Soil Fertility

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Soil Fertility

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  • BASIC TIPS FOR USING THE WEB SOIL SURVEY TO RETRIEVE INFORMATION FOR NUTRIENT MANAGEMENT PLANNING

    The USDA-NRCS has created the Web Soil Survey (WSS) as a clearance house for soil survey data from the Soil Survey Geographic Database (SSURGO). Currently, there are data available for almost all counties in the U.S.

  • CALCULATING THE LIME RECOMMENDATION USING THE ADAMS-EVANS SOIL BUFFER

    The University of Delaware Soil Testing Lab uses the Adams-Evans buffer pH test to determine lime requirement for a field based on soil test analysis of an 8-inch composite soil sample. In this quick reference guide, we will walk through the steps for determining the lime recommendation using the Adams-Evans buffer pH. 

  • DEFINING HIGH PHOSPHORUS SOILS IN DELAWARE

    Phosphorus (P) is an essential nutrient for optimum plant growth. However, continued application of manures and fertilizers to soils has led to an accumulation of P in many Delaware soils to levels well above those needed for optimum crop growth. 

  • DELAWARE GARDENER’S GUIDE TO LAWN AND LANDSCAPE FERTILIZERS

     Fertilizers contain one or more essential plant nutrients and can be applied to landscapes to improve plant growth and quality or to correct a nutrient deficiency. There are many fertilizers available to consumers at local lawn and garden centers. 

  • DELAWARE GARDENER’S GUIDE TO SOIL PH

    Soil pH is a measure of soil acidity or alkalinity. On the pH scale a value of 7 is neutral, pH values less than 7 are acidic, and pH values greater than 7 are alkaline. Homeowners and gardeners are interested in soil pH because soil pH directly affects the growth and quality of many landscape plants.

  • FERTILIZER BASICS

    Proper fertilization will enhance plant growth without polluting the environment. However, misuse of fertilizer can harm the environment and injure landscape plants by causing fertilizer burn to leaves and/or roots.

  • HOW TO TAKE A SOIL SAMPLE?

    Soil tests such as those conducted by the University of Delaware Soil Testing Laboratory will help you to develop and maintain more productive soil by providing more information about the fertility status of your soil. This helps you to select the proper lining and fertilization program so that you can obtain optimal growth of lawn, garden and ornamental plants.

  • MEASUREMENT AND MANAGEMENT OF SOIL PH FOR CROP PRODUCTION IN DELAWARE

    The pH scale ranges from 0 to 14; a pH value of 7 is considered neutral, while pH values less than 7 are acidic, and pH values greater than 7 are alkaline. The pH values of soil usually range from pH 4.0 to pH 8.0; higher or lower pH values are very rare and are normally found only in severely disturbed soils or in soils that have been amended with some type of acidic or alkaline material.

  • NITROGEN CYCLING IN AGRICULTURE

    Understanding how N reacts in the landscape can help us maximize plant growth and crop yields, while minimizing harmful losses of N to the environment. This document helps agricultural producers understand how N interacts in the environment through the N cycle to guide maintenance and sustainability of agricultural crop production.

  • NUTRIENT RECOMMENDATIONS

    Nutrient recommendations are based upon soil test calibration studies that relate the probability of a profitable plant response to nutrient addition to the plant nutrient concentration in the soil as measured by a soil test.

  • PHOSPHORUS CYCLING IN AGRICULTURE

    Crops often receive beneficial nutrients such as phosphorus (P) from manure and/or commercial fertilizer applications. However, the Delaware Nutrient Management Law limits the amount of P that can be applied to many agricultural soils in Delaware. 

  • PHOSPHORUS MANAGEMENT STRATEGIES FOR DELAWARE’S AGRICULTURAL SOILS: THE PHOSPHORUS SITE INDEX

    Long-term use of fertilizer and manure nutrients on the Delmarva Peninsula has led to an enrichment of agricultural soils with phosphorus (P). Consequently, many soils in Delaware are now considered high or excessive in soil test P (Fig. 1). In some situations, high P soils contribute to eutrophication of surface waters; therefore, P management strategies that maintain both agricultural profitability and environmental quality are necessary. 

  • PHOSPHORUS REMOVAL BY DELAWARE CROPS

    In Delaware, applications of phosphorus to “high P” soils (soil test P ≥ 150 FIV, as defined by the Delaware Nutrient Management Commission) cannot exceed a three-year crop removal rate unless alternative P management strategies (i.e. N-based management during one or more years of a crop rotation) are permitted based on results of a P Site Index.

  • RECOMMENDED SOIL TESTING PROCEDURES FOR THE NORTHEASTERN UNITED STATES

    Northeastern Regional Publication No. 493
    3rd Edition- Agricultural Experiment Stations of Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, and West Virginia. Prepared by: The Northeast Coordinating Committee for Soil Testing (NECC-1312)

  • SOIL MANAGEMENT OPTIONS BASED ON THE PHOSPHORUS SITE INDEX

    Minimizing nonpoint source pollution of surface waters by P from agricultural cropland requires management practices that control both the supply and transport of soil P. The basic objective of environmentally sound P management is to maintain soil P fertility levels in a range that is optimum, but not excessive, for crop growth while reducing the loss of particulate and soluble P by processes such as erosion, runoff, or drainage. 

  • THE IMPACTS OF NITROGEN AND PHOSPHORUS FROM AGRICULTURE ON DELAWARE’S WATER QUALITY

    Nitrogen (N) and phosphorus (P) are essential nutrients for all living organisms.  Soil, fertilizer, and manure are all sources of N and P to growing crops.  Atmospheric deposition (the air we breathe is mostly N gas) and irrigation water are also N sources.  If not managed efficiently, much of the N and P applied to and present in agricultural systems can be lost to the environment.

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