SOIL ACIDITY AND LIME RESPONSES IN THE PACIFIC NOTHWEST

Authors: CARTER, PAUL - WA STATE UNIV EXT; BROWN, TABITHA - WA STATE UNIV; Porter, Lyndon; Huggins, David; WYSOCKI, DON - OREGON STATE UNIV; KOENING, RICHARD - WA STATE UNIV

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/27/2006
Publication Date: 11/15/2006
Citation: Carter, P., Brown, T., Porter, L., Huggins, D.R., Wysocki, D., Koening, R. 2006. SOIL ACIDITY AND LIME RESPONSES IN THE PACIFIC NOTHWEST. ASA-CSSA-SSSA Annual Meeting Abstracts. Published online. http:a-c-s.confex.com/crops/2006am/techprogram/p23914.htm.

Interpretive Summary:

Technical Abstract: Soil quality and conservation is improved with minimum or no-tillage farming practices. Soils of the Palouse region of Washington, Oregon, and Idaho have developed stratified layers of acidity when tillage has been reduced or eliminated. Some soil pHs have become strongly acidic (4.4-5.0) in the upper 10 cm; however, it is not known whether this acid layer is impacting crop yields. The objective of this research was to determine the influence of lime rate on wheat, pea, and other rotational crop yields and, if necessary, to develop lime recommendations. On-farm trials were established in fields under continuous no-till or reduced-tillage cropping. Treatments include a non-treated control, elemental sulfur application at 2240 kg/ha, and applications of pelletized lime at rates of 2240 to 11200 kg/ha. Soil samples were collected at 0 to 15 cm and 15 to 30 cm increments, and in 1-cm increment to a depth of 15 cm to characterize initial soil pH conditions. Initial soil pHs (0 to 15-cm depth) ranged from 4.9 to 5.6. Detailed (1 cm increment) sampling indicated an acidic band at the 2 to 8 cm depth at no-till locations. Soil pH in this acid band was as low as 3.9. Wheat and pea yield responses to lime application have been small and inconsistent.