Organic potato farming accounts for only 0.3% of the total potato growing area in Québec (CARTV 2012). Recent consultations with a number of producers and extension agents revealed the lack of an established, effective nitrogen fertilization program that ensures a balanced phosphorus budget. Since potatoes have high nitrogen requirements, using manure to meet this need leads to phosphorus saturation of the soil and its use is necessarily limited on phosphorus-rich soils. The problem is particularly severe with potatoes because fresh manure cannot be used because of the risk of potato scab while composting reduces effective nitrogen content and concentrates the phosphorus. Pelleted chicken manure offers an alternative because it is high in effective nitrogen, but it is costly and also high in phosphorus. So there is a great need to test green manure as a main source of nitrogen. An added benefit is that green manure helps maintain soil quality and control weeds. Testing and validating a nitrogen fertilization program will support the transition to and expansion of organic farming in line with MAPAQ’s strategy in that regard.
From 2016 to 2019
Green manure applied to potato growing areas helps maintain soil quality and control weeds.
Growing Forward 2 | Ministère de l'Agriculture, des Pêcheries et de l'Alimentation du Québec - Innov'Action Programme | Agriculture and Agri-Food Canada
The fungal pathogen Helminthosporium solani causes silver scurf, a disease that is hard to detect, both in the soil and on harvested potatoes.
Researcher: Richard Hogue
Meeting nitrogen requirements mainly through the use of a highly stable form of fertilizer can minimize nitrogen losses, provide nitrogen amounts closer to the plant’s actual needs.
Researcher: Christine Landry