AgronomyCrop InputsUsing Manure to Fertilize Spuds

Using Manure to Fertilize Spuds


How good is using livestock manure as a fertilizer for your potatoes?

Livestock manure has been used as a fertilizer for potato fields for decades, however the exact benefits of using it hasn’t always been clear. As part of an eight-year study Amber Moore, a soil fertility specialist at Oregon State University, looked into how effective dairy cow manure is for crops. Her findings at the United States Department of Agriculture Agricultural Research Service station in Kimberly, Idaho highlighted the pros and cons of using livestock manure to fertilize spuds. She presented these highlights during a session at the virtual Washington-Oregon Potato Conference on Jan. 27, 2021.

Between 2014 to 2018, Russet Burbanks were grown in a field at the research station as part of the study. Spring wheat was grown in the fields before potatoes, with barley grown after. Manure was spread on the fields during the fall either every year or every other year. It was applied at rates of approximately eight, 16 and 24 tonnes per acre on a dry weight basis, or on a wet basis at 16, 32 and 48 tonnes per acre.

In the fields where manure was spread every other year, Moore found increases in nitrogen organic matter, potassium, boron, soluble potassium and sodium absorption ratio, and phosphorus. When manure was applied annually, almost all nutrients saw a boost except for soil iron and phosphorus, with calcium levels dropping.

“This suggests that manure could be used to improve soil health by improving soil organic matter concentrations in the soil with repeated applications. Although with that said, we’re also accumulating nitrogen, phosphorus, salts, especially at the highest application rates and frequencies. Nitrogen and phosphorus may contribute to water quality issues. Also, potatoes are salt sensitive, therefore excessive salt accumulations above established thresholds are not ideal,” Moore explains.

For plant uptake, they discovered large amounts of potassium in the tops of potato plants, and drops in magnesium, copper and chloride levels. In the tubers phosphorus levels jumped, with increases also noted in potassium, magnesium and manganese levels and decreases in zinc, copper and chloride levels.

“Potatoes receiving manure application treatments took up significantly more phosphorus and potassium than fertilizer treatments,” Moore says. “Usually, we think of corn or wheat or other crops where you remove the whole plant as plants that you use to remove phosphorus from the field and not potatoes. But because the majority of the phosphorus is found in the tubers, the potato harvest is actually quite effective for removing phosphorus.”

It was determined biennial manure treatments didn’t affect yield, tuber size, gravity, tuber moisture, sugar ends, fry quality glucose, sucrose, bruising, shatter, modeling, hollow heart, pinkeye, or wireworm damage. Annual treatments though did see some effect on yield with gravities dropping and more small tubers instead of larger ones developing, however other characteristics weren’t affected.

Related Articles

Roundtable — The Latest Practices for Use of Liquid and Dry Fertilizers

Increasing the efficiency of fertilizer use in potatoes

Conservation Measures Outperform Conventional Yields

Trending This Week

Spudnik 8312 planter

Manitoba Potato Planting Nearing Finish Line

Almost 95 per cent of Manitoba's processing potato crop has been planted, the May 26 provincial potato report from Manitoba Agriculture’s Vikram Bisht said. Seed...
Person making a plan

Setting Goals in Cover Cropping — A Key to Success

Where are you going? How soon do you want to get there? These are questions we need to ask before we head out on...
Newly emerged rows of potatoes

It’s Go-time for Growing Season 2023 (But Don’t Forget Storage, Too)

Planting is on the horizon in some areas and in full swing in others! After a frustratingly cool and slow spring in most potato-growing...
Beer at bar

What About Sustainability in Storage?

I was having a beer with a potato farming buddy a couple nights ago and – as usual - we started talking shop: what’s...
Green potato field

How Do We Achieve Meaningful Sustainability?

It seems everyone is talking sustainability today. But, what does sustainability really mean in the context of today’s farming realities, and how do we...