C fractions are in dynamic equilibrium with each other. The increase or decrease in one fraction may shift this equilibrium and also affect the size of the other fractions.
3. Manure and fertilizer application increased the recalcitrant C fraction (Cfrac3and Cfrac4) of total SOC compared with control and fertilizer only treatments. At Gongzhuling and Chongqing, the significantly highest recalcitrant C pool of66.1and56.6Mg ha-1was observed in1.5NPKM treatment. While, at Jinxian the significantly highest recalcitrant C pool of39.6Mg ha-1was found in NPK+M treatment. The long-term manure and fertilizers application decreased the labile:recalcitrant ratio of SOC compared with the no-fertilization control. The SOC retention was higher in the NPK and manure treated plots compared to control plots. The active C pool (Cfrac1and Cfrac2) constituted52-56%and recalcitrant C pool (Cfrac3and Cfrac4) constituted44-48%of total SOC at all five sites.
4. Manure and fertilizers showed the different roles in increasing the fraction contents with the soil depth. Manure increases the recalcitrant fraction (Cfrac3and Cfrac4) in deep layer. For Qiyang, the recalcitrant C fraction was55%of total SOC at20-40cm in M treatment compared with the surface layer (51%). Fertilizers showed to increase the active fractions (Cfrac1and Cfrac2) in the surface layer much. For Gongzhuling, the labile fraction was55%of total SOC in0-20cm soil layer compared with50%at20-40cm in NPK treatment. The labile:recalcitrant ratio of SOC was lower in20-40cm soil layer compared with the surface layer in all the treatments. A larger proportion of more oxidizable C was recorded in upper layer. With the increase in depth the proportion of resistant C fractions was increased.
5. Serial H2SO4concentrations were used to divide SOC into different fractions. But, the very labile fraction measured by12N H2SO4was higher than the active carbon measured by traditional KMnO4method. So, I modified this method and decreased the concentration of H2SO4to6N, The results revealed that labile fractions determined by the KMnO4and6N H2SO4methods showed a significantly positive correlation in four sites. Therefore, it is suggested that6N H2SO4method may be used for determination of labile fraction of SOC.
I concluded that the combined application of manure and fertilizers has the potential to significantly increase the SOC and its fractions in agricultural soils of China. The inorganic plus manure fertilizer treatments contained a larger proportion of total SOC in recalcitrant fraction compared with NPK and no-fertilizer treatments indicating that manure application helped in promoting the formation of SOC in the recalcitrant fraction and thus protecting SOC from decomposition losses. Fertilizer treatment had the higher labile:recalcitrant ratio in surface layer than the sub-surface layer implied that fertilizer helped to increase the surface SOC activity. The higher labile:recalcitrant SOC ratio in surface layer than deeper soil layer indicating that improving the depth distribution may be practical suggestion to achieve C retention.
引文
[1]Allen D.E., Pringle M.J., Page K.L. and Dalal R.C., A review of sampling designs for measurement of soil organic carbon in Australian grazing land. Journal of Rangelands 2010,32:227-246.
[2]Anderson D.W. and Paul E.A., Organo-mineral complexes and their study by radiocarbon dating. Soil Science Society of America Journal 1984,48:298-301.
[3]Baldock J.A., and Skjemstad J.O., Soil organic carbon/soil organic matter. In 'Soil Analysis:an Interpretation Manual. Eds. Peverill K.I., Sparrow L.A. and Reuter D.J., CSIRO Publishing: Collingwood 1999, pp.159-170.
[4]Belay-Tedla A., Zhou X.H., Su B., Wan S.Q. and Luo Y.Q., Labile recalcitrant, and microbial carbon and nitrogen pools of a tall grass prairie soil in the US Great Plains subjected to experimental warming and clipping. Soil Biology and Biochemistry 2009,41:110-116.
[5]Bhattacharyya R., Chandra S., Singh R.D., Kundu S., Srivastva A.K., Gupta H.S., Long-term farmyard manure application effects on properties of a silty clay loam soil under irrigated wheat-soybean rotation. Soil & Tillage Research 94,2007:386-396.
[6]Bhattacharyya R., Kundu S., Pandey S., Singh K.P. and Gupta H.S., Tillage and irrigation effects on crop yields and soil properties under rice-wheat system of the Indian Himalayas. Agricultural Water Management 2008,95:993-1002.
[7]Bhattacharyya R., Kundu S., Srivastva A.K., Gupta H.S., Prakash V. and Bhatt J.C., Long term fertilization effects on soil organic carbon pools in a sandy loam soil of the Indian sub-Himalayas. Plant and Soil 2011,341:109-124.
[8]Bhattacharyya R., Pandey S.C., Chandra S., Kundu S., Saha S., Mina B.L., Srivastva A.K., Gupta H.S., Fertilization effects on yield sustainability and soil properties under irrigated wheat-soybean rotation of an Indian Himalayan upper valley. Nutrient Cycling in Agroecosystems 2010,86: 255-268.
[9]Bhattacharyya R., Prakash V., Kundu S., Srivastva A.K. and Gupta H.S., Effect of long term manuring on soil organic carbon, bulk density and water retention characteristics under soybean-wheat cropping sequence in N-W Himalayas. Journal of Indian Society of Soil Science 2004,52:238-242.
[10]Black C.A., Methods of soil analysis, part 2.1965 Madison, Wisconsin, USA.
[11]Blair G.J., Chapman L., Whitbread A.M., Ball-Coelho B., Larsen P. and Tiessen H., Soil carbon changes resulting from sugarcane trash management at two locations in Queensland, Australia, and in North-East Brazil. Australian Journal of Soil Research 1998,36:873-882.
[12]Blair G.J., Lefroy R.D.B. and Lisle L., Soil carbon fractions based on their degree of oxidation and the development of a carbon management index for agricultural systems. Australian Journal of Agricultural Research 1995,46:1459-1466.
[13]Blake GR. and Hartge K.H., Bulk density. In:Klute A. (ed.) Methods of" soil analysis. Part 1. Physical and mineralogical methods. (2nd Ed.) Agronomy Monograph 9, ASA and SSSA, Madison, WI.1986:363-375.
[14]Carter M.R., Soil quality for sustainable land management:Organic matter and aggregation interactions that maintain soil functions. Agronomy Journal 2002,94:38-47.
[15]Chan K.Y., Bowman A. and Oates A., Oxidizable organic carbon fractions and soil quality changes in an oxic paleustaff under different pastures leys. Soil Science 2001,166:61-67.
[16]Chen H.Q., Hou R.X., Gong Y.S., Li H.W., Fan M.S. and Kuzyakov Y., Effects of 11 years of conservation tillage on soil organic matter fractions in wheat monoculture in Loess Plateau of China. Soil & Tillage Research 2009,106:85-94.
[17]Cole C.V., Flach K., Lee J., Sauerbeck D. and Stewart B., Agricultural sources and sinks of carbon. Water Air Soil Pollution 1993,70:111-122.
[18]Cong R.H., Wang X.J., Xu M.G., Zhang W.J., Xie L.J., Yang X.Y., Huange S.M. and Wang B.R., Dynamics of soil carbon to nitrogen ratio changes under long-term fertilizer addition in wheat-corn double cropping systems of China. European Journal of Soil Science 2012, doi: 10.1111/j.1365-2389.2012.01448.x.
[19]Conteh A., Lefroy R.D.B. and Blair G.J., Dynamics of organic matter in soil as determined by variations in 13C/12C isotopic ratios and fractionation by ease of oxidation. Australian Journal of Soil Research 1997,35:881-890.
[20]Coumou D. and Rahmstorf S., A decade of weather extremes. Nature Climate Change 2012, pp.1-6. DOI:10.1038/NCLIMATE1452.
[21]Debreczeni K. and Korschens M., Long-term field experiments of the world. Archives of Agronomy and Soil Science 2003,49:465-483.
[22]Ding X., Han X., Liang Y., Qiao Y., Li L. and Li N., Changes in soil organic carbon pools after 10 years of continuous manuring combined with chemical fertilizer in a Mollisol in China. Soil & Tillage Research 122,2012:36-41.
[23]Ding X.L., Zhang B., Zhang X.D., Yang X.M. and Zhang X.P., Effects of tillage and crop rotation on soil microbial residues in a rainfed agroecosystem of northeast China. Soil & Tillage Research 2011,114:43-49.
[24]Doran J.W. and Zeiss, M.R., Soil health and sustainability:managing the biotic component of soil quality. Applied Soil Ecology 2000,15:3-11.
[25]Doran J.W., Sarrantonio M. and Liebig M., Soil health and sustainability. In:Sparks D.L. (Ed.), Advances in Agronomy 1996,56:1-54. Academic Press, San Diego.
[26]FAOSTAT,2012. http://faostat3.fao.org/home/index.html#VISUALIZE_BY_AREA.
[27]Franzluebbers A.J., Soil organic matter stratification ratio as an indicator of soil quality. Soil and Tillage Research 2002,66:95-106.
[28]Ghosh S., Wilson B.R., Mandal B., Ghoshal S.K. and Growns I., Changes in soil organic carbon pool in three long-term fertility experiments with different cropping systems and inorganic and organic soil amendments in the eastern cereal belt of India. Australian Journal of Soil Research 2010,48:413-420.
[29]Global Carbon Project, Carbon budget 2008:An annual update of the global carbon budget and trends.2009. http://www.globalcarbonproject.org/carbonbudget/index.htm.
[30]Gong W., Yan X.Y., Wang J.Y., Hu T.X. and Gong Y.B., Long-term manuring and fertilization effects on soil organic carbon pools under a wheat-maize cropping system in North China Plain. Plant and Soil 2009,314:67-76.
[31]Graham M.H., Haynes R.J. and Meyer J.H., Soil organic matter content and quality:effects of fertilizer applications, burning and trash retention on long-term sugarcane experiment in South Africa. Soil Biology and Biochemistry 2002,34:93-102.
[32]Gregorich E.G. and Janzen H.H., Storage of soil carbon in the light fraction and macro-organic matter.1996, p.167-190. In:Carter M.A. and Stewart B.A. (ed.) Structure and organic matter storage in agricultural soils. Lewis Publ., Boca Raton, FL.
[33]Gregorich E.G, Carter M.R., Angers D.A., Monreal C.M. and Ellert B.H., Towards a minimum data set to assess soil organic matter quality in agricultural soils. Canadian Journal of Soil Science 1994, 74:367-385.
[34]Heanes D.L., Determination of total organic-C in soils by an improved chromic acid digestion and spectrophotometric procedure. Communication in Soil Science and Plant Analysis 1984,15: 1191-1213.
[35]Houghton R.A., Balancing the global carbon budget. Annual Review of Earth and Planetary Science 2007,35:313-347.
[36]Hoyle F.C., Baldock J.A. and Murphy D.V., Soil Organic Carbon-Role in Rainfed Farming Systems. In:Tow P. et al. (eds.), Rainfed Farming Systems 2011, DOI 10.1007/978-1-4020-9132-2_14, Springer Science+Business Media B.V.
[37]IPCC (Intergovernmental Panel on Climate Change), Climate Change 2007:Mitigation of Climate Change 2007, Working Group Ⅲ. Cambridge, UK:Cambridge University Press.
[38]IPCC, Climate Change, Scientific Basis. Cambridge University Press:Cambridge 2001, pp.851.
[39]IPCC, The Climate Change:The Physical Science Basis. IPCC Working Group 12007, Cambridge, UK:Cambridge Univ. Press.
[40]Jagadamma S. and Lal R., Distribution of organic carbon in physical fractions of soils as affected by agricultural management. Biology and Fertility of Soils 2010,46:543-554.
[41]Janzen H.H., Campbell C.A., Gregorich E.G. and Ellert B.H., Soil carbon dynamics in Canadian agroecosystems. In:Lal R., Kimble J.M., Levine E. and Stewart B.A., (eds) Soil processes and carbon cycles 1998, CRC, Boca Raton, pp 57-80.
[42]Johnston A.E., Soil organic matter, effects on soils and crops. Soil Use and Management 1986,2: 97-105.
[43]Kalembasa S.J. and Jenkinson D.S., A comparative study of titrimetric and gravimetric methods for the determination of organic carbon in soil. Journal of the Science of Food and Agriculture 1973,24: 1085-1090.
[44]Karl T.R. and Trenberth K.E., Modern Global Climate Change. Science, Washington DC 2003,302: 1719-1723.
[45]Karlen D.L., Andrews S.S. and Doran J.W., Soil quality:Current concepts and applications. Advances in Agronomy 2001,74:1-40.
[46]Karlen D.L., Doran J.W., Weinhold B.J. and Andrews S.S., Soil quality:Humankind's foundation for survival. Journal of Soil and Water Conservation 2003,58:171-179.
[47]Karlen D.L., Mausbach M.J., Doran J.W., Cline R.G., Harris R.F. and Schuman G.E., Soil quality:a concept, definition, and framework for evaluation. Soil Science Society of America Journal 1997, 61:4-10.
[48]Kong A.Y.Y., Six J., Bryant D.C., Denison R.F. and Kessel C.V., The relationship between carbon input, aggregation, and soil organic carbon stabilization in sustainable cropping systems. Soil Science Society of America Journal 2005,69:1078-1085.
[49]Krull E.S., Jeffrey A.B. and Skjemstad J.O., Importance of mechanisms and processes of the stabilization of soil organic matter for modeling carbon turnover. Functional Plant Biology 2003,30: 207-222.
[50]Krull E.S., Skjemstad J.O. and Baldock J.A., Functions of soil organic matter and the effect on soil properties. GRDC report 2004, Project CSO 00029.
[51]Kundu S., Bhattacharyya R., Prakash V., Ghosh B.N. and Gupta H.S., Carbon sequestration and relationship between carbon addition and storage under rainfed soybean-wheat rotation in a sandy loam soil of the Indian Himalayas. Soil & Tillage Research 2007,92:87-95.
[52]Lal R., Global potential of soil carbon sequestration to mitigate the greenhouse effect. Critical Review in Plant Sciences 2003,22:151-184.
[53]Lal R., Kimble J.M., Follett R.F. and Cole C. V., The potential of U.S. cropland to sequester carbon and mitigate the greenhouse effect. Ann Arbor Press, Chelsea, MI.1998 pp.128.
[54]Lal R., Offsetting China's CO2 emissions by soil carbon sequestration. Climatic Change 2004a,65: 263-275.
[55]Lal R., Soil Carbon sequestration impacts on global climate change and food security. Science 2004b,304:1623-1627.
[56]Lai R., Soil carbon sequestration in Latin America. In:Carbon Sequestration in Soils of Latin America, ed. Lal R.C., Cerri M., Bernoux J.E. and Cerri E.2006:49-64. New York, NY:Food Products Press.
[57]Larson W.E. and Pierce F.J., Conservation and enhancement of soil quality. In:Evaluation for Sustainable Land Management in the Developing World, Vol.2:Technical papers. Bangkok, Thailand:International Board for Research and Management,1991. IBSRAM Proceedings No. 12(2):175-203.
[581 Letey J., Sojka R.E., Upchurch D.R., Cassel D.K., Olson K.R., Payne W.A., Petrie S.E., Price G.H., Reginato R.J., Scott, H.D., Smethurst P.J. and Triplett G.B., Deficiencies in the soil quality concept and its application. Journal of Soil and Water Conservation 2003,58:180-187.
[59]Li Z.P., Lin X.X. and Che Y.P., Analysis for the balance of organic carbon pools and their tendency in typical arable soils of Eastern China. Acta Pedologica Sinica 2002,39:351-360 (in Chinese).
[60]Li Z.P., Liu M., Wu X.C., Han F.X. and Zhang T.L., Effects of long-term chemical fertilization and organic amendments on dynamics of soil organic C and total N in paddy soil derived from barren land in subtropical China. Soil & Tillage Research 2010,106:268-274.
[61]Li Z.P., Liu M., Wu X.C., Han F.X. and Zhang T.L., Effects of long-term chemical fertilization and organic amendments on dynamics of soil organic C and total N in paddy soil derived from barren land in subtropical China. Soil & Tillage Research 2010,106:268-274.
[62]Liang Q., Chen H., Gong Y., Fan M., Yang H., Lal R. and Kuzyakov Y., Effects of 15 years of manure and inorganic fertilizers on soil organic carbon fractions in a wheat-maize system in the North China Plain. Nutrient Cycling in Agroecosystems 2012,92:21-33.
[63]Liu X.B., Han X.Z., Song C.Y., Herbert S.J. and Xing B.S., Soil organic carbon dynamics in black soils of China under different agricultural management systems. Communications in Soil Science and Plant Analysis 2003,34:973-984.
[64]Liu X.B., Zhang X.Y., Wang Y.X., Sui Y.Y., Zhang S.L., Herbert S.J. and Ding G., Soil degradation:a problem threatening the sustainable development of agriculture in Northeast China. Plant Soil and Environment 2010,56:87-97.
[65]Lopez-Capel E., Krull E.S., Bol R. and Manning D.A., Influence of recent vegetation on labile and recalcitrant carbon soil pools in central Queensland Australia:evidence from thermal analysis-quadrupole mass spectrometry-isotope ratio mass spectrometry. Rapid Communications in Mass Spectrometry 2008,22:1751-1758.
[66]Majumder B., Mandal B. and Bandyopadhyay P.K., Soil organic carbon pools and productivity in relation to nutrient management in a 20-year-old rice-berseem agroecosystem. Biology and Fertility of Soils 2008a,44:451-461.
[67]Majumder B., Mandal B., Bandyopadhyay P.K. and Chaudhury J., Soil organic carbon pools and productivity relationships for a 34 year old rice-wheat-jute agroecosystem under different fertilizer treatments. Plant and Soil 2007,297:53-67.
[68]Majumder B., Mandal B., Bandyopadhyay P.K., Gangopadhyay A., Mani P.K., Kundu A.L. and Mazumdar D., Organic amendments influence soil organic carbon pools and rice-wheat productivity. Soil Science Society of America Journal 2008b,72:775-785.
[69]Mandal B., Majumder B., Adhya T.K., Bandyopadhyay P.K.,Gangopadhyay A., Sarkar D., Kundu M.C., Choudhury S.G., Hazra G.C., Kundu S., Samantaray R.N. and Misra A.K., The potential of double-cropped rice ecology to conserve organic carbon under subtropical climate. Global Change Biology 2008,14:2139-2151.
[70]Mandal B., Majumder B., Bandopadhyay P.K., Hazra G.C., Gangopadhyay A., Samantaroy R.N., Misra A.K., Chowdhuri J., Saha M.N. and Kundu S., The potential of cropping systems and soil amendments for carbon sequestration in soils under long-term experiments in subtropical India. Global Change Biology 2007,13:357-369.
[71]McLauchlan K.K. and Hobbie S.E., Comparison of labile soil organic matter fractionation techniques. Soil Science Society of America Journal 2004,68:1616-1625.
[72]McLauchlan K.K., Hobbie S.E. and Post W.M., Conversion from agriculture to grassland builds soil organic matter on decadal timescales. Ecological Applications 2006,16:143-153.
[73]Merry R.H. and Spouncer L.R., The measurement of carbon in soils using a microprocessor-controlled resistance furnace. Communications in Soil Science and Plant Analysis 1988,19:707-720.
[74]Miao Y., Stewart B.A. and Zhang F., Long-term experiments for sustainable nutrient management in China. A review. Agronomy for Sustainable Development 2010:1:14. DOI: 10.1051/agro/2010034.
[75]Morgan J.A., Follett R.F., Allen L.H.Jr., Grosso S.D., Derner J.D., Dijkstra F., Franzluebbers A., Fry R., Paustian K. and Schoeneberger M.M., Carbon sequestration in agricultural lands of the United States. Journal of Soil and Water Conservation 2010,65(1):6A-13A.
[76]Murphy D.V., Cookson W.R., Braimbridge M., Marschner P., Jones D.L., Stockdale E.A. and Abbott L.K., Relationships between soil organic matter and the soil microbial biomass (size, functional diversity, and community structure) in crop and pasture systems in a semi-arid environment. Soil Research 2011,49:582-594.
[77]National Environment Trust, Leadership and Equity:The United States, Developing Countries and Global Warming. National Environment Trust, Washington, D.C.1998, pp.68.
[78]National Soil Survey Office,1998. Soils of China. China Agriculture Press, Beijing (in Chinese).
[79]Nelson D.W. and Sommers L.E., Total carbon, organic carbon and organic matter. In:Page A.L. Miller R.H. and Keeney D.R. (eds). Methods of Soil Analysis, Part 2. Agronomy Monograph No 12, (2nd ed.). ASA and SSSA, Madison, WI 1982, pp.101-129.
[80]Nick P., Iain S., Jonathan L., Pen H. and Ian M., Climate Change. Met Office (UK) 2012, http://www.metoffice.gov.uk/climate-change.
[81]Papendick R.I. and Parr J., Soil quality-the key to a sustainable agriculture. American Journal of Alternative Agriculture 1992,7:2-3.
[82]Parton W.J. and Rasmussen P.E., Long-term effects of crop management in wheat-fallow:II. CENTURY model simulations. Soil Science Society of America Journal 1994,58:530-536.
[83]Pastor J., Dewey B., Naiman R.J., McInnes P.F. and Cohen Y., Moose browsing and soil fertility in the boreal forests of Isle Royale National Park. Ecology 1993,74:467-480.
[84]Paul E.A., Harris D., Klug M.J. and Ruess R.W., The determination of microbial biomass.1999, p. 291-317. In:Robertson G.P. (ed.) Standard soil methods for long-term ecological research. Oxford University Press, New York.
[85]Powlson D.S., Smith P., Coleman K., Smith J.U., Glendining M.J., Korschens M. and Franko U., A European network of long-term sites for studies on soil organic matter. Soil & Tillage Research 1998,47:263-274. doi:10.1016/S0167-1987(98)00115-9.
[86]Purakayastha T.J., Rudrappa L., Singh D., Swarup A. and Bhadraray S., Long-term impact of fertilizers on soil organic carbon pools and sequestration rates in maize-wheat-cowpea cropping system. Geoderma 2008,144:370-378.
[87]Rasmussen P.E., Allmaras R.R., Rohde C.R. and Roager Jr. N.C., Crop residue influences on soil carbon and nitrogen in a wheat-fallow system. Soil Science Society of America Journal 1980,44: 596-600.
[88]Richter D.D., Hofmockel M., Callaham M.A., Powlson D.S. and Smith P., Long-term soil experiments:Keys to managing Earth's rapidly changing ecosystems. Soil Science Society of America Journal 2007,71:266-279.
[89]Rice C.W., Soil organic C and N in rangeland soil under elevated CO2 and land management. In: Proceedings of Advances in Terrestrial Ecosystem Carbon Inventory, Measurement, and Monitoring, October 3-5,2000. USDA-ARS, USDA-FS, USDA-NRCS, US Dept. Energy, NASA, and National Council for Air and Stream Improvement 2000, p 83.
[90]Rovira P. and Vallejo V.R., Labile and recalcitrant pools of carbon and nitrogen in organic matter decomposing at different depths in soil:an acid hydrolysis approach. Geoderma 2002,107: 109-141.
[91]Rudrappa L., Purakayastha T.J., Singh D. and Bhadraray S., Long-term manuring and fertilization effects on soil organic carbon pools in a Typic Haplustept of semi-arid sub-tropical India. Soil & Tillage Research 2006,88:180-192.
[92]Schlesinger W.H. and Andrews J.A., Soil respiration and the global carbon cycle. Biogeochemistry 2000,48:7-20.
[93]Schneider S.H., Geosphere-biosphere Interactions and Climate. Lennart O.B. and Hammer C.U. eds., Cambridge University Press 2001, pp.90-91.
[94]Schuman G.E., Janzen H.H. and Herrick J.E., Soil carbon dynamics and potential carbon sequestration by rangelands. Environmental Pollution 2002,116:391-396.
[95]Shrestha B.M., Certini G., Forte C. and Singh B.R., Soil organic matter quality under different land uses in a mountain watershed of Nepal. Soil Science Society of America Journal 2008,72: 1563-1569.
[96]Simon T., The influence of long-term organic and mineral fertilization on soil organic matter. Soil and Water Research 2008,3:41-51.
[97]Six J., Elliott E.T., Paustian K. and Doran J.W., Aggregation and soil organic matter accumulation in cultivated and native grassland soils. Soil Science Society of America Journal 1998,62: 1367-1377.
[98]Six J., Feller C., Dencf K., Ogle S.M., Moraes de J.C. and Albrecht A., Soil organic matter, biota, and aggregation in temperate and tropical soils-effects of no-tillage. Agronomie 2002,22: 755-775.
[99]Skjcmstad J.O. and Taylor J.A., Does the Walkley-Black method determine soil charcoal? Communications in Soil Science and Plant Analysis 1999,30:2299-2310.
[100]Smith P., Martino D., Cai Z., Gwary D., Janzen H.H., Kumar P., McCarl B., Ogle S., O'Mara E, Rice C., Scholes R.J., Sirotenko O., Howden M., McAllister T., Pan G., Romanenkov V., Schneider U., Towprayoon S., Wattenbach M. and Smith J.U., Greenhouse gas mitigation in agriculture. Philosophical Transactions of Royal Society 2008,363:789-813.
[101]Sperow M., Eve M. and Paustian K., Potential soil C sequestration on US agricultural soils. Climate Change 2003,57:319-339.
[102]Stevenson F.J., Carbon balance of the soil and role of organic matter in soil fertility. In:Cycles of Soil-Carbon, Nitrogen, Phosphorus, Sulphur, Micronutrients. John Wiley & Sons, New York 1986, pp.45-77.
[103]Strosser E., Methods for determination of labile soil organic matter:An overview. Journal of Agrobiology 2010,27(2):49-60.
[104]Sun W., Huang Y., Zhang W. and Yu Y., Carbon sequestration and its potential in agricultural soils of China. Global Biogeochemical Cycles 2010,24:1-12. GB3001, doi:10.1029/2009GB003484.
[105]Vieira F.C.B., Bayer C., Zanatta J.A., Dieckow J., Mielniczuk J. and He Z.L., Carbon management index based on physical fractionation of soil organic matter in an Acrisol under long-term no-till cropping systems. Soil & Tillage Research 2007,96:195-204.
[106]VijayaVenkataRaman S., Iniyan S., Goic R., A review of climate change, mitigation and adaptation. Renewable and Sustainable Energy Reviews 2012,16:878-897.
[107]Walkley A. and Black I.A., An examination of the Degtjareff method for determining soil organic matter and a proposed modification of the chromic acid titration method. Soil Science 1934,37: 29-38.
[108]Walkley A., A critical examination of a rapid method for determining organic carbon in soils:Effect of variations in digestion conditions and inorganic soil constituents. Soil Science 1947,63: 251-263.
[109]WMO, The Greenhouse Gas Bulletin:The State of Greenhouse Gases in the Atmosphere Using Global Observation through 2009. Geneva, Switzerland:The World Meteorological Organization 2010.
[110]World reference base for soil resources, Food and Agriculture Organization of the United Nations, Rome 1998,84 World Soil Resources Reports.
[111]Xu M., Zhang W., Zhang H. and Wang X., Long-term experiments and soil organic carbon sequestration in arable land of China. Proceedings of the 2nd International workshop on carbon sequestration and climate change mitigation in agriculture, June 27-30,2010, Beijing, China.
[112]Yan D.Z., Wang D.J. and Yang L.Z., Long-term effect of chemical fertilizer, straw and manure on labile organic matter fractions in a paddy soil. Biology and Fertility of Soils 2007,44:93-101.
[113]Zhang W., Xu M., Wang B. and Wang X., Soil organic carbon, total nitrogen and grain yields under long-term fertilizations in the upland red soil of southern China. Nutrient Cycling in Agroecosystems 2009,84:59-69.
[114]Zhang W., Xu M., Wang X., Huang Q., Nie J., Li Z., Li S., Hwang S.W. and Lee K.B., Effects of organic amendments on soil carbon sequestration in paddy fields of subtropical China. Journal of Soils and Sediments 2012,12(1):DOI 10.1007/s11368-011-0467-8.
[115]Zhang W.J., Wang X.J., Xu M.G., Huang S.M., Liu H. and Peng C., Soil organic carbon dynamics under long-term fertilizations in arable land of northern China. Biogeosciences 2010,7:409-425.
[2]Anderson D.W. and Paul E.A., Organo-mineral complexes and their study by radiocarbon dating. Soil Science Society of America Journal 1984,48:298-301.
[3]Baldock J.A., and Skjemstad J.O., Soil organic carbon/soil organic matter. In 'Soil Analysis:an Interpretation Manual. Eds. Peverill K.I., Sparrow L.A. and Reuter D.J., CSIRO Publishing: Collingwood 1999, pp.159-170.
[4]Belay-Tedla A., Zhou X.H., Su B., Wan S.Q. and Luo Y.Q., Labile recalcitrant, and microbial carbon and nitrogen pools of a tall grass prairie soil in the US Great Plains subjected to experimental warming and clipping. Soil Biology and Biochemistry 2009,41:110-116.
[5]Bhattacharyya R., Chandra S., Singh R.D., Kundu S., Srivastva A.K., Gupta H.S., Long-term farmyard manure application effects on properties of a silty clay loam soil under irrigated wheat-soybean rotation. Soil & Tillage Research 94,2007:386-396.
[6]Bhattacharyya R., Kundu S., Pandey S., Singh K.P. and Gupta H.S., Tillage and irrigation effects on crop yields and soil properties under rice-wheat system of the Indian Himalayas. Agricultural Water Management 2008,95:993-1002.
[7]Bhattacharyya R., Kundu S., Srivastva A.K., Gupta H.S., Prakash V. and Bhatt J.C., Long term fertilization effects on soil organic carbon pools in a sandy loam soil of the Indian sub-Himalayas. Plant and Soil 2011,341:109-124.
[8]Bhattacharyya R., Pandey S.C., Chandra S., Kundu S., Saha S., Mina B.L., Srivastva A.K., Gupta H.S., Fertilization effects on yield sustainability and soil properties under irrigated wheat-soybean rotation of an Indian Himalayan upper valley. Nutrient Cycling in Agroecosystems 2010,86: 255-268.
[9]Bhattacharyya R., Prakash V., Kundu S., Srivastva A.K. and Gupta H.S., Effect of long term manuring on soil organic carbon, bulk density and water retention characteristics under soybean-wheat cropping sequence in N-W Himalayas. Journal of Indian Society of Soil Science 2004,52:238-242.
[10]Black C.A., Methods of soil analysis, part 2.1965 Madison, Wisconsin, USA.
[11]Blair G.J., Chapman L., Whitbread A.M., Ball-Coelho B., Larsen P. and Tiessen H., Soil carbon changes resulting from sugarcane trash management at two locations in Queensland, Australia, and in North-East Brazil. Australian Journal of Soil Research 1998,36:873-882.
[12]Blair G.J., Lefroy R.D.B. and Lisle L., Soil carbon fractions based on their degree of oxidation and the development of a carbon management index for agricultural systems. Australian Journal of Agricultural Research 1995,46:1459-1466.
[13]Blake GR. and Hartge K.H., Bulk density. In:Klute A. (ed.) Methods of" soil analysis. Part 1. Physical and mineralogical methods. (2nd Ed.) Agronomy Monograph 9, ASA and SSSA, Madison, WI.1986:363-375.
[14]Carter M.R., Soil quality for sustainable land management:Organic matter and aggregation interactions that maintain soil functions. Agronomy Journal 2002,94:38-47.
[15]Chan K.Y., Bowman A. and Oates A., Oxidizable organic carbon fractions and soil quality changes in an oxic paleustaff under different pastures leys. Soil Science 2001,166:61-67.
[16]Chen H.Q., Hou R.X., Gong Y.S., Li H.W., Fan M.S. and Kuzyakov Y., Effects of 11 years of conservation tillage on soil organic matter fractions in wheat monoculture in Loess Plateau of China. Soil & Tillage Research 2009,106:85-94.
[17]Cole C.V., Flach K., Lee J., Sauerbeck D. and Stewart B., Agricultural sources and sinks of carbon. Water Air Soil Pollution 1993,70:111-122.
[18]Cong R.H., Wang X.J., Xu M.G., Zhang W.J., Xie L.J., Yang X.Y., Huange S.M. and Wang B.R., Dynamics of soil carbon to nitrogen ratio changes under long-term fertilizer addition in wheat-corn double cropping systems of China. European Journal of Soil Science 2012, doi: 10.1111/j.1365-2389.2012.01448.x.
[19]Conteh A., Lefroy R.D.B. and Blair G.J., Dynamics of organic matter in soil as determined by variations in 13C/12C isotopic ratios and fractionation by ease of oxidation. Australian Journal of Soil Research 1997,35:881-890.
[20]Coumou D. and Rahmstorf S., A decade of weather extremes. Nature Climate Change 2012, pp.1-6. DOI:10.1038/NCLIMATE1452.
[21]Debreczeni K. and Korschens M., Long-term field experiments of the world. Archives of Agronomy and Soil Science 2003,49:465-483.
[22]Ding X., Han X., Liang Y., Qiao Y., Li L. and Li N., Changes in soil organic carbon pools after 10 years of continuous manuring combined with chemical fertilizer in a Mollisol in China. Soil & Tillage Research 122,2012:36-41.
[23]Ding X.L., Zhang B., Zhang X.D., Yang X.M. and Zhang X.P., Effects of tillage and crop rotation on soil microbial residues in a rainfed agroecosystem of northeast China. Soil & Tillage Research 2011,114:43-49.
[24]Doran J.W. and Zeiss, M.R., Soil health and sustainability:managing the biotic component of soil quality. Applied Soil Ecology 2000,15:3-11.
[25]Doran J.W., Sarrantonio M. and Liebig M., Soil health and sustainability. In:Sparks D.L. (Ed.), Advances in Agronomy 1996,56:1-54. Academic Press, San Diego.
[26]FAOSTAT,2012. http://faostat3.fao.org/home/index.html#VISUALIZE_BY_AREA.
[27]Franzluebbers A.J., Soil organic matter stratification ratio as an indicator of soil quality. Soil and Tillage Research 2002,66:95-106.
[28]Ghosh S., Wilson B.R., Mandal B., Ghoshal S.K. and Growns I., Changes in soil organic carbon pool in three long-term fertility experiments with different cropping systems and inorganic and organic soil amendments in the eastern cereal belt of India. Australian Journal of Soil Research 2010,48:413-420.
[29]Global Carbon Project, Carbon budget 2008:An annual update of the global carbon budget and trends.2009. http://www.globalcarbonproject.org/carbonbudget/index.htm.
[30]Gong W., Yan X.Y., Wang J.Y., Hu T.X. and Gong Y.B., Long-term manuring and fertilization effects on soil organic carbon pools under a wheat-maize cropping system in North China Plain. Plant and Soil 2009,314:67-76.
[31]Graham M.H., Haynes R.J. and Meyer J.H., Soil organic matter content and quality:effects of fertilizer applications, burning and trash retention on long-term sugarcane experiment in South Africa. Soil Biology and Biochemistry 2002,34:93-102.
[32]Gregorich E.G. and Janzen H.H., Storage of soil carbon in the light fraction and macro-organic matter.1996, p.167-190. In:Carter M.A. and Stewart B.A. (ed.) Structure and organic matter storage in agricultural soils. Lewis Publ., Boca Raton, FL.
[33]Gregorich E.G, Carter M.R., Angers D.A., Monreal C.M. and Ellert B.H., Towards a minimum data set to assess soil organic matter quality in agricultural soils. Canadian Journal of Soil Science 1994, 74:367-385.
[34]Heanes D.L., Determination of total organic-C in soils by an improved chromic acid digestion and spectrophotometric procedure. Communication in Soil Science and Plant Analysis 1984,15: 1191-1213.
[35]Houghton R.A., Balancing the global carbon budget. Annual Review of Earth and Planetary Science 2007,35:313-347.
[36]Hoyle F.C., Baldock J.A. and Murphy D.V., Soil Organic Carbon-Role in Rainfed Farming Systems. In:Tow P. et al. (eds.), Rainfed Farming Systems 2011, DOI 10.1007/978-1-4020-9132-2_14, Springer Science+Business Media B.V.
[37]IPCC (Intergovernmental Panel on Climate Change), Climate Change 2007:Mitigation of Climate Change 2007, Working Group Ⅲ. Cambridge, UK:Cambridge University Press.
[38]IPCC, Climate Change, Scientific Basis. Cambridge University Press:Cambridge 2001, pp.851.
[39]IPCC, The Climate Change:The Physical Science Basis. IPCC Working Group 12007, Cambridge, UK:Cambridge Univ. Press.
[40]Jagadamma S. and Lal R., Distribution of organic carbon in physical fractions of soils as affected by agricultural management. Biology and Fertility of Soils 2010,46:543-554.
[41]Janzen H.H., Campbell C.A., Gregorich E.G. and Ellert B.H., Soil carbon dynamics in Canadian agroecosystems. In:Lal R., Kimble J.M., Levine E. and Stewart B.A., (eds) Soil processes and carbon cycles 1998, CRC, Boca Raton, pp 57-80.
[42]Johnston A.E., Soil organic matter, effects on soils and crops. Soil Use and Management 1986,2: 97-105.
[43]Kalembasa S.J. and Jenkinson D.S., A comparative study of titrimetric and gravimetric methods for the determination of organic carbon in soil. Journal of the Science of Food and Agriculture 1973,24: 1085-1090.
[44]Karl T.R. and Trenberth K.E., Modern Global Climate Change. Science, Washington DC 2003,302: 1719-1723.
[45]Karlen D.L., Andrews S.S. and Doran J.W., Soil quality:Current concepts and applications. Advances in Agronomy 2001,74:1-40.
[46]Karlen D.L., Doran J.W., Weinhold B.J. and Andrews S.S., Soil quality:Humankind's foundation for survival. Journal of Soil and Water Conservation 2003,58:171-179.
[47]Karlen D.L., Mausbach M.J., Doran J.W., Cline R.G., Harris R.F. and Schuman G.E., Soil quality:a concept, definition, and framework for evaluation. Soil Science Society of America Journal 1997, 61:4-10.
[48]Kong A.Y.Y., Six J., Bryant D.C., Denison R.F. and Kessel C.V., The relationship between carbon input, aggregation, and soil organic carbon stabilization in sustainable cropping systems. Soil Science Society of America Journal 2005,69:1078-1085.
[49]Krull E.S., Jeffrey A.B. and Skjemstad J.O., Importance of mechanisms and processes of the stabilization of soil organic matter for modeling carbon turnover. Functional Plant Biology 2003,30: 207-222.
[50]Krull E.S., Skjemstad J.O. and Baldock J.A., Functions of soil organic matter and the effect on soil properties. GRDC report 2004, Project CSO 00029.
[51]Kundu S., Bhattacharyya R., Prakash V., Ghosh B.N. and Gupta H.S., Carbon sequestration and relationship between carbon addition and storage under rainfed soybean-wheat rotation in a sandy loam soil of the Indian Himalayas. Soil & Tillage Research 2007,92:87-95.
[52]Lal R., Global potential of soil carbon sequestration to mitigate the greenhouse effect. Critical Review in Plant Sciences 2003,22:151-184.
[53]Lal R., Kimble J.M., Follett R.F. and Cole C. V., The potential of U.S. cropland to sequester carbon and mitigate the greenhouse effect. Ann Arbor Press, Chelsea, MI.1998 pp.128.
[54]Lal R., Offsetting China's CO2 emissions by soil carbon sequestration. Climatic Change 2004a,65: 263-275.
[55]Lal R., Soil Carbon sequestration impacts on global climate change and food security. Science 2004b,304:1623-1627.
[56]Lai R., Soil carbon sequestration in Latin America. In:Carbon Sequestration in Soils of Latin America, ed. Lal R.C., Cerri M., Bernoux J.E. and Cerri E.2006:49-64. New York, NY:Food Products Press.
[57]Larson W.E. and Pierce F.J., Conservation and enhancement of soil quality. In:Evaluation for Sustainable Land Management in the Developing World, Vol.2:Technical papers. Bangkok, Thailand:International Board for Research and Management,1991. IBSRAM Proceedings No. 12(2):175-203.
[581 Letey J., Sojka R.E., Upchurch D.R., Cassel D.K., Olson K.R., Payne W.A., Petrie S.E., Price G.H., Reginato R.J., Scott, H.D., Smethurst P.J. and Triplett G.B., Deficiencies in the soil quality concept and its application. Journal of Soil and Water Conservation 2003,58:180-187.
[59]Li Z.P., Lin X.X. and Che Y.P., Analysis for the balance of organic carbon pools and their tendency in typical arable soils of Eastern China. Acta Pedologica Sinica 2002,39:351-360 (in Chinese).
[60]Li Z.P., Liu M., Wu X.C., Han F.X. and Zhang T.L., Effects of long-term chemical fertilization and organic amendments on dynamics of soil organic C and total N in paddy soil derived from barren land in subtropical China. Soil & Tillage Research 2010,106:268-274.
[61]Li Z.P., Liu M., Wu X.C., Han F.X. and Zhang T.L., Effects of long-term chemical fertilization and organic amendments on dynamics of soil organic C and total N in paddy soil derived from barren land in subtropical China. Soil & Tillage Research 2010,106:268-274.
[62]Liang Q., Chen H., Gong Y., Fan M., Yang H., Lal R. and Kuzyakov Y., Effects of 15 years of manure and inorganic fertilizers on soil organic carbon fractions in a wheat-maize system in the North China Plain. Nutrient Cycling in Agroecosystems 2012,92:21-33.
[63]Liu X.B., Han X.Z., Song C.Y., Herbert S.J. and Xing B.S., Soil organic carbon dynamics in black soils of China under different agricultural management systems. Communications in Soil Science and Plant Analysis 2003,34:973-984.
[64]Liu X.B., Zhang X.Y., Wang Y.X., Sui Y.Y., Zhang S.L., Herbert S.J. and Ding G., Soil degradation:a problem threatening the sustainable development of agriculture in Northeast China. Plant Soil and Environment 2010,56:87-97.
[65]Lopez-Capel E., Krull E.S., Bol R. and Manning D.A., Influence of recent vegetation on labile and recalcitrant carbon soil pools in central Queensland Australia:evidence from thermal analysis-quadrupole mass spectrometry-isotope ratio mass spectrometry. Rapid Communications in Mass Spectrometry 2008,22:1751-1758.
[66]Majumder B., Mandal B. and Bandyopadhyay P.K., Soil organic carbon pools and productivity in relation to nutrient management in a 20-year-old rice-berseem agroecosystem. Biology and Fertility of Soils 2008a,44:451-461.
[67]Majumder B., Mandal B., Bandyopadhyay P.K. and Chaudhury J., Soil organic carbon pools and productivity relationships for a 34 year old rice-wheat-jute agroecosystem under different fertilizer treatments. Plant and Soil 2007,297:53-67.
[68]Majumder B., Mandal B., Bandyopadhyay P.K., Gangopadhyay A., Mani P.K., Kundu A.L. and Mazumdar D., Organic amendments influence soil organic carbon pools and rice-wheat productivity. Soil Science Society of America Journal 2008b,72:775-785.
[69]Mandal B., Majumder B., Adhya T.K., Bandyopadhyay P.K.,Gangopadhyay A., Sarkar D., Kundu M.C., Choudhury S.G., Hazra G.C., Kundu S., Samantaray R.N. and Misra A.K., The potential of double-cropped rice ecology to conserve organic carbon under subtropical climate. Global Change Biology 2008,14:2139-2151.
[70]Mandal B., Majumder B., Bandopadhyay P.K., Hazra G.C., Gangopadhyay A., Samantaroy R.N., Misra A.K., Chowdhuri J., Saha M.N. and Kundu S., The potential of cropping systems and soil amendments for carbon sequestration in soils under long-term experiments in subtropical India. Global Change Biology 2007,13:357-369.
[71]McLauchlan K.K. and Hobbie S.E., Comparison of labile soil organic matter fractionation techniques. Soil Science Society of America Journal 2004,68:1616-1625.
[72]McLauchlan K.K., Hobbie S.E. and Post W.M., Conversion from agriculture to grassland builds soil organic matter on decadal timescales. Ecological Applications 2006,16:143-153.
[73]Merry R.H. and Spouncer L.R., The measurement of carbon in soils using a microprocessor-controlled resistance furnace. Communications in Soil Science and Plant Analysis 1988,19:707-720.
[74]Miao Y., Stewart B.A. and Zhang F., Long-term experiments for sustainable nutrient management in China. A review. Agronomy for Sustainable Development 2010:1:14. DOI: 10.1051/agro/2010034.
[75]Morgan J.A., Follett R.F., Allen L.H.Jr., Grosso S.D., Derner J.D., Dijkstra F., Franzluebbers A., Fry R., Paustian K. and Schoeneberger M.M., Carbon sequestration in agricultural lands of the United States. Journal of Soil and Water Conservation 2010,65(1):6A-13A.
[76]Murphy D.V., Cookson W.R., Braimbridge M., Marschner P., Jones D.L., Stockdale E.A. and Abbott L.K., Relationships between soil organic matter and the soil microbial biomass (size, functional diversity, and community structure) in crop and pasture systems in a semi-arid environment. Soil Research 2011,49:582-594.
[77]National Environment Trust, Leadership and Equity:The United States, Developing Countries and Global Warming. National Environment Trust, Washington, D.C.1998, pp.68.
[78]National Soil Survey Office,1998. Soils of China. China Agriculture Press, Beijing (in Chinese).
[79]Nelson D.W. and Sommers L.E., Total carbon, organic carbon and organic matter. In:Page A.L. Miller R.H. and Keeney D.R. (eds). Methods of Soil Analysis, Part 2. Agronomy Monograph No 12, (2nd ed.). ASA and SSSA, Madison, WI 1982, pp.101-129.
[80]Nick P., Iain S., Jonathan L., Pen H. and Ian M., Climate Change. Met Office (UK) 2012, http://www.metoffice.gov.uk/climate-change.
[81]Papendick R.I. and Parr J., Soil quality-the key to a sustainable agriculture. American Journal of Alternative Agriculture 1992,7:2-3.
[82]Parton W.J. and Rasmussen P.E., Long-term effects of crop management in wheat-fallow:II. CENTURY model simulations. Soil Science Society of America Journal 1994,58:530-536.
[83]Pastor J., Dewey B., Naiman R.J., McInnes P.F. and Cohen Y., Moose browsing and soil fertility in the boreal forests of Isle Royale National Park. Ecology 1993,74:467-480.
[84]Paul E.A., Harris D., Klug M.J. and Ruess R.W., The determination of microbial biomass.1999, p. 291-317. In:Robertson G.P. (ed.) Standard soil methods for long-term ecological research. Oxford University Press, New York.
[85]Powlson D.S., Smith P., Coleman K., Smith J.U., Glendining M.J., Korschens M. and Franko U., A European network of long-term sites for studies on soil organic matter. Soil & Tillage Research 1998,47:263-274. doi:10.1016/S0167-1987(98)00115-9.
[86]Purakayastha T.J., Rudrappa L., Singh D., Swarup A. and Bhadraray S., Long-term impact of fertilizers on soil organic carbon pools and sequestration rates in maize-wheat-cowpea cropping system. Geoderma 2008,144:370-378.
[87]Rasmussen P.E., Allmaras R.R., Rohde C.R. and Roager Jr. N.C., Crop residue influences on soil carbon and nitrogen in a wheat-fallow system. Soil Science Society of America Journal 1980,44: 596-600.
[88]Richter D.D., Hofmockel M., Callaham M.A., Powlson D.S. and Smith P., Long-term soil experiments:Keys to managing Earth's rapidly changing ecosystems. Soil Science Society of America Journal 2007,71:266-279.
[89]Rice C.W., Soil organic C and N in rangeland soil under elevated CO2 and land management. In: Proceedings of Advances in Terrestrial Ecosystem Carbon Inventory, Measurement, and Monitoring, October 3-5,2000. USDA-ARS, USDA-FS, USDA-NRCS, US Dept. Energy, NASA, and National Council for Air and Stream Improvement 2000, p 83.
[90]Rovira P. and Vallejo V.R., Labile and recalcitrant pools of carbon and nitrogen in organic matter decomposing at different depths in soil:an acid hydrolysis approach. Geoderma 2002,107: 109-141.
[91]Rudrappa L., Purakayastha T.J., Singh D. and Bhadraray S., Long-term manuring and fertilization effects on soil organic carbon pools in a Typic Haplustept of semi-arid sub-tropical India. Soil & Tillage Research 2006,88:180-192.
[92]Schlesinger W.H. and Andrews J.A., Soil respiration and the global carbon cycle. Biogeochemistry 2000,48:7-20.
[93]Schneider S.H., Geosphere-biosphere Interactions and Climate. Lennart O.B. and Hammer C.U. eds., Cambridge University Press 2001, pp.90-91.
[94]Schuman G.E., Janzen H.H. and Herrick J.E., Soil carbon dynamics and potential carbon sequestration by rangelands. Environmental Pollution 2002,116:391-396.
[95]Shrestha B.M., Certini G., Forte C. and Singh B.R., Soil organic matter quality under different land uses in a mountain watershed of Nepal. Soil Science Society of America Journal 2008,72: 1563-1569.
[96]Simon T., The influence of long-term organic and mineral fertilization on soil organic matter. Soil and Water Research 2008,3:41-51.
[97]Six J., Elliott E.T., Paustian K. and Doran J.W., Aggregation and soil organic matter accumulation in cultivated and native grassland soils. Soil Science Society of America Journal 1998,62: 1367-1377.
[98]Six J., Feller C., Dencf K., Ogle S.M., Moraes de J.C. and Albrecht A., Soil organic matter, biota, and aggregation in temperate and tropical soils-effects of no-tillage. Agronomie 2002,22: 755-775.
[99]Skjcmstad J.O. and Taylor J.A., Does the Walkley-Black method determine soil charcoal? Communications in Soil Science and Plant Analysis 1999,30:2299-2310.
[100]Smith P., Martino D., Cai Z., Gwary D., Janzen H.H., Kumar P., McCarl B., Ogle S., O'Mara E, Rice C., Scholes R.J., Sirotenko O., Howden M., McAllister T., Pan G., Romanenkov V., Schneider U., Towprayoon S., Wattenbach M. and Smith J.U., Greenhouse gas mitigation in agriculture. Philosophical Transactions of Royal Society 2008,363:789-813.
[101]Sperow M., Eve M. and Paustian K., Potential soil C sequestration on US agricultural soils. Climate Change 2003,57:319-339.
[102]Stevenson F.J., Carbon balance of the soil and role of organic matter in soil fertility. In:Cycles of Soil-Carbon, Nitrogen, Phosphorus, Sulphur, Micronutrients. John Wiley & Sons, New York 1986, pp.45-77.
[103]Strosser E., Methods for determination of labile soil organic matter:An overview. Journal of Agrobiology 2010,27(2):49-60.
[104]Sun W., Huang Y., Zhang W. and Yu Y., Carbon sequestration and its potential in agricultural soils of China. Global Biogeochemical Cycles 2010,24:1-12. GB3001, doi:10.1029/2009GB003484.
[105]Vieira F.C.B., Bayer C., Zanatta J.A., Dieckow J., Mielniczuk J. and He Z.L., Carbon management index based on physical fractionation of soil organic matter in an Acrisol under long-term no-till cropping systems. Soil & Tillage Research 2007,96:195-204.
[106]VijayaVenkataRaman S., Iniyan S., Goic R., A review of climate change, mitigation and adaptation. Renewable and Sustainable Energy Reviews 2012,16:878-897.
[107]Walkley A. and Black I.A., An examination of the Degtjareff method for determining soil organic matter and a proposed modification of the chromic acid titration method. Soil Science 1934,37: 29-38.
[108]Walkley A., A critical examination of a rapid method for determining organic carbon in soils:Effect of variations in digestion conditions and inorganic soil constituents. Soil Science 1947,63: 251-263.
[109]WMO, The Greenhouse Gas Bulletin:The State of Greenhouse Gases in the Atmosphere Using Global Observation through 2009. Geneva, Switzerland:The World Meteorological Organization 2010.
[110]World reference base for soil resources, Food and Agriculture Organization of the United Nations, Rome 1998,84 World Soil Resources Reports.
[111]Xu M., Zhang W., Zhang H. and Wang X., Long-term experiments and soil organic carbon sequestration in arable land of China. Proceedings of the 2nd International workshop on carbon sequestration and climate change mitigation in agriculture, June 27-30,2010, Beijing, China.
[112]Yan D.Z., Wang D.J. and Yang L.Z., Long-term effect of chemical fertilizer, straw and manure on labile organic matter fractions in a paddy soil. Biology and Fertility of Soils 2007,44:93-101.
[113]Zhang W., Xu M., Wang B. and Wang X., Soil organic carbon, total nitrogen and grain yields under long-term fertilizations in the upland red soil of southern China. Nutrient Cycling in Agroecosystems 2009,84:59-69.
[114]Zhang W., Xu M., Wang X., Huang Q., Nie J., Li Z., Li S., Hwang S.W. and Lee K.B., Effects of organic amendments on soil carbon sequestration in paddy fields of subtropical China. Journal of Soils and Sediments 2012,12(1):DOI 10.1007/s11368-011-0467-8.
[115]Zhang W.J., Wang X.J., Xu M.G., Huang S.M., Liu H. and Peng C., Soil organic carbon dynamics under long-term fertilizations in arable land of northern China. Biogeosciences 2010,7:409-425.