University of Vermont

Enhancing Nectar Production with Clover - Innovative Methods to Utilize Alsike and White Clover in Vermont Hay Fields Northeast SARE Partnership Project
Enhancing Nectar Production with Clover - Innovative Methods to Utilize Alsike
and White Clover in Vermont Hay Fields

Principle Investigator

Sid Bosworth, Associate Extension Professor, Plant and Soil Science Dept.

Project Partners:
Charles Mraz
, Champlain Valley Apiaries, Middlebury, VT
Art Huestis, Huestis Farm, Bridport, VT
Tom Duclos
, Dulcos and Thompson Farm, Weybridge, VT



Duration: 2013 - 2014

Introduction

Honeybee on White CloverA decline in honeybee populations in Vermont over the past few decades has been attributed to many factors including mites, disease and a loss of nectar and pollen resources.  The Vermont Beekeepers Association believes that an important stressor on honeybees in Vermont is the lack of food available to them throughout the summer.   One reason is that over the years, dairy farmers have increased their intensity of hay crop cutting practices in order to maximize feed quality resulting in no to very little bloom from legume hay crops such as alfalfa or clover.


The goal of this project is to increase the acreage of flowering clovers that provide sustained nectar flows during this critical summer period.  Most clover species are excellent sources of nectar and pollen for honeybees.  In Vermont, the best clovers for honeybees are white clover (Trifolium repens L.) and Alsike clover (Trifolium hybridum L.) since their florets are small and accessible.  Red clover (Trifolium pratense L.) has larger florets more suited for larger pollinators such as bumblebees.

The Vermont Beekeepers Association, working with UVM Extension, has set an initiative to promote the use of more pollinator plants that would enhance food resources for honeybees and other wild pollinators.   As part of this initiative, the VBA would like to promote hay and pasture crops that are more ‘bee friendly’ without sacrificing forage quality that dairy and other livestock farmers are dependent upon.  However, there is a need to conduct field trials on farms to actually determine the feasibility of various mixtures and management practices that would help the VBA meet these goals while dairy livestock farmers still meet their feed goals.  

Objectives

Champlain Valley Apiary Bee Yard at Duclos FarmThe primary purpose of this project is to conduct field trials to test the feasiblity of using clovers in hay systems to enhnace nectar production during the mid to late summer periods.  The first study objective is to test the feasibility of improving nectar flow for honeybees by introducing Dutch white clover into grass hay cropping systems and assess its impact on flower production and foraging honeybees.  The second study objective is to test the feasibility of improving nectar flow by growing mixtures of various early maturing legumes with alfalfa managed for hay and assess its impact on flower production, honeybee activity, forage yield and forage quality. 
 

Study 1: Utilizing Dutch White Clover in Grass Hay Fields 
The first objective is to test the feasibility of improving nectar flow for honeybees by introducing Dutch white clover into grass hay cropping systems and assess its impact on flower production and foraging honeybees.  There are three general types of white clover based on size - large, intermediate and short.  The 'Dutch' white clover are of the shortest types and are often found in lawns and other  intensely defoliated areas.  Our hypothesis is based on the observation that there can sometimes be a flush of white clover bloom in between cuttings of grass hay.    But there are challenges that need to be tested.  First, the success rate of overseeding white clover into an existing grass hay field can vary greatly depending on time of seeding, environmental conditions, soil type, amount of thatch and competition from existing vegetation.  Secondly, even if the clover is in flower between cuttings, we really don't know the extent of nectar production from these flowers.  Weather conditions as well as competition for light and water from the grasses in the hay mixture can greatly influence nectar production.  By measuring the consistency and duration of bloom throughout the growing season as well as making visual data of bee activity during bloom, we will be able to assess the the nectar contribution of this system.

In April 2013, a strip trial was planted into an existing grass hay field at the Duclos-Thompson Farm in Weybridge, Vermont with the assistance of Mr. Tom Duclos.  Treatments includes a no-treatment control plus four different seeding scenarios using Dutch white clover: two seeding rates, 2 vs. 4 lbs./a using two methods of seeding,  no-till planted with  a  Haybuster 107C drill. Strips were 50 feet wide and 150 feet long.  Within a month after planting, we did measure more white clover seedlings with either method of planting particularly at the 4 lb/a seeding rate; however, by the middle of the summer, the actual flower head populations were similar across treatments including the control.  It is likely that since white clover is a stoloniferous creeping perennial, flower population is more affected by stolon population rather than actual plant population.  The strips will continue to be monitored in 2014 for both white clover seedhead populations and bee activity.

Broadcast Seeding Dutch White CloverNo-till seeding Dutch White CloverDutch white clover seedlings
Broadcast seeding white cloverNo-till drill used to seed studyClover seedlings 3 weeks after planting

Study 2: Alfalfa-Clover Mixtures To Enhance Summer Nectar Production
Our second objective is to test the feasibility of improving nectar flow by growing mixtures of various early maturing clovers with alfalfa managed for hay and assess its impact on flower production, honeybee activity, forage yield and forage quality.  Our hypothesis is that early maturing legumes such as medium white clover and/or alsike clover will bloom before the alfalfa is ready to cut.  This used to be a common practice in New England since so many fields vary in drainage and  alsike clover is more tolerant of wet soils.  Over the years, Art Huestis, a dairy farmer in Bridport, VT and one of the project partners, has observed that alsike clover will bloom between cuttings. However, we do not know if this practice will actually result in increased nectar flow and no studies were found in peer reviewed literature to evaluate this approach of growing legume mixtures.  Therefore, we planted a field trial at the Huestis farm as well as a small plot study at the University of Vermont research farm in South Burlington, VT to test various mixtures for flower production and bee activity.  In addition, we will evaluate the affect of growing these mixtures on forage yield and quality as compared to growing pure alfalfa.  Due to record rainfall in May and June, 2013 was a rough year to establish an alfalfa crop on clay soil.  The stand did survive with one harvest made in early August.    An assessment of the stand early September showed that the percentage of alfalfa in the stands ranged from 47 to 55 percent in the clover mixture plots and 71% in the alfalfa-only control plots.  The clovers ranged from 21 to 41% of their respective stands depending on clover variety and seeding rate.  The alfalfa-only control had about 10% clover reflecting what was in the soil seedbank prior to planting.Next year, we will begin measurments.  The earliest flowering variety of white clover, 'Pinnacle', did show bloom in September compared to the other clovers.  We will begin monitoring yield, quality, bloom and bee activity in 2014.

Huestis Study Site
Huestis Site in September 2013
White clover varieties at Huestis Study
Preparation of Huestis Study SiteHuestis Site in SeptemberCrusade and Pinnacle white clover 

First Year Results
Our primary focus of the first year was to establish field trials and work out methodology.  Data from the first years are presently undergoing analysis.  

Northeast SARE is a regional program of the nationwide SARE which offers competitive grants to projects that explore and address key issues affecting the sustainability and future economic viability of agriculture. The program is authorized under Subtitle B of Title XVI of the Food, Agriculture, Conservation, and Trade Act of 1990.  It's wider mission is to advance, to the whole of American agriculture, innovations that improve profitability, stewardship, and quality of life by investing in groundbreaking research and education. For more information go to, http://www.nesare.org/

This site is maintained by Sid.Bosworth@uvm.edu, Plant & Soil Science Department, University of Vermont.

Sponsored by:
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Last modified January 03 2014 08:17 AM

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