engleski

Response of Field Crops to Ameliorative Phosphorus Fertilization

Different types of nutritional unbalances, including also low levels of plant available phosphorus (P), are often limiting factor of soil fertility in Croatia and in countries of the region, particularly in Bosnia and Herzegovina (B&H). Aim of this study was survey our recent investigations (eight stationary field experiments) of maize, soybean, wheat and barley responses to ameliorative P fertilization up to different levels (depending on the trial up to from 825 to 1580 kg P2O5 ha- 1). Either MAP (monammonium phosphate: 12% N + 52% P2O5) or triplephosphate (45% P2O5) were used as source of P. Selection of soil was made based on the previous soil test. In spite of low levels of available P (ammonium lactate method: below 10 mg P2O5 100 g-1 of soil), response of the field crops to applied fertilization in four experiments in Croatia was mainly moderate or without significant differences. However, in B&H by using the rate of 1580 kg P2O5 ha-1 maize yields were increased depending on year in municipality Kozarska Dubica from 16 to 40%, Gradiska from 8 to 38%, and in Laktasi from 6 to 18% Also, by using 975 kg P2O5 ha-1 soybean yield in Odzak municipality was increased for 20%. In general, year effect (weather characteristics) was the most influencing factor of yields in our investigations. We presume that ammonium- lactate method is not suitable as criterion of P supplies in all tested soils. From other side, majority of tested soils have additional soil fertility limitations as low pH or unfavorable physical properties.

phosphorus fertilization ; grain yield ; maize ; wheat ; soybean ; barley

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