Insect Management in Grass Buffer Strips

on the Texas Blackland Prairie

  Frederick P. Baxendale1, Dennis W. Hoffman2, 

Wesley Rosenthal2 and Monty Dozier3

1Department of Entomology

University of Nebraska--Lincoln

2Blackland Research Center

3Texas Agricultural Extension Service

Texas A&M University System

Temple, Texas 76502  

 

BRC Report No. 00/04

June 2000

PROJECT PURPOSE/ACTIVITIES  

Perennial vegetation (grass, shrubs, and/or trees) buffer strips can be used to remove sediment, nutrients, pesticides and organic materials transported in water runoff. Buffer strips are bands of land in permanent or semi-permanent vegetation designed to intercept pollutants and manage other environmental concerns. Buffer strips are a part of a larger group of vegetative conservation structures known as buffers. Buffers include: contour grass strips, filter strips, riparian buffers, grass waterways, cross wind trap strips, shelter belts, field windbreaks, alley cropping, and vegetative barriers.

 

Buffer strips work by slowing the movement of runoff water, trapping sediments suspended in the runoff water and enhancing infiltration of the runoff water within the buffer strip. They also trap fertilizers and pesticides that are adsorbed to soil sediment and reduce the amount of soil lost to wind erosion during periods of strong winds. If properly established and maintained, grass filters have the capacity to remove 50% or more of the nutrients and pesticides, 60% or more of certain pathogens and 75% or more of the sediment from surface runoff. When coupled with good crop management and sound integrated pest management practices, buffer strips will assist farmers who desire a measure of economic and environmental sustainability in their operations.

 

Drs. Dennis Hoffman, Wesley Rosenthal and Monty Dozier have been investigating the potential of native grass (buffalograss, indiangrass, big bluestem, little bluestem and switchgrass) buffer strips for reducing runoff-carried pollutants at the Texas Agricultural Experiment Station’s Blackland Research Center in Temple, TX. However, little was known about the arthropod community associated with these native grass buffer strips. Under the auspices of the Big 12 Faculty Fellowship Program, Dr. Fred Baxendale traveled to the Blackland Research Center to survey the insects and mites inhabiting these strips, evaluate their potential impact, and make Integrated Pest Management (IPM) recommendations to TAES and TAEX.

 

PROJECT OUTCOMES AND IMPACTS

Efficiency of grass buffer strips in reducing non‑point source runoff losses of atrazine in surface runoff:

Atrazine is a widely used herbicide, but concerns about pesticide contamination of surface water associated with off‑target losses of atrazine threaten its continued use of Contour buffer strips, designed to remove sediment, chemicals and organic material transported in surface runoff, were established on nine watersheds at Blackland Research Center to determine the efficiency of grass filter strips in reducing non‑point source runoff losses of atrazine in surface runoff. Results from the studies at BRC demonstrated that bermudagrass and wheat buffer strips can reduce atrazine concentrations in surface runoff. Additional results of this study suggest:

  • Buffer strips reduce total runoff by increasing infiltration

  • Grass buffer strips remove atrazine from runoff

  •  Buffer strips reduce sediment losses

  • Establishing buffer strips on the contour increases effectiveness

  • Grass waterways may be needed to channel water down slope on large fields.


Arthropod Surveys and IPM Recommendations for Buffer Strips:  

Arthropods associated with the buffer strips were surveyed on 2 occasions (September 14-17, 1999 and May 16-19, 2000) at research locations on and near the Blackland Research facility in Temple, TX. Among the potential pests identified were aphids, armyworms, chinch bugs, cutworms, grasshoppers, leafhoppers, plant bugs, white grubs and spider mites. In addition, numerous beneficial arthropods including lady beetles, lacewings, syrphid flies, ground beetles, rove beetles, big-eyed bugs, spiders and parasitoid wasps were observed inhabiting the buffer strips. Based on these surveys, the following Integrated Pest Management/Best Management Practices were developed for buffer strips on the Texas Blackland Prairie:  

  •  Select adapted and insect resistant plant material for buffer strips. Tall stiff grasses such as indiangrass, switchgrass, big bluestem and little bluestem are preferred, but selected turfgrasses including bermudagrass, buffalograss, tall fescue and zoysiagrass may be acceptable. In addition, wheat and/or oats buffer strips would provide both sediment runoff protection and a cash crop.

  •   Identify potential arthropod pests associated with each plant species and become familiar with each pest’s biology, behavior and damage symptoms. Establish treatment thresholds and develop a management plan for potential pests.

  •  Conduct regular monitoring of buffer strips to detect the presence of insect pests, weeds, plant diseases and any indicators of agronomic problems.

  •  When possible, maintain plant diversity in and around buffer strips to encourage the  conservation of beneficial insects.

Agricultural producers and other landowners who install buffer strips can reduce sediment losses due to erosion, minimize losses of agricultural chemicals, improve soil, air and water quality, enhance wildlife habitat, restore biodiversity and create scenic landscapes. Through project such as this, and with the assistance of university, government and private industry partners, farmers, ranchers and other landowners will learn to appreciate the economic and environmental benefits of installing and maintaining buffers.

Partial funding for this brochure and buffer strip research provided by USEPA and Big12 Faculty Fellowship Program

The information given herein is for educational purposes only. References to commercial products or trade names are made with the understanding that no discrimination is intended and no endorsements are implied by the Texas A&M University System. Research and educational programs conducted by the Texas A&M University System serve people of all ages regardless of socio- economic level, race, color, sex, religion, disability or national origin, economic level, race, color, sex, religion, disability or national origin.


June 20, 2000
Dennis Hoffman, Project Leader;
Steve Dagitz, Webmaster