California farmers deal with complex irrigation and fertilization requirements of "specialty" crops within diverse rotations. Some of these so-called specialty crops have a farm value of more than $4 billion per year. These high-value crops demand careful management of both water and nutrients to achieve high yield and consistently high quality.
Nitrogen (N) is one of the most widely distributed elements in nature, since it’s the most abundant gas in the atmosphere. While N isn’t found in mineral forms like phosphorus (P) or potassium (K), it’s largely present in organic compounds. Soil-based N undergoes many complex biological transformations that make it challenging to manage.
Potassium nitrate (KNO₃) is a soluble source of two major essential plant nutrients. It’s commonly used as a fertilizer for high-value crops that benefit from nitrate (NO₃-) nutrition and a source of potassium (K+) free of chloride (Cl⁻).
Liquid fertilizer solutions and fluid fertilizers are popular in many areas because they’re safe to handle, convenient to mix with other nutrients and chemicals, and are easily applied. A solution of urea [CO(NH₂)₂] and ammonium nitrate [NH₄NO₃] containing between 28 and 32 percent nitrogen (N) is the most popular fluid N fertilizer.
A variety of coatings have been applied to fertilizer particles to control their solubility in soil. Controlling the rate of nutrient release can offer multiple environmental, economic, and yield benefits.
Sulfur deficiency in corn can masquerade as nitrogen deficiency. Boron deficiency in soybeans may remain hidden — the only sign being a yield below optimal.
Managing nitrogen nutrition makes a big contribution to the yield and quality of winter wheat. Choosing the right source, rate, time and place of nitrogen application improves not only your own profit, but also, food and nutrition security for people around the world.
Some growers are considering a shift from a corn and soybeans rotation to continuous corn. More nitrogen (N) will be needed since soybeans will no longer provide some residual N. Other nutrient needs will also change, especially phosphorus (P). Corn, unlike soybeans, is planted early in soils that are more likely to be cool, moist and with a heavier residue cover. These conditions can suppress the uptake of P by corn and increase the likelihood of crop response to fertilizer P. Research shows that P, with some N, applied in a band two inches to the side and below the seed, boosts seedling access to a readily available supply of P.
Risks associated with fall nitrogen (N) applications fit into four categories: logistical, agronomic, environmental and economic, the last of which currently ties very closely to the others and will be discussed in conjunction with them.
Ammonium nitrate was the first solid nitrogen (N) fertilizer produced on a large scale, but its popularity has declined in recent years.
Ammonia (NH₃) is the foundation for the nitrogen (N) fertilizer industry.
Ammonium sulfate [(NH₄)₂ SO₄⁴] was one of the first and most widely used nitrogen (N) fertilizers for crop production.