Organic Fertilizer for Potatoes

Organic fertilizer for potatoes ensures growing plants receive adequate nutrients, particularly nitrogen.

Organic fertilizer benefits potato plants by increasing nutrients and organic matter in the soil and improving soil structure. Homemade organic fertilizers also can be less expensive than commercial products, another incentive for organic gardeners.

Nutrient and Soil Requirements of Potatoes

The National Sustainable Agriculture Information Service notes developing potatoes need high levels of nitrogen and potassium. As a guideline, Utah State University Cooperative Extension recommends 4 to 6 pounds of nitrogen per 1,000 square feet, added two or more times during the growing season. Acceptable soil pH can vary, but a level between 5.0 and 5.2 is recommended to prevent potato scab.

Organic Options

Organic nitrogen is commonly supplied to potatoes as fertilizer in compost and dairy and poultry manures. For growing potatoes, Steve Solomon, writing in the June/July 2006 "Mother Earth News" suggests making an organic fertilizer of seed meal, agricultural lime, gypsum, dolomitic lime, bone meal, rock phosphate, guano and kelp meal and using steer manure or finished compost. Sulfur is a good organic option to lower soil pH.

Warnings

If overapplied, organic matter can burn and damage young plants because it contains high levels of salts. Follow all fertilizer instructions carefully. Watch for signs of nitrogen imbalance in growing potatoes. Nitrogen-deficient potatoes are stunted and older leaves turn yellow; too much nitrogen delays tuber development and causes thick vine growth.

References

• National Sustainable Agriculture Information Service: Potatoes: Organic Production and Marketing
• Utah State University: Selecting and Using Organic Fertilizers
• University of Minnesota Extension: Potato Fertilization on Irrigated Soils
• University of Maine: Potato Facts Producing Potatoes Organically in Maine
• "Mother Earth News"; A Better Way to Fertilize Your Garden; Steve Solomon; June/July; 2006