Nitrogen-Fixing Crops Compared – Finding the Most Efficient N Source

Overview

Biological nitrogen fixation through leguminous crops is the most sustainable and cost-effective way to supply nitrogen to farming systems. Among the major nitrogen-fixing crops, sesbania stands out for its exceptionally high fixation rates of 80-200 kg N/ha — enough to replace most or all synthetic nitrogen inputs for a subsequent cereal crop.

Details

Comparative nitrogen fixation rates (kg N/ha/season): Sesbania 80-200, Sunn hemp 60-170, Lablab 50-150, Cowpea 40-120, Soybean 60-160, Groundnut 40-100, Mung bean 30-80. These values vary with soil conditions, climate, and management, but sesbania consistently ranks among the highest fixers.

Why Choose Us

The economic value of biologically fixed nitrogen is substantial. At current urea prices (USD 350-500/ton), the nitrogen fixed by sesbania is worth USD 50-180 per hectare, while the seed cost is only USD 10-20 per hectare — a 5-10x return on investment from nitrogen alone, not counting other soil health benefits.