Interactions of nitrogen sources and excess nickel on bush beans

Abstract

Bush bean (Phaseolus vulgaris L. cv. Improved Tendergreen) plants were grown in a glasshouse in 3700 ml nutrient solutions for 15 days with three nitrogen sources and different levels of NiSO₄. All NH₄ ⁺ and urea treatments received CaCO₃ (10 g/3700 ml) in the nutrient solution to protect against excess acidity. In general, plants receiving the NH₄ ⁺ source of N had less growth than those receiving urea or NO₃ ^‐ and 5 X 10^‐4 M Ni treatments greatly inhibited growth. There was, however, no indication of interactions of N source and Ni on yield. Plants receiving NH₄ ⁺ and urea had higher Ni concentrations than NO₃ ^‐ plants. Nickel resulted in decreased Fe in trifoliate leaves but not in primary leaves and the reverse occurred in roots. There was no interaction of Ni and Fe in roots but there was a Mh‐Ni‐N‐source interaction in roots.

Key words:

• Urea
• nitrate‐nitrogen
• ammonium‐nitrogen
• iron
• phosphorus