ABSTRACT

Carbon (C) inputs, soil C and Nitrogen (N), biomass C and N, and pH of several different cropping systems are shown in Table 5. In general, annual cropping favors greater soil C and N retention than does wheat/fallow rotation. The total C/N ratio in soil is generally higher and biomass C/N ratio lower in cultivated soil than in pasture soil. The different N rates created a pH difference that currently ranges from 5.2 for low N to 4.6 for high N. This site currently serves as a cereal monoculture baseline for comparing changes in crop rotation systems. The Pendleton Agricultural Research Center was established in 1929 as a branch station of Oregon State University. It is presently known as the Columbia Basin Agricultural Research Center, and is administered by the OSU Agricultural Experiment Station. The Columbia Plateau Conservation Research Center, administered by USDA-ARS, is immediately adjacent. Research facilities are shared jointly by the staff of both agencies.