Submitted to: Columbia Basin Agricultural Research Annual Report
Publication Type: Experiment Station
Publication Acceptance Date: 3/25/2008
Publication Date: 6/10/2008
Citation: Williams, J.D. 2008. Soil loss from long-term winter-wheat/summer fallow residue and nutrient management experiment at Columbia Basin Agricultural Research Center, Pendleton, Oregon. In 2008 Dryland Agricultural Research Annual Report SR ---, ed. D.S. Long, S.E. Petrie and P.M. Frank, __ - __. Oregon State University Agricultural Experiment Station in cooperation with USDA-ARS, Corvallis, Oregon.
Interpretive Summary: Changes in soil properties resulting from management practices are often not readily apparent for decades. Agricultural researchers initiated a cropping system study in 1931 at the Columbia Basin Agricultural Research Center in 1931 to evaluate the effects of fertilization and residue management. The research reported here evaluated the influence a number of those treatments had on the ability of soil to absorb water from natural rainfall. Runoff and sediment sample were collected for three years, from 1998 through 2000. Soil erosion and water loss were greatest from treatments that received no fertilizer and the crop residues were burned. Maintaining residue and soil nutrient levels are critically important for soil and water conservation.
Technical Abstract: Changes in soil property resulting from crop production practices are not often readily apparent after a few years or decades. The objective of the research reported here was to evaluate soil erodibility in treatments representing past and current cultural practices in a winter wheat–fallow field experiment established in 1931 near Pendleton, OR. Five treatments were evaluated: 1) fall burned residue/0 lb N/ acre/crop (no fertilizer), 2) spring burned residue/0 lb N/acre/crop (no fertilizer), 3) spring burned residue / 80 lb N/acre/crop commercial fertilizer, 4) residue not burned/80 lb N/acre/crop commercial fertilizer, and 5) residue not burned/100 lb N/acre/crop from manure. All treatments were moldboard plowed by multiple passes with secondary tillage equipment. Weirs, stage recorders, and sediment samplers were used to collect data from January through March of 1998, 1999, and 2000. Grab samples (1-quart) were collected to confirm digital stage data. Measured soil erosion increased from plots with standing stubble (0.04 tons/acre/year), to plots in crop with manure and commercial fertilizer amendments with and without the crop residue burned (0.38 tons/acre/year), to plots in crop with crop residue burned and no fertilizer (1.47 tons/acre/year). These results provide direct evidence of the relationship between reduced soil organic matter and increasing erodibility, and demonstrates the importance of maintaining soil organic matter levels in semiarid dryland soils.