Table 1 Description of study sites, cropping systems and treatments.
Field Studies | Location | Treatments and abbreviations |
|---|---|---|
Grassland pasture (GP) 1931-present | Oregon State University’s Columbia Basin Agricultural Research Center (CBARC) at Pendleton, OR. (45°42′N, 118°36′W, elevation 438 m asl) | • GP: The grassland pasture has been under undisturbed/unmanaged mixed species native perennial grass dominated by |
◦ Bluebunch wheatgrass (Agropyron spicatum Pursh) | ||
◦ Idaho fescue (Festuca idahoensis Pursh) | ||
Wheat-Pea (WP) 1963- current | CBARC at Pendleton, OR. (45°42′N, 118°36′W, elevation 438 m asl) | • CTWP: Chisel tilling to 20 cm depth (twice) in fall + sweeping to 5 cm depth + roto-tilling twice to 10 cm depth |
• PTWP: Moldboard plowing to 20 cm depth in fall + disc harrowing to 10 cm depth (twice) + roller disc harrowing | ||
• NTWP: No tillage + rotary mowing of wheat stubble + sweeping to 5 cm depth | ||
Crop Residue Management (CR) 1931—current | CBARC at Pendleton, OR. (45°42′N, 118°36′W, elevation 438 m asl) | • NB90: No residue burning + 90 kg N ha−1 (UAN) + moldboard plowing to 20 cm depth + harrowing to 10 cm depth + rod-till weeding (3 times) |
• NBFM: No residue burning + Farmyard Manure (FYM) at rate of 11.2 Mg ha–1 yr–1 (47.5% DM, 0.85 Mg C ha–1, and 70 kg N ha–1 yr−1) + moldboard plowing to 20 cm depth + harrowing 10 cm + rod-till weeding (3 times) | ||
• SB90: Spring burning of crop residue + 90 kg N ha−1 (UAN) + moldboard plowing to 20 cm depth + harrowing to 10 cm depth + rod-till weeding (3 times) | ||
• NBPV: No residue burning + Pea Vine at a rate of 1.12 Mg ha–1 yr–1 (Dry matter 87.8%, 0.41 Mg C ha–1 yr–1, and 18.5 kg N ha–1 yr–1) + moldboard plowing to | ||
• 20 cm depth + harrowing 10 cm + rod-till weeding (3 times) | ||
Wheat-tillage (WT) 2003—present | CBARC at Moro, OR. 45°29′N and 120°43′W, elevation 575 m asl) | • NTWC: No tillage + drill seeding of wheat (240 seeds m−2) + winter pea cover crop |
• NTWF: No tillage + drill seeding of wheat (240 seeds m−2) + fallowing for 14 months | ||
• TTWF: Chisel tilling to 15 cm depth + sweeping to 10 cm depth + rod-till weeding to 10 cm depth (3 times) + drill seeding of wheat (240 seeds m−2) + fallowing for 14 months |
