Forage Growth and Yield Components as Influenced by Subsurface Compaction
1998
Mapfumo, E. | Chanasyk, David S. | Naeth, M Anne | Baron, Vern S.
Subsurface soil compaction is a global problem that causes reduced plant growth and yield. The objective of this study was to evaluate responses of various growth and yield components of smooth bromegrass (Bromis inermis L. cv. Magna) and alfalfa (Medicago sativa L. cv. Rambler) to subsurface compaction of sandy loam and clay loam soils. Regression analysis indicated that all growth variables measured (shoot biomass, root biomass, number of alfalfa branches, number of smooth bromegrass tillers per plant, and leaf blade or leaflet width and length) had a negative relationship with soil bulk density in a linear nature. However, these growth responses varied in their sensitivity to subsurface compaction. For alfalfa, the most sensitive variable was the number of tertiary branches; for smooth bromegrass, shoot biomass was most sensitive. Leaf blade or leaflet length was the least sensitive variable to subsurface compaction. The study is unique in that it provides response curves for various plant growth responses, an assessment of the sensitivity of these parameters to subsurface compaction, and a data base for modeling these relationships. This study also provides Plant-based indicators that should be related to soil-based indicators of compaction problems such as bulk density and soil strength, which are often used to determine the extent of compaction.
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