Appraisal of maize yield and its traits with different nitrogen fertilization levels under intercropping cultivation, Upper Egypt

A field experiment was conducted during summer season of 2017 and 2018 at the experimental farm of El-Mattaena Agricultural Research Station, Luxor Governorate, Upper Egypt, which is located at a 25o 18- N latitude and 32o 34- E longitude. The study aimed to evaluate the effect of nitrogen fertilizer levels on maize growth and its yield under sole and intercropping maize with green bean system as well as water productivity and saved land. The experiment was laid out in a split-plot design with four replicates. The main plots were assigned for two cropping system; (1) maize crop only and (2) maize intercropped with green bean. The split plots were occupied by urea fertilizer (46.5% N) levels of 90, 120 and 150 kg N/fed (fed = feddan = Acre). The maximum maize yield (grain and straw) and its component (plant height, stem diameter, leaves number/plant, grains number/cob and weight of 1000 grains) as well as NPK content in maize grain were observed under intercropping system that received 150 kg N/fed. The maximum value of partial land equivalent ratio (LER) of maize or green bean was recorded when they fertilized by 150 kg N/fed. The LERs of intercrops between maize and green bean showed that the saved lands were over 36%. The highest values of crop water productivity of 1.40 kg grain /m3 under intercropping system and 1.18 kg grain /m3 under mono-cropping system were recorded with application of 150 kg N/fed. In general, fertilization at 150 kg N/ fed. proved to be the most effective treatment for maize grain yield and its component as well as maize water relationships especially crop water productivity.