A field experiment was conducted at Tamil Nadu Agricultural University during 2011-2012 and 2012-2013 on a maize-cowpea (Vigna unguiculata (L.) Walp.) cropping system. Split plot design with three replications was adopted in maize and the main plot treatments comprised of three organic sources viz., FYM @ 12.5 t ha-1 , biochar @ 5 t ha-1 and vermicompost @ 5 t ha-1.The sub-plot treatments comprised of seven fertilizer levels with foliar spray treatments. Split-split plot design was adopted for the succeeding cowpea crop and two fertilizer levels were tried in cowpea viz. F1- 100 per cent RDF (25:50:25 kg NPK ha-1 ) and F2 – No fertilizer in the sub-sub plot. The results of the study revealed that application of vermicompost @ 5 t ha-1 significantly increased the yield attributes and yield of maize followed by FYM 12.5 t ha-1. Among the fertilizer level with foliar spray treatments, application of 100 percent RDF with foliar spray of 2% poly feed spray significantly enhanced the yield attributes and grain yield. The interaction effect between organics and fertilizer levels with foliar spray on maize grain yield was significant. In both the years of study, vermicompost application along with soil application of 100% RDF with 2% poly feed as foliar spray recorded the highest grain yield of 9293 and 8830 kg ha-1 and stover yield of 13403 and 12802 kg ha-1, during 2011-12 and 2012-13, respectively. From the result of the study, application of vermicompost @ 5 t ha-1 along with 100 percent RDF(150:75:75 kg NPK ha-1) with foliar spray of 2% poly feed on 30th and 45th DAS may be recommended for increasing hybrid maize yield. In cowpea, the results showed application of either FYM or vermicompost to maize had significant residual effect on the succeeding cowpea crop and significantly influenced yield of succeeding cowpea in both the years of study. Among the residual effect of different fertilizer levels along with foliar spray in maize, irrespective of foliar spray tried, application of 100 per cent RDF to maize significantly increased yield of succeeding cowpea compared to 75 per cent RDF to maize. Between the two fertilizer levels tried in cowpea the grain and haulm yield of cowpea were significantly higher due to application of recommended dose of fertilizer compared to no fertilizer application. Thus, application of FYM 12.5 t ha-1 or vermicompost 5 t ha-1 with RDF to maize (150:75:75 kg NPK ha-1) and application of RDF (25:50:25 kg NPK ha-1) to succeeding cowpea crop can be recommended for enhancing the grain and haulm yield in the succeeding cowpea crop.