Effect of Fertiliser Rates and Splits on Lowland Rice in two Temperature Environments in Rwanda - With a Special Focus on the Effectivity of Basal Applications
Boshuwenda Andre Chuma1, Kalimuthu Senthilkumar2, Arisoa Rajaona2, Kalisa Alain3, Marc Cotter1, Folkard Asch1
1University of Hohenheim, Inst. of Agric. Sci. in the Tropics (Hans-Ruthenberg-Institute), Germany
In Rwanda, rice is cultivated across a large altitude gradient. However, the recommended fertiliser application rate does not differ across these altitude gradients, resulting in a mismatch between nutrient requirements in specific growth stages of the plant and fertiliser application strategies. Hypothetically, in early growth stages rice at high altitudes will take up smaller amounts of nitrogen as compared to lower altitudes as low root zone temperatures may slow down growth and N uptake rates. Therefore, the basal N application could be reduced or omitted thus reducing unproductive losses of applied fertiliser. To test this hypothesis, field trials were established at two locations (900 and 1600m a.s.l.) in Rwanda, investigating the response of 5 contrasting rice varieties to three N application rates (80, 120 and 160 kg ha-1). Different splits of these fertilisers were tested, with and without basal dressing and three further top dressings at mid-tillering, panicle initiation and heading. Two sowings were conducted in 2016 (February and July) and two others in 2017 (January and April).
Keywords: Altitude gradient, nitrogen, planting dates
Contact Address: Folkard Asch, University of Hohenheim, Inst. of Agric. Sci. in the Tropics (Hans-Ruthenberg-Institute), Garbenstr. 13, 70599 Stuttgart, Germany, e-mail: fauni-hohenheim.de