Narrow Results

A two compartment mathematical model for the individual plant growth under the stress of toxic metal is studied. In the model it is assumed that the uptake of toxic metal by the plant is through root compartment. The toxic metal present in the soil interfere with the uptake and distribution of essential nutrients in plant causing decrease in the nutrient uptake eventually damaging the root structure. In the model it is further assumed that the resistance to nutrient transport from root to shoot compartment increases and nutrient use efficiency decreases due to the presence of toxic metal. In order to visualize the effect of toxic metal on plant growth, we have studied two models, that is, model for plant growth with no toxic effect and model for plant growth with toxic effect. From the analysis of the models the criteria for plant growth with and without toxic effects are derived. The numerical simulation is done using Matlab to support the analytical results.

With Elaeocarpus Sylvestris seedlings as the experimental materials, the density effect on nutrient distribution of the seedlings was studied. The results showed that nitrogen concentration decreased in the order of leaves > branches > roots > stem, phosphorus concentration varied without regular patterns, whereas potassium concentration was leaves > branches > stem > roots in E. Sylvestris seedlings. Accumulation of nitrogen, phosphorus and potassium increased with increasing density. Generally, the nutrient accumulation was great in roots and small in branches.