Gheith E M S, El-Badry Ola Z, Lamlom Sobhi F, Ali Hayssam M, Siddiqui Manzer H, Ghareeb Rehab Y, El-Sheikh Mohamed H, Jebril Jebril, Abdelsalam Nader R, Kandil Essam E
Agronomy Department, Faculty of Agriculture, Cairo University, Giza, Egypt.
Department of Plant Production, Faculty of Agriculture Saba Basha, Alexandria University, Alexandria, Egypt.
Front Plant Sci. 2022 Jul 1;13:941343. doi: 10.3389/fpls.2022.941343. eCollection 2022.
Productivity of maize ( L.) and nitrogen use efficiency (NUE) as affected by nitrogen application levels and timing were studied. The experimental design was a three-replication randomized complete block design (RCBD). The first factor was nitrogen levels (122, 240, 288 and 336 kg N/ha) and the second factor was nitrogen timing (50% of N at sowing and 50% of N before the first irrigation; T, 50% of N at sowing and 50% of N before the second irrigation; T and 50% of N before the first irrigation and 50% of N before the second irrigation; T). Results indicated that plant height, ear length, kernel weight, number of grains/rows, number of grains/ear and grain yields all increased significantly as nitrogen levels increased and the level of 336 kg N/ha significantly exhibiting the highest values in both seasons. In terms of nitrogen application time, maize yield parameters such as plant height, ear length, kernel weight/ear, number of grains/rows, number of grains/ear and grain yield were significantly affected by nitrogen timing, with the highest values obtained at T3 while the lowest values obtained at T1 in both seasons. The interaction had a significant impact on plant height and grain yield/ha, with the tallest plants, the highest yields and its components observed at 336 kg N/ha, with 50% of N applied during the first irrigation and 50% of N applied during the second. Furthermore, under the study conditions, NUE decreased dramatically as nitrogen levels increased and increased significantly as nitrogen application time changed.
研究了施氮水平和施氮时间对玉米（L.）生产力和氮素利用效率（NUE）的影响。试验设计为三次重复的随机完全区组设计（RCBD）。第一个因素是氮水平（122、240、288和336千克氮/公顷），第二个因素是施氮时间（播种时施氮量的50%，第一次灌溉前施氮量的50%；T，播种时施氮量的50%，第二次灌溉前施氮量的50%；T，第一次灌溉前施氮量的50%，第二次灌溉前施氮量的50%；T）。结果表明，随着氮水平的增加，株高、穗长、粒重、每行粒数、每穗粒数和籽粒产量均显著增加，在两个季节中，336千克氮/公顷水平均显著表现出最高值。就施氮时间而言，玉米产量参数如株高、穗长、穗粒重、每行粒数、每穗粒数和籽粒产量受施氮时间的显著影响，在两个季节中，T3处理的值最高，T1处理的值最低。交互作用对株高和公顷籽粒产量有显著影响，在336千克氮/公顷、第一次灌溉时施氮量的50%和第二次灌溉时施氮量的50%处理下，植株最高，产量及其构成因素最高。此外，在研究条件下，随着氮水平的增加，氮素利用效率急剧下降，随着施氮时间的变化，氮素利用效率显著增加。
