The effect of different levels of cattle manure (0; 8; 16; 24; 32 and 40 t ha-1) on yield of green corn ears and grains of two maize cultivars was evaluated (Centralmex and AG-9012). The study was carried out at Mossoró, Rio Grande do Norte State, Brazil, from September to Dezember 1999 using sprinkler irrigation. The experimental design was complete random blocks arranged in splitplot with three replications. The manure was applied to main plots and cultivars in the subplots. The green corn yield was evaluated by total number and weight of green ears with husk and by marketables ears, with husk and without husk. The grain yield was evaluated by grain weight corrected for 15,5% humidity. The soil analysis, carried out 120 days after planting, indicated that the manure increased the water retention, water availability and the potassium, sodium and phosphorus contents, however, did not influence pH, calcium, sum of bases and organic matter contents. The manure levels x cultivars interaction was significant for number of marketable ears with husk only. All evaluated traits increased with the increase of manure levels. The cultivar AG-9012 was superior to the cultivar Centralmex for the evaluated traits. The net income, obtained with the sale of marketable ears with husk, was higher when no manure was applied for AG-9012. For the cultivar Centralmex, the net income was higher with 8 t ha-1 cattle manure application.
Zea mays L.; organic fertilization; green corn; economic indicators
