Hammerschmiedt Tereza, Holatko Jiri, Bytesnikova Zuzana, Skarpa Petr, Richtera Lukas, Kintl Antonin, Pekarkova Jana, Kucerik Jiri, Jaskulska Iwona, Radziemska Maja, Valova Radmila, Malicek Ondrej, Brtnicky Martin
Department of Agrochemistry, Soil Science, Microbiology and Plant Nutrition, Faculty of AgriSciences, Mendel University in Brno, Zemedelska 1, 613 00, Brno, Czech Republic.
Agrovyzkum Rapotin, Ltd., Vyzkumniku 863, 788 13, Rapotin, Czech Republic.
Heliyon. 2024 Sep 25;10(19):e38439. doi: 10.1016/j.heliyon.2024.e38439. eCollection 2024 Oct 15.
Sulphur (S) deficiency has emerged in recent years in European soils due to the decreased occurrence of acid rains. Elemental sulphur (S) is highly beneficial as a source of S in agriculture, but it must be oxidized to a plant-accessible form. Micro- or nano-formulated S may undergo accelerated transformation, as the oxidation rate of S indirectly depends on particle size. Graphene oxide (GO) is a 2D-carbon-based nanomaterial with benefits as soil amendment, which could modulate the processes of S oxidation. Micro-and nano-sized composites, comprised of S and GO, were tested as soil amendments in a pot experiment with unplanted soil to assess their effects on soil microbial biomass, activity, and transformation to sulphates. Fourteen different variants were tested, based on solely added GO, solely added micro- or nano-sized S (each in three different doses) and on a combination of all S doses with GO.
Compared to unamended soil, nano-S and nano-S+GO increased soil pH(CaCl). Micro-S (at a dose 4 g kg) increased soil pH(CaCl), whereas micro-S+GO (at a dose 4 g kg) decreased soil pH(CaCl). The total bacterial and ammonium oxidizer microbial abundance decreased due to micro-S and nano-S amendment, with an indirect dependence on the amended dose. This trend was alleviated by the co-application of GO. Urease activity showed a distinct response to micro-S+GO (decreased value) and nano-S+GO amendment (increased value). Arylsulfatase was enhanced by micro-S+GO, while sulphur reducing bacteria (dsr) increased proliferation due to high micro-S and nano-S, and co-amendment of both with GO. In comparison to nano-S, the amendment of micro-S+GO more increased soluble sulphur content more significantly.
Under the conditions of this soil experiment, graphene oxide exhibited a significant effect on the process of sulphur oxidation.
由于酸雨发生频率降低，近年来欧洲土壤中出现了硫（S）缺乏现象。元素硫作为农业中硫的来源非常有益，但它必须被氧化成植物可利用的形式。微纳形式的硫可能会加速转化，因为硫的氧化速率间接取决于颗粒大小。氧化石墨烯（GO）是一种二维碳基纳米材料，作为土壤改良剂具有益处，它可以调节硫的氧化过程。在未种植土壤的盆栽试验中，测试了由硫和氧化石墨烯组成的微米和纳米复合材料作为土壤改良剂，以评估它们对土壤微生物生物量、活性以及向硫酸盐转化的影响。测试了14种不同的变体，包括单独添加氧化石墨烯、单独添加微米或纳米尺寸的硫（每种有三种不同剂量）以及所有硫剂量与氧化石墨烯的组合。
与未改良土壤相比，纳米硫和纳米硫+氧化石墨烯提高了土壤pH（CaCl）。微米硫（剂量为4 g/kg）提高了土壤pH（CaCl），而微米硫+氧化石墨烯（剂量为4 g/kg）降低了土壤pH（CaCl）。由于微米硫和纳米硫的改良，总细菌和铵氧化微生物丰度下降，且与改良剂量间接相关。氧化石墨烯的共同施用缓解了这一趋势。脲酶活性对微米硫+氧化石墨烯（值降低）和纳米硫+氧化石墨烯改良（值增加）表现出明显反应。芳基硫酸酯酶因微米硫+氧化石墨烯而增强，而由于高剂量的微米硫和纳米硫以及两者与氧化石墨烯的共同改良，硫酸盐还原菌（dsr）增殖增加。与纳米硫相比，微米硫+氧化石墨烯的改良更显著地提高了可溶性硫含量。
在该土壤实验条件下，氧化石墨烯对硫的氧化过程表现出显著影响。
