Yield and yield components of low land rice (<i>Oryza sativa</i> L.) as affected by different cultivation methods in the Sudan Savannah

Abstract

A field experiment was conducted during 2012 and 2013 wet seasons, at the Institute for Agricultural Research (IAR) Ahmadu Bello University farm, situated at the Irrigation Station Kadawa, Sudan Savannah, to investigate the effect of nitrogen fertilizer (0, 50 and 100 kgha^–1),poultry manure (pm) (0, 3 and 6 tha^–1), green manure (gm) rates (with and without green soyabean biomass) and method of cultivation (system of rice intensification (SRI) and conventional farmers’ practice). The experiment was laid out in a split plot design, with the factorial combination of pm and nitrogen fertilizers assigned to main plots while the combination of gm and cultivation methods were assigned subplots. SRI recorded average respective grain yields of 5.59 and 6.05 t ha^–1 as compared 4.75 and 4.86 t ha^–1respectively under conventional practice. The yield and yield components of rice were improved as a result of applied green soyabean manure but not significant in both years. Yield and the panicle number m^-2were greatly increased up to the levels of 100kg N ha^-1. Whilst the absolute use of pm significantly increased filled grain number panicle^-1 up to 6 t ha^-1 in both years, increased grain yield up to the 3t ha^-1 in 2012 and up to 6 t ha^-1in the following year of 2013. Application of absolute pm and nitrogen fertilizer gave significantly higher values than in the control in both years. The interaction between nitrogen fertilizer and pm and cultivation method on grain yield was significant in both 2012 and 2013. The 6t ha-1 poultry manure +100kgNha^-1and 100kgNha^-1+ 3t ha^-1 pm produced the highest grain yield of 7.842 and 7.532 t ha^-1 respectively in 2012 under the SRI method compared to the others. While 8.054 and 7.967 were obtained from 6 t ha^-1 pm +50kgN ha^-1 and 100kgN ha^-1 + 3t ha^-1 pm respectively in the SRI method compared to others. The use of soyabean green manure, application of 3 t/ha poultry manure and 100 kg N/ha and 6t ha^-1 pm + 50kgN ha^-1 under SRI had produced better rice crop when compared to use of same fertility improvement technique under conventional method of rice production.