Does long-term center-pivot irrigation increase soil carbon stocks in semi-arid agro-ecosystems?

摘要: Abstract This study was conducted to determine the effect of center-pivot irrigation management on soil organic carbon and inorganic stocks in semi-arid agroecosystems. We sampled two locations Central Great Plains, USA: an area near Imperial, Nebraska a more arid Otis, Colorado. At both locations, three different agroecosystems were sampled: non-cultivated native grassland (NG), irrigated (CP) adjacent dryland (DL) cultivated system. All soils classified as Aridic, Pachic or Calcidic Argiustoll. Soil (SOC) (SIC) analyzed at 0–5, 5–20, 20–50 50–75 cm depths. Although significantly greater SOC found surface (0–20 cm) layers CP compared DL systems when entire 0–75 profile considered, increased only Imperial site (on average 7626 g m− 2 versus 6637 g 6769 g 5698 g Otis). C soils, but did not differ between systems. Over profile, differences SIC depth important than changes storage by 0–20 cm depth. Further, though highly variable, accounted for nearly 50% total Otis 30% Imperial. Large proportions these lands are most likely due cultivation-induced properties, water regime carbonate-forming ion concentrations. These factors must be considered accurately assess management-induced effects carbon.