COMPARISON OF NUTRIENT SOLUTIONS FOR GROWTH OF PLANTS IN SAND CULTURE

S ummary A comparison of eight different nutrient solutions showed large differences in ability to support growth of maize, ryegrass and white clover in silica sand. Plants grown with the Ruakura solution, a solution especially designed for pasture species, consistently outyielded those grown with the other nutrient solutions. Insufficient iron was a major cause of poor growth with many of the solutions, particularly for maize. However, where deficiencies of iron were corrected, growth differences, although smaller, still persisted among the nutrient solutions. Results of tissue analysis and measurements of the solution surrounding the roots showed a considerable number of individual factors which were likely to be yield limiting.