Worldwide, weeds constitute a major constraint to the production of food legumes. Weeds can reduce crop yields more than 50% through competition for moisture, and this can be aggravated under the anticipated climate change scenarios. In the future, the spread of invasive alien species of weeds and herbicide resistance, which are partly aggravated by increased global trade and climate change, are likely to pose challenges to weed management and water conservation. In this chapter we will synthesize the state-of-art knowledge on weed management in legume production systems with a major emphasis on anticipated impacts of climate change and alien invasive species on weed management and water conservation. We provide a brief review of the types of weeds and weed effects followed by review of recent developments in the management of weeds in legume cropping systems. We also assess the strength and limitations of each practice and suggest the need for emphasis on the integration of different environmentally friendly control measures that are economically feasible to smallholder farmer
Tag: legume crops
Boron fertilisation of organically managed grass-clover swards on coarse-textured soils: effects on botanical and element composition
Three trials were performed on two organic farms with dairy and suckler cows and using home-produced forage and feed crops, predominantly grass-clover ley, in order to determine whether boron (B) is a limiting factor for legumes on coarse-textured soils in an area predisposed to low B soil concentrations. The effects of B fertilisation (applied as sprayed liquid) on biomass yield, botanical composition and plant macro- and micronutrient concentrations relative to soil concentrations and livestock requirements were investigated. Boron fertilisation (i) did not affect any yield, (ii) increased the white clover percentage significantly in forage on one farm and (iii) increased B concentrations in plants and soil on both farms, and (iv) did not affect concentrations of other nutrients in forage on either farm. Thus, B was not an obvious limiting factor on these farms. Effects of management practices on interactions and ratios between B, calcium (Ca), potassium (K), magnesium (Mg) and sodium (Na) and their implications are discussed.