Soil Organic Carbon Management Research Articles

Sustainable Crop Production Through Management of Soil Organic Carbon in Semiarid and Tropical India

ABSTRACT Enhancing the long-term sustainability in productivity of crops and cropping systems is directly related to maintenance of an adequate level of soil organic matter. Indian soils contain about 0.1 to 1% organic carbon. The maintenance of soil organic matter in agricultural soils, particularly of semiarid and subtropical regions of India, is generally governed by annual temperature, precipitation and many interacting factors such as soil types, tillage, application of fertilizers, quality and quantity of organics returned to soil, and the method of residue management. In India most residues used are as feed and fuel and one-third of crop residues is used as a source of organic matter. Continuous use of the same crops in the cropping system, unbalanced and inappropriate use of chemical fertilizer, and minimum or no use of organic matter year after year are a major constraints to soil organic carbon accumulation. Alternate land use systems, viz., agro-forestry, agro-horticultural, agro-pastoral, and agro-silvipasture are more effective for soil organic matter restoration than monocropping systems. The constraints for organic matter management are reviewed, possible solution are presented, and future research needed are outlined.

Soil factors influencing atrazine sorption: Implications on fate

AbstractThe effects of two soil properties—soil organic carbon (SOC) content and landscape position—and a management factor (tillage) from Iowa and South Carolina soils on the sorption of the herbicide atrazine (6‐chloro‐N‐ethyl‐Nǐ‐(1‐methylethyl)‐1,3,5‐triazine‐2,4‐diamine) were evaluated to assess their influence on atrazine fate in the soil environment. In both Iowa and South Carolina, the magnitude of atrazine sorption was strongly and positively correlated with SOC, landscape position, and tillage. Landscape position was especially important for Iowa soils because SOC‐enriched depressional areas (potholes) on the Wisconsin glacial surface could sorb more atrazine than soils in sloping positions. Our data suggest that herbicide management strategies such as application rates or herbicide selection will require some adjustments to account for the effects of SOC, landscape position, and tillage management on herbicide sorption in to augment effective weed control and prevent herbicide movement to groundwater.

Eye-dropper technique proves effective method of testing steel

The importance of soil organic carbon (SOC) sequestration in agricultural soils as climate-change-mitigating strategy has become an area of focus by the scientific community in relation to soil management. This study was conducted to determine the temporal effect of different tillage systems and residue management on distribution, storage and stratification of SOC, and the yield of rice under double rice (Oryza sativa L.) cropping system in the southern China. A tillage experiment was conducted in the southern China during 2005–2011, including plow tillage with residue removed (PT0), plow tillage with residue retention (PT), rotary tillage with residue retention (RT), and no-till with residue retention on the surface (NT). The soil samples were obtained at the harvesting of late rice in October of 2005, 2007 and 2011. Multiple-year residue return application significantly increased rice yields for the two rice-cropping systems; yields of early and late rice were higher under RT than those under other tillage systems in both years in 2011. Compared with PT0, SOC stocks were increased in soil under NT at 0–5, 5–10, 10–20, and 20–30 cm depths by 33.8, 4.1, 6.6, and 53.3%, respectively, in 2011. SOC stocks under RT were higher than these under other tillage treatments at 0–30 cm depth. SOC stocks in soil under PT were higher than those under PT0 in the 0–5 and 20–30 cm soil layers. Therefore, crop residues played an important role in SOC management, and improvement of soil quality. In the 0–20 cm layer, the stratification ratio (SR) of SOC followed the order NT>RT>PT>PT0; when the 0–30 cm layer was considered, NT also had the highest SR of SOC, but the SR of SOC under PT was higher than that under RT with a multiple-year tillage practice. Therefore, the notion that conservation tillage lead to higher SOC stocks and soil quality than plowed systems requires cautious scrutiny. Nevertheless, some benefits associated with RT system present a greater potential for its adoption in view of the multiple-year environmental sustainability under double rice cropping system in the southern China.