Yield and Physiological Response of Barley and Beans Grown in Artificially Compacted Soils

Three soils of the Atlantic Coastal Plain were compacted into steel drums with a vibrating probe. The physiological responses of barley and snap beans to changes in soil physical properties due to compaction were measured. On Galestown sand an increase in bulk density from 1.3 to 1.6 g. per cc. resulted in a 50% increase in yield of barley which was linearly and significantly correlated with increased available water. A 37% barley yield decrease with increasing bulk density from 1.3 to 1.65 g. per cc. on Freehold loamy sand was attributed to increased mechanical impedance. Compaction reduced barley yield on Penn silt loam, the response being correlated with oxygen diffusion. Density‐yield relations were not clear in the case of snap beans, but significant differences in concentration of maturity of the beans were observed on the Penn and Freehold soils. Hydraulic conductivity and available moisture on the sandy soils and hydraulic conductivity and oxygen diffusion rates on the finer textured soil, were found to correlate best with plant response.