Changes in nitrogen concentrations of corn leaves near silking time1
作者:
N. M. El‐Hout,
A. M. Blackmer,
期刊:
Communications in Soil Science and Plant Analysis
(Taylor Available online 1990)
卷期:
Volume 21,
issue 1-2
页码: 169-178
ISSN:0010-3624
年代: 1990
DOI:10.1080/00103629009368222
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
Precision in tissue testing to characterize the nitrogen (N) status of corn (Zea maysL.) is more important than ever before because of current concerns about the effects of N fertilizers on environmental quality. This study was conducted to assess the importance of errors associated with differences in physiological age of plants when plots receiving various rates of N fertilizer are sampled at a single time during the period of silk emergence. Ear leaf samples were collected at four times between early and late silking from five experiments at different locations in Iowa during 1987. Nitrogen deficiencies delayed silking by less than 2 days. After adjustments for delays in the onset of silking, the rates of silk emergence were similar for all N rates. Rapid rates of silk emergence indicated that it is practically impossible to sample leaves at a specific silking percentage such as 50 or 75%. Leaf N concentrations were not significantly influenced by time of sampling during the period of silk emergence. However, variability in N concentrations during the sampling period indicated that the practice of sampling leaves from all plots within a site at one time is more appropriate than the practice of sampling plots at the same percentage silking.
点击下载:
PDF (305KB)
返 回