N2O emissions depend on the type of crop as in a study by Smith et al. (1998), comparing different grassland and arable soils, it was observed that emissions were in the order of highest grassland, followed by grassland cut for conservation, potatoes and lowest, from crops cereals. Emissions varied greatly from year to year depending on precipitation at the time of fertilization. There was an exponential relationship between N2O flux and water-filled pore space and temperature where soil nitrogen was not a limiting factor (Smith et al., 1998). Exponential increases in N2O flux were observed with increasing soil water-filled pore space, temperature, and soil mineral N content. This differs depending on crop type, soil type, weather conditions and agricultural management practices (Dobbie et al., 1999). In Alberta, emissions were high when nitrogen fertilizers were applied in the fall compared to those applied in the spring. Removing straw during fall harvest increased N2O emissions when fertilizer was applied in fall, but emissions decreased when fertilizer was not applied. Fall plowing also increased N2O emissions compared to spring plowing or direct seeding (Hao et al., 2001). In loamy loam soils, the highest N2O flux was observed in organically managed soils after incorporation of manure and legume cover crops and in conventionally managed soils after application of inorganic nitrogen fertilizers. High N2O emissions occurred in a pore space filled with water by more than 60% and lasted less than 2 days after wetting (Burger et al., 2005). According to a study by Barnard et al. (2005), field and laboratory nitrogen addition significantly increased N2O emissions due to gross and net nitrification, but the effect of nitrogen addition on field N2... ... middle of paper ...... total global fiber use. In 2011, the United States (15,573,000 lb bales) was the world's third largest producer of cotton after China (33,100,000 lb bales) and India (27,500,000 lb bales), accounting for 14%. of total world cotton production (NCCA). , 2011). Additionally, the United States is the largest exporter of cotton with 11,714,000 pounds of cotton bales exported in 2011 (NCCA, 2011). Additionally, in the United States, California-based SJV is one of the country's leading cotton producers. Over the past decade, total cotton acreage in California has declined, but now the downward trend in plantings is reversing with acreage increasing from 76,890 ha in 2009, to 123,429 ha in 2010 This increase continued in 2011 with a total planting of 182,109 ha. In California, cotton is also grown in the Palos Verde and Sacramento valleys (NASS USDA, 2012).