The use of filter cake and vinasse in agriculture began in the 1970s and intensified in the 1990s. Currently, the Ukraine war and the high value of fertilizers have created opportunities for fertilization programs in agricultural systems with sustainable goals. This review presents updated data (1988–2024) and a discussion on the potential agricultural use of filter cake and vinasse and indicates the current progress of research on this subject in addition to future prospects. Filter cake stands out due to the formulation of organomineral fertilizers with direct application of composted or fresh forms, favoring the agronomic efficiency of phosphorus. The use of vinasse in fertigation is feasible and replaces potassium mineral fertilizers and other nutrients following an organic matrix. Future perspectives point to the agricultural use of filter cake and vinasse on a sustainable basis from different approaches. The aim is to potentiate their benefits in the soil-plant-atmosphere system. It is noteworthy that filter cake or vinasse, when combined with growth-promoting bacteria in irrigated crops, can nullify the negative effects of climate change due to increased productivity and, at the same time, meet the United Nations Sustainable Development Goals by 2030. This contributes to facing global challenges related to food security by recycling nutrients for agriculture and generating clean bioenergy from sugarcane biomass.

Understanding the efficacy of alternative phosphorus (P) sources in tropical soils is crucial for sustainable farming, addressing resource constraints, mitigating environmental impact, improving crop productivity, and optimizing soil-specific solutions. While the topic holds great importance, current literature falls short in providing thorough, region-specific studies on the effectiveness of alternative P sources in Brazilian tropical soils for maize cultivation. Our aim was to assess the agronomic efficiency of alternative P sources concerning maize crop (Zea mays L.) attributes, including height, shoot dry weight, stem diameter, and nutrient accumulation, across five Brazilian tropical soils. In greenhouse conditions, we carried out a randomized complete block design, investigating two factors (soil type and P sources), evaluating five tropical soils with varying clay contents and three alternative sources of P, as well as a commercial source and a control group. We evaluated maize crop attributes such as height, dry weight biomass, and nutrient accumulation, P availability and agronomic efficiency. Our results showed that, although triple superphosphate (TSP) exhibited greater values than alternative P sources (precipitated phosphorus 1, precipitated phosphorus 2 and reactive phosphate) for maize crop attributes (e.g., height, stem diameter, shoot dry weight and phosphorus, nitrogen, sulfur, calcium and magnesium accumulation). For instance, PP1 source increased nutrient accumulation for phosphorus (P), nitrogen (N), and sulfur (S) by 37.05% and 75.98% (P), 34.39% and 72.07% (N), and 41.94% and 72.69% (S) in comparison to PP2 and RP, respectively. Additionally, PP1 substantially increased P availability in soils with high clay contents 15 days after planting (DAP), showing increases of 61.90%, 99.04%, and 38.09% greater than PP2, RP, and TSP. For Ca and Mg accumulation, the highest values were found in the _COxisol₂ soil when PP2 was applied, Ca = 44.31% and 69.48%; and Mg = 46.23 and 75.79%, greater than PP1 and RP, respectively. Finally, the highest values for relative agronomic efficiency were observed in _COxisol₂ when PP1 was applied. The precipitated phosphate sources (PP1 and PP2) exhibited a similar behavior to that of the commercial source (TSP), suggesting their potential use to reduce reliance on TSP fertilization, especially in soils with low clay contents. This study emphasized strategies for soil P management, aimed at assisting farmers in enhancing maize crop productivity while simultaneously addressing the effectiveness of alternative P sources of reduced costs.

Aluminum (Al) toxicity is a major constraint on crop growth and productivity in acidic soils, affecting root development, nutrient uptake, and photosynthetic performance. The use of Si is a promising strategy to overcome the adverse effects of Al toxicity on species of agronomic interest. Between 2020 and 2026, 15 studies across nine species consistently demonstrated that silicon mitigated aluminum toxicity, regardless of their classification as silicon accumulators. In plants, Si mitigates Al toxicity through a combination of physical, chemical, and biochemical mechanisms that operate simultaneously. In the rhizosphere, Si interacts directly with Al³⁺ ions, favoring the formation of hydroxyaluminosilicates (HASs), which reduces the bioavailable fraction of Al. Evidence indicates that solution pH is a critical factor governing HAS formation, with minimal attenuation of Al toxicity observed at pH values below 4.5. Within the plant, Si modulates the antioxidant defense system by enhancing the activity of enzymes such as catalase, peroxidase, and ascorbate peroxidase, thereby reducing oxidative stress typically triggered by Al toxicity. Moreover, Si influences the biosynthesis of lignin and phenolic compounds with Al-chelating capacity, contributing to detoxification at the cellular level. In soybean and rice, Si supply substantially reduced Al deposition in the root apical cell wall, with decreases of approximately 52% and 41.3%, respectively. This reduction was consistently associated with improved root elongation, maintenance of root structural integrity, mitigation of cellular deformation, and preservation of root thickness and vascular organization. Although these mechanisms have been described, a comprehensive synthesis of studies published from 2020 to 2026 has been lacking, particularly regarding the integration of in-plant processes and species-specific responses. This review fills this gap by critically examining recent findings, highlighting the multifaceted role of Si in alleviating Al stress, and discussing implications for agronomic applications in acidic soils. Collectively, the evidence underscores Si as an effective tool to enhance plant tolerance to Al; however, most available evidence is derived from early plant developmental stages and hydroponic or highly controlled systems, which limits the direct extrapolation of these findings to soil and field conditions. Future advances will require studies under soil environments, accounting for species-specific responses, soil properties, management systems, and plant developmental stages.

Backgrounds and Aims: Silicon (Si) is a beneficial element known to attenuate biotic and abiotic stress in plants. The objective of this study was to verify whether Si increases the efficiency of phosphate fertilization and improves the yield components of rainfed rice grown in tropical soils. Methods: The experiment was conducted in a randomized block design and in a 4 × 4 × 2 factorial scheme, with four P levels (0, 50, 100 and 200 mg kg ⁻¹ ) four Si levels (0, 240, 480 and 960 mg kg ⁻¹ ) and two soil texture types [clay and sandy clay loam (referred to as sandy texture soil)], with four replication. In the flag leaf emergence growth stage to determine shoot biomass, concentrations of Si and P and photosynthetic and water regime parameters and at the end of the experiment to determine grain yield components and pH and available Si and P in soils. Results: The applying 960 mg kg⁻ ¹ of Si improved the efficiency of phosphate fertilization, specifically at P concentrations of 100 and 200 mg kg⁻ ¹ . The Si increases the photosynthesis rate and rice yield components. Conclusion: Si can enhance soil-available P and plant P status under acidic conditions without changing soil pH, but these effects were mainly observed at high Si supply and were strongly modulated by soil texture. Si also improved selected yield components.

Rice is essential for global food security. However, the effects of phosphorus (P) and silicon (Si) interaction on macronutrient accumulation in rice grown in tropical soils remain poorly understood, particularly regarding the persistence of these effects in subsequent crops. This study aimed to investigate the combined influence of Si and P levels on the accumulation of macronutrients (N, P, K, Ca, Mg, and S) and Si in the shoots of rice plants grown in two consecutive cycles in tropical soils with contrasting textures. Experiments were conducted in a randomized block design using a 4 × 4 × 2 factorial scheme with four P levels (0, 50, 100, and 200 mg kg⁻¹), four Si levels (0, 240, 480, and 960 mg kg⁻¹), and two soil types (clayey and sandy), with four replications. In experiment I, Si and P levels were applied, whereas experiment II evaluated only their residual effects. In both experiments, the accumulation of N, P, K, Ca, Mg, and S in rice shoots was determined. The combined application of Si and P significantly affected macronutrient accumulation, and responses varied with soil texture. In general, the Si–P interaction increased P and other nutrient accumulation, with stronger responses in the first cycle, although residual effects were also observed in the subsequent cycle. The interaction between Si and P can improve nutrient use in rice plants, and its effectiveness depends on soil texture.