Impact of Nitrogen Fertilization and Cropping System on Carbon Sequestration in Midwestern Mollisols

Abstract

Growing interest in the potential for agricultural soils to provide a sink for atmospheric C has prompted studies of effects of management on soil organic carbon (SOC) sequestration. We analyzed the impact on SOC of four N fertilization rates (0-270 kg N ha −1 ) and four cropping systems: continuous corn (CC) (Zea mays L.); corn-soybean [Glycine max (L.) Merr.] (CS); corn-corn-oat-alfalfa (oat, Avena sativa L.; alfalfa, Medicago sativa L.) (CCOA), and corn-oat-alfalfa-alfalfa (COAA). Soils were sampled in 2002, Years 23 and 48 of the experiments located in northeast and north-central Iowa, respectively. The experiments were conducted using a replicated split-plot design under conventional tillage. A native prairie was sampled to provide a reference (for one site only). Cropping systems that contained alfalfa had the highest SOC stocks, whereas the CS system generally had the lowest SOC stocks. Concentrations of SOC increased significantly between 1990 and 2002 in only two of the nine systems for which historical data were available, the fertilized CC and COAA systems at one site. Soil quality indices such as particulate organic carbon (POC) were influenced by cropping system, with CS < CC < CCOA. In the native prairie, SOC, POC, and resistant C concentrations were 2.8, 2.6, and 3.9 times, respectively, the highest values in cropped soil, indicating that cultivated soils had not recovered to precultivation conditions. Although corn yields increased with N additions, N fertilization increased SOC stocks only in the CC system at one site. Considering the C cost for N fertilizer production, N fertilization generally had a net negative effect on C sequestration. RightsWorks produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.

Soil Organic Carbon Changes in Diversified Rotations of the Western Corn Belt

“…Maintenance of SOC levels over the 18 yr of this study in our 4-yr cropping systems with clover ( Fig. 1) also agree with results recently reported by Russell et al (2005) in Iowa, where they found that cropping systems including alfalfa for 1 to 2 yr in a 4-yr rotation are a viable management option for increasing SOC stocks. Together, these results point to the importance of diversification of crops and longer-term rotations in maintaining SOC levels.…”

“…Similarly, Booker et al (2005) reported similar results on the long-term effects of tillage and corn stalk return on soil C dynamics from a study conducted for 28 yr in Connecticut. In Iowa, Russell et al (2005) reported results taken from two studies 23 and 48 yr old on the effects of N fertilization and cropping system on C sequestration. In each of these reports, the importance of data from long-term studies becomes evident by quantifying the impact that small changes in management practices have with time.…”

Soil organic carbon in the Sanjiang Plain of China: storage, distribution and controlling factors

“…Generally, fertilization can raise SOC storage by enhancing the carbon input from plant productivity and crop biomass (Ren et al, 2012, Zhao et al, 2013. However, overapplication of fertilizer can have negative net effects on carbon sequestration because organic carbon mineralization neutralizes the carbon input (Russell et al, 2005). Influences of fertilization on SOC are complicated and can be related to the history of cropland and vegetation types, as well as soil types and texture.…”

Carbon mineralization and carbon dioxide emission from organic matter added soil under different temperature regimes

“…We hypothesized that CO 2 emission from soil would vary with different organic materials and temperature levels during decomposition process. Moreover, proper management of such organic materials may improve soil biodiversity, microaggregation, and reduction in CO 2 emission from soil (Rastogi et al 2002;Lal 2004;Russell et al 2005). The national and global concerns about the effects of CO 2 emission have spawned research avenues on soil organic C, its transformation under different soil and crop environments.…”