Moving toward more sustainable sources for managing phosphorus (P) nutrition in agroecosystems, organic phosphorus (Po) derived from organic inputs and soil is increasingly considered to complement mineral P fertilizer. However, the dynamics of P added by organic input in soil-plant systems is still poorly understood and there is currently no clear information on how the Po composition of these amendments determines P availability through interactions with the soil microbiome and root traits. Here, we review the main mechanisms of rhizosphere microbiome and root traits governing the dynamics of organic input/soil-derived Po pools in the soil-plant system. We discuss the extent to which the major forms of Po derived from organic input/soil can be used by plants and how this could be improved to provide efficient utilization of organic inputs as potential P sources. We provide new insights into how a better understanding of the interactions between Po forms, root traits, and rhizosphere microbiomes can help better manage P fertilization, and discuss recent advances in the mobilization and recovery of Po from organic inputs. We then develop proposed strategies in agroecology that could be used to improve Po utilization, specifically by better linking plant traits and Po forms, and developing new cropping systems allowing more efficient Po recycling.

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Land application of organic waste products (OWPs), catch crops and reduced soil tillage are accepted as sustainable management practices in agriculture. They can optimize resources by supplying nutrients to plants and helping to maintain soil fertility. They also can influence soil functions in agricultural production systems. Soil microorganisms can feed on fresh organic matter by producing extracellular enzymes. Enzyme production responds to resource availability and soil C:N:P ratios, which could limit biogeochemical cycling. Allocating resources to produce nutrient-acquiring enzymes requires a large amount of energy to achieve optimal growth. In this context, studying the use of OWPs is important, as alternatives to long-term use of mineral fertilizers, to understand the dynamics of response and how the OWPs influence production of extracellular enzymes in the soil. Effects of OWPs on soil enzymatic activities have been studied widely, but long-term effects remain poorly understood, and no information is available about differences in dynamics among systems for each biogeochemical cycle. The data described here were collected during two trials from an initial state, and they allow assessment of long-term effects of OWP application, mineral nitrogen fertilization, tillage and vegetation cover on soil enzymatic activities. Data are presented for the activities of five soil enzymes measured from 2012 to 2019: β-glucosidase, phosphatase, urease, arylamidase and arylsulfatase. Five additional enzymes were included in 2019 to supplement the analysis of biogeochemical cycles: alkaline phosphatase, phosphodiesterase, α-glucosidase, β-galactosidase and n-acetyl-glucosaminidase. These activities were measured in two trials at the EFELE study site: PROs (five OWPs applied to a corn-wheat rotation) and TS/MO (four treatments that examine interactions between OWP and type of tillage). These data can be used as a reference for future studies of soil enzymes in France and other regions (e.g. for developing reduced-tillage systems and organic or inorganic amendments, and to assess dynamics of the systems).

AimsOrganic P (OP) accounts for significant fractions of the total phosphorus (P) pool in soils, especially in soils treated with organic inputs. In soils, OP compounds can be sorbed onto soil minerals but the consequences of these interactions on P availability and plant uptake are poorly known. This research aims at elucidating the extent to which adsorbed OP compounds to major soil minerals may be available to plants.MethodsRyegrass (Lolium multiflorum) plants were grown in RHIZOtest devices in the presence of OP (myo-inositol hexakisphosphate (IHP), glycerophosphate (GLY) and glucose-6-phosphate(G6P)) and inorganic P (IP) compounds that were previously adsorbed onto Fe and Al oxides (goethite and gibbsite, respectively) and clay minerals (montmorillonite and kaolinite). Phosphorus availability and P uptake were then determined through rhizosphere and plant characterization. ResultsIrrespective of the type of mineral, ryegrass was able to take up about 3-18% of adsorbed OP compounds. The magnitude of availability and uptake depended on the OP compounds and the type of soil minerals. The potential availability of OP adsorbed by different minerals was strongly mediated by mineral-OP interaction types and properties. The P uptake increased in the following order: kaolinite-OP << gibbsite-OP ≤ goethite OP << montmorillonite-OP. Phosphorus uptake from adsorbed OP compounds showed contrasting pattern compared to adsorbed IP and depended on available P in the rhizosphere and not necessarily on the binding strength of OPs to the mineral surface.ConclusionsUnravelling the role of both OP and soil minerals properties on P availability constitutes an important knowledge to understand P dynamic in soil-plant system. Our results evidenced that the forms of OP adsorbed on Fe and Al oxides or clay minerals are available for plants to an extent which is strongly driven by OP forms and mineral types.