b"Fertilizing Spuds with ManureHow good is using livestock manure for your potatoes?BY: ASHLEY ROBINSONLIVESTOCK MANURE HAS been used as a fertilizer forconcentrations in the soil with repeated applications. Although potato fields for decades, however the exact benefits of using itwith that said, we're also accumulating nitrogen, phosphorus, hasnt always been clear. As part of an eight-year study Ambersalts, especially at the highest application rates and frequencies. Moore, a soil fertility specialist at Oregon State University, lookedNitrogen and phosphorus may contribute to water quality into how effective dairy cow manure is for crops. Her findingsissues. Also, potatoes are salt sensitive, therefore excessive at the United States Department of Agriculture Agriculturalsalt accumulations above established thresholds are not ideal, Research Service station in Kimberly, Idaho highlighted theMoore explains.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. This suggests that manure could Between 2014 to 2018, Russet Burbanks were grown in a fieldbe used to improve soil health at the research station as part of the study. Spring wheat was grown in the fields before potatoes, with barley grown after.by improving soil organic matter Manure was spread on the fields during the fall either everyconcentrations in the soil with year or every other year. It was applied at rates of approximatelyrepeated applications. 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. AMBER MOOREIn the fields where manure was spread every other year, Moore found increases in nitrogen organic matter, potassium, boron, soluble potassium and sodium absorption ratio, andFor plant uptake, they discovered large amounts of potassium phosphorus. When manure was appliedin the tops of potato plants, and drops in magnesium, copper annually, almost all nutrients saw a boostand chloride levels. In the tubers phosphorus levels jumped, with except for soil iron and phosphorus,increases also noted in potassium, magnesium and manganese with calcium levels dropping. levels and decreases in zinc, copper and chloride levels. This suggests that manurePotatoes receiving manure application treatments took up could be used to improvesignificantly more phosphorus and potassium than fertilizer soil health by improvingtreatments, Moore says. Usually, we think of corn or wheat or soil organic matterother 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 didnt 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 werent affected. SPUDSMART.COM Summer 202115"