**5. Pulses and sustainability**

The most potential technologies in pulse production include improved crop establishment and management practices, integrated soil fertility and pest management practices, etc., which enhance not only the productivity and profitability but also warrant environmental and social sustainability besides nutritional security [17]. Role of pulses in maintaining sustainability is very wide since pulses are an important component of crop rotations, requiring very less fertilizers than other crops. Legumes are beneficial part of the rotational crops to maintain soil fertility.

Good soil management practices for crop rotation also includes pulses with different crops like wheat, barley, oats, oilseeds such as canola, flax, sunflowers, etc. The nitrogen fixing ability of pulses enriches the soil quality and fertility and hence leading to enhanced productivity in subsequent crop rotations. Soil health in also improved through pulses as they feed soil microbes. Even the crop residue of pulses contains different amino acids and bio-chemicals than non-legumes. This diversity in soil composition provides better protection against disease-causing microbes and thus helps crops to thrive under adverse conditions. The number and diversity of soil microbes is markedly increased with intercropping of pulses [17, 18]. An environment of 'live' soil with diversity of soil micro-organisms is considered best for crops because these micro-organisms enhance the nutrient uptake rate and efficiency in different soils. Additionally, the abundance of diverse soil microorganisms 'crowd out' the disease-causing bacteria and fungi, and thus protects the plants.

Pulses are considered as low carbon footprint crops since they use half energy inputs than other crops. Soil bacteria are utilized for nitrogen fixation from air which replaces additional requirement of nitrogen fertilizers in pulse crops. Nitrogen enriches the soil in different forms like fertilizer, manure or crop residue, then most part of it is converted into a powerful greenhouse gas, nitrous oxide. Globally, nitrous oxide represents around 46% of the greenhouse gas emissions from agriculture and is almost 300 times more potent than carbon dioxide (CO2) [19]. As nitrogen fertilizers are related directly with greenhouse gas emissions therefore, pulses have lower carbon footprint than other crops due to their nitrogenfixing ability. Nitrogen is manufactured from natural gas and is the most needed fertilizer in crop production. The unique feature of pulses is that they take nitrogen

from the air directly and fix at their own, hence, application of nitrogen as fertilizer in pulses is minimal in comparison to other crops.

The nitrogen fixation property of pulses reduces the footprint of other crops in the soil adding to the food production cycle. In a study on durum wheat, it was found that carbon footprint was reduced by 17% in durum wheat when preceded by chickpeas or lentils, nitrogen-fixing crops, than preceded by a cereal crops. The impact of pulse-pulse intercropping with wheat system was much stronger than traditional cereal-cereal-durum rotation by reducing the carbon footprint of durum wheat up to 34%.

The water requirement of pulses is also very less i.e., 1/2 to 1/10 of water in comparison to other protein rich crops [20]. Few pulses are well adapted to dry climates and hence can be produced better under dry/drought conditions, e.g., peas and lentils roots absorb less water from a lower depth. The water available in deep soil is, in this way, used by next crop, thereby increasing the water use efficiency of the entire cropping system.
