Influence of phosphate fertilisation on the mineral nutrition and yield of barley on a soil with low plant-available phosphorus

Abstract

In a permanent field experiment carried out in southern France on a soil with low available P, four P rates (0, 13, 26, 44kg P ha⁻¹) were applied over ten years, each year on the same, fully-randomised plots with four replicates. The effect of P fertilisation on the mineral nutrition, growth and yield of a barley crop was investigated on the year 1999–2000.

The strong increase of the grain yield related to the P rates was only due to an increase of the number of ears per m² which is the yield component that is formed during the first stages of the crop development. The P rates also influenced the growth of the plants and N, P, K amounts accumulated in the aboveground plant part, mainly during the first stages of the crop development, i.e. from sowing to growth stage GS 38. During the second phase of the crop development, from GS 38 to maturity, although the plants accumulated more P and dry matter in the aboveground part, P rates had not effect on growth and N, P, K uptake despite great differences of P availability in the soil.

Thus it seems that in soils with low P availability the P fertilisation improves barley yield largely by improving the nutritional status during the early stages of the crop development.