非充分滴灌下施氮量对棉花生长特性、产量及水氮利用率的影响

Effects of different nitrogen fertilizer levels on growth,yield,water and nitrogen use efficiency of cotton under non-sufficient drip irrigation

以新陆中54号为试材,采用裂区试验设计,主区为总灌溉量为2 800 m3·hm^(-2)(非充分滴灌)和3 800m3·hm^(-2)(常规滴灌),副区为4个施氮(纯N)水平,N0(0 kg·hm^(-2))、N1(150 kg·hm^(-2))、N2(300 kg·hm^(-2))、N3(450 kg·hm^(-2)),研究棉花在非充分滴灌条件下最佳的施氮量。结果表明:同一滴灌量下,生育进程随着施氮量的增加而明显延迟,株高、真叶数和果枝数随着施氮量的增加而增加,倒四叶宽和有效果枝数随着施氮量的增加呈先增后减的趋势;同一氮肥处理下,株高随着滴灌量的增加而增大,真叶数、倒四叶宽、茎粗随着滴灌量的增加略有降低;现蕾数、成铃数、干物质积累量、持续时间和最大积累速率随着施氮量的增加呈先升后降的趋势,以N2处理较高,生长特征值较为协调;两灌溉量间单铃重、皮棉产量及水氮利用效率差异不显著,但随着施氮量的增加其呈先增后降的趋势,以N2处理最高,分别比N0、N1、N3平均增产39.9%、20.1%、4.3%,水分利用效率分别提高了40.97%、19.02%、4.88%,氮肥利用率较N1、N3分别提高了53.91%、21.36%。因此,在南疆阿克苏地区,棉花滴灌量在2 800 m3·hm^(-2)条件下,施氮量以300 kg·hm^(-2)适宜。

The optimal amount of nitrogen fertilizer oncotton was investigated under the condition of non-sufficient drip irrigation to provide scientific basis for highly efficient use of water and fertilizer of cotton in arid regions.Xinluzhong 54 was used as test material in split plot experiment design,the total drip-irrigation amount of 2 800 m3·hm^(-2)( non full irrigation) and 3 800 m3·hm^(-2)( conventional drip irrigation) for the main plot,four nitrogen( N) level,N0( 0 kg·hm^(-2)),N1( 150 kg·hm^(-2)),N2( 300 kg·hm^(-2)),N3( 450 kg·hm^(-2)) for sub-plot.Results showed that with the same irrigation amount,the growth process prolonged significantly with the increase in nitrogen fertilization. The plant height,the number of main leaf and fruit spur increased with the increase in nitrogen fertilization. The fourth from top leaf width,and effective fruit spur number first increased and then decreased with the increase in nitrogen fertilization. With the same nitrogen fertilization,plant height increased,and the number of main leaf,the fourth from top leaf width,stem diameter slightly decreased with the increase indrip irrigation.The number of bud and boll,the accumulation amount of dry matter,time of duration and the maximum rate of accumulation of dry matter first increased and then decreased with the increase in nitrogen fertilization,which was more significantin N2,and the growth characteristic value was more coordinated in N2. The difference in single boll weight and lint yield between the two irrigation quantity was not significant,but single boll weight and lint yield firstincreased and then decreased with the increase in nitrogen fertilization. Those in N2 wasthe highest,39. 9%,20.1% and 4. 3 % higher than N0,N1,N3 respectively in average yield. Compared with N1 and N3,the water use efficiency increased by 40. 97%,19. 02% and 4. 88% respectively. The nitrogen utilization efficiency increased by53. 91% and 21. 36% respectively compared with N1 and N3. Therefore,in the Nanjiang Akesu area,drip irrigation of 2 800 m3·hm^(-2),and 300 kg·hm^(-2)nitrogen fertilization was the optimal condition for cotton.