00565 a2200193 4500 631.451 WIJ 21854 34233 Wijewardene, Ray Systems,techniques & tools conservation farming for small farmers in the humid tropics Colombo Marga publications v,38p. 29cm Agriculture and related technologies Conservation tillage Soil erosion Soil science Specific techniques Waidyanatha, Parakrama sc 49286 49286 0 0 0 0 SLC MKDL MKDL SLC 2009-08-10 0 631.451WIJ 61892 2009-08-10 00:00:00 0.00 2016-10-31 PR