Legumes and pulses do not require nitrogen fertilisers as they produce nitrogen themselves. They live in a symbiotic relationship with nitrogen-binding rhizobia bacteria: these bacteria live in the plant’s root nodules and bind enough nitrogen from the atmosphere to increase the nitrogen content of the soil for other plants. Thus, Fabacea varieties are very popular as and preceding crops in agriculture, thanks to their ability to improve the fertility of nitrogen-low soils.
Crop rotation with pulses requires less fertiliser, thus, having a positive effect on climate protection. The industrial production of nitrogen fertiliser uses large amounts of energy: about 1 litre of petroleum is needed to produce 1 kg of nitrogen.
Pulses and legumes leave a minute ecological footprint with regards to both carbon dioxide emissions and water usage. Comparing these plant-based protein sources with animal-based ones shows that up to 18 times more water is required to produce 1 kg of beef, pork or poultry. One kilogram of pulses produces only 0.5 kg CO2, while 1 kg of beef produces about 17 kg CO2.