Comments on "Synthetic Nitrogen Fertilizers Deplete Soil Nitrogen: A Global Dilemma for Sustainable Cereal Production," by R.L. Mulvaney, S.A. Khan, and T.R. Ellsworth in the Journal of Environmental Quality 2009 38:2295-2314/Reply to Comments on "Synthetic Nitrogen Fertilizers Deplete Soil Nitrogen: A Global Dilemma for Sustainable Cereal Production," by R.L. Mulvaney, S.A. Khan, and T.R. Ellsworth in the Journal of Environmental Quality 2009 38: 2295-2314

• Published in: Journal of environmental quality 2010-03, Vol.39 (2), p.749
• Main Authors: Powlson, D S, Jenkinson, D S, Johnston, A E, Poulton, P R, Glendining, M J, Goulding, K W T, Mulvaney, R L, Khan, S A, Ellsworth, T R
• Format: Article
• Language: English
• Subjects: Agricultural practices; Alfalfa; Carbon; Cereal crops; Corn; Crop rotation; Environmental quality; Fertilizers; Nitrogen; Oats; Soil depth; Soils; Soybeans; Sustainable production
• ISSN: 0047-2425; 1537-2537

(2009) compare soil N concentration in selected treatments of the Morrow Plots measured in 1955 and 2005, for three soil depths (0-15, 15-30, and 30-46 cm) and three crop rotations: continuous corn, corn-oats (oats replaced by soybean since 1967), and corn-oats-alfalfa hay. In the HNPK treatment, it was 336 kg ha^sup -1^ (1967-1997), reduced to 224 kg ha^sup -1^ from 1998. [...] for the last 8 yr of the study period, the rates of N applied in HNPK and NPK were the same. [...] the observation that soil N and C declines in the HNPK treatment were greater than in the unamended and NPK treatments is entirely understandable on the basis of the cessation of manure applications.