Wisconsin Integrated Cropping Systems Trial (WICST) Project
The Wisconsin Integrated Cropping System Trial (WICST) began in 1990 to address issues of sustainability associated with various farming systems. The 25 ha experiment is located on highly productive, prairie-derived Mollisols at the University of Wisconsin’s Arlington Agricultural Research Station in Columbia County, Wisconsin, USA. The main experiment compares six Midwestern agricultural production systems: Three of the systems are typical of cash grain enterprises and three are typical of forage-based dairy enterprises. A nested study consisting of three native perennial grass systems was established in 1999. The production systems vary in crop diversity and use of purchased inputs. They range from continuous corn to rotational grazing, and the performance criteria which are used to evaluate these systems include productivity, environmental impact, and profitability. Plot sizes are relatively large at WICST (0.3 ha) and all management is conducted with production scale agricultural equipment. The trial is set up so that every phase of each rotation is present with a field replicate (block) each year. The Arlington site is now heading into its 25th field season.
WICST Cropping System Treatments
Continuous Corn (CS1):
This system represents a conventional, continuous corn rotation. Fertility is derived from applied synthetic N, P, and K, weed control is achieved via a combination of tillage and herbicides, and top yielding corn hybrids with advanced genetic traits are planted.
Corn – Soybean (CS2):
This system represents a corn – soybean rotation using minimum tillage. Fertility is derived from applied synthetic N, P, and K, and weed control is achieved via herbicides. Top yielding corn hybrids and soybean varieties with advanced genetic traits are planted. Soybeans are no-till drilled into corn stover, and corn is strip-till planted in soybean stubble.
Corn – Soybean – Wheat/Clover (CS3):
This system is managed according to the USDA’s National Organic Program Standards. Fertility is derived from biologically fixed N, composted poultry manure, and potassium sulfate. Weed control is achieved via mechanical means as well as by using cover crops. High yielding organically certified corn hybrids, and organically certified soybean and wheat varieties are planted.
Corn – Alfalfa – Alfalfa – Alfalfa (CS4):
This system is representative of a high input, high yielding dairy forage rotation. Fertility is derived primarily from the application of dairy manure, weed control is achieved via herbicides, and top yielding corn hybrids and alfalfa varieties with advanced genetic traits are planted. Typically two forage harvests occur during the alfalfa seeding year and between three and four during the production years of the alfalfa phase of the rotation.
Corn – Oats/alfalfa – Alfalfa (CS5):
This system is managed according to the USDA’s National Organic Program Standards. Fertility is derived from the application of dairy manure, weed control is achieved via tillage, and organically certified top yielding corn hybrids and organically certified leaf hopper resistant alfalfa varieties are planted. Typically two forage harvests occur during the alfalfa seeding year and between three and four during the production year of the alfalfa phase of the rotation.
Rotational Grazing (CS6):
This system is designed to represent a custom heifer operation. Heifers are brought on to pasture at the beginning of May and then returned to the UW’s herd at the end of the season. Managed grazing is used to maximize the productivity and health of both the heifers and pasture. Fertility is derived from biologically fixed N and manure as well as applied synthetic N, P, and K on an “as needed” basis. Red clover is seeded biennially or as needed to maintain a 35% legume stand in the cool season grass sward.
Switchgrass:
Switchgrass (Panicum virgatum L.) was established in 2007 to serve as a low diversity comparison to our native prairie plantings and to provide data on the production potential and environmental impacts of dedicated cellulosic bioenergy systems. The plots are seeded to a northern-upland ecotype (“Forestberg”) and receive a minimal amount of N fertilizer each season (56 kg N ha-1). These plots are unique in that they are subdivided into three different management categories: 1) biofuels – harvested once, post frost, 2) grazing – grazed once or twice per season and burned each spring to minimize non-native cool season grasses, and 3) control – burned each spring to minimize non-native cool season grasses but never harvested or grazed.
Low Diversity Prairie:
This system typifies a standard CRP planting with 6 native species (two grasses, two legumes, and two forbs). This system was established in 1999 and is subdivided into three different management categories: 1) biofuels – harvested once, post frost, 2) grazing – grazed once or twice per season and burned each spring to minimize cool season grasses, and 3) control – burned each spring to minimize cool season grasses but never harvested or grazed.
High Diversity Prairie:
This system is designed to represent a native prairie community that might have existed pre-settlement in southern Wisconsin. Planted in 1999 the system initially included three grasses, four legumes, and 18 forbs. These plots are unique in that they are subdivided into three different management categories: 1) biofuels – harvested once, post frost, 2) grazing – grazed once or twice per season and burned each spring to minimize cool season grasses, and 3) control – burned each spring to minimize cool season grasses but never harvested or grazed.
