engleski

Soil, genotype and fertilization influences on magnesium concentrations in seven inbred lines of maize (Zea mays L.)

Magnesium uptake by plants is under influences of environment and heredity. Seven corn (Zea mays L.) genotypes were grown under field conditions of the northwestern Croatia. (two soils differing properties as follows: pH in KCl = 4.19 and 7.27, exchangeable Ca = 1900 and 5100 mg/100g, exchangeable Mg = 50 and 55 mg/100g, for stagnosol and cambisol, respectively.) for the growing seasons 1992 and 1993. The field trials (four replications, randomized block design, experimental plots 168.0 m2 and 22.5 m2, for fertilization and genotype, respectively ) included fertilization treatments (kg/ha) as follows: a) unfertilized plot ; b) ordinary fertilization (180 N + 130 P2O5 and 180 K2O) ; c) b+480 P2O5 ; d) b+480 K2O and e) b+480 P2O5+ 480 K2O. Ear-leaf was taken from each plot at beginning of silking stage. Dry ashing procedure (500oC) and digestion with HNO3 and HCl were applied for leaf samples digestion. Mg was determined in diluted filtrate by atomic absorption. Plant available P and K were determined by AL-method, while, exchangeable soil Mg and Ca were extracted by neutral (pH = 7.0) 1N CaCl2 solution. Although similar amounts of exchangeable Mg were found in tested soils there were considerable differences of plant Mg status. We presume that applied soil testing procedure is not acceptable for both tested soils. In general, soil, growing season and genotype were more influencing factors of Mg status in corn leaves in comparison to applied fertilization, probably because of adequate soil Mg supplies. For example, mean plant Mg concentrations (2-year means) were 0.250% and 0.445% Mg, for growing in acid and neutral soil, respectively. Depending on genotype, differences were in ranges (2-years mean) from 0.20 to 0.30% Mg (acid soil) and from 0.38 to 0.46% Mg (neutral soil). Similar trends of influences were found by the earlier study (comparison of grain yields, ear-leaf K and Mg status).

Soil; Genotype; Fertilization; Magnesium; Corn

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