Analysis of yield constraints and seasonal solar radiation and temperature limits for stable cultivation of dry direct-seeded rice in northeastern Japan
Analysis of yield constraints and seasonal solar radiation and temperature limits for stable cultivation of dry direct-seeded rice in northeastern Japan
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DOI：
10.1016/j.fcr.2023.108896
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发表时间：
2023-03-16
影响因子：
5.8
通讯作者：
Hasegawa, Toshihiro
中科院分区：
文献类型：
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作者：
Namikawa, Mari;Matsunami, Toshinori;Hasegawa, Toshihiro
旱直播水稻种植是农民降低劳动力成本的重要选择，特别是在日本东北部。然而，低和可变的产量限制了它在这个凉爽的温带地区的传播。灌浆期的气象条件是影响水稻产量的主要制约因素，但其对作物生长发育的限制作用在数量上仍知之甚少。目的：通过研究小穗密度、冠层覆盖度和太阳辐射等源、库相关因子之间的定量关系，确定冷凉地区水稻产量的限制因子。我们试图提供一个框架，估计季节性的最新限制抽穗期，一个重要的决定因素，适合种植季节的温度或太阳辐射conditions.Methods：我们使用了4个品种不同的氮制度（3盛冈和5花卷，都在岩手县，日本）在干直播水稻的田间试验数据。利用灌浆期颖花密度和冠层太阳辐射截获量进行多元回归分析，分析其对产量的影响。我们使用结构方程模型来解释N，气候和品种成熟度对粮食产量的影响，通过调节冠层覆盖在抽穗期和小穗密度的模型。根据气温或太阳辐射推算出保证一定产量水平的最迟抽穗期。结果：颖花密度和冠层太阳辐射截获量可解释产量变异的82%。结构方程模型分析表明，抽穗期源相关冠层覆盖对产量的影响大于库相关小穗密度。抽穗期作物氮素含量对籽粒产量有显著影响，且对冠层覆盖度的影响大于对小穗密度的影响。在过去的10年中，盛冈县根据太阳辐射估算的旱直播稻季节最迟抽穗期比根据气温估算的平均早2.5天，这表明太阳辐射在确定旱直播稻适宜地区方面的重要性。通过考虑灌浆期的冠层覆盖和太阳辐射条件来提高源容量是日本东北部旱直播稻成功传播的关键。含义：我们确定的产量限制和太阳辐射和温度限制的生长季节，可以帮助当地的推广服务，指示合适的地区和品种的旱直播水稻。太阳辐射限制生长季节的估计是这项研究中的一个新发现。
Context: Dry direct-seeded rice cultivation is an important option for farmers to reduce labor costs, particularly in northeastern Japan. However, low and variable yields limit its dissemination in this cool temperate zone. Meteorological conditions during the grain-filling period pose the major constraints on yield, but the limitations they impose on crop development remain poorly understood quantitatively.Objective: We aimed at determining factors limiting rice production in a cool region by examining the quanti- tative relationships among the sink- and source-related factors, including spikelet density, canopy cover, and solar radiation. We attempted to provide a framework to estimate the seasonal latest limit of heading date, an important determinant for suitable cropping seasons based on temperature or solar radiation conditions.Methods: We used field experimental data of four cultivars with different nitrogen regimes (3 in Morioka and 5 in Hanamaki, both in Iwate Prefecture, Japan) on dry direct-seed rice. We performed multiple regression using spikelet density and canopy solar radiation interception during grain filling to analyze their effect of grain yield. We used structural equation modeling to develop a model explaining the effects of N, climate, and cultivar maturity on grain yield through regulation of canopy cover at the heading stage and spikelet density. We derived the seasonal latest heading date for securing a certain yield level based on air temperature or solar radiation.Results: Spikelet density and canopy solar radiation interception explained 82% of the variation in grain yield. Structural equation modeling revealed that grain yield was affected more by source-related canopy cover at heading than by sink-related spikelet density. Crop nitrogen content at heading strongly affected grain yield, and its effect appeared to be stronger on canopy cover than on spikelet density. For the past 10 years, the seasonal latest heading date estimated from solar radiation for dry direct-seeded rice in Morioka was on average 2.5 days earlier than that estimated from air temperature; this suggests the importance of solar radiation in determining suitable areas for dry direct-seeded rice.Conclusions: Enhancing source capacity by considering canopy cover and solar radiation conditions during the grain-filling period is key to successful dissemination of dry direct-seeded rice in northeastern Japan. Implications: Our determination of yield constraints and of solar radiation- and temperature-limited growing seasons can assist local extension services by indicating suitable areas and cultivars for dry direct-seeded rice. The estimation of the solar radiation-limited growing season is a novel finding in this study.