Sustainability Evaluation of Manure Distribution with Dynamic Simulation Model

Sustainability Evaluation of Manure Distribution with DynamicSimulation Model Sustainability Evaluation of Manure Distribution with DynamicSimulation Model The continuous development of new crops for anaerobic digestion has led to the need to manage in a rational and environmental-friendly way the distribution of the digested products that comes out of the digesting process. The EU, national, and regional regulations set the time windows when it is allowed to carry out the slurry applications and the limits on the amount of Nitrogen per hectare from livestock to be distributed in the field. The purpose of the study was to compare the use of traditional liquid slurry tanks [LST] vs. the drag hose system [DHS] in terms of application performance and operation costs. Based on the field trials carried out in 2008 and 2009 a dynamic, discrete-event simulation model using Extendsim® software (Imaginethat Inc, USA) was built. The experiments considering the following factors: field distance (1 to 10 km step 1 km), field size (2, 4, and 6 ha) and rates of Nitrogen distributed per ha, included the EU regulation limits (170 and 340 Kg N.ha-1, as were the maximum Nitrogen rates imposed by the European directive and Italian law on vulnerable and non-vulnerable soils). Slurry applied using the LST system was shown to be more economical fertilizer vs. mineral fertilizers if the transport distances were below 9 km, with an application rate of 170 kg N/ha. The DHS was shown to be more economical for all the simulated scenarios. The DHS allowed, however, a very important reduction in working time (up to 71% for 10 km pipeline) compared with the LST system, allowing covering of a large area within the available days completing the seeding operation in a timely manner.