Importance of Grain Legumes

Legumes draw nitrogen from the surrounding air and fix it to the soil, supplying the soil with this essential nutrient. This nitrogen fixing aids in the health of the soil, particularly for subsequent crops such as broccoli and cabbage, both heavy nitrogen feeders.

Legumes also benefit humans. High in protein and low in fats, legumes are important to vegetarian and vegan diets as a source of protein. Legumes are high in fiber and plant sterols, both important elements in a heart-healthy diet.

a. Soil natural rely:

• Legumes are high in protein, and therefore, nitrogen rich.
• Because most crop residues incorporate a lot extra carbon than nitrogen, and microorganism in the soil need both, the nitrogen provided by legumes allows the decomposition of crop residues in the soil and their conversion to soil constructing natural matter.

b. Soil porosity:

• Several legumes have aggressive taproots reaching 6–8 feet deep and a half inch in diameter that open pathways deep into the soil.
• Nitrogen-rich legume residues inspire earthworms and the burrows they create. The root channels and earthworm burrows make bigger soil porosity, promotion air movement and water percolation deep into the soil.

c. Recycle vitamins:

• Because perennial and biennial legumes root deeply in the soil, they have the capability to recycle crop nutrients that are deep in the soil profile.
• This effects in a more environment friendly use of utilized fertilizer and prevents nutrients (particularly nitrate nitrogen) from being lost due to leaching under the root region of shallower-rooted crops in the rotation.

d. Improve soil structure:

• The improvements are attributed to increases in more stable soil aggregates.
• The protein, glomalin, symbiotically along the roots of legumes and other plants, serves as a “glue” that binds soil together into stable aggregates.
• This aggregate stability increases pore space and tilth, reducing both soil erodibility and crusting.

e. Lower soil pH:

• Because inoculated, nodulated legumes acquire their N from the air as diatomic N rather than from the soil as nitrate, their net effect is to lower the pH of the soil.
• In greenhouse studies, alfalfa and soybeans lowered the pH in a clay loam soil by one whole pH unit.
• Legumes could lower the pH and promote increased plant-soil-microbial activity on soils with a pH above the range for optimum crop growth and development.

f. Biological diversity:

• Legumes contribute to an increased diversity of soil flora and fauna lending a greater stability to the total life of the soil.
• Legumes also foster production of a greater total biomass in the soil by providing additional N. Soil microbes use the increased N to break down carbon-rich residues of crops like wheat or corn.

g. Legumes in human nutrition:

• As a supply of protein, grain legumes (such as pigeon pea, chickpea, soybean or mung bean) are a true supply of protein, with a protein content material ranging from 17 to 40%.
• By combining cereal and grain consumption, farmers and their families can achieve protein stability and dietary improvement.