Abstract:

Graphene is now widely used in agricultural production because of its unique structure and excellent properties. To investigate the effects of graphene on soil nutrients， enzyme activities and maize root development， the pot experiment using ‘Zhengdan 958’ as the test material was carried out to examine the effects of single-layer graphene （TS） and few-layer graphene （TF） at 0 （CK）， 25， 50， 100 and 150 g·kg^-1 on the transformation of soil nutrients and the root development of maize seedlings， respectively. The results showed that， compared with the control （CK）， the soil available nutrient content increased significantly with the increase of graphene concentration and reached the maximum at the concentration of 150 g·kg^-1， in which， the available nitrogen， available phosphorus and available potassium of single-layer graphene treatment significantly increased by 21.85%， 76.56% and 30.69%， and those of few-layer graphene treatment significantly increased by 23.05%， 82.16% and 47.20%， respectively. Meanwhile， the addition of graphene also contributed to the increase of soil enzyme activity， but the soil enzyme activity showed a trend of increasing firstly and then decreasing with increasing concentration， and the sucrase and urease activities of few-layer of graphene at a concentration of 50 g·kg^-1 significantly increased by 6.67% and 21.26% compared to CK. Low levels （25， 50， and 100 g·kg^-1） promoted inhibition at high level （150 g·kg^-1）. Low levels of graphene inhibited the rate of superoxide anion （{\mathrm{O}}_{\mathrm{2}}^{·-}） production and the accumulation of malondialdehyde （MDA）， and increased the contents of soluble protein and proline， which helped to timely scavenge reactive oxygen species， inhibit membrane lipid synthesis， lessen the harm done to the root system. In conclusion， the applied properly graphene could enhance soil nutrients， boost soil enzyme activity， and encourage the development of maize plants. And the effect of few-layer graphene was better than that of the single-layer graphene.

Key words: graphene, maize, root, soil nutrient, enzyme activity

摘要：

石墨烯因具有独特结构及优异性能，在农业生产中被广泛应用。为探究石墨烯对土壤养分、酶活性及玉米根系发育的影响，以‘郑单958’为试材，进行盆栽试验，研究单层石墨烯（TS）和少层石墨烯（TF）分别在0（CK）、25、50、100和150 g·kg^-1用量时对土壤养分转化及玉米苗期根系生长的影响。结果表明，与对照（CK）相比，随石墨烯施用量的增加，土壤速效养分含量呈显著增加趋势，在施用量为150 g·kg^-1时达最大值，其中，单层石墨烯处理的碱解氮、有效磷和速效钾含量较CK分别显著增加21.85%、76.56%和30.69%；少层石墨烯处理较CK分别显著增加23.05%、82.16%和47.20%。同时，添加石墨烯还有助于土壤酶活性的提高，但随施用量的增加，土壤酶活性呈先升高后降低趋势，少层石墨烯处理在施用量为50 g·kg^-1时土壤蔗糖酶和脲酶活性较CK分别显著增加6.67%和21.26%。单层和少层石墨烯处理均有利于增加植株干重和鲜重，但对根长增加效果不显著。根系中抗氧化酶活性和非酶抗氧化剂含量表现为低水平（25、50和100 g·kg^-1）促进高水平（150 g·kg^-1）抑制，且低水平时抑制了超氧阴离子（superoxide anion production rate，{\mathrm{O}}_{\mathrm{2}}^{·-}）的产生速率和丙二醛（malonaldehyde，MDA）的积累，增加了可溶性蛋白和脯氨酸的含量，有助于及时清除活性氧，减轻对根系造成的损伤。综上，合理施用石墨烯可改善土壤养分、提高土壤酶活性、促进玉米植株生长，且少层石墨烯处理的效果优于单层石墨烯处理。

关键词: 石墨烯, 玉米, 根系, 土壤养分, 酶活性