Nutrient Runoff Losses from Liquid Dairy Manure Applied 
with Low‐Disturbance Methods. Issue 5 (1st September 2016)

• Record Type: Journal Article
• Authors: Jokela, William; Sherman, Jessica; Cavadini, Jason
• Is Part Of: Journal of Environmental Quality. Volume 45:Issue 5(2016)
• Page Start: 1672
• Page End: 1679
• Publication Date: 2016-09-01
• Subjects: Agricultural ecology -- Periodicals; Environmental engineering -- Periodicals; Pollution -- Periodicals; 630
• DOI: 10.2134/jeq2015.09.0498
• Languages: English
• ISSNs: 0047-2425

Abstract

Abstract : Manure applied to cropland is a source of phosphorus (P) and nitrogen (N) in surface runoff and can contribute to impairment of surface waters. Tillage immediately after application incorporates manure into the soil, which may reduce nutrient loss in runoff as well as N loss via NH3 volatilization. However, tillage also incorporates crop residue, which reduces surface cover and may increase erosion potential. We applied liquid dairy manure in a silage corn ( Zea mays L.)–cereal rye ( Secale cereal L.) cover crop system in late October using methods designed to incorporate manure with minimal soil and residue disturbance. These include strip‐till injection and tine aerator–band manure application, which were compared with standard broadcast application, either incorporated with a disk or left on the surface. Runoff was generated with a portable rainfall simulator (42 mm h −1 for 30 min) three separate times: (i) 2 to 5 d after the October manure application, (ii) in early spring, and (iii) after tillage and planting. In the postmanure application runoff, the highest losses of total P and dissolved reactive P were from surface‐applied manure. Dissolved P loss was reduced 98% by strip‐till injection; this result was not statistically different from the no‐manure control. Reductions from the aerator band method and disk incorporation were 53 and 80%, respectively. Total P losses followed a similar pattern, with 87% reduction from injected manure. Runoff losses of N had generally similar patterns to those of P. Losses of P and N were, in most cases, lower in the spring rain simulations with fewer significant treatment effects. Overall, results show that low‐disturbance manure application methods can significantly reduce nutrient runoff losses compared with surface application while maintaining residue cover better than incorporation by tillage. Core Ideas: Injection of manure greatly reduced P and N runoff losses. Banded aerator reduced dissolved P and N runoff losses compared with surface manure. Low‐disturbance methods conserved residue better than tillage incorporation of manure. Manure as surface residue contributes to reduced runoff sediment concentration.