Question

use of pulses on crop rotation has an impact on sustianiblity

Answer 1

Pulses play an important role for sustainability in many ways. They are an important component of crop rotations, they require less fertilisers than other crops and they are a low carbon source of protein.

Legumes are part of the rotational crops farmers can use to maintain soil fertility. In Canada for instance, where pulses are often integrated in good soil management practices, a good crop rotation includes a variety of crops grown in sequence, including cereals (wheat, barley, oats), oilseeds (canola, flax, sunflowers), and legumes (pulses).

Pulses have a positive impact on soil quality because they help fix nitrogen in the soil. This contributes to higher yields in subsequent crop rotations.

However it is not the only reason. Pulses have a direct positive impact on soil quality because they help feed soil microbes, which benefits soil health. Pulses have also been shown to produce greater amounts and different types of amino acids than non-legumes and the plant residues left after harvesting pulse crops have a different bio-chemical composition than other crop residues.

It is this diversity in soil composition that comes from a good pulse rotation, which help crops to thrive and which offers greater protection against disease-causing bacteria and fungi.

Pulses are also a protein source with a low footprint, in both carbon and water. For instance, the water footprints to produce a kilogram of beef, pork, chicken and soybeans are 43, 18, 11 and 5 times higher than the water footprint of pulses.

Pulses have a lower carbon footprint in production than most animal sources of protein. In fact, one study showed that one kilogram of legume only emits 0.5kg in Co2 equivalent, whereas 1kg of beef produces 9.5 kg in CO2 equivalent.