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.

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

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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.

The accompanying Soil Test 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 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 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.Zachary M. Easton, Assistant Professor and Extension Specialist, Biological Systems Engineering, Virginia Tech Emily Bock, Graduate Research Assistant, Biological Systems Engineering, Virginia Tech

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 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

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.