Transforming soil phosphorus fertility management strategies to support the delivery of multiple ecosystem services from agricultural systems

Abstract

Despite greater emphasis on holistic phosphorus (P) management, current nutrient advice delivered at farm-scale still focuses almost exclusively on agricultural production. This limits our ability to address national and international strategies for the delivery of multiple ecosystem services (ES). Currently there is no operational framework in place to manage P fertility for multiple ES delivery and to identify the costs of potentially sacrificing crop yield and/or quality. As soil P fertility plays a central role in ES delivery, we argue that soil test phosphorus (STP) concentration provides a suitable common unit of measure by which delivering multiple ES can be economically valued relative to maximum potential yield, in $ ha yr units. This value can then be traded, or payments made against one another, at spatio-temporal scales relevant for farmer and national policy objectives. Implementation of this framework into current P fertility management strategies would allow for the integration and interaction of different stakeholder interests in ES delivery on-farm and in the wider landscape. Further progress in biophysical modeling of soil P dynamics is needed to inform its adoption across diverse landscapes.

The Science of 4R Nutrient Stewardship for Phosphorus Management across Latitudes

“…Macintosh et al (2019) also identified fertilizer source, placement, and timing as factors influencing these outcomes on a practical scale. The optimization of the 4Rs of nutrient stewardship to support a full range of ecosystem services is thus shown to be a rich field for further scientific exploration.…”

Options for Improved Phosphorus Cycling and Use in Agriculture at the Field and Regional Scales

“…As farm management changes to promote beneficial biota and their functions, changes to future fertility guidelines and recommendations will be required. Attitudes regarding achieving maximum yields or maximum economic profit will have to shift to increase nutrient use efficiency and maintain environmental quality (Withers et al, 2015; Macintosh et al, 2019). Admittedly, fertilizer additions to soils managed to promote biological contributions to PUE and plant P uptake may still achieve a yield response; however, the reduction in yield may be regarded as acceptable and still profitable.…”

“…A critical soil P concentration can be defined as the soil test P (STP) concentration that corresponds with achieving 90 to 95% of maximum crop yield (Manschadi et al, 2014). However, prescribing a single critical soil P concentration for a given region and crop species is problematic because the critical soil P concentration will vary depending on soil characteristics, crop rooting depth, climatic conditions, supply of other nutrients, and agroecosystem management (Manschadi et al, 2014; Macintosh et al, 2019). It also does not capture the ability of rhizosphere processes to contribute to plant P supply (Rowe et al, 2016).…”

“…We now know that while soil chemical analyses provide an indication of STP at a point in time, they do not account for biologically mediated P transformations that occur over time and can vary with agroecosystem management (Oberson et al, 1993; Condron, 2005; Haygarth et al, 2005; Nash et al, 2014; Braman et al, 2016; Schneider et al, 2017). In addition, the accuracy of STP sampling and analysis and resultant soil P fertility recommendations has been questioned (Withers et al, 2014; Nawara et al, 2017), and crop yields have reportedly been maintained at critical soil test P concentrations lower than those recommended (Withers et al, 2014; Macintosh et al, 2019; Rowe et al, 2016). Thus, there is a growing awareness of the need to update soil fertility recommendations that have been developed on the basis of STP concentrations and maximizing short‐term economic profitability (Sharpley et al, 2018; Smith et al, 2018).…”

“…Thus, there is a growing awareness of the need to update soil fertility recommendations that have been developed on the basis of STP concentrations and maximizing short‐term economic profitability (Sharpley et al, 2018; Smith et al, 2018). As discussed by Withers et al (2015) and Rowe et al (2016), it is time for a paradigm shift from current philosophies of nutrient management to one that addresses P use efficiencies in agriculture and also considers other ecosystem services when making STP recommendations (Macintosh et al, 2019). …”