Entrust 80WP® is a new insecticide manufactured by Dow, and it will be available commercially by mid-April 2003. Entrust contains the active ingredient spinosad, which is in the naturalyte class of chemistry. Spinosad is a fermentation product produced by the soil-dwelling actinomycete Saccharopolyspora spinosa.

When growing vegetables and specialty crops, a soil high in organic matter is very desirable. When examining soils in Virginia, we struggle to find soils that are naturally high in organic matter.

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.

An adequate supply of plant-available nitrogen (N) is crucial for efficient corn production, and corn N requirements are greater than any other nutrient. For example, a corn crop yielding 150 bushels per acre typically contains about 165 lbs N in the grain and stover, or approximately 1.1 lbs N/bu grain. These calculations are based on actual N uptake, and allowances must be made for actual fertilizer use efficiency and soil N availability.

Fall is an excellent time to clean-up fields and plan for future crop nutrient requirements as well as increasing soil organic matter content for your farm field management program.

Across the state, organic production of specialty crops is on the increase, particularly on small farms and direct market operations.

Phosphorus (P) is a naturally occurring element that can be found in the earth's crust, water, and all living organisms. Phosphorus (P) is one of 16 elements that are essential for plant growth. Soils in Virginia are naturally low in phosphorus, and most cropping systems on these soils require supplemental phosphorus to maximize their yield potential.

Soil electrical conductivity (EC) is a measurement that correlates with soil properties that affect crop productivity, including soil texture, cation exchange capacity (CEC), drainage conditions, organic matter level, salinity, and subsoil characteristics. This publication discusses: 1) How, with field verification, soil EC can be related to specific soil properties that affect crop yield, such as topsoil depth, pH, salt concentrations, and available water-holding capacity; 2) Soil EC maps often visually correspond to patterns on yield maps and can help explain yield variation; and 3) Other uses of soil EC maps (Table 1), including developing management zones, guiding directed soil sampling, assigning variable rates of crop inputs, fine tuning NRCS soil maps, improving the placement and interpretation of on-farm tests, salinity diagnosis, and planning drainage remediation.

In organic growing the philosophy behind soil fertility is to feed the soil and the soil in turn will feed the cash crop. Cover crops, green manures, animal manures and sound crop rotations are used to improve and/or maintain soil fertility. This article focuses on the use of green manures.