ABSTRACT

This chapter discusses both the direct and the indirect effects of soil air on plants. The extreme case in the soil-air to plant relation is that in which the soil is submerged and the soil air is almost completely replaced by water. Such conditions may be permanent, intermittant, or sporadic and of short duration. It is difficult to separate the direct effects of soil air on plants from the indirect ones caused by the soil processes. It is especially difficult in the case of soil compaction and/or its flooding with water or sewage. The carbohydrate content in plants may depend on the oxygen status of the soil. The effects of deficient aeration on plants may be direct and indirect; the direct being related to the interaction of the main components of soil air with the plant roots, while indirect effects result from air-related changes occurring in the soil environment.