Soil carbon and nitrogen sequestration as affected by long-term tillage, cropping systems, and nitrogen fertilizer sources

Effect of Improved Management Practices on Soil Organic Carbon Sequestration in Wheat-maize Double Cropping System in North China

“…OM can increase the input of SOC, and accelerate SOC accumulation in the soil (Chen, Wang, & Wang, 2008). In the study area, OM can sequester SOC an average of 260 kg ha -1 yr -1 , which was higher than that of 150 kg ha -1 yr -1 in Europe cropland concluded by Vleeshouwers and Verhagen (Vleeshouwers & Verhagen, 2002), lower than that of previous researchers with an effect of 390 kg ha -1 yr -1 of USA cropland estimated by Jarecki et al (Jarecki, Lai, & James, 2005), 350 kg ha -1 yr -1 of Belgium cropland evaluated by Dendoncker et al and 510 kg ha -1 yr -1 in southeastern USA estimated by Upendra et al ( Upendra et al, 2008;Dendoncker, Wesemael, & Rounsevell, 2004). SR achieves SOC sequestration through increasing the carbon input to the soil.…”

“…As a global basis, Lal estimated that agricultural soils could potentially sequester 0.4-0.8 Pg C year -1 by adopting IMPs (Lal, 2004), which accounts for about 33.3-100% of the total potential of C sequestration in global soils. Although many researchers have studied the effects of the IMPs on C sequestration in cropland soils through long-term experiments (Morari, et al, 2006;John, Marcus, Ronald, & James, 2008;Upendra, Zachary, Ermson, Irenus, & Reddy, 2008;Wang & Kang, 2009), the results among them were always inconsistent and uncertain varying from significant increase to significant decrease (Alvaro-Fuentes, Lopez, Cantero-Martinez, & Arrue, 2008;Christopher, Lal & Mishra, 2009). Moreover, it was unclear whether this inconsistency was caused by environmental, or management factors or by sampling errors and analysis methodology (Luo, Wang, & Sun, 2010).…”

Fertilization increases paddy soil organic carbon density

“…The SOC density tends to increase as the ratio of inorganic fertilizers to organic amendments decreases (Hao X.Y. et al, 2003;Rasool et al, 2007;Sainju et al, 2008;Pan et al, 2009;Bhattacharyya et al, 2010). The increase in SOC density values ranged from <0 to >8 Mg/(ha·a), with an average of 0.33 Mg/(ha·a) (Franzluebbers, 2005;West and Six, 2007;López-Bellido et al, 2010).…”

“…In addition, N fertilizer has a C cost [C:N: about 0.50 to 1.74 (w/w)] for its manufacture, distribution, and application (West and Marland, 2002;Franzluebbers, 2005). Many reports indicate that it would be beneficial to sequestrate SOC through organic amendments, which themselves contain C (Sainju et al, 2008). Bhattacharyya et al (2010) observed that the rate of conversion of the applied C to SOC was approximately 19%.…”

Carbon and Nitrogen Stocks and C: N Ratio of Harran Plain Soils

“…Other researchers argue that there is a positive relationship between C:N ratios, precipitation and temperature (Callesen, 2007). It is argued that although the cultivation systems and farming activities used 10 years ago did not affect C:N ratios (Sainju et al, 2008;Fu et al, 2010), today's farming techniques and agriculture do affect C:N ratios (Puget and Lal, 2005;Yimer et al, 2007).…”