A comparison of soil quality and yield parameters under organic and conventional vineyard systems in Mediterranean conditions (West Turkey)

Abstract

Soil chemical and microbial parameters are commonly used as soil quality indicators to evaluate sustainable land management in agroecosystems. The objective of this research was to evaluate the impact of organic and conventional management strategies on biological, chemical and yield parameters in vineyards (Vitis vinifera cv. Sultani seedless). Organic plots received a mixture of barley, vetch and broad bean (25+35+75 kg seed ha^− 1) as green manure, and farmyard manure (15 t ha^− 1) every year. Inorganic fertilizers (NPK) and pesticides were used in the conventional managed vineyards. Conventional and mulch tillage methods were used in conventional and organic plots, respectively. Microbiological and chemical soil properties were determined in the soil samples which were taken four times in 2004, 2005, 2006 and 2007. In addition, the yield and some quality parameters of vineyards were also determined. Soil microbial biomass, and dehydrogenase, β-glucosidase and alkaline phosphatase activity were significantly higher in organic management than in conventional management. Higher C_mic/C_org and lower qCO₂ values were found with the organic management. The response of the chemical indicators (C_org, N_t and available nutrient content) of the soils to different management systems appeared after a longer time than with the biological indicators. In the transition zone between continental and Mediterranean climates of West Turkey, soil quality of organically managed vineyards improved after 2 years of the transition period prescribed for organic certification. However, soil quality improvements in organic plots did not result in higher yield.

Keywords:

• available plant nutrient
• enzyme activity
• microbial biomass
• organic farming

Acknowledgements

This work was supported by the TAGEM [Grant number 111.05.2.001].

Disclosure statement

No potential conflict of interest was reported by the authors.