The impact of management on global warming potential (GWP), crop production, and greenhouse gas intensity (GHGI) in irrigated agriculture is not well documented. A no‐till (NT) cropping systems study initiated in 1999 to evaluate soil organic carbon (SOC) sequestration potential in irrigated agriculture was used in this study to make trace gas flux measurements for 3 yr to facilitate a complete greenhouse gas accounting of GWP and GHGI. Fluxes of CO2, CH4, and N2O were measured using static, vented chambers, one to three times per week, year round, from April 2002 through October 2004 within conventional‐till continuous corn (CT‐CC) and NT continuous corn (NT‐CC) plots and in NT corn–soybean rotation (NT‐CB) plots. Nitrogen fertilizer rates ranged from 0 to 224 kg N ha−1 Methane fluxes were small and did not differ between tillage systems. Nitrous oxide fluxes increased linearly with increasing N fertilizer rate each year, but emission rates varied with years. Carbon dioxide efflux was higher in CT compared to NT in 2002 but was not different by tillage in 2003 or 2004. Based on soil respiration and residue C inputs, NT soils were net sinks of GWP when adequate fertilizer was added to maintain crop production. The CT soils were smaller net sinks for GWP than NT soils. The determinant for the net GWP relationship was a balance between soil respiration and N2O emissions. Based on soil C sequestration, only NT soils were net sinks for GWP. Both estimates of GWP and GHGI indicate that when appropriate crop production levels are achieved, net CO2 emissions are reduced. The results suggest that economic viability and environmental conservation can be achieved by minimizing tillage and utilizing appropriate levels of fertilizer.

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To evaluate the impact of N placement depth and no-till (NT) practice on the emissions of NO, N 2 O, CH 4 and CO 2 from soils, we conducted two N placement experiments in a long-term tillage experiment site in northeastern Colorado in 2004. Trace gas flux measurements were made 2-3 times per week, in zero-N fertilizer plots that were cropped continuously to corn (Zea mays L.) under conventional-till (CT) and NT. Three N placement depths, replicated four times (5, 10 and 15 cm in Exp. 1 and 0, 5 and 10 cm in Exp. 2, respectively) were used. Liquid urea-ammonium nitrate (UAN, 224 kg N ha )1 ) was injected to the desired depth in the CT-or NT-soils in each experiment. Mean flux rates of NO, N 2 O, CH 4 and CO 2 ranged from 3.9 to 5.2 lg N m )2 h )1 , 60.5 to 92.4 lg N m )2 h )1 , )0.8 to 0.5 lg C m )2 h )1 , and 42.1 to 81.7 mg C m )2 h )1 in both experiments, respectively. Deep N placement (10 and 15 cm) resulted in lower NO and N 2 O emissions compared with shallow N placement (0 and 5 cm) while CH 4 and CO 2 emissions were not affected by N placement in either experiment. Compared with N placement at 5 cm, for instance, averaged N 2 O emissions from N placement at 10 cm were reduced by more than 50% in both experiments. Generally, NT decreased NO emission and CH 4 oxidation but increased N 2 O emissions compared with CT irrespective of N placement depths. Total net global warming potential (GWP) for N 2 O, CH 4 and CO 2 was reduced by deep N placement only in Exp. 1 but was increased by NT in both experiments. The study results suggest that deep N placement (e.g., 10 cm) will be an effective option for reducing N oxide emissions and GWP from both fertilized CT-and NT-soils.

The Internet of Robotic Things is an emerging vision that brings together pervasive sensors and objects with robotic and autonomous systems. This survey examines how the merger of robotic and Internet of Things technologies will advance intelligent manufacturing, thus enabling the creation of new, potentially disruptive services. This paper discusses some of the new technological challenges created by this merger and concludes that a truly holistic view is needed but currently lacking.