Performance of traditional and improved upland rice cultivars under nonfertilized and fertilized conditions in northern Laos

摘要: Shortened fallows have reduced the productivity of traditional upland rice (Oryza sativa L.)-based slash-and-burn systems in northern Laos. New cultivars and management methods are needed for food security region. To assess their potential increasing productivity, this study compared two improved three fertilizer treatments: no fertilizer, nitrogen (90 kg N/ha), N plus phosphate (50 P/ha), six trials over 2 yr. The had consistently higher grain yields than across all treatments (3.9 vs. 2.1 t/ha). greater total biomass harvest index, more panicles, were shorter cultivars. They also responsive to without applied P Two gave a response that was similar when both applied. In addition, on-farm conducted at 13 locations compare with (N–P–K 60–26–50 kg/ha) farmers’ practice consisting fertilizer. these trials, achieved much (3.0 1.8 Improved moderate inorganic application offer new approach