In the current geopolitical context, the development of nutrient-conserving systems in agriculture environments is increasingly urgent, particularly with the rise of inaccessible or undesirable fertilizer use (Sanchez 2002; Vitousek et al. 2009). Thus, the advancement of low-input agriculture dependent on plant-based nutrient supply, such as through N2-fixation, is very important for best management practices. Deciphering nutrient acquisition strategies is necessary to encourage positive interactions for improved low-input agriculture. However, accurate estimates of nutrient sources, rhizosphere uptake and mineral transfer processes under varying abiotic gradients are necessary to minimize interspecific competition in intercropped production systems (Vance et al. 2003; Isaac et al. 2007). Our research objectives were to 1) compare plant performance and rhizosphere processes along a pre-contact P gradient in an N2-fixing tree-cereal crop association in comparison to a monoculture crop, and 2) quantify N and P acquisition and N transfer from the N2-fixing tree to the crop with varying root contact intensity.