Manure injection and rye double cropping increase nutrient recovery and dairy forage production

Authors: BINDER, JONATHAN - Pennsylvania State University; KARSTEN, HEATHER - Pennsylvania State University; BEEGLE, DOUGLAS - Pennsylvania State University; Dell, Curtis

Submitted to: Journal of Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/31/2020
Publication Date: 4/24/2020
Citation: Binder, J., Karsten, H., Beegle, D., Dell, C.J. 2020. Manure injection and rye double cropping increase nutrient recovery and dairy forage production. Journal of Agronomy. 112(4):2968-2977. https://doi.org/10.1002/agj2.20181.
DOI: https://doi.org/10.1002/agj2.20181

Interpretive Summary: Winter cover crops are important for preventing soil erosion and nutrient losses, but the farmer must decide whether to harvest the cover crop for forage (double cropping) or leave it in the field as green manure and whether to apply manure before or after the cover crop is planted. Penn State and ARS scientists conducted field studies to test combinations of ryegrass cover crop harvest options and manure application timing with both surface applied and injected manures. The study showed that double cropping can increase the annual forage production on the farm. Establishing the cover crop before manure application and injecting manure also increased the productivity of the cover crop and yield of the following corn silage crop.

Technical Abstract: Double-cropping forage cereal rye (Secale cereal L.) after corn silage (Zea mays L.), injecting manure, and prioritizing timing of rye planting over manure application in the fall may increase manure nutrient utilization and total farm production. We conducted a two-year full-factorial experiment in Pennsylvania to quantify the effects of (i) cereal rye management (RyeM) (cover crop [CC] vs. double-crop [DC]), (ii) fall-applied liquid dairy (Bos taurus L.) manure application method (ManM) (broadcast [BM] vs. inject [IM]), and (iii) field operation priority (priority) (manure first priority [MP] vs. rye first priority [RP]) on rye biomass, rye apparent manure-N and -P recovery (ANR, APR), corn silage yield, and total forage production. After MP rye establishment failure in the second year, we divided the data into two datasets: a RP-only dataset of RP treatment combinations pooled over two years, and a priority comparison dataset of one year of all treatment combinations. Our results showed that DC, IM, and RP increased rye biomass, nutrient utilization, and forage production in general compared to CC, BM, and MP. Managing rye as DC increased nutrient recovery and total forage production by between 11 and 45% with BM and between 27 and 56% with IM. Injecting manure increased N recovery in both priority systems and increased subsequent corn yields, but increased N recovery due to IM was greater when manure was applied earlier with MP system. Prioritizing rye planting over manure application increased rye biomass and nutrient recovery and may be important for ensuring winter annual establishment.