The tables below present agricultural soils nitrous oxide emissions data from the US. Table 6.18 presents the teragrams of CO₂ eq. in the form of nitrous oxide from direct and indirect sources. Table 6.19 presents the actual amounts of N₂O emitted for the same direct and indirect sources. Tables 6-20 and 6-21 provide the direct and indirect nitrous oxide emission sources, respectively. Let's analyze and discuss some of the data.  

Instructions: 

1. Speculate as to why the direct cropland emission of nitrous oxide showed a downward trend whereas the direct grassland emission remained stable for the 2008-2012 period?


2. What are the top two sources of nitrous oxide from cropland and what are the top two sources of nitrous oxide from grassland? Explain.


3. List the indirect sources of nitrous oxide emission and provide suggestion on how to reduce these emissions. 

Source: "Chapter 6: Agriculture" of the latest EPA report (downloadable from National GHG Emission Data page of EPA)

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