Phosphorus Availability and Spring Barley Yields Under Graded P-Doses in a Pot Experiment

Abstract

The pot experiment with graded P doses was carried out in 2015 and 2016 in the Crop Research Institute, Prague – Ruzyně (undermentioned CRI). Three soil types were chosen for the experiment – Chernozem, Cambisol, Haplic Luvisol. The soils were treated by graded P doses (0.3–0.6–1.2 g P/5 kg of soil). The soil without any treatment served as a control. The spring barley (variety KWS Irina) was grown up to the milky ripeness stage. Plants were regularly watered with the deionised water. Two-year results of experiments showed that the increase of spring barley dry matter was noted under graded P doses particularly in the year 2015, whereas in the year 2016 the plant growth despite to increasing trends generaly was not significant. The P-uptake by plants increased in correspondence to graded P doses and correlated with the P contents in soils determined by Mehlich 3 and NH4-acetate soil tests. The proportion of readily available P-NH4-acetate fractions increased in Chernozem and Luvisol in comparison with total available P-Mehlich 3 fractions under graded P doses. No evident increase of P-NH4-acetate fractions was obtained in Cambisol having the lowest CEC from all tested soils. The correlations between P content in plants of spring barley, P-uptake and phosphorus determined by Mehlich 3 and NH4‑acetate methods, with exception of relationship between P-barley and Mehlich 3, showed significant positive relationships. The highly positive relationship between P-Mehlich 3 and NH4-acetate methods indicating the suitability of both tests to predict phosphorus supply in soils.

Keywords

• fertilization
• barley
• phosphorus
• supply
• soil tests