Effects of organic amendments and cover crops on soil characteristics and potato yields

ABSTRACT

Intensive potato production may reduce the soil organic matter content (SOM), which may impact several soil functions and increase the incidence of potato diseases. We examined if cover crop and addition of organic materials may counteract these effects. Organic materials were one application of biochar mixed with liquid digestate (BLD); solid digestate (SD); or farmyard manure (FYM); with or without winter rye as cover crop, in a field with regular potato growing. Organic amendment increased SOM, especially for FYM and BLD, while cover crop did not affect SOM. Yet, cover crop increased tuber yields in the second year, and reduced the severity of potato diseases by 10% in post-harvest potatoes in both years. In the second year, the number of marketable potatoes after storage increased by 37% with cover crop. Organic amendments did not affect potato yield or quality, but the proportion of marketable potatoes tended to be higher in the amended soil. By lab incubation, BLD showed the largest potential for SOM storage, up to 32 years, followed by FYM and SD. Cover crops and organic amendments is recommended in potato production, especially for early potatoes where there is sufficient time after harvest to establish a good cover crop.

KEYWORDS:

• Biochar
• farmyard manure
• liquid digestate
• potato disease
• potato quality
• solid digestate
• soil organic matter

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors thank the Regional Research Fund of Mid-Norway for financial support (project number 299125).

Notes on contributors

Tatiana Francischinelli Rittl

Tatiana Francischinelli Rittl is a researcher at the Norwegian Centre for Organic Agriculture, her work aims to contribute to sustainable solutions for agriculture at the interface between soil health and climate change.

Frode Grønmyr

Frode Grønmyr is an advisor at Landbruk Nordvest, he works directly with the farmers to overcome local challenges and implement sustainable solutions on vegetables and cereals production.

Ivar Bakken

Ivar Bakken was the former CEO of Sunndalspotet, he has a large experience on potato production from the farm to the market.

Anne-Kristin Løes

Anne-Kristin Løes is a senior researcher at the Norwegian Centre for Organic Agriculture with an extended experience on plant nutrition, recycled fertilisers, interdisciplinary research.