Nutrient Management

A late August seeding of forage radish (Raphanus sativus L.) can eliminate the need for tillage before many early spring vegetable crops like spinach, beets, peas, onions, and even carrots under certain soil conditions in Maryland. In addition to reducing soil disturbance, not having to till prior to spring planting reduces labor requirements at a critical point in the season and may allow earlier planting. Forage radish, which winterkills when temperatures drop to 17-20°F, suppresses early spring weeds, allows soil to dry out and warm up, and provides an increased supply of N, S, P and other nutrients to crops in early spring. Because of the minimal amount of residue after forage radish, conventional planting equipment can effectively seed directly into the winterkilled cover crop without tillage. For early transplanted crops like onions, rows of radish can create holes into which transplants can be dropped. Experiment station results in Maryland and farmer trials throughout the mid-Atlantic and northeast have shown that this system requires a closed cover crop canopy in fall and may be ineffective in poorly structured, heavy soils.

Recent research has demonstrated that winter wheat and barley grain yields and economic return to fertilizer applications are not reliably improved by a fall nitrogen application when an adequate amount of nitrate already exists in the soil. Regulations effective October 2012 require that farmers who plant wheat and barley for grain production must test for soil nitrate concentration before they may apply nitrogen in fall.