TY - JOUR
T1 - Soil fungal distribution and functionality as affected by grazing and vegetation components of integrated crop-livestock agroecosystems
AU - Davinic, M.
AU - Moore-Kucera, J.
AU - Acosta-Martínez, V.
AU - Zak, J.
AU - Allen, V.
N1 - Funding Information:
The authors would like to thank Dr. Lisa Fultz for assistance with sample collection and valuable comments during manuscript preparation, Jon Cotton for assistance with GC-analysis of FAME samples, Phil Brown and Paul Green for plot maintenance at the TTEF, and Rick Kellison for valuable input on the history and management of the TAWC sites. Funding was provided by the USDA-SSARE grant (Project number LS10-229).
PY - 2013/4
Y1 - 2013/4
N2 - Integrated crop and livestock (ICL) agroecosystems are characterized by a mixture of perennial or annual vegetation grazed by livestock and annual harvested crops. Compared to annual crops, ICLs hold the potential to enhance soil organic matter (OM) inputs, carbon sequestration, nutrient cycling, and water conservation. Soil fungi play an essential role in the transformation of OM and nutrients and soil structure stabilization; however their specific role in OM transformations in ICL agroecosystems has not been studied. This study evaluated mycorrhizal and saprophytic fungal populations (via fatty acid methyl ester profiles; FAME) and saprophytic fungal functionality (via FungiLog analysis) under two ICL agroecosystems and a continuous cotton (Gossypium hirsutum L.) system in the Southern High Plains of the U.S. The first ICL system included non-irrigated perennial native grasses, an annual cotton and foxtail millet (Setaria italica) rotation and deficit-irrigated 'WW-B. Dahl' old world bluestem (Bothriochloa bladhii; OWB). The second ICL agroecosystem consisted of deficit-irrigated OWB and bermudagrass (Cynodon dactylon). The effect of grazing by cattle was evaluated via grazing exclusion areas. Abundance of saprophytic fungal FAMEs (10-26% of total FAMEs) and mycorrhizal FAMEs (2-24% of total FAMEs) were higher under ICLs compared to the continuous-cotton system at 0-5. cm. Overall, vegetation impacted the distribution of the fungal FAME markers, whereas the fungal saprophytic functionality was more sensitive to grazing. Perennial vegetation of ICLs was associated with an increase in fungal markers (saprophytic and mycorrhizal) as well as increased soil OM content. Greater utilization of multiple C sources and increased saprophytic fungal functional indices were found under cotton, non-grazed perennial vegetation (with exception of bermudagrass) and the rotation under millet. Among the grazed perennial vegetation, bermudagrass showed the highest fungal FAMEs abundance and functional diversity values. These fungal improvements were also reflected in the highest OM content under this grass, potentially indicating improved sustainability under the OWB and bermudagrass agroecosystem.
AB - Integrated crop and livestock (ICL) agroecosystems are characterized by a mixture of perennial or annual vegetation grazed by livestock and annual harvested crops. Compared to annual crops, ICLs hold the potential to enhance soil organic matter (OM) inputs, carbon sequestration, nutrient cycling, and water conservation. Soil fungi play an essential role in the transformation of OM and nutrients and soil structure stabilization; however their specific role in OM transformations in ICL agroecosystems has not been studied. This study evaluated mycorrhizal and saprophytic fungal populations (via fatty acid methyl ester profiles; FAME) and saprophytic fungal functionality (via FungiLog analysis) under two ICL agroecosystems and a continuous cotton (Gossypium hirsutum L.) system in the Southern High Plains of the U.S. The first ICL system included non-irrigated perennial native grasses, an annual cotton and foxtail millet (Setaria italica) rotation and deficit-irrigated 'WW-B. Dahl' old world bluestem (Bothriochloa bladhii; OWB). The second ICL agroecosystem consisted of deficit-irrigated OWB and bermudagrass (Cynodon dactylon). The effect of grazing by cattle was evaluated via grazing exclusion areas. Abundance of saprophytic fungal FAMEs (10-26% of total FAMEs) and mycorrhizal FAMEs (2-24% of total FAMEs) were higher under ICLs compared to the continuous-cotton system at 0-5. cm. Overall, vegetation impacted the distribution of the fungal FAME markers, whereas the fungal saprophytic functionality was more sensitive to grazing. Perennial vegetation of ICLs was associated with an increase in fungal markers (saprophytic and mycorrhizal) as well as increased soil OM content. Greater utilization of multiple C sources and increased saprophytic fungal functional indices were found under cotton, non-grazed perennial vegetation (with exception of bermudagrass) and the rotation under millet. Among the grazed perennial vegetation, bermudagrass showed the highest fungal FAMEs abundance and functional diversity values. These fungal improvements were also reflected in the highest OM content under this grass, potentially indicating improved sustainability under the OWB and bermudagrass agroecosystem.
KW - Agroecoystem
KW - Arbuscular mycorrhizae
KW - C Utilization profiles
KW - Ester-linked fatty acid methyl esters
KW - Grazing
KW - Saprophytic fungi
UR - http://www.scopus.com/inward/record.url?scp=84875275729&partnerID=8YFLogxK
U2 - 10.1016/j.apsoil.2013.01.013
DO - 10.1016/j.apsoil.2013.01.013
M3 - Article
AN - SCOPUS:84875275729
SN - 0929-1393
VL - 66
SP - 61
EP - 70
JO - Applied Soil Ecology
JF - Applied Soil Ecology
ER -