Rhizosphere organic anions don't play a big role in helping crops absorb leftover phosphorus in low-phosphorus soils. Different crops release different types and amounts of organic anions in their roots, but these don't significantly improve phosphorus uptake. Avena sativa had the highest root colonization by helpful fungi and absorbed the most phosphorus in low-phosphorus soil. Brassica napus had more enzyme activity and absorbed more phosphorus in certain soil types. Overall, the type of organic anions released by plants didn't have a major impact on phosphorus availability and uptake in agricultural soils.