Early Detection of Soybean Yield Reduction Risk: SIF Technology Supports Stable Yield Management

在之前的(dí)文章中，我們介紹了(liǎo)日(rì)光誘導葉綠素(sù)熒光(guāng)（SIF）的(dí)基(jī)本(běn)原(yuán)理(lǐ)及(jí)其在森林(lín)，濕(shī)地等生(shēng)態係(xì)統(tǒng)中的廣泛應用(yòng)
。

本(běn)期我(wǒ)們(mén)將聚焦(jiāo)大豆這一重要作(zuò)物(wù)，探(tàn)討SIF技(jì)術(shù)如(rú)何通過(guò)早期監測環境(jìng)脅(xié)迫（如高(gāo)溫(wēn)，幹旱(hàn)等(děng)），來(lái)預(yù)警(jǐng)最(zuì)終的(dí)減產(chǎn)風(fēng)險，成為保(bǎo)障(zhàng)穩產管(guǎn)理(lǐ)的關鍵工(gōng)具
。

In previous articles, we introduced the basic principles of Sun-Induced Chlorophyll Fluorescence (SIF) and its broad applications in ecosystems such as forests and wetlands.

This issue focuses on the important crop of soybean, exploring how SIF technology can serve as a key tool for ensuring stable yield management by early monitoring of environmental stresses (e.g., high temperature, drought) to warn of potential yield losses.

1. SIF與(yǔ)大豆光合作(zuò)用的(dí)關係 / Relationship Between SIF and Soybean Photosynthesis

SIF是植(zhí)物吸收太(tài)陽(yáng)光後，葉(yè)綠(lǜ)素分(fēn)子(zǐ)重(zhòng)新(xīn)發射出的一(yī)小部分光(guāng)能(néng)
。它與光(guāng)合作(zuò)用(yòng)初級生產(chǎn)力（GPP）緊(jǐn)密相關(guān)，被認為(wéi)是評估GPP的有(yǒu)效替(tì)代指標(biāo)
。

SIF信(xìn)號的(dí)產生源於(yú)光合係(xì)統II（PSII）的光(guāng)化(huà)學反(fǎn)應，其強度(dù)受(shòu)到光照強度，葉綠素含量(liáng)以及光能分(fēn)配(pèi)途徑的(dí)動態(tài)調控(kòng)
。研究表明，SIF與(yǔ)GPP之間存(cún)在(zài)顯(xiǎn)著的綫(xiàn)性或(huò)非(fēi)綫性(xìng)關係(xì)，這使得SIF成(chéng)為監測(cè)植被光(guāng)合作(zuò)用的重要(yào)手段
。

由於(yú)SIF與光合(hé)作(zuò)用過程直接關(guān)聯(lián)，當(dāng)大(dà)豆遭(zāo)遇環境脅迫時(shí)，其光合(hé)機構(gòu)會受到影(yǐng)響(xiǎng)，進(jìn)而(ér)引起SIF信(xìn)號的(dí)變化(huà)，這為(wéi)利(lì)用SIF監測大豆的(dí)環境(jìng)脅(xié)迫提供(gōng)了理論(lùn)基礎(chǔ)
。

SIF is a small portion of light energy re-emitted by chlorophyll molecules after plants absorb sunlight. It is closely related to Gross Primary Production (GPP) and is considered an effective proxy for assessing GPP.

The generation of SIF signals originates from the photochemical reactions of Photosystem II (PSII). Their intensity is dynamically regulated by light intensity, chlorophyll content, and the pathways of light energy allocation (photochemistry, non-photochemical quenching, and fluorescence). Research shows significant linear or nonlinear relationships between SIF and GPP, making SIF an important means for monitoring vegetation photosynthesis.

Since SIF is directly linked to the photosynthesis process, when soybeans encounter environmental stress, their photosynthetic apparatus is affected, leading to changes in SIF signals. This provides a theoretical basis for using SIF to monitor environmental stress in soybeans.

圖：愛(ài)博能無(wú)人(rén)機載日(rì)光誘導葉綠素熒光(guāng)監(jiān)測係(xì)統，ABN-SIF-UAV
。該係統(tǒng)通(tōng)過探測日光(guāng)誘(yòu)導葉綠素熒(yíng)光（SIF），可實(shí)現對大(dà)範圍農田(tián)的無損監測，精準(zhǔn)評估作(zuò)物長勢，為病蟲(chóng)害(hài)與水肥脅迫的(dí)早期預警提供關鍵數據
。

ABN-SIF-UAV Unmanned Aerial Vehicle-borne Sun-Induced Chlorophyll Fluorescence Monitoring System by Exponentsci. This system detects Sun-Induced Chlorophyll Fluorescence (SIF), enabling non-destructive monitoring of large-scale farmland, accurately assessing crop growth status, and providing critical data for early warning of pests, diseases, and water/fertilizer stresses.

2. SIF在大豆環(huán)境(jìng)脅(xié)迫檢測中(zhōng)的應(yīng)用(yòng) / Application of SIF in Detecting Environmental Stress in Soybeans

高溫(wēn)脅迫(pò)：高溫(wēn)及其伴隨的高(gāo)水汽(qì)壓差通(tōng)常(cháng)會影響植物(wù)，但(dàn)不會引起明(míng)顯(xiǎn)的冠(guān)層結(jié)構變化(huà)或(huò)光譜(pǔ)特(tè)征改(gǎi)變(biàn)
。SIF因(yīn)其與光合作(zuò)用的聯係，能(néng)更(gēng)好地檢測這種脅迫(pò)
。例如，有研究(jiū)通過溫度自(zì)由空氣控製(zhì)增強(qiáng)（T-FACE）實驗，利用(yòng)SIF量(liáng)化了高溫(wēn)對(duì)大豆(dòu)冠(guān)層光合(hé)作用(yòng)的(dí)影響
。大豆在高熱條件下會影響比(bǐ)葉重，氣孔密(mì)度，光(guāng)合(hé)作(zuò)用(yòng)和葉(yè)綠(lǜ)素(sù)熒光(guāng)參(cān)數(shù)
。

High-Temperature Stress: High temperature and accompanying high vapor pressure deficit often affect plants without causing obvious changes in canopy structure or spectral characteristics. Due to its connection to photosynthesis, SIF can better detect such stress. For example, one study used the Temperature Free-Air Controlled Enhancement (T-FACE) experiment to quantify the impact of high temperature on soybean canopy photosynthesis using SIF. Under high-temperature conditions, soybeans experience changes in specific leaf weight, stomatal density, photosynthesis, and chlorophyll fluorescence parameters.

日光誘(yòu)導葉綠素熒(yíng)光(guāng)（SIF），SIF產額(é)，吸收性光合有效輻(fú)射(shè)（APAR），全冠層APAR吸收(shōu)比(bǐ)例（fAPAR）以及光(guāng)合有(yǒu)效(xiào)輻射(shè)（PAR）與冠層溫(wēn)度之間(jiān)的(dí)相(xiāng)關係(xì)數(shù)（r）
。

Correlation coefficients (r) between Sun-Induced Chlorophyll Fluorescence (SIF), SIF yield, Absorbed Photosynthetically Active Radiation (APAR), fraction of whole canopy APAR (fAPAR), and PAR against canopy temperature.

臭(chòu)氧脅迫(pò)：高濃度(dù)臭(chòu)氧(yǎng)會導致(zhì)大豆冠層SIF760顯著下降，特別是在(zài)生長後(hòu)期(qī)下(xià)降幅度更(gēng)大（36%），這(zhè)表(biǎo)明(míng)SIF能夠(gòu)有效捕捉(zhuō)臭氧對(duì)大(dà)豆冠層結(jié)構(gòu)和衰(shuāi)老加(jiā)速的影(yǐng)響(xiǎng)
。臭氧(yǎng)脅(xié)迫還會與輻(fú)射(shè)減少(shǎo)產(chǎn)生(shēng)協(xié)同(tóng)效應(yīng)，影響(xiǎng)大豆的葉綠素熒(yíng)光特性和(hé)產(chǎn)量
。

Ozone Stress: High ozone concentrations cause a significant decrease in soybean canopy SIF760, particularly during later growth stages (up to 36% reduction). This indicates that SIF can effectively capture ozone's impact on canopy structure and accelerated senescence in soybeans. Ozone stress also interacts with reduced radiation, affecting soybean chlorophyll fluorescence characteristics and yield.

在(zài)整(zhěng)個(gè)大豆生(shēng)長(cháng)季(jì)中(zhōng)觀測(cè)到(dào)的冠層(céng)頂部SIF760（A），光合有(yǒu)效輻射(shè)PAR（B），綠(lǜ)色植(zhí)被(bèi)光合有效(xiào)輻射吸收(shōu)比例(lì)FPARgreen（C）以及表觀(guān)SIF產率（D）的測量結果，分別對應生長在環境臭氧濃(nóng)度（白色(sè)條形）與升高(gāo)臭(chòu)氧(yǎng)濃度(dù)（灰(huī)色條形(xíng)）條件下的大豆(dòu)
。*代表(biǎo)差(chà)異顯著（P<0.05）
。

Measured top-of-canopy SIF760 (A), PAR (B), FPARgreen (C), and apparent SIF yield (D) throughout the growing season in soybeans grown under ambient O₃ (white bars) and elevated O₃ (grey bars). * indicates significant differences between treatments at each measurement date (P < 0.05).

其(qí)他脅迫(pò) / Other Stresses：

缺水(shuǐ)會(huì)迫使氣孔關(guān)閉，從(cóng)而抑製光(guāng)合作用和蒸騰作(zuò)用(yòng)
。這一過程(chéng)會(huì)引起非光化學猝滅和(hé)光合電(diàn)子(zǐ)傳遞(dì)的(dí)變化，而SIF信號對(duì)這些微(wēi)小(xiǎo)的變(biàn)化非(fēi)常(cháng)敏(mǐn)感
。

雙(shuāng)酚(fēn)A（BPA）作(zuò)為(wéi)一種環(huán)境內分泌幹(gān)擾(rǎo)物(wù)，對大豆幼(yòu)苗的生(shēng)長(cháng)，光(guāng)合作(zuò)用(yòng)和葉綠素熒(yíng)光(guāng)參(cān)數（如初始熒(yíng)光，最大(dà)光(guāng)化學效率(shuài)，PSII有(yǒu)效量(liáng)子(zǐ)產率和(hé)光(guāng)合電子(zǐ)傳(chuán)遞速率）有顯著(zhù)影(yǐng)響，SIF技術可以(yǐ)檢測這(zhè)些變化
。

Water Deficit: Water shortage forces stomatal closure, thereby inhibiting photosynthesis and transpiration. This process induces changes in non-photochemical quenching and photosynthetic electron transport, to which SIF signals are highly sensitive.

Bisphenol A (BPA): As an environmental endocrine disruptor, BPA significantly affects the growth, photosynthesis, and chlorophyll fluorescence parameters (such as initial fluorescence, maximum photochemical efficiency, effective quantum yield of PSII, and photosynthetic electron transport rate) of soybean seedlings. SIF technology can detect these changes.

日光誘導葉綠(lǜ)素熒(yíng)光（SIF）技術通過捕(bǔ)捉與(yǔ)光(guāng)合作用(yòng)機理(lǐ)直接相關的(dí)光(guāng)信號(hào)，為大豆(dòu)的環(huán)境脅迫(pò)監(jiān)測提供了一(yī)種(zhǒng)直接(jiē)，非(fēi)侵入性(xìng)的(dí)方法
。利(lì)用(yòng)這項技術(shù)，我們(mén)能(néng)夠更及(jí)時(shí)地(dì)掌握(wò)作物的(dí)健(jiàn)康狀況，為精(jīng)準農(nóng)業管理和保(bǎo)障作(zuò)物(wù)穩產(chǎn)提供(gōng)重要(yào)的技術(shù)支撐
。

Sun-Induced Chlorophyll Fluorescence (SIF) technology provides a direct, non-invasive method for monitoring environmental stress in soybeans by capturing light signals directly linked to the mechanism of photosynthesis. Utilizing this technology enables more timely assessment of crop health, offering important technical support for precision agriculture management and ensuring stable crop yields.

案(àn)例(lì)來(lái)源(yuán) /  Sources：

1. KQuantifying high‐temperature stress on soybean canopy photosynthesis: The unique role of sun‐induced chlorophyll fluorescence. (2021)

2. Quantifying high-temperature stress on canopy photosynthesis at the Temperature Free-Air Controlled Enhancement (T-FACE) experiment: the unique role of sun-induced chlorophyll fluorescence in capturing plant physiological stress. (2020)

3. Solar-induced chlorophyll fluorescence captures the effects of elevated ozone on canopy structure and acceleration of senescence in soybean. (2023)

4. Effects of bisphenol A on growth, photosynthesis and chlorophyll fluorescence in above-ground organs of soybean seedlings. (2013)