Answer & Solution
Answer: Option D
Solution:
The salt index of fertilizer is a measure of the salt concentration that fertilizer induces in the soil solution. Puri’s salt index accounts relationship between concentrations of sodium and calcium ions in given irrigation water.
Parker's nutrient index is a three-tier used to evaluate the fertility status of soils based on the percentage of samples in each of the three classes, that is low, medium and high.
A value concept was given by fried and Dean in 1952. The concept is when the plant is confronted with two sources of a nutrient, the plant will absorb from each of these in proportion to the respective amounts available.
DRIS is Diagnosis and recommendation irrigated system given by
Beaufills. It is a widely used statistical approach for interpretation of the plant tissue analysis data and diagnosing the plant nutrient needs much earlier than the reduction of crop yield with great accuracy.
