Argonomic rate / capacity of Willamette Valley Grass Hay Mixture
I am working on a DEQ Water Pollution Control Facilities Permit 1400-B for a new Hard Cider Production Facility to be built on my land. I plan on land applying all of my PW (Process Wastewater) using traditional irrigation techniques, K-Line sprinklers, drip etc. Part of the requirements of the DEQ Permit is to identify the maximum agronomic capacity of the vegetation that will be irrigated with the PW in order to make sure the nitrogen uptake levels in the vegetation being irrigated are not being exceeded. From what I understand the nitrogen and ammonia load for hard cider PW is negligible. The three types of crops that will be irrigated with PW will be typical mixed grass hay, hops and apple trees. I would appreciate any help or guidance regarding this subject. Thank you very much.
I am not an expert in this area, but I will share some basic resources and refer you to some other Extension faculty.
People use the Fertilizer Guides published by OSU Extension researchers. I am assuming that you are testing the wastewater so you know how much nutrients you will be applying, and so you will need to know the recommended fertilizer rates for the crops. The guides may be found on this website https://catalog.extension.oregonstate.edu/topic/agriculture. I took a quick look and I found one for hay and one for apples. I did not find one specific for hops.
You will have to seek further assistance if you are applying more than these recommended rates. These crops and soils may be able to take up higher rates than the guides recommend.
I recommend following up with Dan Sullivan in the Crop and Soils department - 541-737-5715 or firstname.lastname@example.org. He has worked on municipal sludge applications on crops in the Willamette Valley. He might be able to help you. You could also try Clare Sullivan, field crops faculty for Linn, Benton and Polk counties (email@example.com, no relation to Dan). She is new to the area but might be able to research the question related to hops and hay.
Good luck on your project.