Effects of Chlorella on Wheat Growth and Soil Properties

BIAN Jianwen, WANG Meng, LIU Baoyou, WANG Xueying, ZHANG Xingang, WANG Wenrui

PDF(1122 KB)
PDF(1122 KB)
Chinese Agricultural Science Bulletin ›› 2023, Vol. 39 ›› Issue (12) : 8-12. DOI: 10.11924/j.issn.1000-6850.casb2022-0509

Effects of Chlorella on Wheat Growth and Soil Properties

Author information +
History +

Abstract

In order to study the potential of Chlorella as bio-fertilizer, potted wheat was used as the experimental material, and the effects of Chlorella on wheat growth and soil properties were analyzed under different concentrations. The results showed that irrigation with Chlorella at wheat root could improve the growth of wheat. The plant height was increased by 4.01%-11.99%, and the fresh weight of the aboveground part was increased by 16.01%-29.42%. In addition, the content of chlorophyll a was increased by 4.90%-80.72%, the content of chlorophyll b was increased by 9.38%, and the total content of chlorophyll was increased by 11.99%-48.56%. Meanwhile, soil qualities were improved under Chlorella treatment. The organic matter of soil was increased by 5.26%-6.93%, alkali-hydrolyzed nitrogen was increased by 2.89%-10.14%, available phosphorus was increased by 3.79%-13.11%, available potassium was increased by 6.63%-13.08%, and soil pH was increased by 0.46%-1.62%. In conclusion, the application of Chlorella can not only promote the growth and biomass increase of wheat, but also improve soil quality to a certain extent.

Key words

Chlorella / wheat growth / fertilizer effect / soil properties

Cite this article

Download Citations
BIAN Jianwen , WANG Meng , LIU Baoyou , WANG Xueying , ZHANG Xingang , WANG Wenrui. Effects of Chlorella on Wheat Growth and Soil Properties. Chinese Agricultural Science Bulletin. 2023, 39(12): 8-12 https://doi.org/10.11924/j.issn.1000-6850.casb2022-0509

0 引言

为了满足人口日益增长对粮食的大量需求,在农业生产中人们使用化肥来提高粮食产量,而长期单一大量的使用化肥对土壤环境造成了严重的破坏,土壤板结、酸碱化、肥力下降等问题层出不穷,严重影响到农业的可持续发展[1]。因此化肥的减肥增效是当前农业生产的重要目标,开发新的安全生物肥料迫在眉睫。
目前,以大藻为来源的海藻肥已作为生物肥料被广泛应用于农业生产中,但受到生长地域及采收时间的限制。微藻是一类能进行光合作用的微生物(原核或真核微生物),可以生长在各种生境中,如池塘、河流、湖泊、海洋、废水和土壤等[3]。微藻能产生多种生物活性物质,如生长素、细胞分裂素、甜菜碱、氨基酸、维生素、多胺和赤霉素等[7],现开始应用于农业生产中,可作为植物生物刺激素或土壤改良剂[4-6]。但微藻在生物肥料这一领域未得到广泛应用和开发。世界已知的微藻大约有10000种左右,小球藻因其高生长速率和蛋白质含量而备受关注。
小球藻(Chlorella)为绿藻门小球藻属普生性单细胞绿藻,是一种直径大小为2~10 μm的球形单细胞淡水藻类,许多细胞结构与植物相似,光合效率高,分布极广[8]。小球藻蛋白质含量占干重的42%~58%,高浓度的碳水化合物(15%~55% DW)、脂肪(5%~40% DW)和蛋白质在动物饲料、化妆品和食物营养等方面应用广泛[8]。近年来,小球藻在农业领域的应用逐渐被探索研究。国外许多研究者进行了相关研究,KHOSSI等[9]研究发现,小球藻藻液能促进小麦的生长,相比于对照处理,小麦株高增加30%,地上部和地下部干重分别提高了22%和51%。ALOBWEDE等[10]研究发现,在温室条件下,当小球藻和螺旋藻粉施用量为4 g/kg时,与对照相比,土壤总碳提高了17%,土壤有效磷提高了约50%,铵态氮提高了8%,同时促进了小麦和豌豆的生长和产量。AGWA等[11]研究发现使用小球藻藻液浸种缩短了秋葵种子的萌发时间,加快了秋葵的成熟,提高了株高和产量,同时也改善了土壤养分,增加了土壤微生物数量。在国内,微藻在农业中的应用研究仍处于探索阶段,相关研究鲜有报道。目前研究主要集在微藻提取液或活藻营养液的应用,但若进行大规模生产,这两种使用方式存在成本高、不宜储存、保质期短等缺点,而利用异养方式培养小球藻制得藻粉,具有生长期一致、易于储存、运输方便、成本低的优点,且藻粉仍具有较好的肥效效果。
本研究探讨小球藻藻粉施用对小麦生长和土壤质量的影响,以期为小球藻在农业生产中应用提供参考与理论依据。

1 材料和方法

1.1 试验材料

供试土壤为本地荒废的农田土,采集地表10~20 cm的耕层土供盆栽试验;供试小球藻藻粉由烟台泓源生物肥料有限公司提供,采用高密度异养培养,经酶解干燥后制得粉剂。供试小麦种子为‘长丰2112’,购于种子市场。

1.2 试验设计

采用口径为230 mm、高为170 mm的带拖盘花盆,将过筛且混合均匀的土壤每盆装3 kg,挑选大小和形态一致的种子播种,每盆种植30株,种植深度为3 cm。盆栽试验在温度25℃、湿度60%左右、光暗周期16 /8 h的阳光房中进行。待小麦长出后保留20株长势基本一致的进行后续试验。
试验设置5个小球藻浓度处理,分别为0、0.125、0.25、0.5、1.0、2.0 g/L,每个处理3个重复,每隔5 d小麦根部冲施500 mL,共处理3次。种植30 d后,测定植株生长指标和土壤理化指标。植物生长指标包括鲜重、干重、株高和叶绿素含量,土壤理化指标包括土壤有机质、碱解氮、有效磷、速效钾和pH。

1.3 测定指标及方法

株高和根长采用直尺测量,鲜重和干重采用分析天平测量。叶绿素含量采用80%(体积分数)丙酮提取,参照高俊风[12]的方法进行测定。用pH计测定土壤pH;用重铬酸钾容量法测定土壤有机质含量;用碱解扩散法测定土壤碱解氮含量;用钼锑抗比色法测定有效磷含量;用火焰光度计测定速效钾含量[13]

1.4 统计与分析

采用Excel 2013整理试验数据及作图,用SPSS 20.0软件进行单因素方差显著性检验,P<0.05认为达到显著差异水平。

2 结果与分析

2.1 施用小球藻对小麦株高的影响

随着小球藻浓度的增加小麦株高逐渐增加,与对照相比,当小球藻浓度高于0.25 g/L时,对小麦株高有明显的促进作用(P<0.05),当小球藻浓度为2.0 g/L和1.0 g/L时小麦株高较高,分别增加11.99%和8.26%,其次浓度为0.5 g/L时,增加4.01%,而当小球藻浓度小于等于0.25 g/L时,对小麦株高促进作用不显著(P>0.05)(图1)。
图1 施用小球藻对小麦株高的影响
不同字母表示处理间差异显著(P<0.05),下同

Full size|PPT slide

2.2 施用小球藻对小麦地上部鲜重和干重的影响

施用小球藻后地上部鲜重和干重随小球藻浓度的增加而增加(图2)。与对照相比,当小球藻浓度为2.0 g/L和1.0 g/L时小麦地上部鲜重较高,分别增加29.41%和27.38%,其次是浓度为0.5 g/L,增加16.01%,各组处理对小麦地上部鲜重促进作用均显著(P<0.05)。而当小球藻浓度为0.125 g/L和0.25 g/L时,对小麦地上部鲜重促进作用不显著(P>0.05)。同样,对于地上部干重的影响,与鲜重一致。当小球藻浓度高于0.25 g/L时促进作用明显(P<0.05),分别增加11.63%、16.92%和19.15%,而当小球藻浓度小于等于0.25 g/L时,对地上部干重促进作用不显著(P>0.05)。
图2 施用小球藻对小麦地上部鲜重和干重的影响

Full size|PPT slide

2.3 施用小球藻对小麦叶绿素含量的影响

图3所示,施用小球藻后,小麦叶片中叶绿素a和总叶绿素的含量,随小球藻浓度的增加,显著增加(P<0.05)。当小球藻浓度为2.0 g/L时,叶绿素a和总叶绿素含量最高,与对照相比,分别增加80.72%和48.56%,当小球藻浓度为0.125 g/L时,叶绿素a含量增加4.90%,总叶绿素含量最低。当小球藻浓度为1.0 g/L时,叶绿素b含量增加9.38%,其他处理组叶绿素b含量均低于对照。
图3 施用小球藻对小麦叶片叶绿素含量的影响

Full size|PPT slide

2.4 施用小球藻对土壤理化性质的影响

图4所示,施用小球藻后土壤有机质、碱解氮、有效磷、速效钾和土壤pH均有不同程度的增加,其中当小球藻浓度为2.0 g/L时,土壤有机质和碱解氮显著增加(P<0.05),与对照相比,土壤有机质增加6.93%,碱解氮增加10.14%。土壤有效磷在小球藻浓度为0.125 g/L和2.0 g/L时增加明显(P<0.05),分别增加3.78%和13.11%,而其他浓度下低于对照。施加小球藻处理中土壤速效钾明显高于对照处理(P<0.05),浓度为0.125 g/L时增加6.63%,2.0 g/L时增加13.05%,但不同浓度小球藻处理组之间无明显差异(P>0.05)。土壤pH随着小球藻浓度的增加pH也逐渐升高,且小球藻浓度越高差异越显著(P<0.05),施用1.0 g/L的小球藻后,土壤pH增长1.52%。
图4 施用小球藻对土壤理化指标的影响

Full size|PPT slide

3 讨论

3.1 小球藻对小麦生长的影响

目前在国外基于微藻的生物刺激素的研究已在不同作物上进行了应用,如水稻、番茄、黄瓜、小麦和玉米等作物[14-15],这说明利用微藻作为生物肥料的可能性。但微藻促进植物生长方面的生理和分子机制的研究较少,可能的机制主要是:(1)微藻分泌的活性物质被植物吸收后提高其光合效率,促进叶绿素和类胡萝卜素的合成而延迟植物衰老;(2)通过向根际释放低分子量和高分子量有机化合物,提高根际微生物群落(根际细菌和菌根)的活性;(3)调节根系结构,提高根系对宏观和微量养分的吸收和吸收效率[16-17]
小球藻是目前规模化大量生产的主要绿藻,属于可持续能源物质。其含有大量的营养物质,能够分泌促进植物生长的活性物质,如植物生长素、细胞分裂素、甜菜碱、多糖、氨基酸等[18],这些生物活性物质在植物发育、植物代谢和植物生长调节等方面具有重要的作用,可以促进幼苗生长,影响果实品质以及作物产量[19-20]。此外,存在于根际的一些细菌也可以与小球藻一起被消耗利用,以提高土壤肥力。
本研究结果表明,添加小球藻后小麦株高增加了4.01%~11.99%,地上部鲜重增加了16.01%~29.42%,地上部干重增加了11.63%~19.15%。这与KHOLSSI等[9]研究结果一致。此外,小麦叶片中叶绿素含量也不同程度的增加,叶绿素a增加了4.90%~80.72%,叶绿素b增加了9.38%,总叶绿素增加了11.99%~48.56%。这与FAHEED等[21]研究结果一致。

3.2 小球藻对土壤理化性质的影响

植物生长与土壤肥力密切相关,土壤肥力的改善都反映在植物生长中。微藻是土壤微生物的重要组成部分,研究微藻对土壤生态环境至关重要。微藻具有固氮和固碳作用,研究表明微藻能够改善土壤质量,如增加土壤有机碳、氮磷钾含量及土壤微生物的活性[22-24]。此外,微藻分泌的胞外聚合物(大多数为多糖)能够增强土壤团聚体的稳定性和土壤保水性。在治理土壤荒漠化过程中微藻也是不可或缺的,藻类可与细菌、真菌、地衣和苔藓等形成土壤生物结皮,这对于水土保持、流沙固定、其他生物类群的生长繁殖以及土壤微生态系统的最终形成具有重要的促进作用[25]
本研究结果表明,接种小球藻后,土壤有机质和碱解氮含量显著增加,这与ALOBWEDE等[10]研究结果一致。土壤有机质的增加,可能是因为施入含有丰富的氨基酸、低聚肽等有机物的小球藻粉后,促进了微生物的扩繁,进而导致土壤中有机质含量的增加。土壤碱解氮含量的增加可能是由于小球藻的加入促进了根际细菌数量的增加,而根际细菌中可能含有自由存活的固氮细菌,也有学者认为小球藻对土壤氮素的增加可能是由于其吸收了空气中的氨氮和氮氧化物[26]。同时,观察到的随着小球藻浓度增加土壤pH逐渐增加,可能是由于小球藻中存在大量的有机质,同时藻生物质中蛋白质在降解过程中释放NH4-N引起的[27]

4 结论

小球藻是一种可再生资源,具有一定的肥效作用,能够促进小麦的生长、改善土壤质量。本研究发现小球藻大于0.25 g/L时对小麦生长具有促进作用,当施用浓度为2 g/L时效果最明显,小麦株高、地上部鲜重、地上部干重、叶绿素a和总叶绿素含量分别增加11.99%、29.41%、19.15%、80.72%、48.56%。同时,土壤有机质增加6.93%、碱解氮增加10.14%,速效钾增加13.06%、有效磷增加13.11%、土壤pH也不同程度的增加。针对小球藻在不同作物上的应用及其促生机制,仍需要进一步探究。对土壤环境的影响机制也是有待进行更深入的研究。

References

[1]
石元亮, 王玲莉, 刘世彬, 等. 中国化学肥料发展及其对农业的作用[J]. 土壤学报, 2008, 45(5):852-864.
[2]
范丙全. 我国生物肥料研究与应用进展[J]. 植物营养与肥料学报, 2017, 23(6):1602-1613.
[3]
CHANDA M, MERGHOUB N, El ARROUSSI H. Microalgae polysaccharides: the new sustainable bioactive products for the development of plant bio-stimulants?[J]. World journal of microbiology and biotechnology, 2019, 35(11):1-10.
[4]
MARTINI F, BEGHINI G, ZANIN L, et al. The potential use of Chlamydomonas reinhardtii and Chlorella sorokiniana as biostimulants on maize plants[J]. Algal research, 2021, 60:102515.
[5]
SILVA T A, CASTRO J S, RIBEIRO V J, et al. Microalgae biomass as a renewable biostimulant: meat processing industry effluent treatment, soil health improvement, and plant growth[J]. Environmental technology, 2021:1-17.
[6]
KAPOOREAPOORE R V, WOOD E E, LLEWELLYN C A. Algae biostimulants: a critical look at microalgal biostimulants for sustainable agricultural practices[J]. Biotechnology advances, 2021, 49:107754.
[7]
GONZÁLEZ-PÉREZ B K, RIVASIVAS-CASTILLO A M, VALDEZ-CALDERÓN A, et al. Microalgae as biostimulants: a new approach in agriculture[J]. World journal of microbiology and biotechnology, 2022, 38(1):1-12.
[8]
SAFI C, ZEBIB B, MERAH O, et al. Morphology, composition, production, processing and applications of Chlorella vulgaris: a review[J]. Renewable and sustainable energy reviews, 2014, 35:265-278.
[9]
KHOLSSIHOLSSI R, MARKS E A N, MIÑÓN J, et al. Biofertilizing effect of Chlorella sorokiniana suspensions on wheat growth[J]. Journal of plant growth regulation, 2019, 38(2):644-649.
[10]
ALOBWED E E, LEAKE J R, PANDHAL J. Circular economy fertilization: testing micro and macro algal species as soil improvers and nutrient sources for crop production in greenhouse and field conditions[J]. Geoderma, 2019, 334:113-123.
[11]
AGWA O K, OGUGBUE C J, WILLIAMS E E. Field evidence of Chlorella vulgaris potentials as a biofertilizer for Hibiscus esculentus[J]. International journal of agricultural research, 2017, 12(4):181-189.
[12]
高俊凤. 植物生理学实验指导[M]. 北京: 高等教育出版社, 2006.
[13]
鲍士旦. 土壤农化分析第3版[M]. 北京: 中国农业出版社, 2000.
[14]
BUMANDALAI O, TSERENNADMID R. Effect of Chlorella vulgaris as a biofertilizer on germination of tomato and cucumber seeds[J]. International journal of aquatic biology, 2019, 7(2):95-99.
[15]
YERRAPRAGADA L, ELHAFIZ A A. Chlorella vulgaris and Chlorella pyrenoidosa live cells appear to be promising sustainable biofertilizer to grow rice, lettuce, cucumber and egg plant in the UAE soils[J]. Recent research in science and technology, 2015, 7:14-21.
[16]
CHIAIES E P, CORRADO G, COLLA G, et al. Renewable sources of plant biostimulation: microalgae as a sustainable means to improve crop performance[J]. Frontiers in plant science, 2018, 9:1782.
Plant biostimulants (PBs) attract interest in modern agriculture as a tool to enhance crop performance, resilience to environmental stress, and nutrient use efficiency. PBs encompass diverse organic and inorganic substances (humic acids and protein hydrolysates) as well as prokaryotes (e.g., plant growth promoting bacteria) and eukaryotes such as mycorrhiza and macroalgae (seaweed). Microalgae, which comprise eukaryotic and prokaryotic cyanobacteria (blue-green algae), are attracting growing interest from scientists, extension specialists, private industry and plant growers because of their versatile nature: simple unicellular structure, high photosynthetic efficiency, ability for heterotrophic growth, adaptability to domestic and industrial wastewater, amenability to metabolic engineering, and possibility to yield valuable co-products. On the other hand, large-scale biomass production and harvesting still represent a bottleneck for some applications. Although it is long known that microalgae produce several complex macromolecules that are active on higher plants, their targeted applications in crop science is still in its infancy. This paper presents an overview of the main extraction methods from microalgae, their bioactive compounds, and application methods in agriculture. Mechanisms of biostimulation that influence plant performance, physiology, resilience to abiotic stress as well as the plant microbiome are also outlined. Considering current state-of-the-art, perspectives for future research on microalgae-based biostimulants are discussed, ranging from the development of crop-tailored, highly effective products to their application for increasing sustainability in agriculture.
[17]
RONGA D, BIAZZI E, PARATI K, et al. Microalgal biostimulants and biofertilisers in crop productions[J]. Agronomy, 2019, 9(4):192.
Microalgae are attracting the interest of agrochemical industries and farmers, due to their biostimulant and biofertiliser properties. Microalgal biostimulants (MBS) and biofertilisers (MBF) might be used in crop production to increase agricultural sustainability. Biostimulants are products derived from organic material that, applied in small quantities, are able to stimulate the growth and development of several crops under both optimal and stressful conditions. Biofertilisers are products containing living microorganisms or natural substances that are able to improve chemical and biological soil properties, stimulating plant growth, and restoring soil fertility. This review is aimed at reporting developments in the processing of MBS and MBF, summarising the biologically-active compounds, and examining the researches supporting the use of MBS and MBF for managing productivity and abiotic stresses in crop productions. Microalgae are used in agriculture in different applications, such as amendment, foliar application, and seed priming. MBS and MBF might be applied as an alternative technique, or used in conjunction with synthetic fertilisers, crop protection products and plant growth regulators, generating multiple benefits, such as enhanced rooting, higher crop yields and quality and tolerance to drought and salt. Worldwide, MBS and MBF remain largely unexploited, such that this study highlights some of the current researches and future development priorities.
[18]
LU Y, XU J. Phytohormones in microalgae: a new opportunity for microalgal biotechnology[J]. Trends in plant science, 2015, 20(5):273-282.
[19]
TAHA T M, YOUSSEF M A. Improvement of growth parameters of Zea mays and properties of soil inoculated with two Chlorella species[J]. Report and opinion, 2015, 7(8):22-27.
[20]
边建文, 崔岩, 杨宋琪, 等. 微藻生物肥料的农业应用研究进展[J]. 中国土壤与肥料, 2020(5):1-9.
[21]
FAHEED F A, FATTAH Z A. Effect of Chlorella vulgaris as biofertilizer on growth parameters and metabolic aspects of lettuce plant[J]. Journal of agriculture and social sciences, 2008, 4(4):165-169.
[22]
ABDEL-RAOUF N. Agricultural importance of algae[J]. African journal of biotechnology, 2012, 11(54):11648-11658.
[23]
RENUKA N, GULDH E A, PRASANNA R, et al. Microalgae as multi-functional options in modern agriculture: current trends, prospects and challenges[J]. Biotechnology advances, 2018, 36(4):1255-1273.
Algae are a group of ubiquitous photosynthetic organisms comprising eukaryotic green algae and Gram-negative prokaryotic cyanobacteria, which have immense potential as a bioresource for various industries related to biofuels, pharmaceuticals, nutraceuticals and feed. This fascinating group of organisms also has applications in modern agriculture through facilitating increased nutrient availability, maintaining the organic carbon and fertility of soil, and enhancing plant growth and crop yields, as a result of stimulation of soil microbial activity. Several cyanobacteria provide nitrogen fertilization through biological nitrogen fixation and through enzymatic activities related to interconversions and mobilization of different forms of nitrogen. Both green algae and cyanobacteria are involved in the production of metabolites such as growth hormones, polysaccharides, antimicrobial compounds, etc., which play an important role in the colonization of plants and proliferation of microbial and eukaryotic communities in soil. Currently, the development of consortia of cyanobacteria with bacteria or fungi or microalgae or their biofilms has widened their scope of utilization. Development of integrated wastewater treatment and biomass production systems is an emerging technology, which exploits the nutrient sequestering potential of microalgae and its valorisation. This review focuses on prospects and challenges of application of microalgae in various areas of agriculture, including crop production, protection and natural resource management. An overview of the recent advances, novel technologies developed, their commercialization status and future directions are also included.Copyright © 2018 Elsevier Inc. All rights reserved.
[24]
GAUTAM K, RAJVANSHI M, CHUGH N, et al. Microalgal applications toward agricultural sustainability: recent trends and future prospects[J]. Microalgae, 2021:339-379.
[25]
吴丽, 张高科, 陈晓国, 等. 生物结皮的发育演替与微生物生物量变化[J]. 环境科学, 2014, 35(4):1479-1485.
[26]
NAYAK M, SWAIN D K, SEN R. Strategic valorization of de-oiled microalgal biomass waste as biofertilizer for sustainable and improved agriculture of rice (Oryza sativa L.) crop[J]. Science of the total environment, 2019, 682:475-484.
[27]
PASSOSASSOS F, FERRER I. Microalgae conversion to biogas: thermal pretreatment contribution on net energy production[J]. Environmental science & technology, 2014, 48(12):7171-7178.
Share on Mendeley
PDF(1122 KB)

Collection(s)

Triticum aestivum L.

354

Accesses

0

Citation

Detail

Sections
Recommended

/