EFFECT OF SOIL TYPE AND AERATION UPON ROOT SYSTEMS OF CERTAIN AQUATIC PLANTS

Abstract

It is well known that the amount and movement of soil air are important factors in plant development. Because of the fact that many crop and aquatic plants are often forced to develop under conditions of minimal soil aeration, many investigations have been undertaken to determine the effects of restricted soil oxygen availability (1, 5, 7, 8, 14, 19, 20, 24). Such studies have disclosed that aeration is important in root respiration (8, 12, 20) , nutrient absorption (5, 6, 18, 20), rate of elongation (2, 6, 7, 8, 13, 21, 24), development of hair roots (11, 23, 24), aerenchyma formation (3, 16, 21), adventitious root development (10, 24, 25), as well as in modifications of the gross anatomy of the entire root system (6, 8, 9, 24). The many papers reviewed by Clements (8) indicate that the role of oxygen in root activity is a primary factor influencing, and in wet soils controlling, the functions of the root system that may determine the destiny of the plant. But few studies (2, 4, 17) have been made of root response in greatly increased soil aeration, although some data are available on the effects of culture solution aeration (6, 13, 18). This report embodies results of an experiment to determine the effects of soil aeration, increased well above the maximum usually encountered in nature, on several species of plants with relatively low oxygen requirements.