Concepts and techniques for sustainable slurry management on farms

Byproducts of animal husbandry (excreta) can cause pollution of the environment and secondary effects like damage to the atmosphere, hydrosphere, and biosphere by nutrients, hazardous compounds and pathogens. For sustainable development the challenge is to balance the input and output of nutrients concerning organic crop fertilization and minimizing environmental impacts. Therefore, the requirements are defined by the amount of fertilizer based on the physiological nutrient uptake of crops. Based on data from long-term experiments, a time scheduler for organic fertilization can be established. Treatment techniques for liquid manure on farm sites were designed to decrease environmental impacts and to optimize manure characteristics for fertilization. The techniques of solid-liquid separation and anaerobic digestion are the main focus. Main requirements upon the application technique are: distribution precision (dosage/accuracy) and low air pollution. Therefore, systems with speed-independent application quantity ("flow control") and integration into existing on-board computer systems were developed and improved concerning precision of dosage and distribution accuracy and reduction potentials for ammonia emissions.