Farm results

Although not all the results reviewed support the hypothesis that organic farming results in less nitrate leaching than conventional farming, a strong tendency towards a decreased risk of and absolute levels of nitrate leaching can be deduced. 

In order to compare farming systems CO2 emissions need to be differentiated between the emission due to the burning of fuel (direct energy) and the fuel used for the production and transport of fertilisers, machinery and synthetic pesticides (indirect energy). Haas et al. (1995) found that 70% of CO2 in organic farming resulted from fuel consumption and the production of machinery, whereas 75% of the CO2 emissions in conventional systems were due to N fertilisers, feedstuff and fuels. 

While we were seeking commercial support, one replicated experiment per year was conducted at the Purdue Agronomy Farm. Results continued to show promise although the optimum rate seemed to get higher as each year passed. The DNBP source provided an explanation. The same bottle of reagent which Hatley had obtained from the herbicide research group at Purdue in 1968 was used in 1972. Thus, it was at least five years old and may well have been six or seven years old. Shelf life according to the herbicidal handbook is two years (6). 

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