Effect of specific leaf nitrogen content on photosynthesis of sugarcane
Effect of specific leaf nitrogen content on photosynthesis of sugarcane
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DOI：
10.1111/j.1744-7348.1997.tb05160.x
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发表时间：
1997-10-01
影响因子：
2.6
通讯作者：
Pammenter, NW
中科院分区：
文献类型：
--
作者：
Allison, JCS;Williams, HT;Pammenter, NW
在实验室中，无论是4个月大的甘蔗植株还是8个月大的甘蔗植株，新梢上最年轻的完全出苗的叶片的光合作用速率(P)随着比叶片含氮量(SLN)的增加而近似线性增加，范围为1.0~1.7gm(-2)；在80~1600mmolm(-2)的范围内，光合作用有效辐射(PAR)通量密度越高，增加的速度越大。在接受150 kg N ha(-1)标准肥料的大田作物中，绿叶冠层的SLN随着深度的增加或多或少呈线性下降，15wk龄时从顶部的1.7g m(-2)下降到底部的约1.0g m(-2)，到45周时随着时间的推移从冠层顶部到底部逐渐减少到1.2~0.85g m(-2)。在顶层追施300N ha(-1)的情况下，SLN随时间的下降幅度较小，到第45周时从冠层顶部到底部的SLN下降到1.3~0.9g m(-2)。模型的计算表明，在只接受标准肥料的作物中，从wk 15到wk 45，冠层总磷下降约25%，冠层净磷下降约30%；在作物接受额外氮素的情况下，计算的降幅分别约为17%和20%。似乎有必要改变品种类型，以便有利可图地利用增施氮肥。
In the laboratory, rate of photosynthesis (P) of the youngest fully emerged leaf lamina on a shoot, whether taken from a 4 or 8 month old sugarcane plant, increased approximately linearly with specific leaf nitrogen content (SLN) from < 1.0 to c. 1.7 g m(-2); the rate of increase was greater the higher the incident photosynthetically active radiation (PAR) flux density, over the range 80 to 1600 mu mol m(-2) s(-1). In a field crop receiving standard fertiliser, including 150 kg N ha(-1), SLN of the green leaf canopy decreased more or less linearly with depth, from >1.7 g m(-2) at the top to c. 1.0 g m(-2) at the bottom at 15 wk of age, and progressively with time to 1.2 to 0.85 g m(-2) from top to bottom of the canopy by week 45. Where an extra 300 N ha(-1) were applied in top-dressings, the decrease in SLN with time was somewhat smaller, to 1.3 to 0.9 g m(-2) from top to bottom of the canopy by week 45. Calculations with a model, using the data from laboratory and field, suggest a decrease of about 25% in canopy gross P and about 30% in canopy net P from wk 15 to wk 45 in the crop receiving standard fertiliser only; the calculated decreases where the crop received additional nitrogen were about 17% and 20% respectively. There would seem to be a need for a change in type of cultivar to make profitable use of augmented nitrogen fertiliser.