Excess liquid manure confronts agriculture with ever greater challenges. The ecosystems soil, water and air are extremely polluted by the application of large quantities of liquid manure and thus by the nitrogen it contains on the fields. To reduce this problem in the long term, sustainable solutions are urgently needed.
The C.R.O.P.® process (Combined Regenerative Organic food Production) makes it possible to process liquid manure into a high-quality fertilizer using a purely biological method. The use of this fertilizer instead of untreated liquid manure enables a more specific use of nutrients, so that soils and waters are relieved of a massive nitrogen input.
The C.R.O.P.® process was developed at the Institute of Aerospace Medicine. It was originally designed for use in closed systems such as Moon or Mars base. By treating nitrogenous waste water to a fertilizer solution that is directly available to plants, the operation of soilless greenhouses and thus the production of vegetables is made possible. The underlying concept is shown in the following figure:
Scheme of the C.R.O.P.® cycle for the treatment of waste water
This approach to closing nutrient cycles is transferable to an application in agriculture. For this purpose, the C.R.O.P.® technology is currently being further developed in order to process liquid organic fertilizers such as liquid manure from agriculture into a higher-quality product. After this refinement, mainly nutrients that are directly available to plants are present in the solution. This biologically produced fertilizer reduces the uncontrolled and excessive application of nitrogen into the soil and groundwater and prevents the emission of environmental toxins (e.g. ammonia) from arable land. As a result, the usual smell of liquid manure is no longer produced during application, which also strengthens the social acceptance of organic fertilizers. After treatment with the C.R.O.P.® process, the nutrients are available in stable, non-volatile nitrogen compounds, which allows loss-free storage of the fertilizer or volume reduction.
Mode of operation
The C.R.O.P.® process completely avoids the use of chemicals and hazardous substances, as the process is based on natural metabolic processes that occur in nature. Due to a simple process control, without technically complex elements and with low energy input, the process requires little maintenance and can regenerate itself without any major delay even after possible incidents such as a pump or power failure. In the future, the processed liquid manure can also be used in closed systems similar to a Moon base. Instead of being spread on the field, it would be channeled into a soilless greenhouse right next to the barn, where, for example, protein-containing algae would be cultivated to serve as food for the animals.
Contribution to sustainable development in the agricultural sector
The C.R.O.P.® process developed by DLR is based on the United Nations' goals for sustainable development. The innovative treatment of nitrogen-containing wastewater from stables or a biogas plant not only reduces largely uncontrolled nitrate pollution, but also uses the resources gained from waste to increase nutrient cycles and contribute to sustainable agriculture. Here, the nutrients are returned to the cycle without major energy input, which means that energy-intensive techniques such as nitrogen recovery from the air can be saved.
The targeted application of C.R.O.P.® in agriculture can contribute to improved soil biodiversity by cultivating soil-living microorganisms in the process. Through this efficient fertilization with biologically processed organic fertilizers, higher yields can be achieved in agriculture and also in plant cultivation, and ultimately also contribute to improving nutrition.
C.R.O.P.® Biological manure treatment - Factsheet
DLR at AGRITECHNICA 2019
Hannover Messe: DLR zeigt Innovationsideen und Möglichkeiten zur Flexibilisierung des Energiesystems
C.R.O.P.® life support system at the Hannover Messe