POSSIBILITY OF PREDICTING SOLUTE UPTAKE AND PLANT-GROWTH RESPONSE FROM INDEPENDENTLY MEASURED SOIL AND PLANT CHARACTERISTICS .7. GROWTH AND NITRATE UPTAKE OF RAPE IN SOIL AT 2 NITRATE CONCENTRATIONS AND A COMPARISON OF THE RESULTS WITH MODEL PREDICTIONS

Rape plants were grown in a constant environment for 24 days in a sandy loam soil initially at soil solution nitrate concentrations of 1.54×10-2M and 3.72×10-3M. Nutrients other than nitrate were maintained at adequate levels. The growth and nitrate uptake were followed by successive harvests of replicate plants. The dry weights and N contents of plants were compared with those predicted by the model in Paper I of this series8, based on parameters of solution cultured plants. Similar environmental conditions were reproduced for these soil culture experiments and soil characteristics were measured separately. The predicted and observed N contents agreed well over the entire growth period. The dry weights were predicted accurately for 15 days in both cases, but were overestimated when extrapolated beyond the range of the model. The dry weight and N content were most sensitive to the relative growth rate. © 1979 Martinus Nijhoff Publishers.