eOrganic author:
Heather Darby, University of Vermont Extension
Introduction
Organic milk production is one of the fastest growing segments of organic agriculture today. From 2000 to 2005 the number of certified organic milk cows on U.S. farms grew about 25% each year from 36,000 to 86,000 (McBride et al., 2007). Relative to this increase, more than 80% of organic dairy operations are in either the Northeastern or Upper Midwestern United States. A primary difference in production practices between organic and conventional dairy farms is the feeding system. Most organic dairies center their feeding systems around pasture-based cropping systems that provide a minimum of 30% of the dry matter from seasonal forage. These organic dairies must supplement the herd during the winter months with stored feed and, often, feed concentrates. Currently, organic grain prices are three times that of conventional grains. This easily explains why feed costs can be to $4 to $5 per cwt higher for organic operations.
Given this information, it should come as no surprise that top quality forage production should be the main component of any profitable organic dairy cropping system. The objective should be to produce sufficient quantities and quality of forage to meet the majority of the energy and protein requirements of the dairy cow while reducing the quantity of expensive purchased concentrate feeds (Weller et al., 2001).
It is important that you develop a cropping system that fulfills the needs and functions of your own farm. As you plan a cropping system for your farm, there are several factors to consider, including but of course not limited to:
- Producing the quantity and quality of forages that can meet the majority of the nutrients and dry matter requirements to maintain production and growth of each group of cattle on the farm;
- Maintaining sufficient acreage of managed pasture for grazing heifers, dry cows, and milking cows; and
- Maintaining fertility levels through proper management of manure resources, legume crops, rotational crops, and limited purchase of soil amendments.
Farmers can achieve these by growing any number of combinations of perennial and annual forage crops that will benefit animal productivity and health, soil health, environmental health, and farm profitability.
Farmer demonstrating field cultivation. Photo credit: Heather Darby, University of Vermont Extension
Perennial Forage Crops
Let's start with perennial forage crops. Some farms grow only perennial grass and legumes crops. This is sometimes called grass-based dairying. The cows provide most of their diet through grazing, and most of the stored feed is harvested as dry hay, baleage, and/or haylage. These farms often, but not always, supplement the diets with purchased concentrates to balance the protein and energy requirements of the animal. The equipment requirements are focused on haying implements such as mowers, rakes, and balers. Energy input in these systems can be low, and they generally have low or no tillage requirements. Nonetheless these perennial crops must be managed to continuously produce high-yielding and quality feed. Reseeding to improved varieties of perennial forages is expensive, but can potentially yield significant quality forage to improve animal performance.
The most important practice to maintain pasture production is the utilization of management-intensive grazing strategies. Soil fertility is most often maintained through a combination of manure/ compost applications combined with judicious use of soil nutrient amendments, such as lime and micronutrients. A diverse combination of perennial forages within pasture stands will aid in meeting the fertility requirements of the plants and the animals. For example, legumes such as white clover grown with grasses will increase overall forage protein values as well as provide some nitrogen to the grasses. It is generally promoted that a forage mix that includes one-third legumes will provide a significant portion of the nitrogen requirements of the grasses. Growing a diversity of perennial forages within a field not only helps with fertility, but can also buffer against losses from disease and winter kill. A continuous sod crop often require reestablishment of forage species through the years. Many farmers implement practices such as frost or no-till seeding to maintain or introduce species into established pastures. Some pastures are reinvigorated by a complete reseeding of pasture. This can be expensive due to its high tillage and seed requirements.
Although all organic dairy farms have pastures and perennial forage crop production, some prefer to include annual forage and/or grain crops in their cropping system. Many farms find that the addition of annual crops can provide needed nutrients, diversity, flexibility, extra feed, bedding, and many other benefits. Soil types and equipment resources will influence this decision. There are many cool and warm season annual crops that are suitable for dairy feed. For more information, see Introduction to Grazing Management on Organic Dairy Farms.
Cereal Grains and Brassicas
Cool season forages that are commonly grown by organic dairy farms include cereal grains and brassica crops. Cereal crops can provide a level of flexibility because they can be grown for grazing, stored forage, grain, and/or straw. Cereal crops grow best under cooler conditions. Depending on where your farms is located, they can be planted in the fall, spring, or both. Wheat, barley, oats, triticale, spelt, and rye are all grains that are commonly grown on dairy farms. Cereal grains can extend the grazing season into the late fall and early winter keeping cows on pasture. They can also be used for early season grazing or forage harvest. Cereal crops are often harvested in the boot- or soft dough growth stages. The boot stage provides a high quality forage but relatively low yields compared to harvesting in the dough stage. Harvesting in the early dough stage increases yields but decreases certain quality parameters such as protein. However, cereals harvested in the dough stage can provide a good amount of starch and minimal soluble protein. Which stage you harvest is completely dependent on the forage needs of the farm. This system provides flexibility to the farm manager. Lastly, the grains can be harvested as a grain crop and the remaining straw used as bedding. Cereal grains provide needed energy in a feed ration. Most cereal grains will need to be rolled or ground before feeding.
Other cool season species with forage production value include brassica crops. This includes such plants as turnips, rape, typhon, and kale. The primary advantage of these crops is that they remain green and lush in the fall after most forage crops go dormant. Thus, they can produce good animal gains on pasture at a time when other forage crops are relatively low in quality. Forage brassicas are almost always grazed and not harvested as stored feed (unless grown with grasses). These crops are extremely high in protein and low in fiber and should be managed more as a concentrate than forage. Care must be taken not to overwhelm the animals with this highly digestible feed and adequate effective fiber sources must be added to the animal’s diet to maintain rumen health.
Warm Season Annuals
Warm season annuals are often, but not always, planted in rotation with cool season annuals. Once cool season crops are harvested in the early summer the warm season grasses can be seeded behind them. Warm season annuals include corn, millets, sorghum, sudangrass, or sorghum x sudangrass. These crops grow best under warm and drier climates or seasons. Most of these forages can be dual-purpose crops: grazed or harvested as stored feed. Corn silage is generally only harvested for stored feed in the form of silage, high moisture corn, or shell corn. Warm season annuals can provide grazing during dry, hot conditions when cool season forages slow in growth. These crops also produce significant biomass that can boost forage supplies in marginal years. Many farms produce corn as silage or grain to offset expensive purchased energy concentrates. These systems require effective weed control strategies, including rotations.
Annual Legumes
Annual legume crops, including soybeans and peas, are generally grown for grain but sometimes for forage. Soybeans and peas harvested as forage can provide a significant amount of protein. However, there are some challenges with harvesting and storing these crops as ensiled forage. Fonsult with other farmers and your nutritionist when feeding forage soybeans or peas. More commonly, these legumes are grown as a grain crop with the end use focused on protein supplement. Soybeans require a relatively long growing season and must be either limit-fed, if used raw, or roasted or extruded before feeding. Peas do not require roasting before feeding but can be difficult to grow in humid climates. Peas grown in combination with other cereal grains are a popular method of growing a complete energy/protein grain.
Annual crops must be seeded each year and therefore require yearly tillage and planting. They require thoughtful rotation plans to produce high-quality, high-yielding crops. Proper crop rotation design is also the most successful way to minimize weed, disease, and insect pressure. Lastly, rotations will aid in maintaining fertility for the current and subsequent crops. Although there is no standard recipe for developing a rotation, they almost always include rotation of annual crops with perennial sod crops. Following several years of tillage during annual crop production, the sod crops help improve soil health and fertility. Applying sufficient manure/compost applications during the sod years will help build soil fertility for the annual crop years. The “plow-down” of a healthy diverse sod crop can provide sufficient fertility for 2–3 years of annual crop production. Working with local organic farmers to observe current rotations on their farms can help you develop a successful rotation of your own.
It is obvious from the descriptions above that annual crops can benefit the dairy farm. However, annual cropping systems require more management and energy to maintain. Often, costs and benefits must be evaluated before these crops are grown on traditionally sod-based farms. For example, growing annul crops requires more equipment, specifically tillage implements and sometimes planters and harvesters. When annual forage crops are grown, such as cereal crops or warm season grasses, haying equipment can be used to harvest the crop. In the case of corn silage, a chopper is needed to harvest and a special storage facility is required. If a farmer produces grain crops they must also have a means to harvest (i.e. combine), store, and possibly dry the feed. Annual crops sometimes require the use of mechanical weed control implements. All of this adds new management skills, labor, and expenses. Many organic farmers utilize annual crops successfully. Looking to them for mentorship will be important for your own success.
References and Citations
- McBride, W. D., and C. Greene. 2007. A comparison of conventional and organic milk production systems in the U.S. Selected paper prepared for presentation at the American Agricultural Economics Assoc. Annual Meeting, Portland Oregon. (Available online at: http://purl.umn.edu/9680) (verified 20 March 2010).
- Weller, R. F., and P. J. Bowling. 2007. The importance of nutrient balance, cropping strategy, and quality of dairy cow diets in sustainable organic systems. Journal of the Science of Food and Agriculture. 87: 2768–2773. (Available online at: http://dx.doi.org/10.1002/jsfa.3001) (verified 20 March 2010).
