ABSTRACT

Efficient nitrogen (N) management is considered one of the most important strategies for increasing sustainable crop yield along with maximizing nitrogen use efficiency (NUE). The aim of the study was to evaluate the effects of liquid urea (LU) application frequency on the growth, yield, and NUE of grain corn (Zea mays L.). The application frequencies urea were two split (2S) applied equally at 10 and 28 days after sowing (DAS), three split (3S) applied equally at 10, 40, and 65 DAS, and four split (4S) applied equally at 10, 30, 50, and 70 DAS organized by following randomized completely block design with four replicates. Results showed that stem diameter, ear length, fresh and dry stover weight, fresh cob weight, husk weight, kernel row/cob, and grain yield were higher in the LU treatments than granular urea (GU). Among all the treatments, the grain corn receiving LU3S had the highest stem diameter (2.03 cm), cob weight (248.25 g), 100 grain weight (29.08 g), N uptake (133.96 kg/ha), and NUE (72.84%). The corn grain yield of LU3S was 6.77 t/ha compared to the GU2S, which was only 4.95 t/ha. The N uptake along with NUE was significantly higher in LU3S treatment than other treatments. The results of this study suggest that the yield and NUE of corn were significantly affected by the urea source and application frequency of LU while LU3S was the most efficient treatment for maximizing the growth and yield of grain corn grown in tropical soil.

摘要

高效的氮 (N) 管理被认为是提高可持续作物产量以及最大限度地提高氮利用效率 (NUE) 的最重要策略之一。本研究的目的是评估液体尿素 (LU) 施用频率对谷物玉米 ( Zea mays ) 生长、产量和 NUE 的影响。L.)。尿素的施用频率为在播种后 10 天和 28 天（DAS）平均施用两次（2S），在播种后 10、40 和 65 天平均施用三次（3S），在 10 天平均施用四次（4S）， 30、50 和 70 DAS 按照具有四个重复的随机完全区组设计进行组织。结果表明，LU处理的茎粗、穗长、鲜干秸秆重、鲜穗轴重、果壳重、仁行/穗轴和籽粒产量均高于颗粒尿素（GU）。在所有处理中，LU3S处理的籽粒玉米茎粗（2.03 cm）、穗轴重（248.25 g）、百粒重（29.08 g）、N吸收（133.96 kg/ha）和NUE（72.84%）最高. LU3S 的玉米产量为 6.77 吨/公顷，而 GU2S 仅为 4.95 吨/公顷。LU3S 处理中的 N 吸收和 NUE 显着高于其他处理。本研究结果表明，LU 的尿素来源和施用频率显着影响玉米的产量和 NUE，而 LU3S 是最大化热带土壤中生长的谷物玉米生长和产量的最有效处理。