Soil Phosphorus Modeling for Modern Agriculture Requires Balance of Science and Practicality: A Perspective

Abstract

The use of phosphorus (P) fertilizers in arable crop and pastoral systems is expected to change as modern agriculture is challenged to produce more food with fewer inputs. Agricultural systems models offer a dual purpose to support and integrate recent scientific advances and to identify strategies for farmers to improve nutrient efficiency. However, compared with nitrogen and carbon, advances in P modeling have been less successful. We assessed the potential opportunity of P modeling to increase P efficiency for modern agriculture and identified the current challenges associated with modeling P dynamics at the field scale. Three major constraints were (i) a paucity of detailed field datasets to model strategies aimed at increasing P use efficiency, (ii) a limited ability to predict P cycling and availability under the local effects of climate change, and (iii) a restricted ability to match measured soil P fractions to conceptual and modelable pools in soils with different mineral properties. To improve P modeling success, modelers will need to walk a tightrope to balance the roles of assisting detailed empirical research and providing practical land management solutions. We conclude that a framework for interdisciplinary collaboration is needed to acquire suitable datasets, continually assess the need for model adjustment, and provide flexibility for progression of scientific theory. Such an approach is likely to advance P management for increased P use efficiency. Core Ideas Models can complement research and identify strategies to increase P efficiency. A variety of quality long‐term field trials is needed to advance model capabilities. Well‐calibrated soil models are needed to assess climate change impacts on P cycling. A framework is needed to streamline multidisciplinary research to improve P management.

Development of a Novel Model of Soil Legacy P Assessment for Calcareous and Acidic Soils

“…This is a new function compared with the DPPS model. Most models include available P, non-or low available P, and organic P with varying degrees of stability (Das et al, 2019). However, quantifying these pools is costly and time consuming.…”

“…To do so, soil P models may be used as a tool by providing a platform to estimate soil P processes and crop uptake across cropping systems and growth conditions. The main models currently used include DPPS, EPIC (erosion-productivity impact calculator), DASST (decision support system for agrotechnology transfer), and APSIM (agricultural production simulation model) at the field and global scales, which have been reviewed by Das et al (2019); Sattari et al (2012); and Sattari et al (2014). All of the above models face a common challenge in the initialization of conceptual soil P pools that are defined in models but cannot be directly measured and evaluated by regular chemical analysis.…”

Phosphorus mirabilis: Illuminating the Past and Future of Phosphorus Stewardship

“…Das et al (2019) use soil P modeling to assist in identifying strategies to improve PUE. They underscore the need for long-term field trials, field data, and multidisciplinary collaboration, while noting that climate change presents challenges to predicting P availability and nutrient cycling (Das et al, 2019). Bruulsema et al (2019) discuss opportunities to use P legacies in crop production to increase PUE and decrease water quality impairment.…”

“…Improving PUE in these high‐yield environments requires new technologies to enable high yields, including precision P placement and enhanced efficiency P fertilizer sources (Hopkins and Hansen, 2019). Das et al (2019) use soil P modeling to assist in identifying strategies to improve PUE. They underscore the need for long‐term field trials, field data, and multidisciplinary collaboration, while noting that climate change presents challenges to predicting P availability and nutrient cycling (Das et al, 2019).…”

Modified Biochar—A Tool for Wastewater Treatment

“…Therefore, balancing the complete soil system is the only reliable solution. This also takes into account, in addition to omnidirectional inputs and outputs, P transformations and cycles in the soil [21].…”