- Intended Uses
- Decision Support System
Forbs (sometimes referred to as herbs) are herbaceous (not woody), broadleaf plants that are not grass-like. Rangeland forbs are usually perennial and may be poisonous, but seldom dominate a stand unless there has been serious overgrazing. Cropland forbs are typically annual plants that are used to fill seasonal gaps in high quality forage.
Forbs that are important forages include members of the Brassica genus and related genera of the Cruciferae family. "Brassicas" include forage rape (Brassica napus L.), kale (Brassica oleracea L.), turnips (Brassica rapa L.), swedes (Brassica napus L.), and hybrids like Tyfon.
Other commonly used forbs include chicory (Cichorium intybus L.), fodder beets (Beta vulgaris ssp. Vulgaris), and annual Kochia (Kochia scoparia L.). The perennial Kochia (Kochia prostrada Schrad.) is a woody shrub.
Turnip, rape, and kale are distributed over much of Europe, northern Asia, northern North America, and southern Oceania. These crops are grown year-round in cooler and moist climates and as a winter forage in warmer climates. Most brassicas are cold tolerant, and the leaves can withstand light freezes. Moisture requirements are relatively high for most species. Well- to moderately-well drained loamy soils are preferred, but with adequate moisture and fertility, light or peaty soils produce adeuqate yields. A pH range of 5.5-6.5 is suitable. (Srinivas C. Rao and Floyd P. Horn, 1995. Cereals and Brassicas for Forage. Chapter 36. In: FORAGES: An Introduction to Grassland Management. Vol. 1. 5th ed., Iowa State University Press.)
Strategies for optimal selection of forb species and cultivars involve identifying primary intended use, level of management, and climate and soil tolerances and local conditions.
Intended use. Identifying the primary use is a good starting point. Forbs are almost excluseively used for forage (as hay, silage, greenchop, or pasture).
Single species or mixtures. The relative advantages of pure stands and mixtures should be considered and the relative combining ability of the various species. Mixing species with vastly different tolerances will make management more difficult.
Management level. Management level should be considered, since species differ in their tolerance to low levels of fertility, defoliation schedules, and pests. Personal and professional goals and managerial experience and capability should be considered when selecting a management level that best fits your situation.
Climate and soil conditions. Matching your climate conditions (precipiation amount and distribution, and extremes of temperature) and the characteristics of the soil (drainage, fertility, pH, and salinity) to the species you intend to plant is fundamentally important. Knowing the long term averages and year-to-year variability in climate conditions and the major soil types and characteristics will help you choose species with a high probability of success.