Fertilizing

Most commercial nitrogen fertilizers lower soil pH much more quickly than organic sources of nitrogen such as animal manure or nitrogen resulting from the symbiotic relationship between Rhizobium bacteria and legumes.

When producers think of managing soil nutrients in corn production, they likely think first of nitrogen and rightly so as it is the most common yield-limiting nutrient. But nitrogen is just the beginning of the story. Corn silage growers need to also test for and manage potassium, phosphorus and micronutrients to maximize yields and keep the soil productive over the long term.

Most dairy producers figure that since alfalfa and other legumes can capture nitrogen from the air, they shouldn’t apply manure.

When manure needs to be spread during summer, sometimes the only place available is an alfalfa field.

Manure can provide valuable nutrients to alfalfa, particularly phosphorus, potassium and boron. This may increase alfalfa yield or reduce fertilizer costs. Alfalfa also will absorb the nitrates from manure, reducing the risk of environmental contamination.

But manure can cause problems for alfalfa.

Soil organic matter means there’s much more to dirt than meets the eye.

“Organic matter is critical for healthy soils,” says Dirk Philipp, assistant professor for the University of Arkansas System Division of Agriculture. “It’s storage of available nutrients, it bonds soil particles for stable structure and can hold water.”

Nitrogen is one of the most important and costliest plant nutrients, especially for cattle producers. Knowledge of the nitrogen cycle is an important start in shaving costs off of this expensive fertilizer.