Exploring the effect of soil amelioration on wheat growth, nutrition, and soil microbiomes in acidic sandy soil

Background and aims Soil acidity poses a significant global challenge to soil health and the sustainability of agricultural production. In Western Australia’s grain belt, soil acidification—exacerbated by crop removal and the use of acidifying fertilisers—reduces land productivity. A combination of organic and inorganic soil amendments including lime, gypsum, clay, compost, and synthetic fertilisers could improve soil health and microbial function. Methods A glasshouse experiment was conducted using undisturbed soil cores amended three years earlier in a “re-engineering soils” field trial, which comprised four soil treatments: Control, CLG (clay, lime, gypsum), CLG + NPK (CLG + nitrogen, phosphorus, and potassium fertilisers), and CLG + Compost. The study followed a completely randomised design with three replications. Plant growth, nutrient uptake, and soil chemical and microbial properties were assessed at three key wheat growth stages, according to Zadoks’ scale: Z23, Z61, and Z92. Results These amendments improved plant growth, nutrient uptake, grain yield, and nutrient status, while also enhancing soil chemical properties, microbial biomass carbon (MBC), and microbial composition. CLG was the main amendment used to improve soil conditions, and its application with compost showed greater effectiveness compared to its use with NPK fertilisers. Conclusion This study offers insights into the benefits of organic and inorganic amendments for managing acidic sandy soil. The findings support the development of sustainable soil management strategies. Future work should explore the long-term impacts of these amendments across different soil types and cropping systems.