Effects of Nitrogen Fertilization Combining with Complementary Irrigation at Different Growth Stages on Development and Yield of Winter Wheat

ZHENG Huiling; WU Jicheng; PAN Xiaoying; LI Xuejun; HAN Weifeng

Abstract：The field experiment was conducted to study the effects of applying nitrogen fertilizer and complementary irrigation at different growth stages on the growth and yield of winter wheat varieties Aikang 58 and Zhoumai 18 in Tongxu county. Six fertilization treatments were designed, i. e. no topdressing,once topdressing at returning green stage to jointing stage or at flowering stage to filling stage, and twice topdressings at returning green stage plus filling stage, jointing stage plus filling stage or returning green stage to jointing stage plus flowering stage. The water treatments were set in 3 patterns, including severe water stress ( 50% to 55% of filed capacity ) , mild stress ( 65% to 75% of filed capacity) and full irrigation(75% to 85% of filed capacity ) . The main results showed that the models of nitrogen fertilization plus complementary irrigation had the positive effect on plant height, spike length, spikelet number and grain number per spike. The volume of sterility spike of Aikang 58 reduced under mild stress and full irrigation conditions,while that of Zhoumai 18 reduced under severe stress condition. There was an obvious increase tendency of 1 000-grain weight. The spike rate of Aikang 58 was higher than that of Zhoumai 18 . The mild stress gave the highest yields in both Zhoumai 18 and Aikang 58 , followed by full irrigation, and the severe stress was the lowest. Compared with no fertilization,the grain yield increased by 0 . 78%—9 . 39% for Zhoumai 18 and by 7 . 06%—11 . 15% for Aikang 58 in severe stress condition,it increased by 1. 76%—6. 25% for Zhoumai 18 and by 1. 01%—13. 44% for Aikang 58 in full irrigation, while it increased by 0. 53%—4. 14% for Zhoumai 18 and by 6. 01%—12. 94% for Aikang 58 in mild stress treatment. The yield of Zhoumai 18 under full irrigation and mild stress condition increased by 6. 83%—13. 33% and 12. 24%—19. 74%, respectively, compared with that of severe stress,and it under mild stress increased by 4. 13%—9. 41% compared with that of full irrigation. The yield of Aikang 58 under full irrigation and mild stress condition were 5 . 54%—14 . 18% and 11 . 29%—15. 56% higher than that of severe stress,respectively,while it under mild stress was -0. 75%—6. 70%higher than that of full irrigation. For Zhoumai 18, the best treatments came from topdressing twice at returning green stage plus flowering stage,or topdressing once in returning green to jointing period,while for Aikang 58,the best treatment came from topdressing once from flowering to filling stage or topdressing twice at jointing stage plus filling stage. This suggested that the control time of water and nitrogen fertilizer was different between the two varieties.