Competitive N uptake between rice and weedy rice
Competitive N uptake between rice and weedy rice
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DOI：
10.1016/j.fcr.2006.03.009
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发表时间：
2006-10-30
影响因子：
5.8
通讯作者：
Black, Howard
中科院分区：
文献类型：
--
作者：
Burgos, Nilda R.;Norman, Richard J.;Black, Howard
杂草稻，红米（Oryza sativa L.），在美国南部和世界各地的水稻产区是一个严重的问题。它竞争生产投入，增加杂草控制成本，降低产量和粮食品质，并可能消除经济效益。研究比较了水稻和杂草稻在竞争条件下对肥料氮的相对回收效率、水稻和杂草稻对氮的积累和分配以及水稻和杂草稻对氮的利用效率。实验于1999年和2000年在美国阿肯色州斯图加特的水稻研究和推广中心进行。试验采用裂区-裂区设计，以施氮量（0、5、10、15和20 g/m ~（-2））为主区，以水稻和杂草稻为次区，以地上部组织类型（下叶、叶鞘、顶叶和穗）为次区。“Drew”稻和strawhull杂草稻交替行条播。在种植后26-27天，将金属环打入土壤中，以每个处理建立两个微区。用N-15标记的尿素被施加到干土壤中的微区在永久性洪水之前。在颗粒起始（PI）和抽穗后2周（WAH）收集数据。无论生长阶段，Drew稻和杂草稻产生相同的地上部生物量时，不施肥N。在PI，这两种植物类型表现出二次响应肥料N相对于生物量生产。然而，在对N的反应是积极的情况下，杂草稻积累了42 g地上部生物量g（-1）的添加N，而Drew的地上部生物量积累为33 g g（-1）的添加N。总体而言，杂草稻积累更多的生物量比水稻后，增加氮肥。随着生长季节的推进，Drew和杂草稻之间地上部生物量生产的差异变大。在2 WAH，杂草稻继续产生更多的生物量在最高的N率，但德鲁没有实质性的反应，增加N。杂草稻的秆生物量（占总生物量的55%）高于Drew（48%）。下部叶占总地上部生物量的16-19%，旗叶占6%，其余为圆锥花序。在一般情况下，杂草稻积累更多的N，响应较高的N率，积累更多的N在穗，并有较高的N利用效率（生物量生产）比德鲁水稻。杂草稻能积累肥料N的63%，2 WAH。我们的结论是，杂草稻响应较高的N率，需要更多的N，并具有较高的N利用效率的生物量生产比水稻。当稻田杂草稻严重时，控制杂草稻应是优先事项。否则，施用氮肥（比杂草稻防治更昂贵）是没有利润的。(c)2006 Elsevier B. V.保留所有权利。
Weedy rice, red rice (Oryza sativa L.), is a serious problem in rice-producing areas of the southern U.S. and various regions worldwide. It competes for production inputs, increases weed control cost, reduces yield and grain quality, and could eliminate economic returns. Research was conducted to compare: (i) the relative efficiencies of rice and weedy rice in recovering fertilizer N under a competitive condition, (ii) the accumulation and partitioning of N by rice and weedy rice, and (iii) the N use efficiency of rice and weedy rice. Experiments were conducted in 1999 and 2000 at the Rice Research and Extension Center, Stuttgart, Arkansas, USA. Experimental units were arranged in a split-split plot design with N rate (0, 5, 10, 15, and 20 g m(-2)) as mainplot, plant type (rice and weedy rice) as subplot, and type of shoot tissue (lower leaf, leaf sheath, top leaf, and panicle) as the sub-subplot. 'Drew' rice and strawhull weedy rice were drill-seeded in alternate rows. At 26-27 days after planting, metal collars were driven into the soil to establish two microplots per treatment. Urea labeled with N-15 was applied to dry soil in the microplots immediately before permanent flood. Data were collected at particle initiation (PI) and 2 weeks after heading (WAH). Regardless of growth stage, Drew rice and weedy rice produced equivalent shoot biomass when no fertilizer N was added. At PI, both plant types showed a quadratic response to fertilizer N with respect to biomass production. However, where the response to N was positive, weedy rice accumulated 42 g shoot biomass g(-1) of added N whereas shoot biomass accumulation for Drew was 33 g g(-1) of added N. Overall, weedy rice accumulated more biomass than rice upon addition of N fertilizer. The difference in shoot biomass production between Drew and weedy rice became larger as the growing season progressed. At 2 WAH, weedy rice continued to produce more biomass at the highest N rate, but Drew did not respond substantially to added N. Weedy rice had more culm biomass (55% of total) than Drew (48%). Lower leaves constituted 16-19% of total shoot biomass, flag leaf 6%, and panicles comprised the rest for both plant types. In general, weedy rice accumulated more N, responded to higher N rates, accumulated more N in the panicles, and had a higher N use efficiency (for biomass production) than Drew rice. Weedy rice can accumulate 63% of fertilizer N, 2 WAH. We conclude that weedy rice responds to higher N rates, takes up more N, and has higher N use efficiency for biomass production than rice. Whenever a rice field is heavily infested with weedy rice, controlling weedy rice should be the priority. Otherwise, fertilizer N application (which is more expensive than weedy rice control) is not profitable. (c) 2006 Elsevier B.V. All rights reserved.