Low phosphate (Pi) availability and high aluminum (Al) toxicity constitute two major plant mineral nutritional stressors that limit plant productivity on acidic soils. Advances toward the identification of genes and signaling networks that are involved in both stresses in model plants such as Arabidopsis thaliana and rice (Oryza sativa), and in other plants as well have revealed that some factors such as organic acids (OAs), cell wall properties, phytohormones, and iron (Fe) homeostasis are interconnected with each other. Moreover, OAs are involved in recruiting of many plant-growth-promoting bacteria that are able to secrete both OAs and phosphatases to increase Pi availability and decrease Al toxicity. In this review paper, we summarize these mutual mechanisms by which plants deal with both Al toxicity and P starvation, with emphasis on OA secretion regulation, plant-growth-promoting bacteria, transcription factors, transporters, hormones, and cell wall-related kinases in the context of root development and root system architecture remodeling that plays a determinant role in improving P use efficiency and Al resistance on acidic soils.

The effects of different types of phosphate fertilization on the phosphorus (P) adsorption-desorption in low-P red soil remain unclear. A field plot location test was carried out, and fifteen red soil samples were collected at depths of 0–20 cm from five phosphate fertilizers (CK—no-phosphate, SSP—single superphosphate, CMP—calcium magnesium phosphate, MAP—monoammonium phosphate, and DAP—diammonium phosphate) after the maize was harvested to evaluate the soil physicochemical properties, P adsorption, and desorption characteristics. The structural equation model (SEM) and adjacent tree method (ABT) were used to quantitatively analyze the relative contribution of P adsorption and desorption. The yield, P accumulation, and the P use efficiency of maize were the highest under SSP and CMP treatments. The P adsorption amount was CK > DAP > MAP > CMP > SSP, and the P desorption amount was DAP > MAP > CMP > SSP > CK. Compared with the CK treatment, P adsorption of other P treatments reduced by an average of 21.4%, while P desorption increased by 154.8%. The effect of different types of phosphate fertilizers on soil P adsorption was mainly through regulation of soil organic matter (SOM) and Olsen P, and the effect on soil P desorption was mainly through regulation of SOM and CaCO₃. Al₂O₃ had the greatest effect on P adsorption with a relative contribution rate of 31.52%, and SOM had the greatest effect on P desorption with a relative contribution rate of 53.04%. SSP and CMP treatments had an optimal matching with acidic red soil, which can promote P adsorption, effectively slow down P loss, improve P utilization, and increase crop yield.

Sediment phosphorus (P) is an active component of the P cycle in lakes and its availability and movement could play an important role in eutrophication. Sediments from different depths in five representative sites of Dianchi Lake China, i.e., Haigeng, Dounan, Luojiacun, Xinjie, and Kunyang, were studied from January to December to evaluate the spatial and temporal dynamics in available-P and soluble-P and their impacts on algal growth. The results showed that the average sediment available-P and soluble-P were 41.2 mg kg⁻¹ and 0.27 mg kg⁻¹, respectively. Sediment available-P and soluble-P concentrations varied significantly among seasons, sites, and layers, with the following order: surface (0–5 cm) > middle (5–10 cm) > bottom (10–20 cm). The release and transformation characteristics of available-P and soluble-P at the sediment–water interface varied among sites. The Haigeng site, with the most severe algae blooms, had significantly higher average available-P and soluble-P in sediment than other sites. This indicated that phosphorus release and availability were associated with algal growth, and that the sediment surface (0–5 cm) is an important internal source that supports algal growth in Dianchi Lake.

Cereal and legume intercropping could improve cereal yield, but the role of intercropping in grain quality still lacks a full understanding. A two-year bi-factorial trial was conducted to investigate the role of two planting patterns (mono-cropped wheat (MW) and intercropped wheat+faba bean (IW)) and four nitrogen (N) fertilization levels (N0, no N fertilizer applied to both wheat and faba bean; N1, 90 and 45 kg N ha^–1 applied to wheat and faba bean; N2, 180 and 90 kg N ha^–1 applied to wheat and faba bean; N3, 270 and 135 kg N ha^–1 applied to wheat and faba bean), as well as their interaction on the productivity of wheat grain yield (GY) and quality. The results showed that intercropping increased both the yields of wheat grain protein and amino acids (AAs) relative to MW in both years. No difference in Aas content between IW and MW was found but the 9% grain protein content (GPC) of IW was higher than that of MW in 2020. By contrast, wheat gliadin content was increased by 8–14% when wheat was intercropped with faba bean in both years, and some AAs fractions including essential and non-essential AAs were increased under N0 and N1 levels but declined at the N3 level. This means that intercropping increased the grain quality either for protein and AAs content or for fractions. There was no negative relationship between GPC and GY in the present study, and intercropping tended to increase GPC with increasing GY. In conclusion, wheat and faba bean mainly affected GPC and fractions rather than AAs, and intercropping presented a potential to improve both wheat quality and yield concurrently. Modulated N rates benefitted the stimulation of intercropping advantages in terms of grain yield and quality in the southwest of China and similar regions.