Nutrient Gradient Distribution in Soil around Taproots of Haloxylon ammodendron and Haloxylon persicum
Soil samples around the taproots of Haloxylon ammodendron in the inter-dune area and H.persicum in the top shifting-dune were taken in the Gurbantunggute Desert and were brought to laboratory to measure pH,electrical conductivity and nutrients contents.Results show that soil pH at 0-1 cm off the roots is lower than that at 1-10 cm off the roots,and the larger values of soil electrical conductivity and soil nutrients contents are also at 0-1 cm off the roots,especially at 0-0.2 cm off the roots.The largest rhizosphere effects(R/S) of H.ammodendron and H.persicum are respectively: 1.17 and 1.23 for soil electrical conductivity,2.00 and 2.41 for soil organic matter,2.64 and 2.86 for total N,2.42 and 3.26 for available N,2.14 and 1.71 for available P,1.14 and 1.12 for total P.It indicates that nutrients accumulate in rhizosphere,but the accumulation of total P is not so obvious.Apart from available P,the rhizosphere fertile-island effects of H.persicum are obvious than that of H.ammodendron,demonstrating a phenomenon of "more obvious fertile island effects exist in the more soil nutrient stress environment".
H.ammodendron BgeH.persicum Bgerhizospherefertile island