Solid Cattle Manure Less Prone to Phosphorus Loss in Tile Drainage Water

Area of Science:

• Agricultural Science
• Environmental Science
• Soil Science

Background:

• Phosphorus (P) loss from agricultural lands is a significant environmental concern.
• The form of manure applied (liquid vs. solid) can influence P loss pathways.
• Understanding P loss from different manure types is crucial for sustainable agriculture.

Purpose of the Study:

• To compare P losses in tile drainage water from different forms of cattle manure and inorganic P.
• To evaluate the impact of liquid cattle manure (LCM), solid cattle manure (SCM), and inorganic P (IP) on soil P losses.
• To inform best management practices for manure application to mitigate P loss.

Main Methods:

• A 4-year field experiment was conducted in a clay loam soil.
• Corn-soybean rotation was used.
• P-based application rates of LCM, SCM, and IP (triple superphosphate) were applied.
• Dissolved reactive P (DRP), particulate P, and total P concentrations in tile drainage water were measured.

Main Results:

• Dissolved reactive P (DRP) flow-weighted mean concentration (FWMC) was higher with SCM than with IP or LCM.
• DRP FWMC increased sharply after LCM application, despite lower annual averages.
• Particulate P and total P losses were significantly lower (68% and 47%, respectively) with SCM compared to IP.
• No significant differences in P loads were detected between treatments.
• P loss was similar between IP and LCM treatments for particulate and total P.

Conclusions:

• Solid cattle manure (SCM) is less prone to P loss compared to liquid cattle manure (LCM) and inorganic P (IP).
• Results support SCM as a preferable option for reducing P loss via tile drainage.
• Findings provide a basis for optimizing manure storage and application strategies to minimize P losses and enhance crop production.