Effect of long term organic and conventional fertilization method on chosen soil chemical properties
The aim of the study was to compare a long term effect of oppositional fertilization methods, organic vs. conventional, on chosen soil chemical properties. Soil samples were collected from organic farms with at least 10-years history of organic management and from neighboring conventional farms. In total soil samples from 66 farms distributed all over Poland were collected. The following properties were analyzed: organic carbon (Corg), total nitrogen (Ntot), pH, exchangeable forms of P, K and Mg. In general organic management resulted in slightly higher soil pH. Bigger differences were found in case of C and N content. Thanks to organic fertilization method in loamy and clay soils C content was higher by 13.5% and N content was higher by 20.3%. The same tendency, although not so marked, was found on sandy soils. Conventional fertilization resulted in higher content of exchangeable P, especially on sandy soils. Almost the same content of exchangeable K was found on both farm types. Higher amounts of exchangeable Mg was found on organic farms on each soil type: sandy, loamy and clay. In the same time bigger disproportions of Mg content were found on organic farms (30–112 mg Mg kg−1) than on conventional farms (30–87 mg Mg kg−1).