Response of wheat crop during transition to organic system under Mediterranean conditions

Document Type: Research Paper


1 Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria - Unità di Ricerca per i Sistemi Colturali degli Ambienti Caldo-aridi, via Celso Ulpiani 5, 70125 Bari – Italy.

2 Università degli studi di Bari “Aldo Moro”, Dipartimento di Scienze del Suolo, della Pianta e degli Alimenti, Via Giovanni Amendola165/A, 70126 Bari – Italy.


Organic agriculture is an ecological production management system aimed at sustainable
production of safe food, environmental protection and maintenance of soil health. The objective
of this study was to evaluate, in a period of organic transition, the effects of different organic
fertilizers on wheat yield, grain quality and soil characteristics. The research was performed
in an experimental farm of Southern Italy (Foggia), over a three year period. An organic
commercial fertilizer and compost, obtained from municipal wastes, with and without a
commercial bioactivator, were compared in a randomized block design. Grain yield and quality
and soil total organic carbon content (TOC) were measured. The Henin-Dupuis model was also
tested to simulate soil organic C dynamics after organic fertilizer application. Among the years,
significant differences were observed in grain yield and quality, indicating that wheat crop
response was influenced by the weather conditions. The grain and straw yield was not
significantly affected by the organic fertilizer used, though the compost resulted in significantly
lower grain quality compared with the organic commercial fertilizer. In any case, at the end of
the experimentation, the compost resulted in significantly higher TOC (+4%) compared to the
organic commercial fertilizer. The results showed that the compost may be used as an
alternative to sustain wheat productivity, feasible also from an economic point of view and to
conserve soil fertility. Finally, under the local Mediterranean conditions, the soil organic C
dynamics could be defined by the Henin-Dupuis model, also considering the C supply of annual
root residues.