LTER research at the Kellogg Biological Station (KBS) is centered on row-crop agricultural systems, with particular emphases on ecological constraints to agronomic productivity and on the environmental impact of agriculture in the larger landscape. KBS is located in southern Michigan; the site is thus broadly representative of north-temperate farming systems, in particular of those in the northern corn belt.
The overall aim of the KBS LTER project is to test the hypothesis that management based on ecological concepts can effectively substitute for reliance on chemical subsidies in production-level agronomy. By imposing a range of management treatments on a series of experimental plots, investigators will test specific hypotheses that follow from the general hypotheses that nutrient subsidies can be minimized by manipulating plant-microbe interactions; that herbicide subsidies can be minimized by manipulating crop-weed interactions; and that pesticide subsidies can be minimized by manipulating plant-insect-pathogen interactions.
The project’s main experimental treatments are designed primarily to allow us to examine questions about how long-tern, interactions among populations in these systems affect system-wide attributes such as nutrient availability, herbivory and pathogenesis, plant competition, carbon allocation, and nutrient/pesticide outputs. Field treatment will include four main species levels with two management levels nested within each:
- Conventional corn/soybean cultivation. This treatment provides the most direct link to current agricultural practice; here we will follow typical management strategies for maximizing economic yield. Management treatments will include both
- Moldboard plowing
- No-till cultivation practices
- Low-input corn/legume cultivation. Recent long- term experiments with organic-based farming techniques at Rodale and elsewhere are beginning to demonstrate that these management techniques can provide viable, production-level alternatives to subsidy-intensive conventional cultivation methods. Yet these systems are virtually unexplored from a scientific, process-level endpoint: it’s not at all clear why they work, and without :h information it will be difficult to generalize these low-input techniques to other types of cropping systems or to other areas of the country. Close examination of organic based systems will provide substantial insight into optimal cropping strategies and provide a unique ecological system in which to test hypotheses about SOM turnover, herbivory, C allocation, and other processes in systems that are driven primarily by organism interactions. At KBS the low-input management treatments will include both
- low-input cultivation in which chemicals are used only to control outbreak pest populations
- zero-input cultivation in which no pesticide subsidies are used regardless of pest population status
- Perennial biomass cultivation. The recent arid rapid development of fast-growing, varietal clones of several woody species suggest the likelihood that perennial cropping systems managed for woody biomass production will become a significant pert of the future agricultural landscape. Perennial biomass farms are managed for short-rotation (3-1 0 years) wood production; the biomass produced is used for pulp or fuel. From an ecological standpoint this type of cropping system provides opportunities for examining process and organism interactions in systems that maintain viable root systems from year-to- year vs. interactions in more typical, annual crop systems. Specific management treatments at KBS will include
Both treatments will be harvested on a 4-5 year rotation cycle
- a Populus sp. clone selected for strong above-ground production
- a Populus ap. clone selected for strong below-ground allocation
- Native successional community. An unmanaged, successional community abandoned at the time of plot establishment will be used to contrast organism interactions in a community of co-evolved species against the artificial simplified communities comprising our cropping systems. We expect this system to exhibit tightest temporal and spatial coupling of organism interactions several years after establishment when it reaches a midsuccessional growth state. A second native community on a nearby never-tilled soil of the same series as our main plots will be maintained as a long-term reference plot. This latter plot, with its undisturbed soil profile, will be used mainly to test hypotheses about long-tern, SCM fractionation and turnover
Eighteen senior investigators are directly involved in the KBS LTER program. These include faculty from KBS and from campus-based Departments of Crop and Soil Sciences, Entomology, Botany and Plant Pathology, Microbiology, and Forestry. Co-PIS are Phil Robertson (Managing PI), Mike Klug, and Eldor Paul.
Inquiries about the site should be directed to Phil Robertson at the W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, Ml 49060-9516.