Huber suggests soil nutrition plays an equally important role in plant development. In studies at four Purdue agricultural research farms and at agronomy centers in Alberta, Canada, Huber and Canadian researchers found that micronutrient deficiencies have both a direct and indirect impact on crops. It's not only directly involved in plant photosynthesis but also in defense to disease. Soybeans, wheat, oats and barley are especially vulnerable to manganese shortages. Wheat and corn also need adequate amounts of zinc, Huber says.
Corn is sensitive to imbalances of manganese and nitrogen, which work in concert within the plant.
In extreme cases the imbalance can set off a chain of events resulting in the plant feeding off the nutrient reserves in its own cell walls to ensure kernel development, Huber says. The cannibalization weakens the plant, inviting disease. Farmers should not assume all diseases are connected to nutrient deficiencies, Huber says, but crop malnutrition occurs more frequently than might be believed. You may have a plant that's a little stunted and the yield not as great, and you don't know why. Micronutrient deficiency may be the reason.