Dry Matter Accumulation in Maize as Influenced by Row Arrangement, Nitrogen and Phosphorus Levels in Maize (Zea Mays L)/ Castor (Ricinus Commumis L.) Mixture

Abstract

Field experiment was conducted at the Institute for Agricultural Research farm Samaru, Zaria in the Northern Guinea Savanna zone of Nigeria during the 2007, 2008 and 2009 rainy seasons to evaluate the effect of row arrangements, nitrogen and phosphorus levels on maize dry matter  accumulation. The treatments consisted of factorial combinations of three alternate row arrangements of maize: castor in 1:1, 1:2 and 2:1, four levels of nitrogen (0, 40, 80 and 120 kg N ha^-1) and three levels of phosphorus (13, 26 and 39 kg P ha^-1), laid out in a split plot design and replicated three times.  Nitrogen and phosphorus fertilizer were assigned to the main plots while row arrangements were assigned to the sub-plots. The result showed that row arrangement significantly increased plant height and LAI only at 10 WAS in 2007and 2008. Where 1:2 recorded higher measured parameters than the other patterns. Increase in nitrogen up to 120 kg N ha^-1 resulted in significantly taller plants and higher LAI in 2007 and at 10 WAS in 2009. TDM was also observed to increase throughout the years of study except at 10 WAS. The response was observed up to 120 kg N ha^-1 for most of the parameters. Application of phosphorus significantly increased plant height only in 2009, LAI in 2007 and 2009, and TDM at 6 WAS in 2007 only. These parameters showed no response beyond applied 26 kg P ha^-1. Based on the finding of this study, maize can be intercropped with castor with 1:2 planting pattern with application of 80 kg N ha ^–l plus 26 kg P ha ^–l.

Key words; nitrogen, phosphorus, leaf area index, total dry matter