科研之友
微信
新浪微博
Facebook
分享链接
摘要
Recent trends of planting corn (Zea mays L.) at higher populations and in narrower rows could influence optimum N management. This is study investigates the effects of N rates (0-224 kg ha(-1) N plus a low rate of uniformly applied starter) and timing (at planting, V5-V7 sidedress) on corn in wide and narrow rows (76-102 cm vs. 38-51 cm) at 13 sites over 3 yr in North Carolina. Early season N uptake, grain yield, and yield components were measured. Delaying N until sidedress increased yields, but there was an interaction effect with row spacing. Yields were greater with narrow rows and sidedress N (11.7 Mg ha(-1)) than with narrow rows and all N at planting (11.0 Mg ha(-1)) or with wide rows fertilized at either time (11.0 Mg ha-1), when averaged across N rates. Three ear yield components increased in response to N fertilization, leading to a 35% yield increase. Rows per ear increased from 15.5 to 15.9 ear(-1), kernels per row increased from 27 to 32 row(-1), and individual kernel mass increased from 226 to 253 mg. Aboveground plant N uptake by the V5 to V7 growth stage was only 9 kg ha(-1), with very little additional N uptake in response to higher N rates. Sidedress N application at V5 to V7 maximized the formation of the ear yield components and grain yield for high population corn in narrow rows, but N timing did not affect yield or ear yield components of wide-row corn.
- 出版日期2014-2
