2013 Annual Report
1a.Objectives (from AD-416):
The long-term goal of this project is to develop best management practices for biofuel production systems in the Northwestern Corn Belt (NCB) that actively and purposefully promote populations of beneficial insects, especially pollinators and crop pest predators. Nearly one-third of the nation’s honey bee colonies reside in Minnesota, North Dakota, and South Dakota, yet these and many other beneficial insects are limited in this region by the low abundance and diversity of food resources in spring and autumn. Consequently, supporting objectives of this long-term goal are to: (1) document and compare the basic flowering phenology of a wide variety of NCB-adapted oilseed crops of known economic value with the intent of expanding the availability and diversity of pollen and nectar from April to November; (2) develop management protocols that extend flowering times, especially in spring and autumn; (3) establish indices of rotational compatibility of spring-, summer-, and autumn-flowering oilseed crops with standard biofuel crops, including corn, soybean, and switchgrass; (4) certify beneficial insect use of oilseed floral and vegetative resources; (5) determine beneficial insect community assemblages; and (6) decipher predatory insect spillover benefits for adjacent rotational crops, especially as influenced by habitat edges.
1b.Approach (from AD-416):
Our research will design and test best management practices for economically and agriculturally rational biofuel crop rotations appropriate for northern states. Management practices will be optimized based on their effects on profitability and beneficial insects. This project will diversify the range of biofuel crops available for producers and simultaneously enhance environmental quality for beneficial insects. Specifically, the project will (i) integrate a suite of high-value oilseed crops, selected based on their temporal production of floral resources from April to November, into rotations involving traditional biofuel crops (corn, soybean, switchgrass) and examine their profitability; (ii) identify the diversity and relative abundance of pollinator communities that are associated with each rotation and examine the effects of diversification on pollinator health; and (iii) document spillover effects produced by diverse rotations on natural enemies of pests in adjacent bioenergy crops.
Coordinating with collaborators at USDA-ARS in Morris, MN, the field project was established at the Eastern South Dakota Soil and Water Research Farm near Brookings, SD. In October 2012, three winter crops (winter camelina, pennycress, and winter canola) were planted. Drought conditions resulted in poor fall growth of all three winter crops. We frost-seeded these species in March, 2013 to increase stand establishment; inadequate vernalization resulted in only winter camelina and pennycress producing measurable seed. A late spring delayed harvest of winter crops until July. Short-season corn and soybean were planted following winter crops. Soil water content is being monitored continuously in these plots. Spring camelina, spring canola, calendula, crambe, borage, cuphea, echium, flax, sunflower, and safflower were established, and all were producing strong crops as of 7-30-13. In each plot, water and nutrient use efficiency are being determined; changes in aggregate stability are being measured in select treatments. . Light penetration to the soil surface was measured approximately weekly over the season in each crop. Insect populations were assessed in each of the crops using a variety of sampling procedures. Direct observations of flower visitors were made between 11:00-14:00 twice per week. Suction samples (3 min per field) were collected once per week using a leafblower set to vacuum. Pan traps (blue, yellow, and white) were placed in each plot for 24 h periods once per week. All insects collected have been returned to the lab for eventual curation and identification (this process has already begun). Field plans for 2014 are in development.