Effect of Soil Acidity and Nitrogen on Yield and Elemental Concentration of Bush Bean, Carrot, and Lettuce1

Abstract

Abstract Bush beans ( Phaseolus vulgaris L.), carrots ( Daucus carota L.), and lettuce ( Lactuca sativa L.) were grown for 3 years on soils amended with S or lime and N fertilizer. Yields of all crops increased with lime application but response to N varied among crops and years. Lettuce head weight tended to increase with N application at pH greater than 6.0, but it decreased with N application at lower pH levels. A soil pH of 5.6 to 6.4 was optimal for carrots and beans, and of 6.1 to 6.6 for lettuce. Plant tissue K and Mg concentrations were not affected by soil pH or N rate. Phosphorus and Ca concentration of plant tissue generally increased with lime application. Plant tissue Zn and Mn concentration usually decreased with increasing soil pH between pH 5.1 and 6.4. The reduction in bean and lettuce leaf Mn concentration between pH 5.1 and 5.7 ranged from 30 to 71%. Low bean yields at pH 5.1 were possibly caused by a combination of Mn toxicity and P deficiency. Failure of lettuce to head at low pH may have been caused by Mn toxicity.