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OSU Extension

College of Food, Agricultural, and Environmental Sciences


About: OSU research shows that for each ton of hay produced, 12lbs of P2O5 (phosphorus) & 49lbs of K2O (potassium) are removed. It is common to use a complete balanced fertilizer such as 19-19-19 on hay fields. Therfore, if even amounts of elements are supplied  potassium can become extremly deficient in the field. Building nutirent levels back up can be costly, but is it worth it? We hope to find out!

Our field will start off with the same rate of 9-23-30. Soil samples will be taken 2 months later and potash 0-0-60 will be applied based on the sampled levels. We will make a full application based on recommendations and a 1/2 rate application. Which will show the greatest return on investment? We will also monitor plant growth throughout the season and forage quality at harvest. 

Discussion & Involvement: email James Morris ( for any comments or questions. 

June 24, 2021

Plot harvest in planned to happen in coming days. We collected 26 samples from our soon-to-be treatment rows. The entire field has had the same seeding rate and rate of 9-23-30 fertilizer applied. Sample taken this week will be used to measure our change after multiple rates of 0-0-60 are applied late this year.

June 4, 2021

Plant sward height was about 16". Overall, forage stand has emergened evenly and appears healthy. No nutirent defecienes present. Some low lying areas outside of research areas appear stressed from excessive saturation. Little weed pressure from common ragweed. 

Growing Degree Day since planting: 457


May 10, 2021

Oats are growing well. Orchardgrass and clover beginning to emerge..



April 20, 2021

Approximate planted/acre: 54lbs Oats, 27lbs Orhcardgrass, and 2lbs Clover

Fertilizer: Entire field received ~350lbs/acre of 9-23-30