A Decision Support System (DSS) for Managing N Fertilization in Artichoke.

The present work illustrates the theoretical basis and the methodological approach of a new decision support system (DSS) program - called ArtichoN - for the management of N fertilization in artichoke crop; it uses a simplified N-balance model with the aim of providing to the farmers helpful tools to maintain their profitability, while minimizing the environmental impact of N-fertilization. The methodological approach used for scheduling N-fertilization is based on forecast of the daily amount of N uptake by the crop and of N available into the root zone in order to fulfil N-crop requirements by the soundest N supply to the soil, as follows: N-fertilization = N-crop uptake – N-soil availability. This DSS works on a daily basis through the following steps: a) estimation of a daily dry mass accumulation on the basis of cumulated degree days; b) derivation of the daily N-uptake by the crop as a function of the estimated accumulation of DM using specific N-dilution curves; c) estimation of the daily N-available in the soil intercepted by the roots (mineral and mineralised); d) daily N-balance (N-uptake – N-available in the soil); e) make a decision on the N-application rate and application scheduling on the base of the balance result and on moment of the growing cycle; For the steps a and b, it uses specific regression curves built by fitting non-linear functions on experimental data in Sothern Italy area obtained from literature. For the estimation of N mineralization it uses an approach from literature. The program allows to simulate crop growth by using historical meteorological data (multiannual averaged daily minimum and maximum temperature: Tmin and Tmax) specific of the area where the farm is located and thus producing a foresight N-fertilization plan.