In this study appraisal of four different agricultural land evaluation methods including the so-called Storie method, square root method, maximum limitation method and fuzzy sets method, was done. The study was performed in Bastam region, located in Semnan province at the north east of Iran. Three crops including tomato, wheat and potato were assessed for the purpose of this research. Soil characteristics assessed were rooting depth, CaCo 3, organic carbon content, clay content, pH and slope gradient. Statistical analyses were done at significance levels of α = 0.1 and α = 0.05. Results of regression between land indices, calculated through the four methods, with observed yields of the crops, showed that the regression were significant in fuzzy sets method for all of the assessed crops at p = 0.05 but not significant in maximum limitation method for any of the crops. The Storie and square root methods also showed a significant correlation with wheat yield at p = 0.1. This study was a demonstrative test of fuzzy sets theory in land suitability evaluation for agricultural uses, which revealed that this methodology is the most correct method in given circumstances.Key words: fuzzy sets, land evaluation, land use, soil classification, crop growth conditions, soil suitability, crop selection
IZVLEČEK
UPORABA METODOLOGIJE MEHKIH MNOŽIC PRI OCENI PRIMERNOSTI TAL ZA RAZLIČNE POLJŠČINEV raziskavi so bile ocenjene štiri metode vrednotenja kmetijskih zemljišč vključujoč Storijevo metodo, metodo kvadratnega korena, metodo maksimalne omejitve in metodo mehkih množic. Raziskava je potekala na območju Bastama, v provinci Semnan, v severovzhodnem delu Irana. Primernost zemljišč je bila ovrednotena za tri poljščine, paradižnik, pšenico in krompir. Ocenjene so bile naslednje lastnosti tal: globina koreninjenja, vsebnosti CaCO 3, organskega ogljika in gline, pH in naklon zemljišča. Statistične analize so bile narejene pri stopnji značilnosti α = 0,1 in α = 0.05. Rezultati regresijske analize za odvisnost pridelkov izbranih polščin od indeksov primernosti zemljišč, izračunanih po zgoraj omenjenih metodah je pokazala, da je statistično značilna samo odvisnost pridelka od indeksa primernosti zemljišč dobljenega z metodo mehkih množic" Storijeva metoda in metoda kvadratnega korena sta pokazali značilno odvisnost prideleka pšenice od indeksa primernosti zemljišč pri α = 0,1. Raziskava je bila demonstracijski preskus primernosti uporabe metode mehkih množic pri vrednotenju zemljišč v kmetijski rabi. Ugotovljeno je bilo, da je bila ta metodologija v danih okoliščinah najprimernejša.Ključne besede: mehke množice, vrednotenje zemljišč, raba tal, klasifikacija tal, razmere za rast poljščin, primernost tal, izbira poljščin