Plant ecology

Progress is reported in the following areas of research: effects of chromium toxicity on bush bean plants; role of synthetic chelating agents in mineral cycling; use of waste pyrites from mine operations on highly calcareous soil; roots of higher plants as a barrier to translocation of metals; nitrogen cycle in the northern Mohave desert; plant productivity and nutrient interrelationships of perennials; effects of copper, cobalt, cadmium, zinc, nickel, and chromium on growth and mineral concentration in chrysanthemum; plant uptake of 239Pu, 240Pu, and 241Am through roots from soils containing aged fallout materials; estimated inventory of plutonium and uranium radionuclides for vegetation in aged fallout areas; and temperature and water relations and photosynthesis in desert plants