IMPACT OF CONVENTIONAL AND ORGANIC FARMING ON CHEMICAL SOIL PROPERTIES

Niz istraživanja koja su provedena krajem 20. stoljeća diljem svijeta, a koja su se bavila utjecajem poljoprivrede na tlo, ukazala su na prednosti ekološkog uzgoja u odnosu na konvencionalni uzgoj. Cilj ovog rada bio je utvrditi utjecaj načina gospodarenja tlom na kemijske parametre tla uzorkovanih s parcela pod ekološkim i konvencionalnim poljoprivrednim uzgojem. Uzorkovano je ukupno 30 uzoraka tla, od kojih 20 s površina ekološkog poljoprivrednog gospodarstva Sever (Hrvatska) i 10 uzoraka s konvencionalnih poljoprivrednih gospodarstava Lisičak i Tomaj (Hrvatska). Istraživani kemijski parametri bili su: pH vrijednost (reakcija tla), količina humusa, ukupna količina ugljika, dušika i sumpora, količina fiziološki aktivnog fosfora i kalija, te C/N i N/S odnos. Rezultati ispitivanih pH vrijednosti, količine humusa, fiziološki aktivnog fosfora i kalija te C/N odnos u tlu nisu pokazali značajnu razliku između ispitivanih parcela. Uzorkovane parcele nalaze se na tipovima tala koja su prirodno kisela i slabo humozna, a niti konvencionalni niti ekološki poljoprivredni uzgoj nije uspio poboljšati ove parametre tla. Unatoč tome, treba istaknuti da su parcele pod ekološkim uzgojem u prosjeku imale bolji C/N odnos za 0,7 u odnosu na konvencionalni uzgoj. Parcele pod konvencionalnim uzgojem imale su značajno veću količinu ukupnog ugljika, sumpora i dušika te N/S odnos u odnosu na parcele pod ekološkim uzgojem.In the late 20th century, a number of studies were conducted around the world which deal with different types of farming methods and their influence on the soil. The results of these studies highlighted the advantages of organic farming over conventional farming. The aim of this study was to determine the impact of land management on chemical soil parameters of soils sampled from plots under organic and conventional farming. A total number of taken samples was 30, from which 20 samples were taken from the organic farm Sever (Croatia), and 10 samples were taken from plots on the conventional farms Lisičak and Tomaj (Croatia). Investigated chemical parameters were: soil pH, quantity of organic matter, total nitrogen quantity, the quantity of plant available phosphorus and potassium, the total quantity of carbon and sulphur, and the C/N and N/S rations. The results of soil pH, organic matter quantity, quantity of plant available phosphorus and potassium and C/N ratio showed no significant difference between plots under conventional and organic farming. Sampled plots are located on the types of soil that are originally acidic and with low quantity of organic matter. Neither conventional nor organic farming managed to improve those soil parameters. Despite mentioned, it is necessary to point up that the plots under the organic farming in average had better C/N ratio for 0,7 compared to conventional farming. Plots under conventional farming had significantly higher total carbon, sulphur and nitrogen quantity also as the N/S ratio