Production of Corn and Soybean under Mineral and Biological N Fertilization in Sole and Intercropping Cultures

Intercropping is a viable method to achieve a high land equivalent ratio (LER) and increase production in a given area under sustainable agricultural practices like bio-nitrogen (N) fertilization. A 2-year field study was conducted at the Agricultural Experiments and Research Station of the Faculty of Agriculture, Cairo University, Giza, Egypt, from 2023 to 2024 to compare the effects of bio-N- fertilization and chemical N application on soybean and corn plants in both sole and intercropping systems. The study included two cropping systems (2:2 intercropping and sole cropping of corn and soybean), N-fertilization treatments (N-0 for corn and soybean, 238 kg N/ha for corn, and 142.8 kg N/ha for soybean, biological N-fertilization was used for soybean seeds by inoculating with Bradyrhizobium japonicum , and biological N-fertilization was used for corn grains by inoculating with specialized inoculants). Three replicates of each treatment were used in a split-plot design. Corn grain yield and shelling percentage increased when soybeans and corn were intercropped, but soybean productivity decreased. Corn yields and shelling percentages improved with intercropping. Biological N-fertilization treatments resulted in higher grain yields. Intercropping with biological N-fertilization increased LER by utilizing soybeans to fix atmospheric N and provide natural N to corn. Agg of soybean was positive for N-0 or biological N fertilization, indicating that soybean is dominated component under mineral N-fertilization. Intercropping soybeans with corn generated higher net benefits, ranging from 133.29 to 1302.65 USD per hectare.