Potato Tubers and Soil Aeration1
- J. W. Cary2
Potato plants are more sensitive to soil oxygen stress than many other common crops. Some recent literature suggests this may be due to a relatively high oxygen requirement for tuber growth, rather than a greater requirement for the roots per se. Consequently, the oxygen consumption of growing potato tubers (Solanum tuberosum cv. Russet Burbank) was measured in the field on a Portneuf silt loam (coarse-silty, mixed, mesic Durixerallic Calciorthid). Typical rates were 15 µg 0, cm−2 hr.−1. A simple method for measuring soil oxygen diffusion rates in the laboratory was then devised, utilizing an oxygen meter and a stream of N2 gas. Soil conditions such as texture, bulk density, compaction around expanding tubers, oxygen sinks and water contents were studied with respect to their relative effects on limiting oxygen uptake by tubers. The minimum soil oxygen diffusion coefficient required for adequate tuber aeration is quite sensitive to the soil respiration rate and the depth of soil covering the tubers. Water contents of “field capacity” or a little wetter were found to not necessarily inhibit tuber aeration in loamy sand, silt loam, and silty clay soils provided the bulk densities were not excessive; i.e., greater than 1.6 or 1.7 Mg m−3 in the silt loam. Reduced aeration due to compaction around growing tubers is a possibility in the silty clay, but probably not in well drained silt loam or loamy sand. The criteria for a minimum acceptable soil oxygen diffusion coefficient must be based on tuber periderm permeability, soil ethylene generation, and other anaerobic soil reactions, as well as tuber respiration per se.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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