-It was evaluated the effect of the absence and of application of three nitrogen doses (50, 100 and 200 kg ha -1 of N) and four harvest times in the winter/spring season (from July to October) on dry mass yield (DMY), on the relative chlorophyll contents (ICF -leaf chlorophyll index) and on the contents of total digestible nutrients (TDN), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and lignin, and their respective correlations on Tanzania and Mombaça grasses after intercrop with corn in distroferric red latosol (Oxisol) soil as well. It was used a random block design, in split-plot with four replicates. The greatest DMY occured with the increase of photoperiod (from August), neverthless responses to nitrogen fertilization over cuts difered among the grasses. In an irrigated crop-livestock integration system under cerrado conditions, it is technically feasible the establishment of Tanzania and Mombaça grass intercroped with corn at sowing or if cover nitrogen fertilization is performed because even in the abscence of nitrogen fertilization, great satisfactory quantity of forage was produced, with average DMY of 2,000 kg ha -1 per cut during the highest shortage of roughage for animals (winter/spring). Nitrogen fertilization after corn harvest increases DMY and improves bromatologic composition of the grasses, as contents of chlorophyll and CP in winter/spring is increased, besides the increase of contents of TDN and a reduction on the contents of NDF and ADF until September. Leaf chlorophyll index can be used to estimate the DMY and CP content and as a marker of the need of nitrogen fertilization of Tanzania and Mombaça grasses submitted to cutting.Key Words: crop-livestock integration, crude protein, Megathyrsus maximum, neutral and acid detergent fiber, no-tillage system, total digestible nutrients Produtividade, composição bromatológica e teor relativo de clorofila dos capins tanzânia e mombaça irrigados e adubados com nitrogênio após o consórcio com milho RESUMO -Avaliou-se o efeito da ausência e da aplicação de três doses de nitrogênio (50, 100 e 200 kg ha -1 de N) e quatro épocas de corte no inverno/primavera (julho a outubro) sobre a produtividade de massa seca (PMS), os teores relativos de clorofila (ICF -índice de clorofila foliar) e os teores de nutrientes digestíveis totais (NDT), proteína bruta (PB), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA) e lignina, bem como suas respectivas correlações nos capins tanzânia e mombaça após o consórcio com milho em um Latossolo Vermelho distroférrico. O delineamento experimental utilizado foi o de blocos casualizados, em parcelas subdivididas, com quatro repetições. As maiores PMS ocorreram com o aumento do fotoperíodo (a partir de agosto), no entanto, as respostas à adubação nitrogenada ao longo dos cortes diferiram entre e dentre os capins. Em sistema de integração lavoura-pecuária irrigado sob condições de cerrado, é tecnicamente viável o estabelecimento dos capins tanzânia e mombaça em consórcio c...