|Hao, Y - OHIO STATE UNIVERSITY|
|Lal, R - OHIO STATE UNIVERSITY|
|Izaurralde, R - BATTELLE PACIFIC NW LAB|
|Post, W - OAK RIDGE NAT'L LAB|
|Hothem, D - USDA-ARS-NAEW, RETIRED|
Submitted to: Soil & Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 30, 2002
Publication Date: December 1, 2002
Citation: Hao, Y., Lal, R., Owens, L.B., Izaurralde, R.C., Post, W.M., Hothem, D.L. 2002. Effect of cropland management and slope position on soil organic carbon pool at the North Appalachian Experimental Watersheds. Soil & Tillage Research. 68:133-142. Interpretive Summary: Soil organic matter plays an important role in soil quality and in enhancing crop production. Also carbon stored in the soil is less carbon that enters the atmosphere, which could have adverse climate change impacts. The organic carbon in cropland soils is strongly correlated to crop and soil management practices. These practices include crop species and rotation, tillage methods, fertilizer rates, manure application, irrigation and drainage, and soil and water conservation. Conversion of plow tillage to no tillage can considerably increase the soil organic carbon over several years. Soil organic carbon amounts also depend on landscape slope position due to soil erosion and leaching. This study at the North Appalachian Experimental Watershed determined the long-term effects of management practices and slope position on amounts of soil organic carbon. The management practices studied were no tillage corn with fertilizer; no tillage corn with fertilizer and manure; no tillage corn and soybean rotation with fertilizer; chisel plow corn soybean rotation with fertilizer; moldboard plow crop rotation with fertilizer; and moldboard plow crop rotation with limited fertilizer. The results showed that soil organic carbon can be increased by adding manure, reducing tillage, and increasing soil fertility through a combination of increased amounts of soil amendments (fertilizer, manure, lime). And slope position can exert a significant effect on soil organic carbon where cattle manure was constantly applied. These results are important to land managers, policy makers, and producers who are interested in increasing the amount of soil organic carbon in soil.
Technical Abstract: Soil organic matter is strongly related to soil type, landscape morphology, and soil and crop management practices. Therefore, long-term (15-36 years) effects of six cropland management systems on soil organic carbon (SOC) pool in 0-30 cm depth were studied for the period of 1939-1999 at the North Appalachian Experimental Watersheds (<3 ha, Dystric Cambisol, Haplic Luvisol, and Haplic Alisol) near Coshocton, OH, USA. Six management treatments were: (1) no tillage continuous corn with NPK (NC); (2) no tillage continuous corn with NPK and manure (NTC-M); (3) no tillage corn-soybean rotation (NTR); (4) chisel tillage corn-soybean rotation (CTR); (5) moldboard tillage with cornwheat-meadow-meadow rotation with improved practices (MTR-I); (6) moldboard tillage with corn-wheat-meadow-meadow rotation with prevalent practices (MTR-P). The SOC pool ranged from 24.5 Mg ha-1 in the 32-years moldboard tillage corn (Zea mays L.)-wheat (Triticum aestivum L.)-meadow-meadow rotation with straight row farming and annual application of fertilizer (N:P:K = 5:9:17) of 56-112 kg ha-1 and cattle (Bos Taurus) manure of 9 Mg ha-1 as the prevalent system (MTR-P) to 65.5 Mg ha-1 in the 36-years no tillage continuous corn with contour row farming and annual application of 170-225 kg N ha-1 and appropriate amounts of P and K, and 6-11 Mg ha-1 of cattle manure as the improved system (NTC-M). The difference in SOC pool among management systems ranged from 2.4 to 41 Mg ha-1 and was greater than 25 Mg ha-1 between NTC-M and the other five management systems. The difference in the SOC pool of NTC-M and that of no tillage continuous corn (NTC) were 16-21 Mg ha-1 higher at the lower slope position than at the middle and upper slope positions. The effect of slope positions on SOC pools of the other management systems was significantly less (<5 Mg ha-1). The effects of manure application, tillage, crop rotation, fertilizer rate, and soil and water conservation farming on SOC pool were accumulative. The NTC-M treatment with application of NPK fertilizer, lime, and cattle manure is an effective cropland management system for SOC sequestration.