There is an assumption that organically managed farms must be maintaining a neutral or positive nutrient balance, but we cannot always be certain. Understanding the nutrient dynamics in organic farming across organic crop rotations can be difficult.
A group of UK organic farmers were supported by a researcher from ORC in using a nutrient model (NDICEA) with data of their farms and rotations to simulate nutrient flows. This video shares their findings.
Seven organic farms took the opportunity to look at one or more of their fields. They gained insights into their rotations and NDICEA seems to be a useful tool for assessing nitrogen supply/losses throughout a rotation.
The results on the farms indicate that there is a danger of losing nitrogen even in organic rotations. In the video, the researcher summarises the results and one of farmers taking part shares his thoughts. The common conclusions are that spring ley cultivation and strategic use of organic fertilisers are possible strategies for improving nutrient balances in organic farming. 'Flying livestock' and innovative strategies to keep the soil covered (e.g. living mulches, undersowing) may also help.