Correlations in the Soil – Water – Plant System in Maize from Crişurilor Plain

The paper based on the researches carried out during 2007-2009 in the conditions of the preluvosoil from Agricultural Research and Development Station Oradea. This area is characterized by moderate wet climate. The following indicators for characterization of the soil-water-plant system were used: de Martonne aridity index and Domuţa climate index.Two variants were studied: unirrigated and irrigated. Maintaining the soil water reserve on watering depth between easily available water content and field capacity determined the irrigation use. The irrigation determined the improve of the microclimate conditions, the increase of the plants water consumption, yield gains and protein content very significant bigger than in unirrigated variant. Better correlation coefficients was quantified for links climate conditions-water consumption, climate conditions-yields, climate conditions-protein content using the indicator “Domuta climate index”, than using the indicator “de Martonne index”; the explanation consists of the bigger number of climate elements used: 4 (water, air, humidity, temperature) in comparison with 2 (water, temperature)