Establishment of native pollinator habitat in organic and conventional small ruminant pastures

Final Report for OS13-077

Project Type: On-Farm Research
Funds awarded in 2013: $15,000.00
Projected End Date: 12/31/2016
Region: Southern
State: Arkansas
Principal Investigator:
Dr. Joan Burke
USDA, Agricultural Research Service
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Project Information

Abstract:

Four pollinator plots were planted in fall 2015. Native grasses and forbs or flowering species were established, but weeds or non-native species persisted even though CRP (CP42) guidelines were followed. However, flowering species were present in spring, summer and fall, attracting many pollinator species. By planting a small 0.5 to 1 acre plot near livestock pastures, habitat was established and farmer experience was positive.

Introduction

Close to 75% of flowering plants worldwide rely on pollinators to set seed or fruit, providing food for humans, livestock, and wildlife. The economic value of insect-pollinated crops in the U.S., including crops and pasture grown for livestock, was estimated at $36-54 billion (Xerces, 2011). Some important crops in the southeastern U.S. that rely on pollinators are walnuts, pecans, peaches, berries, squash and other vegetables, and annual flowering forages for livestock such as clovers. Farmers are considered stewards of the land, ensuring continuation of diverse plant and wildlife for future generations. Conservation efforts can benefit both agriculture and wildlife.

An estimated three out of every five bites of food humans take originated from plants that required insect pollination for production (Xerces, 2011). Declining populations of pollinator species such as European honeybees have potentially disastrous implications for world food production. One important way to encourage the natural regeneration of pollinator species is to protect current habitat areas and establish additional habitat. A large proportion of pollination services are carried out by native species of bees, and native pollinator habitat is used to help enhance and restore habitat for ecologically and economically important pollinator species (NRCS CRP Practice CP42). A number of pollinating insects including bees and butterflies are vulnerable to extinction due to human practices and are in critical need of conservation assistance.

Habitat has been lost due to excessive use of herbicides, conversion of native flowering plant species to forages of agronomic value (many are non-native species), use of pesticides, and plowing or burning of nesting sites. A decline in species can also be attributed to pesticide poisoning and spread of diseases and parasites. The result has led to a reduced rate of both native and managed pollinator populations. Declining pollinator populations causes corresponding economic losses in agricultural settings (row crops) and natural areas (wildlife food sources).

European honeybees are non-native species and are susceptible to a variety of problems, including colony collapse disorder. A significant proportion of pollination services for crops come from native pollinator species, such as ground-nesting solitary bees and bumblebees. Establishing additional pollinator habitat has many benefits, including providing habitat for beneficial insects that may prey on crop pests, reducing soil erosion and nutrient runoff, and providing habitat for declining insect species like monarch butterflies.

Project Objectives:
  1. Establish a native pollinator plot and nesting habitat on a certified organic pasture, a conventional pasture at ARS and two farms, all with small ruminants.
  2. Determine establishment of each forage species, bloom date, and persistence.
  3. Determine species of pollinators present in plots and activity in nesting sites.
  4. Determine pollinator plant species response to small ruminant grazing and response of legumes in small ruminant plots to pollinators.

Cooperators

Click linked name(s) to expand
  • Dr. Ken Coffey
  • Margo Hale
  • Alayna Jacobs

Research

Materials and methods:

Objective 1: A native pollinator plot and nesting habitat was established on a certified organic pasture, a conventional pasture at ARS and two farms, all with small ruminants. Most available information evaluating pollinator effects on agricultural production is limited to row crop production. Little information that evaluates pollinator effects on pasture-based production systems is available for landowners. Information regarding effective techniques for establishing and managing pollinator habitat on livestock farms in western Arkansas is especially lacking. Landowners not only need more information about how pollinator populations benefit pasture quality and sustainability, but also need information comparing conventional and organic systems. Collaborators at NRCS (Booneville) provided guidance and expertise in establishing native pollinator habitat in a certified organic and a conventional small ruminant pasture.

Site selection and preparation: To qualify for CRP credits, pollinator habitat plots were at least 20 feet wide, at least 0.5 acres, and included at least 9 species (wildflowers, legumes, or shrubs) in which 3 species would flower in each of spring, summer, and fall. Not more than 25% of the mix included native bunchgrass species, important to prevent soil erosion, weed suppression, and structure for nesting habitat. Establishing diverse wildflower plots is difficult because there are fewer weed control tools, especially in organic plots, making site preparation extremely important.

Two replications were established according to the CRP (CP42). The target was to establish 10 native forages to allow flowering in spring, summer, fall and encourage or provide nesting habitat for pollinator species. Two farm sites were selected. At ARS, two 0.5 acre blocks per site were fenced within existing pastures, and on each farm, a 0.5 acre plot was established adjacent to small ruminant pasture and near a woodlot. Existing pasture species on both sites at ARS contained a mix of bermudagrass, fescue, and other forb species such as white clover. Once plots were established with pollinator seed mix species, sheep flash grazed half of each 0.5 acre plot as needed to evaluate grazing management of the plot. Presence of pollinators near the plots were noted monthly. Changes in grazing by sheep near the plots were monitored, as well as forage production of annual and perennial species each year.

Plot establishment and management: Very few certified organic wildflower seeds are available, so a native pollinator mix (Butterfly and Hummingbird mix; Hamilton Native Outpost, LLC, Elk Creek, MO) was used, to provide as many as 14 flowering species per season. The minimum seeding rate was 1 ounce/acre for each species (CRP Practice CP42), but we used the recommended 7.5 lb./acre. Grasses included ‘Cimmaron’ little blue stem (native warm season) and Virginia wild rye (native cool season) for erosion control and weed suppression, at 25% of seed mix weight, or 2.5 lb./acre. Seed bed preparation differed in organic vs. non-organic pastures. Organic pastures received only tillage to kill existing vegetation. Conventional pastures were sprayed with glyphosate.

Objective 2: Establishment of each forage species, bloom date, and persistence was determined. Establishment success at each site was recorded by frequency measurements in the first year and the number of blooming species in subsequent years.

Objective 3: Species of pollinators present in plots was determined. On all sites, surveys will be conducted in the second year of the project to identify common bee species and species-groups, as well as other pollinators (beetles, flies, butterflies) according to Xerces (2008; this was not conducted yet as an additional year was needed for establishment of species). Each cooperator will make observations recording which insects are visiting which flowers. Photographs may be taken to assist in identification of species. Observations will occur around the same day monthly in morning and afternoon during spring, summer, and fall (until first hard frost) recording time and day of observation, weather conditions, flowering species, activity on 8 flowering plants, and a description of the landscape, including nesting sites.

Objective 4: Pollinator plant species response to small ruminant grazing and response of legumes in small ruminant plots to pollinators (this was not conducted yet as an additional year was needed for establishment of species). Approximately 10 sheep or goats will be used to flash graze half of each replicated plot at ARS (no sheep or goat grazing will occur in farmer plots) in order to manage forage density in the plot. Mowing will be used as needed for the ungrazed plot. Response to grazing will be measured by determining the number of blooming species in grazed vs. ungrazed plots. Animals may provide better habitat for pollinators by selectively consuming grass species, or may cause excessive trampling, requiring more time for the plot to recover compared with mowing. No data exists on using livestock to manage native habitat plots. Caution will be used when toxic forage species are active (eg., milk weed) to minimize plant toxicity to animals.

Existing stands of clover and vetch near and approximately 1000 yards from pollinator plots were examined during the first and subsequent years (plots will be in place for at least 10 years) to determine reseeding rates of legumes.

Research results and discussion:

Objective 1. Both the conventional and organic plots were seeded with a native mix (New England and sky blue asters, white beardtongue, wild bergamot, common black-eyed Susan, compass plant, pale purple coneflower, plains and tickseed coreopsis, gray, rigid, and showy goldenrods, curly cup gum weed, Indian paintbrush, blue and white indigo, leadplant, slender lespedeza, butterfly milkweed, New Jersey tea, partridge pea, purple and white prairie clover, prairie rose, blue sage, Sampson’s snakeroot, slender mountain mint, tickseed and willowleaf sunflower, and yellow wingstem), little blue stem and Virginia wild rye in winter 2014/2015.

The ARS plots were planted in November 2014. Flowering species that established were black-eyed susan, pale purple coneflower, plains and tickseed coreopsis, leadplant, partridge pea, tickseed and willowleaf sunflower. No bumble bees were observed during monthly visits, but several butterfly species, hover flies, and wasps were present. By spring 2016, there appeared to be more butterflies in the sheep pastures that approached the pollinator plot in the organic pasture. The conventional pasture was noted to be surrounded by several species of flowering plants along the roadside (poppy mallow, mistflower, coneflowers, coreopsis, asters, Ohio spiderwort, and others).

On one farm, the mostly tall fescue plot was prepared by mowing short (8-10 inches) in July 2014 and subsequently mob grazed by sheep and goats, fenced off, sprayed with glyphosate in September, then burned, sprayed again as needed in September and October. It was too wet to disk in November, so farmer spread seed by hand. By the following fall 2015, native plant species present included sky blue aster, tickseed coreopsis, tickseed and willowleaf sunflower, black-eyed Susan, partridge pea, leadplant, slender mountain mint, Samson’s snakeroot, and an unknown aster (ox-eye daisy?) and mist flower that were not in the mix. Weeds included wooly croton, sericea lespedeza (sheep and goats willingly consume this), nutsedge, and other grasses. There were at least two butterfly species, but no bumble bees present. Sheep and goats mob grazed in late fall. The farmers are very pleased with the pollinator plot, with the perception of adding diversity and value to the pasture.

The other farm never reported back after planting the mix, even after repeated attempts to contact.

Objectives 2 and 3. Our NRCS cooperator relocated to Mississippi. We became familiar with plant and pollinator species as the plots established at ARS. We wish to continue this project and collaborate with a nearby entomologist.

Objective 4. There does not seem to be any harm in flash grazing pollinator plots with small ruminants, but more research will occur.

Participation Summary

Educational & Outreach Activities

Participation Summary:

Education/outreach description:

Publication in progress.

Workshop occurred August 2014 that provided education to farmers, landowners, and extension specialists on the importance of native plants, native pollinator habitat, changing farmer habits to preserve pollinators, all of which will improve food supply for humans, livestock, and wildlife. As the pollinator plots mature, those interested will be led through the organic and conventional pastures to view the sites and learn the successes and failures of this project. 29 attendants were present.

Project Outcomes

Project outcomes:

Impact is pending. There is wide interest in establishing pollinator plots near pastures.

Farmer Adoption

Because of the commitment needed to prepare the plots and cost of native seed, establishment of pollinator plots should not be taken lightly. However, the increase in diversity and pollinator species should eventually pay for itself. More education is needed, which we will continue to do.

Recommendations:

Areas needing additional study

Modern farming practices have not evolved around native plants and continuous grazing is not recommended; thus, we wish to examine grazing management practices, including rotational grazing schemes. Livestock performance and production should be considered, including animal health (incidence of health issues, including parasitism), growth rate, and time to reach market weight. Pasture inputs should be considered in the sustainability of the system, as well as estimates of future inputs.  Farmers are considered stewards of the land, ensuring continuation of diverse plant and wildlife for future generations. Conservation efforts can benefit both agriculture and wildlife.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.