In a growing world population scenario, greater demand for food and in turn agricultural input is expected in the coming decades. The development of innovative sustainable amendments and fertilizers such as hydrogels (HGs) relies on this context. HGs are defined as 3D polymeric networks with the ability to absorb and retain a large amount of water (i.e., swellability). HGs swellability makes them ideal platforms for water- and nutrient-controlled release. The literature reflects a notable diversity in HGs composition, properties, and impacts on agroecosystems, resulting in the dissemination of information across multiple publications. Within this context, the primary aim of this scientific review is to systematically compile, critically evaluate, and synthesize the latest findings and relevant literature pertaining to the application of HGs in agroecosystems. We found that this class of materials was consistently found on soil bulk density, crop available water, soil electrical conductivity, cation exchange capacity and main cereal or legume crops performances particularly under moderate water deficit conditions, suggesting their effectiveness for arid and semi- arid areas. Encouraging results were also found on pesticide, agrochemicals, and microorganisms delivering. Thus, the delivery of agronomic inputs with loaded-HG may play a key role in forthcoming agriculture that would minimize the agronomic impact on the environment. Nevertheless, some critical issues still remain open, concerning: (i) the decreased of HG effectiveness following wetting and drying cycles, (ii) the impact of Na⁺ contained in HG on crop cells, (iii) the HG effect on soil saturated hydraulic conductivity and pH, and (iv) HG biodegradability and their fate into the environment. In conclusion, HGs seem a promising technology to reach/maintain food security and soil health, but future research should address the development of well-defined protocols for producing biowaste-derived HG that will ensure their biodegradability and non-toxicity and will disclose new insights into a circular economy approach agronomy. One of the biggest challenges would be the synthesis of “smart” HG able to respond to environmental stimuli triggering molecule(s) release in soil.

在世界人口不断增长的情况下，预计未来几十年对粮食和农业投入的需求将会增加。创新的可持续改良剂和肥料（例如水凝胶（HG））的开发依赖于这一背景。 HG 被定义为具有吸收和保留大量水的能力（即膨胀性）的 3D 聚合物网络。 HG 的膨胀性使其成为水和养分控制释放的理想平台。文献反映了汞的组成、特性和对农业生态系统影响的显着多样性，导致信息在多种出版物中传播。在此背景下，本次科学综述的主要目的是系统地汇编、批判性评估和综合有关HG在农业生态系统中应用的最新发现和相关文献。我们发现，这类材料在土壤容重、作物有效水、土壤电导率、阳离子交换能力和主要谷类或豆类作物的表现上始终存在，特别是在中度缺水条件下，表明它们对干旱和半干旱地区的有效性。在农药、农用化学品和微生物输送方面也取得了令人鼓舞的结果。因此，提供负载汞的农业投入可能在未来的农业中发挥关键作用，从而最大限度地减少对环境的农业影响。然而，一些关键问题仍然悬而未决，涉及：（i）干湿循环后HG有效性下降，（ii）HG中含有的Na ⁺对作物细胞的影响，（iii）HG对土壤饱和水力的影响电导率和 pH 值，以及 (iv) HG 生物降解性及其在环境中的归宿。总之，HG 似乎是实现/维持粮食安全和土壤健康的一项有前景的技术，但未来的研究应致力于制定明确的协议来生产生物废物衍生的 HG，以确保其可生物降解性和无毒性，并将揭示新的见解农学进入循环经济方法。最大的挑战之一是合成“智能”HG，能够响应环境刺激，触发土壤中的分子释放。