氮素对滨海盐土棉花产量、品质及生物量的影响

Effect of N Application Rate on Growth, Yield and Fiber Quality of Cotton Grown in Saline Coastal Land

为研究不同施氮量对滨海盐土花后棉株生物量、生物量累积特征及其与产量、品质的关系,于2010年和2012年在江苏滨海盐土设置了氮肥水平试验。结果表明：在0-600 kg·hm-2范围内施氮量越大棉株总生物量累积越多,而皮棉产量2010年和2012年分别在施氮375 kg·hm-2和300 kg·hm-2时达到最大;成铃数在施氮300-375 kg·hm-2范围内达到最大;铃重和衣分随施氮量增加而增加,达到最大值后（≥300 kg·hm-2）差异不显著。在300-375 kg·hm-2施氮量范围内纤维比强度最高;高氮有利于上部、顶部果枝纤维长度、比强度、伸长率的提高和马克隆值的优化,但显著降低中下部果枝棉纤维比强度,导致中部纤维马克隆值变劣、下部果枝纤维伸长率下降,说明高氮对中下部果枝棉纤维品质的形成利弊各半,适量高氮可提高上部及顶部果枝产量、品质。在滨海盐土条件下,利于产量、品质及氮素利用效率提高的适宜施氮量为375 kg·hm-2。

Field experiments were carried out at Dafeng experimental station （33.2~N, 120.5~E） in 2010 and 2012 to study the ef- fects of N application rates on cotton growth, cotton yield and fiber quality by applying six levels （0, 150, 300, 375,450, 600 kg·hm-2） of N fertilization in the saline coastal soil. The results showed that： in the 0-600 kg·hm-2 application range, the plant biomass increased with the increasing of N application rate. The highest cotton yield in 2010 and 2012 were obtained under the 375 and 300 kg. hm 2 nitrogen application rate, respectively. For yield components, the highest boll number was obtained under 300 and 375 kg-hm-2 nitrogen application rates; Boll weight and lint percentage increased with the increase in nitrogen applica- tion rate at the 0-300 kg-hm-2 levels, and then maintained a steady level at the 300-600 kg. hm-2 N application rates. The high- est fiber strength was obtain in 300 and 375 kg·hm-2 nitrogen application treatments. High nitrogen application rate （〉 375 kg. hm 2） increased the fiber length, strength, elongation ratio, and optimized micronaire value of bolls on upper and top fruiting branches; while it was disadvantageous to fiber quality of bolls on middle and bottom fruiting branches. Taken together, we con- eluded that using N fertilizer at an application rate of 375 kg. hm-2 could balance the requirements of high yield, high quality and high N efficiency in saline coastal land around the experimental station.