Suggested soil treatments are tailored to the fertility of the soil, the cropping system and yield goals. Plant analysis offers a method of determining if essential nutrients are getting into plants in amounts needed. Organic acids arise from carbohydrate metabolism in combination with the amino-nitrogen to yield amino acids in the plants. The amino acids are building blocks for proteins. This total process is dependent on sunlight.
Nitrate reduction occurs both in aerial portions and roots of plants.
The relative importance of these two sites of nitrate conversion is considered most important. Nitrate is not found in significant amounts in mature grain and seldom in the accompanying vegetative part of the plant under normal fertility and growth conditions. Good grain yields require conversion of nitrate to seed protein. Young plants in the vegetative stage generally contain more nitrate than more mature plants of the same species. This is especially true of young pasture plants that have been liberally manured or fertilized with nitrogen.