engleski

Response of corn hybrids on two soil types of Slatina podravina area

Ten corn hybrids were grown on two soil types of Drava Valley in Slatina area (alluvial soil and pseudogley) during two growing seasons (1998 and 1999). The field trials were sown by pneumatic sowing machine in four replicates (exp. plot 14m2). Planned plant density (PPD) depends on the hybrids and it was 71428, 63493 or 58310 plants/ha.. Grain yields were calculated on 14% moisture and 90% realization of PPD basis. The ear-leaf at beginning of silking stage was taken for chemical analysis. The total amount of N was determined by Kjeldahl procedure, while P and K in corn leaves samples was measured by ICP-AES technique after their microwave digestion using concentrated HNO3+H2O2. Mobile fraction of these elements in soils was also determined by ICP-AES technique after their extraction by ammonium acetate-EDTA. Alluvial soil is neutral reaction and contains considerable higher levels of total and mobile fractions of calcium, magnesium and phosphorus, as well lower levels of potassium in comparison with pseudogley. The growing seasons 1998 and 1999 were favorable for corn growing under conditions of the eastern Croatia. In both year of testing, corn yields on acid soil were about 25% lower in comparison with alluvial soil. The yields of individual hybrids (2-year means) were from 10.40 to 12.35 t/ha The higher yields (2-year means) on alluvial soil were found by 3 hybrids (OsSK554, OsSK458 and OsSK568exp.: mean 14, 01 t/ha), OsSK332, OsSK444, OsSK458exp found Yields above 10 t/ha on acid soil were found by four corn hybrids (OsSK 332, OsSK 444, OsSK458 and OsSK490exp. : mean 10, 84 t/ha. Significant influences of growing season on ear-leaf composition were found for N and K, while P concentrations were similar in both years of testing. The higher concentrations of N and K, as well the lower P concentrations were found in leaves when corn was grown on alluvial soil (means 3.75 and 3.56% N, 2.44 and 2.62 % K, 0.344 and 0.327 % P, for alluvial soil and pseudogley, respectively). These findings are in accordance with differences of humus contents and mobile fractions of P and K between two tested soils. Also, inheritance factors have considerable role in plant nutrients status because under identical environmental conditions were found significant differences of corn leaves compositions among tested hybrids as follows: from 3.39 to 3.92% N, from 0.311 to 0.366 % P and from 2.20 to 2.81 % K, respectively.

Corn hybrids; Nitrogen; Phosphorus; Potassium; Pseudogley; Alluvial soil; Yield

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