na INLIS000000000003628 0010-0121001994 Refort Concluding Workshop. Improvement of Efficiency and Environmental Impact of Nitrogen Fertilizers in irrigated Rice Cropping in South East Asia FAO Jakarta FAO 1999 7p, 30 cm 633.18-18 633.18-18 IRRIGATED RICE NITROGEN FERTILIZERS ENVIRONMENTAL IMPACT EFFICIENCY. 4880 4880