Deep and Continuous Root Development in Ameliorated Soil Improves Nutrients Uptake and Wheat Yield in Water-Limited Conditions

Abstract Background and Aims Despite the widespread co-occurrence of subsoil acidity and compaction, the interaction between these factors and their combined effects on root system development under water-limited conditions is poorly understood. This study aimed to investigate how the removal of soil strength and acidity in surface and subsurface layers influenced root development in field conditions and examine relationships between root system properties and shoot growth. Methods Images of root growth were obtained in situ by using rhizotron facilities to assess the temporal effects of soil improvement through loosening and lime incorporation on wheat root development in the 2018 season. Following this, we examined the relationship between enhanced root systems, nutrient uptake, and overall crop performance. Results The results indicate that improved soil conditions significantly enhanced total root length (TRL) through the elongation and proliferation of wheat roots in the subsoil. Among the soil parameters assessed, subsoil strength had a more dominant influence on TRL than soil pH or extractable aluminium concentration (EAC). Regression analysis suggests that ameliorated subsoil was the primary driver of significant improvements in nutrient uptake, which subsequently enhanced wheat performance, including head density, biomass, and grain yield. This highlights the critical role of deep root systems in optimising crop productivity. Notably, the loosening and lime treatments improved soil pH and reduced EAC, promoting deeper and continuous root growth, allowing plants to access previously unavailable soil nutrients. Conclusions By integrating root imaging data with soil property measurements, this research provides a deeper understanding of root-soil interactions throughout the cropping season. It offers valuable insights into sustainable soil management practices that optimise root architecture and improve crop productivity in challenging soil conditions.