Nutrient Management

Research is conducted at the University of Idaho Parma Research and Extension Center on nutrient management issues specific to Idaho crops.

Wheat

Wheat protein affects the quality of all wheat market classes. Wheat protein is affected by weather conditions, particularly during grain fill, nutrient management, especially nitrogen, variety selection and many other factors that affect yield.

Low protein in soft white wheat is normally desired and markets will frequently have upper limits in the protein that is acceptable.

Higher protein tends to be associated with higher gluten strength and improved bread making quality. Higher protein is desired for bread making wheats such as hard red or hard white types.

Wheat protein affects the quality of all wheats, but it is particularly important for the hard wheat classes. Hard wheat market prices are generally more closely related to protein concentrations than in other market classes. Hard red spring wheat is typically the highest in protein, the highest price and the market class for which there are the greatest low protein discounts or high protein premiums.

In recent years there has been considerable interest in wheat protein issues. The higher market prices for hard red spring wheat has increased the interest among producers that produce soft white wheat. Several University of Idaho publications deal with wheat protein issues and many of them are linked below.

This publication reviews many of the principles and issues surrounding hard wheat protein as affected by nitrogen management.

• Nitrogen Management for Hard Wheat Protein Enhancement (PNW 578)

The following publications deal with fertilizer issues in southern Idaho

• Saving Energy and Fertilizer Costs (CIS 1127)
• Southern Idaho Fertilizer Guide — Irrigated Winter Wheat (CIS 373)
• Southern Idaho Fertilizer Guide — Irrigated Spring Wheat (CIS 828)

Barley

• Southern Idaho Fertilizer Guide — Irrigated Winter Barley (CIS 1082)

Urea Volatilization

With the loss of dry ammonium nitrate fertilizer due to security concerns, there will be greater reliance on dry urea N for top dressing, banding and broadcasting N. Urea can be an effective N source but does have some characteristics that potentially can reduce its effectiveness under some conditions. Understanding urea and its limitations can better enable us to maximize its effectiveness and save fertilizer expenses.

The following publication from Montana State University provides a detailed description of urea's properties and the conditions that lead to the volatile loss of N. It also includes southern Idaho information on the effectiveness relative to ammonium nitrate or ammonium sulfate top dressed for winter wheat or barley.

• Management Minimize Nitrogen Fertilizer Volatilization