Joint International Conference on Long-term Experiments ...

DRY MATTER PRODUCTIVITY AND NITROGEN UPTAKE OF PERENNIAL
RYEGRASS INFLUENCED BY NITROGEN AND WATER SUPPLY
ABSTRACT
Imre Vágó – János Kátai – Ida Kincses – Andrea Balla Kovács
University of Debrecen, Faculty of Agriculture
Department of Agricultural Chemistry and Soil Science
H-4015 Debrecen, P.O.Box 36.
Besides the genetically coded productivity of the cropped plants, other factors also
determine the quality and the quantity of yields. Among these factors the nitrogen and
water supply is very important. Investigations were made in greenhouse pot
experiments to reckon if these factors influence the effects of each other. The same
nitrogen and water supply has different effect in soil types. That is why vegetation pot
experiment on three extremely different soil types of Hungary, near of Debrecen was
carried out.
Perennial ryegrass (Lolium perenne L.) was used as a test plant. The effect of
nitrogen (0, 40, and 80 mg kg -1 ) and water (50 and 75% of the total water capacity)
supply on the dry matter production of ryegrass was examined. The nitrogen
concentration of the shoot was measured and the nitrogen uptake of plants was
calculated.
The dry matter production of plants reduced during the experimental period from
4.02 g per pot (first cut) to 1.78 g per pot (third cut). The reason is the nutrient
deficiency of small soil mass in the pots and the ageing of grasses. At cuts according to
the mean of treatments the calcareous chernozem was the most productive, while that of
marshy meadow and brown forest soils was similar to each other. The 80 mg kg -1
nitrogen supply doubled the yield in the brown forest soil and calcareous black soil,
while in marshy meadow soil abounding in organic matters the increase of crop mass
was smaller. On the calcareous chernozem and marshy meadow soil, the water supply
increased the yield but on the sand the maximum yield at the 50% water capacity was
detected.
During the three cuts summarized extracted nitrogen amount depending on the
soil type (P=0.1%). The calcareous chernozem soil and the marshy meadow soil
supplied similar (nearby 200 mg per pot) amount of nitrogen for the ryegrass. This fact
can be explained that the higher shoot production of ryegrass on calcareous black soil
and the higher nitrogen content of ryegrass on marshy meadow soil equalise each other.
From the brown forest soil only 110 mg nitrogen per pot in average was extracted by
plant shoots, because of the smaller plant production and its lower concentration of
nitrogen.
Keywords: Nitrogen and water supply, productivity and nitrogen uptake of ryegrass
INTRODUCTION
The productivity of the plants is influenced by a lot of different factors. The most
important of them is the genetic potential, but the environmental and the technological
factors also influence the quantity and the quality of the yields (Mengel, 1976; Loch and
156