Delineation of management zones based on soil mechanical-chemical properties to apply variable rates of inputs throughout a field (VRA)

In the present investigation, field tests were carried out on a field belonging to a farm in the center of Italy. Wheat (Triticum durum) yield maps were acquired for three consecutive growing seasons (2007-2010) with a combine harvester, equipped with grain mass flow sensor, GPS and Precision Land Management Software. At the end of the third season, in the same field, a georeferenced grid sampling to investigate the soil physical-chemical properties, and to produce interpolated maps describing within field spatial variability was performed. The measured parameters were structural stability, water content, shear strength, and total Nitrogen. In order to identify potential management zones and yield limiting factors, two cluster analyses, based on fuzzy algorithm, were conducted considering the acquired soil parameters. The mean value of the three years yield was considered in the evaluation of the performance of the multivariate classification, rather than as layer for delineating management zones. In the field conditions of the performed tests, results show that shear strength and structural stability were the most significant limiting factors for the wheat yield.