What are best management practices (BMPs)?
Best management practices, or BMPs, are recommended structures, methods, and practices designed to protect water quality. BMPs can provide environmental, agronomic, and economic benefits.
The cost, economic return, ease of implementation, and overall effectiveness will vary from practice to practice. Recommended BMPs may include already widely accepted and utilized agricultural practices.
Every farm is unique and requires a particular combination of practices that meets the needs of the land and the producer.
How are the nitrogen and phosphorus cycles relevant to agriculture?
Nitrogen and phosphorus each naturally cycle through the environment through chemical and biological transformations into various forms. Crop growth is dependent on the forms of these nutrients that are available for uptake and use by plants. Understanding nutrient cycles can help maximize plant growth and crop yields while minimizing harmful losses to the environment.
What forms of nitrogen are available to plants?
Plants can use nitrogen in two forms:
- ammonium-nitrogen (NH4+ – N)
- nitrate-nitrogen (NO3– – N)
What is nitrogen mineralization?
The process that converts nitrogen into forms that are available to plants. Microbes decompose organic nitrogen from manure, organic matter and crop residues into ammonium (NH4+).
Rates of mineralization vary with soil temperature, moisture, and soil aeration.
What sources provide nitrogen to the soil?
- Organic matter: crop residue, manure, biosolids, compost
- Synthetic fertilizers
- Atmosphere: nitrogen fixation, lightning, nitrogen deposition
What are quick-release nitrogen fertilizers?
Synthetic nitrogen fertilizers containing ammonium, nitrate, or urea are considered to be “quick-release” fertilizers that rapidly become plant available.
What are slow-release and controlled-release nitrogen fertilizers?
These synthetic fertilizers are designed to delay the release of plant available nitrogen.
What is phosphorus mineralization?
The process that converts phosphorus into forms that are available to plants. Microbes break down organic phosphorus and release inorganic phosphates that are available to plants.
What forms of phosphorus are available to plants?
Plants use forms of phosphorus known as orthophosphates:
What is an “agronomic rate” of nutrient application?
A nutrient application rate based upon current crop needs that takes into account already available residual soil nutrients as well as nutrients from all applied sources, such as commercial fertilizers, manure, and irrigation water.