Root growth and nitrate utilization of maize cultivars under field conditions

摘要: In a 2-year field study conducted on high fertilized Gleyic Luvisol in Stuttgart-Hohenheim significant differences among 10 maize cultivars were observed soil nitrate depletion. The different capability of the to utilize particularly from subsoil was positively correlated with (a) shoot N uptake at maturity, and (b) root length density (Lv) layers silking. “Critical densities” for estimated by calculating rates per unit (U), subsequent calculation needed concentration solution (C1) sustain calculated U according Baldwin formula, (c) reducing measured Lv proportionate increase until equaled concentration. Uptake rate generally increased depth. cultivar Brummi (high densities depletion) 60–90 cm depth ranged 7 % (generative growth) 28 (vegetative Measured each other higher than “critical density” indicating that system examined would have been able ensure Brummi. Positive relationships between utilization as indicated correlation analysis therefore could not be explained model calculations. This might due simplifying assumptions made model, which are contrast non-ideal conditions field, namely irregular distribution roots soil, limited root/soil contact, zones activity. It is concluded experiment growing selected uptake-capacity shoots combined “high” may improve supply.