Soil phosphorus loss in tile drainage water from long-term conventional- and non-tillage soils of Ontario with and without compost addition
Zhang, T.Q., Tan, C.S., Wang, Y.T., Ma, B.L., Welacky, T. (2017). Soil phosphorus loss in tile drainage water from long-term conventional- and non-tillage soils of Ontario with and without compost addition. Science of the Total Environment, [online] 580 9-16. http://dx.doi.org/10.1016/j.scitotenv.2016.12.019
Plain language summary
• Quantification of agricultural practices
on P loss is needed to reduce P loss risk.
• Compost addition increased DRP loss at
a rate 113% higher under NT than under
• DRP loss with NT was solely driven by
DRP concentration in tile drainage water.
• DRP loss with CT was collectively driven
by DRP concentration and flow volume.
• Compost addition did not affect PP loss,
regardless of tillage practices.
Recent ascertainment of tile drainage a predominant pathway of soil phosphorus (P) loss, along with the rise in concentration of soluble P in the Lake Erie, has led to a need to re-examine the impacts of agricultural practices. A three-year on-farm study was conducted to assess P loss in tile drainage water under long-term conventional- (CT) and non-tillage (NT) as influenced by yard waste leaf compost (LC) application in a Brookston clay loam soil. The effects of LC addition on soil P loss in tile drainage water varied depending on P forms and tillage systems. Under CT, dissolved reactive P (DRP) loss with LC addition over the study period was 765 g P ha− 1, 2.9 times higher than CT without LC application, due to both a 50% increase in tile drainage flow volume and a 165% increase in DRP concentration. Under NT, DRP loss in tile drainage water with LC addition was 1447 g P ha− 1, 5.3 times greater than that for NT without LC application; this was solely caused by a 564% increase in DRP concentration. However, particulate P loads in tile drainage water with LC application remained unchanged, relative to non-LC application, regardless of tillage systems. Consequently, LC addition led to an increase in total P loads in tile drainage water by 57 and 69% under CT and NT, respectively. The results indicate that LC application may become an environmental concern due to increased DRP loss, particularly under NT.