[1] Norwegian Ctr Organ Agr, N-6630 Tingvoll, Norway
[2] Norwegian Inst Bioecon NIBIO, Dept Grain & Forage Seed Agron, N-1431 As, Norway
[3] Swedish Univ Agr Sci SLU, Dept Soil & Environm, Skara, Sweden
[4] State Res Inst, Inst Soil Sci & Plant Cultivat, Dept Syst & Econ Crop Prod, PL-24100 Pulawy, Poland
[5] Aarhus Univ, Dept Agroecol, DK-8830 Tjele, Denmark
[6] Res Inst Organ Agr FiBL, Dept Soil Sci, CH-5070 Frick, Switzerland
[7] CIFA, Cantabrian Agr Res & Training Ctr, Muriedas 39600, Cantabria, Spain
[8] Norwegian Univ Life Sci NMBU, Fac Environm Sci & Nat Resource Management MINA, N-1430 As, Norway
[9] Norwegian Inst Bioecon NIBIO, Dept Res, N-1431 As, Norway
[10] Texas A&M, Energy Inst, College Stn, TX 77845 USA
[11] Swedish Univ Agr Sci SLU, Dept Crop Prod Ecol, Uppsala, Sweden
[12] Craibstone Estate, SRUC, Aberdeen AB21 9YA, Scotland