engleski

Fertilization effects on maize and soybean yields

Maize and soybean grown under field conditions in the eastern and northwestern part of Croatia (total seven experiments: A-G) for the growing season 2010. Different NPK combinations, calcium ammonium nitrate (27% N) and urea (46% N) used by different terms (ploughing in autumn, disk-harrowing in spring and to-dressing) and quantities (b – d), while unfertilized treatment was the control (a). Total amounts of nutrients (kg/ha) added by fertilization (N: P2O5:K2O) were as follows: for maize 136:105:180 (b), 172:140:210 (c) and 169:150:100 (d), for soybean 30:90:180 (b), 164:140:210 (c) and 123:112:168 (d). The fertilization treatments distributed in four 1250 m2 blocks. Completed area of individual block was harvested by combine and yields were calculated in tones/ha on 14% (maize) and 13% (soybean) grain moisture basis. The growing season 2010 was favorable for maize and soybean because of adequate and good distributed precipitation. Mean yields of unfertilized plots were 6.4 t/ha and 2.1 t/ha, for maize and soybean respectively. Yield variations among the experiments were in range from 8.9 to 12.3 t/ha (maize) and from 3.2 to 3.6 t/ha (soybean). In general, emphasis of P (d) resulted by 20% lower yields of maize in comparison with K emphasis (b). Additional increases of active matter (c) were not effective in yield increases of maize. The highest rate of fertilization (c) resulted by the highest yields of soybean in two trials (E and G), but in two trials (E and F) two treatments (c and d) had similar effects.

maize; soybean; grain yield; fertilization

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