dc.description.abstract | Over supplied of N..will produces more GHG and this phenomenon has been intensive discussihg to find out the solution. Relate to the loss of N Rolston et al. (1978) reported _73%N will loss after applying of manure and Ryden and Lund (1980) stated that 95-293 kg N/ha annually loss as N20 gas. Indonesia's farmer/crops. growers have been fertilizing their crops .with N by using recommendation dosage. That mean N fertilization executes without take the soil N into account. This method tend to have less efficiency, that is way this method since 1980s not recommended in developed countries (such as European countries, USA, Japan) - because they want reduce the production of GHG from agriculture that according to Bacon (199S) 44% of 1.S Mio. Ton/year of atmospheric N20 originated from agricultural ecosystem. Indonesia has record as ineffiCient country in N use, N loss in maize production SO-S8%(N loss in USA oniy 14-41%), N loss in rice production 77-89% of applied N. Efficient N fertilizing method will reduces N fertilizer production and reduces C02 emission, and at the same time will reduces N loss ihrough denitrification procces in form of N20 gas. That mean efficient method can be a solution to reduce GHG production. Due to inefficient of N fertilization-method loss of N in 4 main crops (rice, maize, vegetables, sugarcane, tobacco) can be predicted as follows: from 8.000.000 hectare of paddy rice""'will occur N loss of 1.600.000 tones, from 3.300.000 hectare of maize field will occur N loss of 1S0.000 tones, from 1.000.000 hectare of vegetables field will occur N loss of 138.000 tones, from SOO.OOOhectare of Sugarcane plantation will occur N loss of 84.000 tones and from 200.000 hectare of tobacco plantation will occur N loss of 18.000 tones. The total loss of N from those crops are 1.990.000 tones, According to Bacon (199S) 0.11.S% of applied N will loss as N20 gas. 1.990-29.8S0 tones of N20 gas produced by cultivation - of rice, maize, vegetables, sugarcane and tobacco annually -in Indonesia. | en_US |