Effects of amino acids and casein on copper uptake from soil by chicory (Cichorium intybus L. cv. Grasslands Puna)

Abstract

A greenhouse pot trial was conducted to investigate the effect of addition of amino acids and casein to Cu fertilisers on Cu uptake by chicory (Cichorium intybus L. cv. Grasslands Puna) plants. Irrespective of the forms and rates of Cu applied, the addition of amino acids and casein had no significant effects on chicory shoot dry weight. CuSO4 resulted in significantly higher shoot Cu accumulation than Cu(OH)2. Addition of histidine (His), methionine (Met), aspartic acid (Asp) and casein to Cu(OH)2 significantly increased Cu uptake at 100 mg Cu/kg soil treatments. Total accumulation of Cu from casein + Cu was significantly higher than from Met + Cu and Cu alone at 50 mg Cu as CuSO4/kg soil treatments. At the rate of 100 mg Cu as CuSO4/kg soil, the addition of His and casein resulted in significantly higher total shoot Cu accumulation than the addition of Met, Asp and CuSO4 alone. When Cu was supplied as Cu(OH)2, addition of His, Met, Asp and casein increased Cu uptake by 2.86-8.85, 3.81-6.19, 3.81-12.39 and 9.52- 15.04% respectively. The corresponding values for CuSO4 with the addition of His, Met, Asp and casein were 10.88-14.60, 4.08-4.32, 3.24-6.80 and 20.41-21.08% respectively. These results suggest that the addition of amino acids or casein to Cu fertilisers can increase chicory Cu uptake, but the agronomic value of the mixtures needs further investigation. Keywords: additives, amino acids, casein, chicory (Cichorium intybus L), copper fertilisers, copper uptake