Multimineral and Organic Composition of a Liquid By-Product from the Pyrobituminous Shale Pyrolysis Process and its Potential Use in Agriculture

Abstract

2 Pyrolysis of pyrobituminous shale rock to extract products such as fuel oil and gas generate a liquid by-product called shale water (SW). In this study, the physical-chemical characterization of SW was performed and the effects on plant growth, mineral nutrition, and food safety were evaluated when applied via foliar in lettuce crop. Shale water showed a great diversity of organic compounds, minerals, and trace elements. The application of SW in lettuce resulted in no phytotoxic effect or accumulation of toxic elements to human health within the doses tested, and increased yield and the accumulation of several mineral nutrients in the leaves. The absorption and accumulation of zinc, copper, cobalt, molybdenum, and manganese was also improved when these minerals were applied together with SW. These results suggest that SW plays a role as a biostimulant and could be used in agriculture as a safety alternative to increase yield and biofortify crops.

Biostimulants Application: A Low Input Cropping Management Tool for Sustainable Farming of Vegetables

“…In this context, the production of dissolved organic matter (DOM) through anaerobic digestion has shown promising results for the design of new biostimulatory products that may improve plant health through an auxin-like mode of action [ 66 ]. According to Messias et al [ 76 ], shale water, which is generated after the pyrolysis of pyrobituminous shale rock, has also shown important biostimulant effects in horticultural crops and could be used as a yield enhancer and biofortifying agent. Finally other compounds such as melatonin and vitamins have shown biostimulatory activities, especially under abiotic stress conditions, and apart from the induction of secondary metabolites biosynthesis they also improve the quality and the functional properties of the final products [ 77 , 78 , 79 ].…”

Yield and quality of maize following the foliar application of a fertilizer based on the byproduct “shale water”

“…All treatments were supplied with a surfactant plus mineral oil as adjuvant and adjusted to pH 5.5 -6.0 using chloridric acid (Vetec®, Rio de Janeiro, Brasil). The mineral and organic composition of the SW used in the experiment was previously describe [12] and is presented in Table 1. The applications of the formulations were performed with the use of a pressurised sprayer (CO 2 ) adjusted to an equivalent nozzle flow rate of 100 L/ha.…”

“…To this purpose, SW was applied via foliar in the lettuce crop that was considered an excellent biological indicator of food quality, because it is usually eaten "fresh"; and environmental quality, because of its high susceptibility to contaminants. As a result, no harmful element or compound was detected in the lettuce leaves treated with SW, indicating that the use of SW as foliar spray in agriculture repre-sents an environmental friendly alternative for the disposal of this by-product [12]. Therefore, in the present study we evaluated the effect of foliar application of formulations based on SW, delivered with or without micronutrients enrichment, on vegetative growth, yield and quality of maize grains.…”

“…The chemical composition of shale water (SW), the constituent water of shale pyrobituminous rock, which is extracted during the pyrolysis process to obtain, for instance, fuel oil, sulfur and gas (LPG), was recently described [12]. The composition of SW is based on several organic compounds, mainly phenols, as well as minerals and trace elements of interest for plant nutrition.…”

“…The composition of SW is based on several organic compounds, mainly phenols, as well as minerals and trace elements of interest for plant nutrition. The application of SW in lettuce [12] and pepper [13] plants resulted in the increase of yield and mineral content, suggesting its potential as a foliar fertilizer. Furthermore, a previous study was performed in order to evaluate the food safety of using SW in agriculture.…”