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Best Management Practices

Why are BMPs Important?

Best management practices (BMPs) are production methods, structures, and management practices designed to protect water quality while maintaining economic returns. Voluntary adoption of these practices by corn producers will help prevent contamination of water resources, improve public perception of the industry, and perhaps eliminate the need for further regulation and mandatory controls.

Read the CSU Extension/Colorado Corn BMP Manual

Dive Into the Details

Hybrid Selection

Affects all other management decisions throughout the growing season. Right plant. Right Place. Right time. Just like fertilizer, these principles ensure that we are maximizing opportunity for the corn plant to be successful. Characteristics that need to be considered include, but are not limited to the following list.

  • Yield potential and consistency
  • Maturity
  • Stalk quality
  • Disease and insect resistance
  • Root lodging resistance
  • Dry-down

Planting Guide

Planting of corn in Colorado may fall between April 15-June 1 depending on where you live in the state and which hybrid has been chosen for the growing year. Below is a table for the various regions and optimized dates of planting. Dryland corn can be planted later than irrigated to save some of the moisture in the soil profile for later growth stages of the plant. There is a map of each region in the BMP guide.

  • Region Date Range NE Plains April 20 – May 15
  • SE Plains April 15 – 30
  • W Slope Valleys April 20 – May 10
  • S Platte May 1 – 15
  • Front Range May 1 – 20
  • Ark Valley April 20 – May 5
  • E Plains Dryland May 10 – June 1

Planting Guide (plant population)

Determining population

  • Field history
  • Fertility
  • Weed pressure
  • Flex ear ability
  • Irrigation

Growth Stages & Diagnostic

There can be problems throughout the growing season, and this chapter helps with identifying problems growers may face during each growth stage of the plant.

Issues can be mechanical or living causes of plant dysfunction. Below are some techniques that can help track down the problem.

  • Tissue samples
  • Images of affected and non-affected plants
  • Soil samples: Salinity, nematodes, and nutrients can be tested for
  • Soil probe: Compaction and moisture levels can be determined
  • Irrigation water samples: Tested for salinity and toxins

Integrated Pest Management

Integrated pest management (IPM) combines chemical control with cultural and biological practices to form a comprehensive program for managing pests.

Things to consider when contemplating a pest management decision are listed below.

  • Will the cost of controlling a pest be offset by a substantial yield bump?
  • Is there a practical non-chemical method of control?
  • Are there multiple pesticide products available if you decide that is prudent?
  • Can the pesticide be applied at a reduced rate, which maximizes effectiveness, and reduces harm to beneficial organisms, pollinators, and non-target species?
  • Does the product label contain groundwater advisories or other environmental caution statements?
  • Are chemicals and control methods rotated to avoid buildup of pest resistance?
  1. Record keeping and scouting
  2. Crop rotation
  3. Pesticides and water quality
  4. Pesticide application

Insect Pests

  • Seed-corn maggot
  • Wireworm
  • Dingy cutworm
  • Pale western cutworm
  • Variegated cutworm
  • Banks grass mite
  • Two-spotted spider mite
  • Corn leaf aphid
  • Corn ear worm
  • Fall army worm
  • European corn borer
  • Grass hoppers
  • Southwestern corn borer
  • Army worm
  • Western bean cutworm
  • Western corn rootworm

Corn Diseases

  • Seedling blights
  • Viruses
  • Nematodes
  • Bacterial leaf streak
  • Goss’s wilt
  • Common/head smut
  • Common rust
  • Stalk roots


There are numerous weed species in the corn fields of Colorado. It is important to know how to control and prevent weed establishment so that economic thresholds are not met. Crop and field rotation together with a good herbicide plan are effective ways to manage most weed issues. This chapter has illustrations to help with weed ID.

Herbicide Injury and Identification

Even correctly applied herbicides can cause injury, but some common causes include:

  • Carryover from a previous crop
  • Drift from nearby operations
  • Improper application

This chapter has illustrations of injury caused by specific herbicides to help with injury ID.

Soil Fertility

Corn plants need at least 17 different nutrients to turn sunlight into a bountiful yield. The best way to know where your nutrients are currently at is to have your soil tested. Soil testing goes a long way in helping protect your bottom line.

Nutrient management: The 4 r’s

  • Right source
  • Right rate
  • Right time
  • Right place

Nitrogen (N)

  • Determining right application rate
    • Nitrogen fertilizer requirement calculation
    • Determining nitrate credits
  • Nitrogen uptake and application timing
  • In season Nitrogen assessment tools

Phosphorus (P)

  • Placement and rate

Potassium (K)

Sulfur (S)


  • Zinc
  • Iron


Stover bailing and removal considerations


  • Soil water holding capacity
  • Soil texture
  • Root depth
  • Estimating soil moisture
  • Evapotranspiration (ET)
  • Weather effects on ET
  • Critical growth stages
  • Limited water management
  • Irrigation scheduling
    • Atmometers
    • Crop coefficient guide
    • First irrigation
    • Last irrigation
    • Center pivot irrigation systems
    • Surface/furrow irrigation
    • Surge irrigation
    • Water quality and salinity


Tillage systems choice is dependent on several factors.

  • Soil erodibility
    • Soil texture
    • Slope
    • Organic matter levels
  • Irrigation system
  • Available equipment
  • Rotation with other crops

These tillage choices have impacts on:

  • Soil organic matter levels
  • Soil compaction
  • Pest control options

Tillage systems

  • Moldboard plowing
  • Reduced tillage
    • No-till
    • Strip-till
    • Vertical tillage and other systems


  • Strategies to avoid compaction
  • Compaction systems
  • Compaction ID
  • Compaction remediation


  • Silage Harvest
  • Grain Harvest
  • Post harvest considerations
  • Yield estimation worksheet

Record Keeping

Some types of information that are worth keeping in your annual records include:

  • Field
  • Hybrid
  • Weed/insect control package
  • Fertilizer rate and amounts
  • Soil type
  • Tillage
  • Irrigation scheme
  • Other management differences


Useful Facts, Figures, and Conversions

  • Spray calibration
    • 3 calibration methods
  • Determining grain and silage yields
  • National crop insurance services hail damage assessment