Soil chemical properties under organic and conventional crop management systems in south Poland

Abstract

There is a great need to assess the impact of farming methods on soil fertility, especially in specific ecoregions. In Poland, relatively limited research has been conducted on soil quality and fertility in organic, dynamically developing agricultural systems. A comparative study on soil parameters under organic and conventional cultivation was performed in 2009. Twenty-two pairs (organic-conventional) of fields located in the south and east of Poland were chosen. All organic sites were certified. The following field crops were investigated: apple, pear, blackcurrant, carrot, beetroot, and celery. The soil granulometric composition, total organic content, total nitrogen, as well as the content of available macroelements (P, K, Ca, Mg, S), microelements (Cu, Fe, Zn, Mn, B), and trace elements (Cd and Pb) were measured. The organic farm soils had a higher level of the total organic matter (2.02%) than the conventional (1.75%). The organic system increased the total soil N level in celery and beetroot fields. Low or very low concentrations of available P in organically managed orchards were observed in individual farms, whereas excessive soil P amounts were noted for organic beetroot and celery fields. Differences in soil K concentration caused by the farming system were found only for red beet. Ca concentration was higher in the conventional than in the organic soil only for celery. There was a higher soil available Cu concentration for all of the investigated conventional vegetable fields than for the organic. The reverse was true for the apple and blackcurrant farms. The highest levels of Cd and Pb were noted in soils sampled from some organic celery fields.