EFFECTS OF EXCESS LEVELS OF A POLYMER AS A SOIL CONDITIONER ON YIELDS AND MINERAL NUTRITION OF PLANTS

We grew wheat (Triticum aestivum L. cv. INIA66R) and tomato (Lycopersicon esculentum Mill. cv. Tropic) in containers with a Xerorthents soil and with levels of an anionic soil conditioner far in excess of that needed for adequate stabilization of soil. The 1% rate increased the vegetative growth of plants over controls, and the 5% rate gave yields more nearly like controls. The anionic polymer decreased accumulation of the anions P and Si in all plants and decreased Mn and B in wheat only. The highest level of polymer also depressed accumulation of some of the macroelement cations. Both levels of polymer created 100% water-stable aggregates compared with only 38% in the control. The potential for toxicity of polyacrylamide soil conditioners is discussed.