Agronomic parameters as indicators of inbred maize nitrogen status

Inbred maize (Zea mays L.) lines are grown for seed in Puerto Rico. In efforts to increase crop yields, some producers may apply nitrogen (N) fertilizer excess of nutrient requirements. The use cover crops (CC) rotation can serve as an alternative continuous cultivation maize. This experiment was conducted field plots Güamaní (fine-loamy over sandy or sandy-skeletal, mixed, superactive, isohyperthermic Torrifluventic Haplustepts) soil Guayama, cropping systems evaluated were a maize-cowpea [Vigna unguiculata (L.) Walp.] versus typical practice fallow (FA), each with five N levels. planting sequence initial spring 2014 planting, followed by winter 2014-2015 and final 2015-2016 planting. cowpea planted the summers 2014, 2015 2016. inbred female used commercial hybrid production. Mean plant densities ranged from 59,391 69,182 plants per hectare seasons. Indicators status Soil Plant Analysis Development (SPAD-502) Chlorophyll Meter®measuring leaf greenness; Normalized Difference Vegetation Index (NDVI, measured GreenSeeker®) height measurements. application significantly influenced (p<0.05) greenness (in out 13 occasions) seven 12 but not NDVI. four nine three eight occasions). agronomic parameters tested did predict yield status, thus recommended decision-making process management