If soil test results for P are available, the optimum amount of P fertilizer to apply to a crop can be best recommended by __________.
A) comparing the cost of P fertilizer to the yield responses measured in the past when P was applied to similar soils with similar soil test P levels
B) subtracting the available soil test P from the total P uptake for the desired yield goal
C) subtracting the soil test P level measured from the soil test P level considered to be on the border of "high" and "very high"
D) calculating the amount of P needed to bring the ratios of soil test P to N, P to K, and P to
E) these days, all four of the above a done, in order, by a computer program

Question

Quizplus · Accepted Answer

The optimum amount of P fertilizer is best recommended by comparing the cost of P fertilizer to the yield responses measured in the past when P was applied to similar soils with similar soil test P levels. This approach considers economic and agronomic factors.

If Soil Test Results for P Are Available, the Optimum