Degree Day Modeling and Economic Considerations of Insects and Weeds in Sheep Grazed Alfafla, Grain, and Range Production Systems

Degree Day Modeling and Economic Considerations of Insects and Weeds in Sheep Grazed Alfafla, Grain, and Range Production Systems

Summary

This project was implemented in spring 2012 at five Montana locations.

Location one was established to evaluate cropping system and sheep grazing influence on Carabid beetle populations. At location one, pitfall trap samples were deployed in annual and perennial crops and in adjacent non-cropped vegetation. Each habitat type was replicated four times in four independent and adjacent fields on three different private properties. Approximately 1,200 hectares of private stakeholder property are committed to this portion of the project.

Locations two, three and four are located in central and central east Montana. All three sites are located on stakeholder private property and serve as locations to evaluate the influence of targeted sheep grazing on pest aphids of alfalfa production. Approximately 250 hectares of private stakeholder property and 3,000 head of domestic sheep are committed to this portion of the project.

Location four is also located in central Montana and serves as the rangeland component to this project. Location four is a mix of public and private properties and was established to evaluate the influence of grazing on Carabid beetle populations located on rangelands. Approximately 20,000 hectares of public and private stakeholder properties are committed to this portion of the project.

Location five is located at Montana State University’s Towne’s Harvest Farm. At location five, our team is evaluating the use of targeted sheep grazing as a means of cover crop termination. We are collecting soil, plant and arthropod data. Approximately six hectares of Montana State University property are committed to this portion of the project.

Our team is also actively involved with the public schools by assisting two local districts with their agricultural and farm to school programs and activities. Additionally, Dr. Hayes Goosey, the project PI, has volunteered as a speaker on the central Montana agricultural extension tours slated for the week of October 8th. During this time Dr. Goosey, as a part of the MSU extension team, will present three one-hour long seminars per day for four days. The targeted audience is producers, governmental agency employees and agricultural professionals, and the topic will be integrated alfalfa production. Dr. Goosey also was sponsored to visit Moscow, Russia where he presented a degree-day grazing model generated from SW07-013 funds. During this time Dr. Goosey was also part of outreach tours to end-product facilities in the Moscow area. Finally, the project has located and hired a graduate who has been involved with all aspects of this project. We are expecting a graduation date of spring 2014.

Objectives/Performance Targets

Our broad objectives are to evaluate how livestock grazing systems influence a diverse set of response variables, incorporate this information into producer recommendations, and then disseminate those recommendations to targeted audiences which encompass secondary public schools, college level courses, governmental agencies and private property producers. We intend to accomplish these objectives by utilizing the scientific method, proper experimental replication and appropriate statistical analyses.

From proposal overview:

1) Compare various intensities (0-200 DD) and model results of sheep grazing (fall and spring) and a no-input control on:

a) pea aphid and ASC populations in alfalfa (Goosey, O’Neill, Johnson, Helle, Lehfeldt, Thomason, Baucus).

The concept of this management tactic is based on sheep consuming and/or trampling pea aphid eggs or ASC infested seed in the fall and/or spring. For targeted grazing to manage these pest populations, appropriate stocking rates must be determined. Simply turning a few sheep onto vast acreage will not be sufficient. Fall stocking rates can be expressed on a purely animal per unit area basis, and the performance target will be calculating what rates are necessary to sufficiently remove pea aphid eggs and ASC infested seed.

Spring grazing, prior to and during the alfalfa green up period, will need to be expressed on a DD basis, similar to Goosey (2009). The spring grazing performance target will be calculation of appropriate stocking rates and grazing durations based on DD rather than calendar dates. To utilize targeted grazing as an IPM tactic, implementation needs to be expressed in terms of temperature.

b) change in alfalfa field plant community and alfalfa aftermath (Goosey, Menalled).

Decreased plant biodiversity in agro-ecosystems has negative consequences to insect biodiversity (Gaines and Gratton (2010). The loss of insect diversity is especially pertinent in agroecosystems, as insects provide a variety of ecosystem services vital to farming (Isaacs et al. 2009). Because of the value of plant biodiversity in agroecosystems, agricultural practices that favor conservation of farmland biodiversity should be encouraged (Butler et al. 2007). Our preliminary data indicates an increase in weed species diversity in a sheep grazed wheat/pea/summer fallow system (Hanson et al. 2010). The performance target is to monitor treatment effect on plant biodiversity, document any changes in yield and/or nutritive quality and correlate this to any recorded changes in insect diversity.

c) pollinator, predator, and parasitoid populations in alfalfa (Goosey, O’Neill, Johnson).

One driving force behind sustainable agriculture practices is utilizing production strategies which enhance beneficial arthropod populations and success rates of pollination, predation and parasitism. Losey and Vaughan (2006) estimated the annual value of pest control and crop pollination attributed to wild insects in the U.S. at $4.5 and $3.1 billion, respectively. However, little is known about how targeted grazing systems impact beneficial species. Our preliminary data indicates greater parasitic hymenoptera in sheep grazed spring and winter wheat/summer fallow farming systems when compared to mechanical and chemical managerial practices. Our team will compile an inventory of beneficial species and assess the treatment influence on populations. The performance target will be a preliminary understanding of how targeted grazing influences beneficials of alfalfa production with the expectation that this knowledge will lead to further research hypotheses and measurable objectives.

d) Carabidae spp. diversity between sheep grazed cropland, improved pasture and rangeland (Goosey, O’Neill, Johnson, Menalled).

Carabid species assemblages differ between habitats and the pest management potential of an assemblage is dependent on species identity (Gains and Gratton 2010). The functional diversity of an assemblage is a measure of the functional roles represented within a community, as compared to diversity per se, which is the number of species present. Previous research has recorded that more functionally diverse assemblages are more capable of providing ecosystem services (Straub and Snyder 2006). Our performance target is to identify differences in species assemblage between natural (i.e., rangeland) and cropped (i.e., alfalfa, wheat/pea/fallow and continuous wheat rotations) habitats to further document how animal grazing acts to alter diversity and arthropod ecosystem services.

2) Develop an economic decision support tool to evaluate long term cost-benefits of sheep grazing in alfalfa production (Goosey, Griffith, Helle).

We propose to utilize an existing decision support tool to analyze the economics of this grazing system. The intent of this program is to be a tool available to producers to assist when developing a grazing program. This program was developed with Western SARE funds (SW07-013) and is currently available online at:
http://www.montana.edu/extensionecon/software/SheepGrazingAlfalfa.swf
Our performance target will be developing a grazing protocol that is effective in terms of dollar cost and pest management potential.

3) Develop and conduct large, multi-farm demonstrations. Communicate results to producers, students, scientists and the public on the advantages of incorporating prescriptive sheep grazing into alfalfa and cereal production systems.

Accomplishments/Milestones

1. Completion of the first field season at five locations around Montana during which we collected an estimated 10,000 arthropod specimens that are currently being identified.

   Locating and hiring a project supported graduate student.

   Dr. Hayes Goosey was selected and sponsored by the Montana Department of Agriculture to present a degree-day grazing model, developed using Western SARE SW07-013 funds, at the 2012 AgroFarm Expo in Moscow, Russia. Dr. Goosey also presented the objectives and justification of project SW11-086 at the AgroFarm Expo.

   Dr. Hayes Goosey will be presenting Western SARE-funded research/results and information relevant to alfalfa production during the week long Central Montana Agricultural Extension tour scheduled for October 2012. These presentations target stakeholders/producers, students, governmental employees and ag professionals.

   Helping sponsor the first annual ‘Yellowstone Food Festival’ to be held in Livingston, MT on September 22, 2012. This is a local food festival at which Dr. Hayes Goosey will set up a display booth of past and present Western SARE-funded ‘targeted grazing’ research programs and how these programs affect the sustainability of Montana’s agricultural systems. Dr. Goosey is also a guest speaker at the event, which will provide an opportunity to highlight the many benefits which integrated and sustainable productions systems have on local markets.

Impacts and Contributions/Outcomes

The main impact of SW11-086 thus far can be measured in the hectares of land and head of livestock committed by stakeholders to each portion of this project. To date, we have access to approximately 21,000 hectares of private and public properties and 3,000 head of domestic sheep. We feel this is a direct representation of the value producers see in these types of research programs.

Additionally, we have focused on informing audiences that we have received funding from Western SARE and what are the project objectives. During this time we continue to utilize the presence of these Western SARE funds to help educate targeted audiences on the benefits of incorporated crop and livestock production systems and more specifically, the degree-day grazing model generated from project SW07-013.

Collaborators: