LAUSR

Tillage incorporation of manure can mitigate nutrient loss but increases erosion potential and damages cover crops. More information on the effects of low-disturbance manure application (LDMA) on corn yield, cover crop establishment, and soil properties is needed to better predict manure management practice trade-offs. Here, corn silage (Zea mays L.) yield, winter rye (Secale cereale L.) establishment, and soil nitrate concentrations were compared for a range of manure application methods, including broadcast incorporation, broadcast/disk, fertilizer N (spring applied at 67, 134, and 202 kg N ha-1 ), and a no-manure control, at the University of Wisconsin's Marshfield Agricultural Research Station from 2012 to 2015. Compared with the control, manure and fertilizer N treatments increased corn yield by an average of 1.1- to 1.6-fold and 1.4- to 1.6-fold, respectively. Of the LDMA treatments (sweep-, strip till-, and coulter-injection; aerator/band; broadcast), corn yield was greatest for sweep injection, which did not differ from the high N fertilizer rate (P < .0001). Corn yield averaged across LDMA treatments did not differ from the 134 or 202 kg N ha-1 yields. Compared with disking, LDMA maintained more crop residue (P < .0001), with levels comparable to the control. Soil nitrate-N at depths of 0-30 and 30-60 cm was influenced by LDMA and fertilizer N; however, leaching to 60-90 cm was comparable among treatments. Results indicate that LDMA with injection conserved more N, caused less damage to winter rye, and had similar yields to fertilizer N treatments with improved soil aggregate stability and higher total carbon content.