The LTAR Cropland Common Experiment in the Upper Chesapeake Bay

Area of Science:

• Agricultural Science
• Environmental Science
• Agronomy

Background:

• Dairy production in the Upper Chesapeake Bay (UCB) basin significantly contributes to phosphorous (P) and nitrogen (N) loading, exacerbating eutrophication.
• Nutrient imbalances in the UCB basin are worsened by the import of feed and the use of mineral fertilizers.

Purpose of the Study:

• To evaluate diverse crop rotations that minimize imported feed, maximize living cover, and reduce nutrient losses in dairy cropping systems.
• To compare an alternative dairy cropping rotation with a prevailing conventional rotation regarding nutrient management and environmental impact.

Main Methods:

• Established a plot-scale experiment in 2018 (building on a 2010 study) and a field-scale experiment in 2019 on a commercial dairy farm.
• Compared an alternative rotation (corn, alfalfa/orchardgrass, rye, sorghum-sudangrass) with manure injection and integrated pest management against a conventional corn-alfalfa rotation with higher manure application rates.
• Monitored alternative practices like manure injection and avoidance of neonicotinoid seed treatments against prevailing practices.

Main Results:

• Findings suggest that crop rotation diversification, manure injection, and integrated pest management show potential for enhancing sustainability.
• The alternative rotation employed less frequent manure application compared to the conventional system.

Conclusions:

• Crop rotation diversification, manure injection, and integrated pest management offer potential benefits for the economic and environmental sustainability of dairy cropping systems.
• Long-term evaluation is necessary to confirm the sustained benefits of these alternative agricultural practices.