Context

Sixty-four per cent of Catalonia’s regions already have nitrate vulnerable zones, where more than 170 kg of N from livestock excrement per hectare and year cannot be applied. One of the tools implemented to monitor the application of N in soil is the incorporation of a remote control system (via GPS) in manure tanks to register location and application information. This system is connected to a web-based data reception platform that enables the real-time reception, verification and storage of data by the Ministry of Agriculture, Livestock, Fisheries and Food (DARP).
The new decree on livestock manure introduces a new improvement to the system for the monitoring and control of the application of manure through the incorporation of conductivity metres in the tanks to estimate the content of N and K that is applied, rather than using the traditional theoretical reference values. Notwithstanding, conductivity is still not an exact or precise means of determining the concentration of nutrients (N, P, K) in liquid manure.
The development of a technology based on NIR (near-infrared spectroscopy) sensors linked to the GPS tank monitoring system that is currently in place would enable the complete monitoring and quantification of the distribution of the application of nutrients from livestock manure throughout Catalonia and especially the quantity of N, P, and K generated at each farm.