To test the ability of plants to integrate small-scale
imbalances in soil nitrate and phosphate patches, plant growth
and acquisition of nitrate and phosphate were measured for the
perennial grass Agropyron desertorum (Fisch. ex
Link) Schult. and the shrub Artemisia tridentata Nutt. ssp.
vaseyana (Rydb.) Beetle in soil where the principal
supply of nitrate and phosphate came from two enriched patches. The
soil was calcareous loamy-skeletal Typic
Haploxerolls. These patches were applied in two treatments: either
nitrate and phosphate were applied in both
patches (balanced treatment) or one patch contained only nitrate and
the other only phosphate (unbalanced
treatment). The same total quantity of nutrients was applied in both
treatments and these included 15N and 32P
tracers. The plants were in large pots in open field conditions. There
were
no significant differences in total
biomass production and nitrogen concentration between the two
treatments, indicating that both species had the
physiological ability to integrate soil nutrient resources.
Artemisia was able to acquire more phosphate in the
unbalanced treatment, probably due to the high local solution phosphate
concentration. Generally Artemisia acquired more N and P than
did Agropyron.