Use of Manure, Compost, and Cover Crops to Supplant Crop Residue Carbon in Corn Stover Removed Cropping Systems

Abstract

A gronomy J our n al • Volume 10 0 , I s sue 6 • 2 0 0 8 1703 Stover from corn grain production has been identifi ed as a probable source of biomass feedstock for cellulosic ethanol production (Graham et al., 2007). Furthermore, the replacement of fossil fuels with renewable fuels has been identifi ed as an eff ective method of reducing greenhouse gas (GHG) emissions (Griffi n and Lave, 2006). However, the loss of SOC associated with the removal of corn fodder for cellulosic ethanol feedstock is of agricultural and environmental concern. Th e decline of SOC in agricultural systems combined with increased awareness of the importance of the terrestrial ecosystem in global C budgets has stimulated evaluations of land management eff ects on soil C dynamics and storage (Lal et al., 1995). Past and present farming practices have resulted in loss of an estimated 4 ± 1 × 10 9 Mg of C from soils of the United States, and 78 ± 12 × 10 9 Mg from the world's soils, a large fraction of which ended up in the atmosphere (Lal, 1999). Soils play a major role in the global C budget not only because of the large amount of C stored in soil, with estimates ranging from 1395 to 1636 × 10 8 Mg (Torbert et al., 1999;Schlesinger, 1984) but also because the annual fl ux of CO 2 to the atmosphere from soil is 10 times the amount of CO 2 contributed by fossil fuel usage (Post et al., 1990). Land use practices that may increase C sequestration include a switch to no-tillage (NT), greater cropping frequency (Bremer et al., 1994;Campbell et al., 1995), and application of organic amendments such as manure (Sommerfeldt et al., 1988), although Janzen et al. (1998) regarded applications of C amendments as a C transfer rather than a gain. Many of these practices (manure, forage production, and reduced harvest removal) that favor C storage appear to interact synergistically with each other, so that increases in SOC under one practice are greater when combined with other practices (Grant et al., 2001).Additional input of organic substances containing high amounts of C, such as farmyard manure or the incorporation of crop residues will increase organic C content in soil (Dersch and Bohm, 2001). Beef cattle feedlot manure contains essential nutrients in addition to approximately 15% C that can be used to improve soil physical and chemical properties (Eghball, 2002).Despite increased oxidative losses it was estimated that approximately half of the added manure C is retained in the soil at the end of the season (Rochette and Gregorich, 1998). Iazurralde et al. (2001) determined that the addition of farmyard manure was a key management component leading to SOC increases. Drinkwater et al. (1998) compared manure and conventional systems and found that even though both systems received equal amounts of C, the manure system showed a signifi cant increase in C stored in soil. Rate of SOC change was directly related to C input from crop residues and amendments (Rasmussen and Parton, 1994). Compared with senescent-crop residues, a larger proportion of manure...

Do cover crops increase or decrease nitrous oxide emissions? A meta-analysis

“…Even though indirect estimates of N 2 O emissions are variable, this is an important impact to consider that would not be included in the LRR for direct emissions used in our analysis. One modeling experiment (De Gryze et al 2010) and two field experiments (Fronning et al 2008;Smith et al 2011) reported net global warming potentials (GWP) that were neutral or negative (indicating mitigative potential) when cover crops were present. In our database, only these three studies included full net GWPs, measuring change in SOC (or soil CO 2 respiration), N 2 O, and CH 4 .…”

Utilization of manure and green organic composts as alternative fertilizers for cauliflower production

“…In a broad sense the productivity of land will be seriously decreased. Therefore it is necessary to addorganic amendments in cultivation practices such as compost of green biomass and cow manure that may function as an alternative to substitutemineral fertilizers and to improve the physical and biological properties of soil (Hue and Silva, 2000;Golabi et al, 2004;Fronning et al, 2008 ).…”

Environmental Comparison of Straw Applications Based on a Life Cycle Assessment Model and Emergy Evaluation

“…A study by Kim and Dale (2004) found that 73.9 Tg of dried waste crop can produce up to 49.1 GL/yr of bioethanol. Although it has been argued that removing crop residue from fields can degrade soil quality, well-managed corn harvest strategies using manure, composite fertilizer, and winter cover can partially compensate the loss of soil quality (Fronning et al 2008). The research of Steubing et al (2011) showed that biomass conversion efficiency was the determining factor for the best use of biomass, and woody biomass was better for combined heat and power generation than non-woody biomass.…”