Effects of Casuarina-amended soil on selected soil and citrus properties

Abstract

Effects of beefwood (Casuarina cunninghamiana Miq.) leaf residues were evaluated on soil pH, soil electrical. conductivity, growth and foliar nutrient ions of rough lemon (Citrus jambhiri Hush) seedlings in two greenhouse experiments. Casuarina- amended soil reduced soil pH, root weight, shoot weight, plant length, shoot/root ratio, foliar Ca/Mg and Mg/K ratios of citrus seedlings, but increased soil electrical conductivity and imbalances of certain chemical nutrient ions. Because dried leaves were used, it was postulated that Casuarina effects were initiated by allelopathic chemical compounds leached out of leaves into the rhizosphere.