The fourth technical session featured organic farming methods of seeding and managing pastures. Sarah Flack was the first speaker and went over recent amendments to the National Organic Program of USDA pasture rules for organic dairies. The main elements to the amendments are: Recognizes pasture as a crop. Producers must manage pastures and other outdoor access areas in a manner that does not put soil or water quality at risk. Producers must establish a functioning management plan for pasture and incorporate the pasture management plan into their organic system plan (OSP). Producers must provide ruminants over 6 months of age with pasture throughout the grazing season at their geographic location and outdoor access during the non-grazing season. Grazing season will be 120 to 365 days. Ensure ruminants derive not less than an average of 30 percent of their dry matter intake (DMI) from pasture during the grazing season. Detailed records must be maintained to keep organic certification intact. They include an OSP – Organic System Plan, which is filled out annually, and dry matter intake records & grazing records. These records are needed to pass the annual inspection. The job of the inspector is to verify management is as stated in the OSP.
Mr. J. Keith Waldron, IPM Coordinator, Cornell Extension, talked about fly management on organic dairy pastures. Potential arthropod related losses of 5 percent for a 65-cow dairy herd can mean an annual loss of \$11,050 in income. Keith said the 3 major flies of pastured cows were face, horn, and stable flies. Each are found on a unique part of the cow. Face flies, as the name implies, are on the cow’s face. Horn flies are found in large numbers on the backs of cows. Stable flies concentrate on the lower legs. The elements of pasture fly management as an integrated approach is to: correctly identify key pests, know their biology and habitat to know when and how to control them, monitor their numbers and assess if it is time to control them, and then use the control tactics that are available. Control tactics are: Cultural, Mechanical, Biological, and Chemical. On organic pastures, there are various fly traps that are available that work to catch different flies.
Dr. Heather Darby of the University of Vermont was the final speaker of this session. She took a soil health approach to producing healthy organic pastures. She explained that soil health is the ability of a soil to provide a physical, chemical, and biological environment for the plant that is health sustaining. Nutrient cycling in the soil is highly dependent on an active and diverse community of microbes. These microbes are dependent on abundant active organic matter for food and shelter. These microbes, once the soil temperature rises above 50F., feed on this organic matter releasing nitrogen tied up in it. This nitrogen then is available for plant uptake. This organic matter also helps glue soil particles together so the soil becomes granular and able to take up water readily, be well aerated, and resist compaction by cattle hooves.
Soil compaction in pastures can be a problem. It can cause forage yield loss, nitrogen loss through denitrification, and higher precipitation runoff due to a lack of soil porosity. Tap rooted crops, such as forage radish, can help break up soil compaction. Key-line plowing can also break up soil compaction. Nutrient distribution on pastures can be greatly enhanced by rotational stocking cattle on paddocks compared to set stocking them on a much larger pasture (curtails selective grazing and use of permanent camp sites, such as at water and shade). Frost crack seeding of legumes and perennial ryegrass can be a good way to renovate organic pastures. The percent of seeds that germinate and grow is low but good stands are possible if seeded at recommended rates. Legumes that are inoculated with rhizobium bacteria add nitrogen to the soil for grass uptake. Off-farm manures and non-synthetic fertilizers, such as rock phosphate and green sand (potassium), can be used to improve soil fertility in organic pastures.