Gnojidba tla za uzgoj povrtnih kultura na širem području grada Ogulina

Provedena istraživanja imala su za cilj utvrditi pogodnost tla na širem području grada Ogulina za uzgoj povrtnih kultura. U tu svrhu utvrđena su fizikalno-kemijska svojstva tla na 250 ha površine u 2014. godini. Na temelju provedenih terenskih i laboratorijskih istraživanja utvrđeno je da istraživana tla spadaju u klasu automorfnih tala s građom profila A-(B)-C. Udio glinenih čestica s dubinom raste, što ukazuje na procese lesivaže. Riječ je o distrično smeđim tlima, lesiviranim s dubokim humusno akumulativnim slojem. Iz rezultatamehaničke analize sitnice utvrđeno je da se radi o homogenim tlima, praškasto ilovaste do praškasto glinasto ilovaste teksture. Dominiraju frakcije sitnog i krupnog praha te frakcije gline. Visoki udio praškastih i glinenih čestica čini ova tla slabo propusnim i sklonim zbijanju. Iz rezultata kemijskih analiza tla utvrđeno je da se radi o heterogenim tlima jako kisele do slabo kisele reakcije u oraničnom sloju tla, te je potrebno provesti kalcizaciju. Tla su umjereno do bogato opskrbljena humusom i ukupnim dušikom. Količina humusa i ukupnog dušika dubinom tla opada. Opskrbljenost tla biljci pristupačnim fosforom kreče se u vrlo širokom rasponu od vrlo slabe do bogate opskrbljenosti. Generalno gledajući, opskrbljenost tla biljci pristupačnim fosforom je slaba na najvećem dijelu površina, te je gnojidba fosfornim mineralnim gnojivima nezaobilazna agrokemijska mjera, dok je opskrbljenost tla biljci pristupačnim kalijem dobra do bogata.Conducted researches were aimed to determine suitability of soils in the wider city area of Ogulin for growing vegetable crops. For that purpose are defined physical and chemical characteristics of the soil on 250 hectares in 2014. Based on the conducted field and laboratory research it was established that investigated soils belong to the class of automorphic soils with profile A- (B) -C. The share of clay particles increases with depth, indicating a leaching process. It is a distric brown soils, leached with a deep humus accumulative layer. From the results of the mechanical analysis of the trinketsit is established that they are homogeneous soils, silty loam to silty clay loam texture. Dominated by fractions of fine and coarse powder and clay fractions. A high proportion of dust and clay particles makes this low permeability soils and prone to compaction. From the results of chemical analyzess showed that it is a heterogeneous soil very acidic to slightly acid reaction in the upper layers of soils, and it is necessary to implement calcification. Soils are moderately to richly supplied with humus and total nitrogen. The amount of humus and total nitrogen with depth of soils decreases. Soils supply of plant available phosphorus ranges in very wide range of very poor to the rich supply. In general, the supply of plant available phosphorus in soils is poor in most parts of the surface, therefore the fertilization with phosphorus mineral fertilizers is the unavoidable agrochemical measure, while the supply of plant available potassium is good to rich