Genotypic variability among peanut (Arachis hypogea L.) in sensitivity of nitrogen fixation to soil drying

Peanuts (Arachis hypogea L.) are often grown on sandy soils and drought stress can be a major limitation on yield. In particular, loss in nitrogen fixation activity associated with soil drying might be limiting due to the need for high nitrogen amounts in both vegetative tissues and seeds of peanut. This study examined the response of nitrogen fixation of intact plants of seventeen peanut genotypes when subjected to soil drying in pots over approximately a 2-wk period. A large range in the sensitivity of nitrogen fixation to soil drying was observed among the seventeen genotypes. Genotype ICGV86015, in particular, was found to have nitrogen fixation that was especially tolerant of soil drying. Significant positive (P?<?0.0001) correlation was found between the soil water content at which nitrogen fixation began decreasing and the amino acid concentration in the leaves of severely stressed plants.