Weed Aboveground and Seedbank Community Responses to Agricultural Management Systems

Strategies for reducing the carbon footprint of field crops for semiarid areas. A review

“…Furthermore, durum wheat had a carbon footprint of 0.301 kg CO 2 e kg −1 of grain when grown after an oilseed crop (canola or mustard), 19% lower than when grown after a cereal. Numerous studies have shown that using improved agronomic practices such as early seeding, optimum plant population density, and proper crop rotation sequences can increase crop yields without increasing production input (Gan et al 2010;Kirkegaard et al 2008;Menalled et al 2001;Miller et al 2003). The intensity of yield increases due to improved crop management is usually greater in the Brown soil zone than in the Dark Brown and Black soil zones.…”

“…In the northern Great Plains of North America, for example, herbicides com- a Commonly used no-till management systems in the production of canola, dry pea, and spring wheat on the Canadian prairie Miller et al 2003); b Improved agronomic practices such as the use of early seeding, optimum crop rotation sequences, and best pest management practices (Gan et al 2010;Kirkegaard et al 2008;Menalled et al 2001); c N use efficiency to be increased by 10% (conservatively), through improved N fertilizer application technology such as side-banding, timely application, site-specific approaches (Malhi et al 2001;Peng et al 2010;Sieling and Kage 2010) d Harvest index to be increased by 0.06-0.08 units from the current level though adaptation of new cultivars such as hybrid canola, semi-leafless dry pea, and short-statues of spring wheat (Annicchiarico et al 2005;Malhi et al 2001;Moot and McNeil 1995) e Use of P. bilaii fungus has been shown to increase crop productivity in canola, dry pea, and spring wheat by an average of 7% (Gan et al 2010;Zhang and Smith 1997) f Arbuscular mycorrhizal (AM) fungi are increasingly used in crop production to improve plant development and health and increase phytoremediation (Gianinazzi and Vosátka 2004;Miransari and Smith 2009;Paradis et al 1995) prise approximately 85% of the pesticide input in cereal crop production (Derksen et al 2002). Weed management through the adoption of diverse cropping systems has been recognized as a key component in the development of sustainable agricultural systems (Menalled et al 2001). In diversified crop sequences, weeds are exposed to a wide range of causes of mortality.…”

“…These changes from one crop species to another generate microenvironments that do not favor the establishment and proliferation of any one particular weed species. As a consequence, crop diversification reduces weed abundance (Westerman et al 2005) and herbicide input (Harker et al 2009), and increases crop productivity (Menalled et al 2001). Integrating various cultural practices will significantly reduce herbicide input in crop production (Harker et al 2009).…”

Weed Problems, Ecology, and Management Options in Conservation Agriculture: Issues and Perspectives

“…The seedbank study revealed a significant increase in the number of weed seeds and species, mainly of annual grasses such as Digitaria sanguinalis and Panicum dichotomiflorum, in CoT and NT (Menalled et al, 2001). Positive relationship was noted among weed seed rain (16-77%), seedbank (12-78%), and seedling recruitment (32% of the emerged seedlings) in NT for the annual grasses viz., yellow foxtail, giant foxtail, and fall panicum (Webster et al, 2003).…”

“…Corn-soybean-wheat with NT at Michigan, the United States has shown that species density and diversity were intermediate in the NT over CoT (Menalled et al, 2001). Short-term changes were related to the adoption of a particular tillage system, like shifts on the disturbance regime, may be cumulative and could not generate a response in weed diversity (Smith et al, 2009) only and so long-term studies are needed.…”