Spatial and temporal variability in costs and effectiveness in phosphorus loss mitigation at farm scale: A scenario analysis

Abstract

Current policy instruments under the EU Water Framework Directive (WFD) to mitigate phosphorus (P) loss require that P use on farms is managed through regulation of farm gate P balances. Regulation at farm scale does not account for spatial variability in nutrient use and soil fertility at field scale, affecting the costs and effectiveness of farm gate measures. This study simulated the implementation of a P loss mitigation measure coupled with improving soil fertility so that farm productivity would not be compromised. The measure was simulated at field scale and the costs and effectiveness assessed at farm scale. Effectiveness was expressed as the time taken for excessive soil P levels to decline to levels that matched offtakes and this varied temporally and spatially within and between farms ranging from 1 to 8 years. Sub-optimum soil fertility was corrected on all fields across both farms, with applications of other soil nutrients and lime to protect productivity. An increase in costs ranging from 1.5-116% was predicted in the first two years of the measure on both farms after-which savings of 15-31% were predicted for each subsequent year until the measure was effective in year 9. Despite initial cost increase, there was no statistically significant difference in costs over the time taken for the measure to be effective, when compared to baseline costs. Successful implementation of measures should consider the impact on farm costs and time taken for measures to environmentally effective. Adoption of measures could improve if demonstrating to farmers that costs will not vary significantly from current practice and in time may results in savings if measures are paired with correcting soil fertility and increasing yields. This 'win-win' approach could be used into the future to ensure successful implementation and uptake of measures within the farming community.

Transforming the European Union's phosphorus governance through holistic and intersectoral framings

“…The objectives of the Act are reflected in the EU legal order through the Nitrates Directive (91/676/EEC) and the Water Framework Directive (2000/60/EC). The regulatory aspirations in these legal acts have sparked a significant amount of academic interest to support policymakers in improving the quality of water bodies by reducing and removing pollution (Bechmann and Stålnacke, 2005;Tangsubkul et al, 2005;Schulte et al, 2010;Jordan et al, 2012;Trevisan et al, 2012;Brownlie et al, 2014;Ford et al, 2015;Jedelhauser and Binder, 2015;Gooddy et al, 2017;Macintosh et al, 2018;Bragina et al, 2019;Van Meter et al, 2021). These predominantly technical studies oftentimes investigate individual modeling parameters or spatial planning practices, which focus on place-sensitive physical properties of the analyzed landscapes and water bodies.…”

A Review of On-farm Roadway Runoff Characterisation and Potential Management Options for Ireland

“…There are many diverse RR management options available which give land owners flexibility. All management options involve costs and this is one of the many complex considerations, which influences land owners' willingness to adopt best management practices (BMPs) or voluntary measures (Bragina et al, 2019). Liu et al (2018) created a conceptual framework for BMP adoption decisions which highlights scale, the tailoring or targeting of information and incentives and expected farm profits as being important factors.…”

Excessive application of chemical fertilizer and organophosphorus pesticides induced total phosphorus loss from planting causing surface water eutrophication

“…The loss of phosphorus from agricultural fields was regarded as an important contributor for the eutrophication of water bodies in recent decades, especially for the situation where the phosphorus fertilizer applications was exceed the demand of the crop 5 , 6 . Excessive P in the soil can not only affect the quality of surface water and groundwater through runoff and infiltration respectively, but also cause soil compaction, thereby reducing cereal production 7 – 9 . Therefore, the loss of phosphorus from planting needs to be highly valued, as it is related to national water resources and food security to some extent.…”