Stephen K. Barnhart, Extension Forage Specialist, Iowa State University, Ames, IA 50011
Establishment of a productive stand is the first major hurdle in profitable forage production. Often the difference between productive hay or pasture stands and near-failures is doing the right things at the right time – paying attention to details. Among the most important steps are selecting the right kind of forage species, planting correctly, and careful attention to the developing seedlings through the early months of the establishment year.
Preliminary Site-Related Factors—Identify site and soil characteristics that will influence decisions and management practices. Use soil tests to determine fertility needs. If fertilizer and lime corrections are needed, incorporating them during tillage is desirable. Ideally, where lime is needed to correct soil pH, lime should be applied and incorporated into the soil six months to a year before the new forage planting is done; so planning for a forage seeding fits into the bigger crop rotation planning. A soil pH above 6.5 improves the probability of establishing forage legumes and their productivity during the life of the stand. Soil pH is not as critical for grass establishment or production, but a soil pH of 6.0 to 6.5 is still recommended. Consider soil drainage or potential for doughtiness when selecting grass or legume species.
Timing—It’s important to have the seed in warm soil when there is sufficient soil moisture for rapid germination and continued development. Climatic probabilities point to spring as the most consistent time that desirable soil temperature and moisture exist. Plantings done in March are at some risk of cold injury from late spring freezes; however, while the risk of a late freeze is still present, it seldom occurs. Late March and April is the target spring planting time. Waiting too late into May will increase the risk of rapid surface soil drying and loss of small seedlings in late-spring or early summer. Annual weed pressure also increases as planting dates are delayed. Where a cereal grain companion crop is to be used (such as oats), an early spring seeding date is necessary for best grain and straw production. If the grain companion crop is to be harvested while still immature, for hay or silage, seeding date is less important.
A Firm Seedbed Is Essential—The guideline is to plant forage grasses and legumes to a final depth of 1⁄4 to 1⁄2 inch after all planting and soil coverage operations are completed. Forage producers who seed into a firm seedbed have a higher percentage of successful establishments. This firm seedbed helps prevent planting too deep, which hinders emergence of small seeded forage grasses and legumes. Firming soil over the planted seed improves the seed-to-soil contact, moisture availability to the germinating seed, and established seedling numbers. Various tillage and planting implements can be used to prepare a firm seedbed, place the seed and provide for good seed-to-soil contact. A complicating factor is when both a cereal grain and forage seeding is being made. If the planting operation will place both small forage seeds and larger cereal grain at the same depth, it is better to plant all at the more shallow depth.
The probability of success with new forage seedings decreases if soil moisture is not adequate. Consider existing soil moisture (both surface moisture and sub-soil moisture) and the probability of average or better Spring/Summer rainfall. Firm seedbeds, good seed-to-soil contact and timeliness of rainfall from now through the growing season are important for the success of your new forage seedings.