Deficit irrigation of rapeseed for water-saving: Effects on biomass accumulation, light interception and radiation use efficiency under different N rates

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• 作者：Javad Hamzei^a ; ^{j.hamzei@basu.ac.ir} ; Jalal Soltani^b
• 关键词：Rapeseed (Brassica napus) ; Nitrogen ; Light interception ; Radiation use efficiency ; Biomass accumulation
• 刊名：Agriculture ; Ecosystems & Environment
• 出版年：2012
• 期刊代码：6_01678809
• 类别：abs
• 出版时间：15 July, 2012
• 卷：155
• 期：Complete
• 页码：153-160
• 文件大小：388 K

摘要

Rapeseed is one of the most important oilseed crops worldwide and there is a high potential for expansion of its cultivation, particularly in arid and semi-arid regions. Management practice effects on radiation use efficiency (RUE) have not been well documented for rapeseed. It is thought that reduction of aboveground dry matter (ADM) in crops after decreased RUE occurs due to shortage of nitrogen and irrigation. To test this hypothesis, we applied deficit watering techniques to rapeseed with contrasting nitrogen supply. Treatments included three levels of nitrogen supply, namely low level (LN, 8 g N m^鈭?), normal level (NN, 12 g N m^鈭?) and high level of nitrogen (HN, 16 g N m^鈭?), in combination with three levels of irrigation (IR₁, 7500; IR₂, 4500; and IR₃, 3000 m³ water ha^鈭?). Then, traits of ADM, grain yield (GY), leaf area index (LAI), nitrogen nutrition index (NNI), leaf chlorophyll (SPADi), capture ratio (CR), penetration ratio (PR), reflection ratio (RR), accumulated PAR (鈭慽PAR) and RUE were measured. The ANOVA revealed that the N and irrigation treatments exerted significant effects on all traits. RUE in IR₁ and IR₂ treatments was comparable to, or higher than, that in IR₃ (0.756 and 0.745 vs. 0.477 g 渭mol^鈭?). However, the interaction of irrigation levels 脳 N rates affected only ADM, GY, 鈭慽PAR and RUE. Maximum values of these traits remained unchanged at IR₁ 脳 NN, IR₁ 脳 HN, IR₂ 脳 NN and IR₂ 脳 HN combined treatments. In conclusion, the IR₂ 脳 NN treatment can be recommended for rapeseed under field conditions in order to maximize the yield.