Organic crop cultivation can survive without animal manure.

Ecologists, who have difficulty obtaining manure, can still achieve reasonable yields through carefully planned crop rotation combined with green manure. The recipe for a crop rotation without manure can be seen at the Organic Market Day on Wednesday, June 3, just outside the Tent, where seven small plots with crops demonstrate the crop rotation that the Innovation Center for Organic Farming has developed, measured, and calculated over the past three years. This is stated by the innovation center in a press release. The crop rotation is based on two years of clover grass for biogas, addition of garden/park compost, as well as catch and cover crops where appropriate. Organic clover grass for biogas plays a dual role: it provides biomass for energy and valuable nitrogen for subsequent crops. "It is a good pre-crop for cereals and rapeseed, but it also produces a liquid biogas slurry that can be distributed in the crop rotation. Besides nitrogen, the crops need phosphorus and potassium, which we supply in the form of garden/park compost, an accessible nutrient source in many parts of the country," explains chief consultant Sven Hermansen from the Innovation Center for Organic Farming. The digested biomass is a valuable, transportable fertilizer that can be used on other fields. Root biomass and catch crops further contribute with a residual effect of about 100 kg N per hectare in the first year after plowing and an additional 50 kg N per hectare the following year, significantly contributing to the overall nitrogen supply of the crop rotation. Innovation Center tests crop rotation on a large scale The crop rotation has been established on a larger scale in a test field at an organic farm west of Aarhus. In the field, the Innovation Center for Organic Farming conducts experiments and collects data, for example, on yields and nitrous oxide production in the years following plowing of clover grass and catch crops. Experiments and recordings provide input on some very central and current challenges for both organic growers and society as a whole: - How can we double the organic area if more livestock are not involved? - How can we maintain and increase yields in a plant-based, organic crop rotation with sale crops? - What role does compost play? Is it basic fertilizer? Does it have nitrogen effects, or is it yield-limiting — and how long after application? - How large is the nitrous oxide emission from plowed clover grass and catch crops, and does adding compost make a difference? - Is the system economically sustainable? At the Tent on Organic Market Day, Morten W. Vestenaa and Sven Hermansen will share much more about the results and yields achieved in the test field and the prospects for organic crop cultivation moving forward. "And we probably can't completely avoid also discussing the consequences of the new nitrogen regulation for organic farmers, since it concerns the organic crop rotation. The two things are very interconnected," says Morten W. Vestenaa. Organic Market Day will be held on Wednesday, June 3, from 9 am to 6 pm in Almind near Kolding. The event is organized by the Innovation Center for Organic Farming, Agriculture & Food Organic, the Organic Association, Velas, Organic Consulting Denmark, Southern Denmark Organic, Agillix, and Icrofs. There is also broad collaboration with machinery manufacturers, seed companies, and other businesses regarding activities on the day. Organic Market Day is supported by the Foundation for Organic Farming.