Nutrients in soil water under three rotational cropping systems, Iowa, USA

Measuring the Contribution of Agricultural Conservation Practices to Observed Trends and Recent Condition in Water Quality Indicators in Ohio, USA

“…Also, fence BMPs include practices to establish perennial forage systems (e.g., NRCS 511 and 512). Perennial forage systems improve soil quality (Karlen et al, 2006) and can reduce nitrogen loss when included in rotations (Tomer and Liebman, 2014; Russelle et al, 2007). The results for NOx regarding fence BMPs are, however, at least partially an artifact of the juxtaposition of tile‐drained land.…”

Maize (Zea mays L.) yield response to nitrogen as influenced by spatio-temporal variations of soil–water-topography dynamics

“…The optimum N rate was positively influenced by the degree of temporal variability in soil water content in both 2008 and 2009 (Table 3). Soil N in areas with temporal unstable soil water content is more likely to be lost in subsurface runoff, leaching, and denitrification processes Tomer and Liebman, 2014). Therefore, the optimum N rate was greater in those areas with greater temporal variability in soil water content.…”

“…In a dry year 2008, the degree of temporal variability in soil water content negatively influenced the minimum yield (Table 3). Areas with temporally unstable soil water content have been associated with subsurface flow pathways (Lin, 2006;Guber et al, 2008), which could flush out the nutrients in the soil and result in low grain yield Tomer and Liebman, 2014). The more frequent and stronger drying and wetting cycles in soils could also reduce the soil N availability and thus decrease maize yield (Zhao et al, 2010).…”

“…Shallow subsurface runoff at the soil-bedrock interface can be observed in these areas under wet conditions . Therefore, N in these areas can be lost by lateral subsurface flow and denitrification Tomer and Liebman, 2014). In addition, the shallow soils with high rock fragment and clay contents could have been the limiting factors of maize production in 2009.…”

Enhancing agroecosystem performance and resilience through increased diversification of landscapes and cropping systems

“…For example, though oat added relatively little revenue to the more diverse systems (Liebman et al, 2008), it served as an effective companion crop for establishing red clover and alfalfa, thereby minimizing erosion and reducing weed growth in the absence of herbicides. Forage crops were generally less profitable than corn (Liebman et al, 2008), but their inclusion in the more diverse systems allowed substantial reductions in the amount of mineral nitrogen fertilizer used for corn production (Fox and Piekielek, 1988;Morris et al, 1993) and contributed to greater nitrogen retention (Drinkwater et al, 1998;Tomer and Liebman, 2014). Integration with livestock, through forage harvest and manure return, fostered nutrient balance and further reduced production costs (Davis et al, 2012).…”