Influence of soil types on the performance of tobacco as affected by rates and sources of nitrogen fertilizer
1994
W.I. Wan Azman | Aziz Bidin | H. Salbiah
Several trials were conducted at several locations in Kelantan and Rudua and Rhu Tapai series between 1986 and 1989.The objective of the study was to determine the effect of these soil types on tobacco performance as influenced by different N sources, i.e ammonium nitrate(AN), sodium nitrate(SN), diammonium phosphate(DAP), urea, Chilean potassium nitrate(CPN) and a mixture of urea and sodium nitrate.The result from the study showed that generally,Rhu Tapai gave higher tobacco yield as compared with Rudua.Increasing the N rates from 40 to 80-100kg N/Na increased the yield linearly.The nicotine level increased with an increase in applied nitrogen while the sugar content decreased.Arising from this study,the recommendation of N for tobacco was increased from 40kg N/ha to 80 kg/ha.A nitrogen rate higher than 80 kg N/ha did not increase yield further but was found to decrease the leaf quality.The recommended is to be applied as 60kg N/ha basal application and 20 kg N/ha sidedressing.The additional sidedressing is necessary for tobacco as the early rains tend to leach the basal N out of the root zone.The N sources study showed that the sources affected the yield significantly on both Rudua and Rhu Tapai series.For Rudua series, the mixture of urea and SN at 1: ratio produced the highest yield in the first year and the ratio 1:3 the highest yield in the following year.For both soil series, DAP produced lowest yield.Although the sources caused marked yield differences, the leaf quality was not affected.Based on the above studies,SN, Urea, PN, CPN, and AN were found suitable for basal fertilizer application.The questions of economics and logistics have to be properly considered before changing the currently recommended sources.
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