The increase in worldwide population observed in the last decades has contributed to an increased demand for food supplies, which can only be attained through an improvement in agricultural productivities. Moreover, agricultural practices should become more sustainable, as the use of chemically-based fertilisers, pesticides and growth stimulants can pose serious environmental problems and lead to the scarcity of finite resources, such as phosphorus and potassium, thus increasing the fertilisers’ costs. One possible alternative for the development of a more sustainable and highly effective agriculture is the use of biologically-based compounds with known activity in crops’ nutrition, protection and growth stimulation. Among these products, microalgal and cyanobacterial biomass (or their extracts) are gaining particular attention, due to their undeniable potential as a source of essential nutrients and metabolites with different bioactivities, which can significantly improve crops’ yields. This manuscript highlights the potential of microalgae and cyanobacteria in the improvement of agricultural practices, presenting: (i) how these photosynthetic microorganisms interact with higher plants; (ii) the main bioactive compounds that can be isolated from microalgae and cyanobacteria; and (iii) how microalgae and cyanobacteria can influence plants’ growth at different levels (nutrition, protection and growth stimulation).

中文翻译：

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微藻和蓝细菌在改善农业实践中的应用：它们的生物肥，生物刺激和生物农药作用的综述

过去几十年来观察到的全球人口增加导致对粮食供应需求的增加，这只能通过提高农业生产率来实现。此外，农业做法应变得更具可持续性，因为使用化学肥料，杀虫剂和生长刺激剂会造成严重的环境问题，并导致有限的资源（如磷和钾）稀缺，从而增加了肥料的成本。发展更可持续，更高效的农业的一种可能选择是使用在作物营养，保护和生长刺激中具有已知活性的生物基化合物。在这些产品中，微藻和蓝细菌生物质（或其提取物）正受到特别关注，由于它们作为具有不同生物活性的必需营养素和代谢物的来源具有不可否认的潜力，因此可以显着提高农作物的产量。该手稿突出了微藻和蓝细菌在改善农业实践中的潜力，并提出：（i）这些光合微生物如何与高等植物相互作用；（ii）可以从微藻类和蓝细菌中分离出的主要生物活性化合物；（iii）微藻和蓝细菌如何在不同水平（营养，保护和生长刺激）上影响植物的生长。介绍：（i）这些光合微生物如何与高等植物相互作用；（ii）可以从微藻类和蓝细菌中分离出的主要生物活性化合物；（iii）微藻和蓝细菌如何在不同水平（营养，保护和生长刺激）上影响植物的生长。介绍：（i）这些光合微生物如何与高等植物相互作用；（ii）可以从微藻类和蓝细菌中分离出的主要生物活性化合物；（iii）微藻和蓝细菌如何在不同水平（营养，保护和生长刺激）上影响植物的生长。