Late-season nitrogen applications improve grain yield and fertilizer-use efficiency of dry direct-seeded rice in the tropics
Late-season nitrogen applications improve grain yield and fertilizer-use efficiency of dry direct-seeded rice in the tropics
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DOI：
10.1016/j.fcr.2019.01.010
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发表时间：
2019-03-01
影响因子：
5.8
通讯作者：
Kato, Yoichiro
中科院分区：
文献类型：
--
作者：
Liu, Hongyan;Won, Phyo L. P.;Kato, Yoichiro
高效的氮（N）管理在水稻种植中发挥着重要作用。以前在热带地区的研究主要集中在插秧水稻穗萌发前的分裂氮应用。在这项研究中，我们在菲律宾国际水稻研究所的田间试验中，在干季和湿季研究了干直播稻穗萌发和开花时追肥对产量和肥料利用率的影响。两个高产籼稻品种（Rc222 和 Rc282）在四种分施氮肥施用方案和不补充氮肥的对照下进行条播。即使总氮输入量不变，分施氮肥的施用时间也会显着影响谷物产量。抽穗期晚季施氮可使旱季增产 6%（0.49 t ha(-1)），湿季增产 7%（0.49 t ha(-1)）。随着生长后期施氮比例的增加，氮回收效率也随之提高。晚季施氮相对于早季施氮（播种到穗开始）的产量优势可能归因于延迟衰老（在成熟时保持更多和更绿的叶子）、更高的冠层光同化、更大的籽粒灌浆和更高的收获指数。我们的结果强调了热带低地条件下旱直播稻晚季施氮的重要性。营养阶段的最佳 split-N 方案可能取决于季节或温度状况，因此该主题需要进行额外的研究。
Efficient nitrogen (N) management plays an important role in rice cultivation. Previous studies in the tropics mainly focused on split-N applications before panicle initiation in transplanted rice. In this study, we examined the effects of top-dressing at panicle initiation and flowering of dry direct-seeded rice on yield and fertilizer-use efficiency in field experiments at the International Rice Research Institute, the Philippines, in the dry and wet seasons. Two high-yielding indica cultivars (Rc222 and Rc282) were drill-seeded under four split-N application regimes and a control with no supplemental N. The timing of the split-N applications significantly affected grain yield, even though the total N input was unchanged. The late-season N application at heading increased yield by 6% (0.49 t ha (-1)) in the dry season and 7% (0.49 t ha( -1)) in the wet season. The N recovery efficiency also increased with an increasing proportion of N applied at later growth stages. The yield advantage of the late-season N application over the early-season N application (seeding to panicle initiation) may be attributable to delayed senescence (maintenance of more and greener leaves toward maturity), higher canopy photoassimilation, greater grain-filling, and a higher harvest index. Our results underline the importance of late-season N application in dry direct-seeded rice under favorable lowland conditions in the tropics. The optimal split-N regimes during the vegetative stage may depend on the season or temperature regime, so this subject requires additional investigation.