Loss of nitrogen (N) as ammonia gas (NH3) is known as volatilization. While volatilization directly from soil can occur, such loss is generally relatively small compared to the amount that can be lost from fertilizers. Volatilization losses can be significant with granular urea and urea-ammonium nitrate (UAN) sources, but the amount of loss varies greatly depending on placement of the fertilizer, soil pH, soil texture, and climatic conditions after application.

The most commonly available nitrogen fertilizer sources used in Virginia are urea, liquid urea-ammonium nitrate (UAN) solution, and ammonium sulfate. Ammonium nitrate is also available in some areas but its use is low relative to urea and UAN solution. Understanding the properties of these fertilizers enables managers to make better decisions as to the most effective way to use these fertilizers as well as to make economic comparisons.

their yield potential. Research has documented that applying fertilizer phosphorus increases crop growth and yields on soils that are naturally low in phosphorus and in soils that have been depleted through crop removal. Crop fertilization represents the greatest use of phosphorus in agriculture today.

Animal manures are a good source of nitrogen (N) and phosphorus (P) for agricultural crops, but they have an imbalance in their N to P ratio, so that if they are applied to meet crop N needs, then P is overapplied. For many years, manures have been applied to meet crop N needs, which has resulted in some soils containing more P than crops require, leading to environmental concerns. Regulations have been developed to limit P losses from manures and soils high in P by moving manure nutrient management from an N basis to a P basis.

This publication explains how to obtain representative soil samples and to submit them for analysis to the Virginia Tech Soil Testing Laboratory.

This directory is intended to provide contact information for service and equipment suppliers, along with sources for information and education. Every attempt has been made to present accurate information. Contents are for informational purposes only and are based on details provided by the organizations and entities listed. Inclusion in this directory does not constitute an endorsement by the publishers of the products or services of any business organization or individual listed herein.

Acid soil limits crop yields on many Virginia farms. This soil acidity can be directly toxic to plants, but more often it reduces the plants' efficiency at nutrient utilization.

Your Soil Test Report and related Soil Test Notes referred to on a report will help you assess your plant’s need for fertilizer and lime.

Most Virginia soils are acidic and require lime applications at three- to five-year intervals. Maintaining the correct soil pH has several benefits, such as encouraging healthy root development and making sure nutrients in the soil are available to the plant. For example, low pH can cause aluminum toxicity and can decrease phosphorus availability.

The only way to accurately predict lime and fertilizer needs in forages is through soil testing, as explained in “Soil Test Note No. 1 – Explanation of Soil Tests,” Virginia Cooperative Extension publication 452-701. See www.soiltest.vt.edu.

If your Soil Test Report indicates that one or more trace elements are needed, then go to the related sections in this note for information on the recommended trace elements and the specific rates and methods of application. Apply only those trace elements that are recommended, and only at the recommended rates!

Animal manures contain valuable crop nutrients and may also have liming value. With high costs for fertilizers, using animal manures to supply the major crop nutrients – nitrogen (N), phosphorus (P), and potassium (K) – may represent an economic savings. However, animal manures present some challenges compared to inorganic nutrient sources.

The procedures for soil analysis used in the Soil Testing Laboratory were established in the early 1950s. A routine test, consisting of eleven separate analyses, is performed on all samples.

This publication describes procedures for revegetating surface coal mine reclamation sites with grasses and herbaceous legumes.

This publication describes procedures for re-establishing native forest trees on surface coal mine reclamation sites in southwestern Virginia and elsewhere in Appalachia.

This publication describes plant communities occurring on mine sites that were reclaimed during different eras, and using different reclamation methods.

This publication describes procedures for converting reclaimed mined lands that are unmanaged into productive forest ecosystems with native trees as dominant vegetation.

This publication presents and discusses concepts that are fundamental to understanding soil, water, and plant relationships and the soil water balance. Knowledge about soil water relationships can inform the decision-making process in agricultural operations or natural resource management, such as determining what crops to plant, when to plant them, and when various management practices should be scheduled. Understanding these concepts is useful for addressing both agronomic and policy issues related to agricultural water management.

The general purpose of a cover crop is to improve the soil, the broader environment, or other crops in rotation, not for direct harvest. Cover crops, depending on which are selected, are capable of providing many diverse assets. This publication provides a short description of these main benefits.

Cover crops increase soil organic matter, reduce erosion, suppress weeds, forage for nutrients, and reduce fertilizer costs (Clark, 2007). Cover crop species vary greatly and provide varied benefits. Performance evaluation of cover crop species and mixtures is needed in Virginia.

Delaware, Pennsylvania, Maryland, Virginia, and West Virginia, and Virginia, the five states in the Mid-Atlantic region, all require Certified Nutrient Management Plans to be completed for certain agricultural programs.

The mature and dried stem, leaves, and chaff remaining after barley and wheat are harvested is known as straw. Many farmers around Virginia harvest straw by baling in small bales, large round bales, or large square bales that range in weight from 40 to 1,000 lbs. plus per bale.

The purpose of this document is to provide guidance on measuring water movement through in situ saturated soil (saturated hydraulic conductivity, or Ksat) as it relates to dispersal and treatment of on-site sewage (wastewater) through an on-site wastewater dispersal area

Composting is a biological heating process that results in the natural degradation of Composting is a biological heating process that results in the natural degradation of organic resources (such as poultry carcasses) by microorganisms. Composting has been successfully used throughout the United States for nearly two decades to control outbreaks of avian influenza. Composting can be effective with most bird types and poultry house designs.organic resources (such as poultry carcasses) by microorganisms. Composting has been successfully used throughout the United States for nearly two decades to control outbreaks of avian influenza. Composting can be effective with most bird types and poultry house designs.

Phosphorus is a naturally occurring element that is one of 16 elements essential for plant growth and animal health. Research has documented that applying phosphorus in fertilizers or manure increases crop growth and yield on soils that are below critical agronomic levels, as measured during routine soil testing. Although the economic benefits of phosphorus fertilization on crop production are well-documented, too much of a good thing can be detrimental to the environment. Excessive soil phosphorus is a potential threat to water quality.

Climate change is documented by research data, yet some deny evidence of the causes, underestimate the impacts, or fail to adjust their activities and choices. Soil is tied to climate change in many ways. Presented on-line to a national professional meeting of soil scientists, this video discusses the way that Americans perceive climate change and the relationships between climate change and soil science.

Correctly collecting a soil sample is one of the most important steps in a soil testing program! The reliability of a soil test can be no better than the sample submitted. For results that can be depended on, it is vitally important to take samples that accurately represent the soil in your fields. When one considers that a one pound soil sample must adequately represent millions of pounds of soil in the area being sampled, the importance of doing a good job of sampling becomes apparent.

Secondary macronutrients are used in relatively large quantities by plants for optimal growth and are sulfur (S), calcium (Ca), and magnesium (Mg). Micronutrients on the other hand are needed in much smaller quantities than both primary and secondary macronutrients; however, micronutrients are still essential for plant growth.

Humans and livestock require a broad range of nutrients to maintain a healthy diet. However, the lack of diversity in diets due to price, geography, and availability makes it difficult to create a well-rounded food supply from staple crops. Biofortification is the process of improving the nutritional quality of food and feed through management practices, plant breeding, and genetic modification. The history, types, and implications of biofortification are discussed with an emphasis on producer, livestock, and human health considerations.