Growth traits and mineral concentrations of maize hybrids grown on unlimed and limed acid soil

Abstract

Growing crop plants tolerant to acid soils is an alternative for successful production on acid soils with limited inputs, especially lime. Acid soil‐ or aluminum (Al)‐tolerant plants offer considerable protection against soil acidity problems. Thirteen maize (Zea mays L.) hybrids developed for production under various environmental conditions were grown (greenhouse) on two acid soils (unlimed and limed) to determine differences among hybrids for growth traits, mineral acquisition, and relative tolerance to acid soil. Porters soil induced greater acid soil stress on maize than did Lily soil, although shoot/root dry matter (DM) ratios were affected more in plants grown on Lily than on Porters soil. Shoot and root DM and total root length (RL) over all hybrids followed sequences of Limed Lily ≥ Limed Porters > Unlimed Lily > Unlimed Porters, and the trait with the greatest variation among hybrids was total RL. Specific RL (total RL/root DM) over all hybrids followed a sequence of Limed Lily=Limed Porters=Unlimed Lily>Unlimed Porters, with relatively small variations among hybrids. Shoot DM/RL among hybrids followed a sequence of Unlimed Porters ≥ Unlimed Lily > Limed Lily = Limed Porters, and had the least variation among hybrids. Two Brazilian hybrids (HD 91102 and HD 9176) had highest DM and total RL to indicate relatively high tolerance to acid soil stresses, while other hybrids (ten from the United States and one from Brazil) had relatively small differences for growth traits to indicate moderate to low tolerance to acid soils. Although genotypes differed widely for mineral element concentrations, no significant differences in mineral elements between more and less tolerant genotypes were noted.