**4. 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.

#### **4.1 Legumes and carbon sequestration**

For a range of years, the practicable importance of legumes in many agroecosystems, but also the restrained extent to which this possible has been realized, has been recognized. Legumes do not just contribute in terms of food, feed and fertility, but are also essential as fuelwood and with admire to carbon (C) sequestration. In this chapter we focal point on the extent to which legumes can contribute to greater C sequestration and the delivery of co-benefits including greater biodiversity and reduced greenhouse fuel (GHG) emissions. We additionally consider briefly the main reasons why legumes are currently underutilized and the possibilities for a larger function in the future. Enhancing C sequestration in the soil is linked to elevated biomass and hence to soil fertility. Raising fertility is perchance the most effective way of rapidly growing carbon sink capacity. Clearly, one way of doing this is through elevated addition of nitrogenous fertilizers. However, caution in the enormous use of nitrogenous fertilizers as a strategy to elevated productivity is excellent for a variety of reasons, consisting of the potential for other emissions. By contrast, the role of legumes in supplying nitrogen (N) through fixation is being increasingly more seen as important as an extra beneficial in terms of common GHG stability than had as soon as been thought. The introduction of legumes and their higher utilization as section of a pasture improvement system are consequently probably to be worthy of serious consideration in many circumstances [11].

#### **4.2 Reduction in greenhouse gasoline emissions**

Legumes are also possibly to have a position to play in lowering GHG emissions from ruminant systems. An approach to decreasing methane emissions of current interest and supported by some initial evidence is the use of tannin containing forages and breeding of forage species with greater tannin content. Forage legumes such as *Lotus corniculatus* (birds foot trefoil) and *L. uliginosus* (greater trefoil) possess secondary metabolites acknowledged as condensed tannins in their leaves. They are no longer present on the leaves of white or purple clover but are existing in the inflorescences. Methane production values had been lower in housed sheep fed on

**21**

*Role of Legumes in Improving Soil Fertility Status DOI: http://dx.doi.org/10.5772/intechopen.93247*

timothy (*Phleum pratense*) as underneath legumes.

**4.3 The potential for legumes to mitigate climate change**

N fertilizer manufacturing and symbiotic N2 fixation.

the crop residue in soil formation and aggregation [18–26].

**4.4 Role of legume vegetation on enhancing soil physical properties**

Important soil physical properties are bulk density, porosity, combination stability, and texture. These properties are additionally associated with waterrelated methods including aeration, runoff, erosion, water maintaining capacity, and infiltration rate [15]. Legume vegetation have a manageable to enhance physical properties of soil by being a soil conditioner and enhancing the physical residences [16]. Leguminous cover crops have a tremendous effect on soil physical properties broadly speaking due to the manufacturing ability of large biomass which affords substrata for soil organic undertaking and soil organic matter [17]. Furthermore, leguminous cover vegetation are grown to protect the soil from loss of plant nutrients and erosion, while green manure plants are grown for the motive of improving soil bodily properties. Moreover, some plants can physically modify the types of soil profile. Legumes additionally have an effect on soil shape by means of their impact on aggregation. Leguminous cover crops can expand or keep an appropriate soil C/N ratio and increase in preserving soil organic carbon stock. Legume plants often result in higher infiltration of water, due to direct effects of

productivity [14].

purple clover and birds foot trefoil than on a ryegrass/white clover pasture [12]. The emissions of nitrous oxide from soils improved linearly with the quantity of mineral nitrogen fertilizer applied and because structures containing legumes produce lower annual nitrous oxide emissions, alfalfa and different legume vegetation need to be regarded differently when deriving national inventories of GHG from agriculture. The nitrous oxide emissions are from soils with alfalfa and soybean cropping, looking at soil floor emissions in evaluation with perennial grass. Low nitrous oxide emissions have been considered under grass and soil mineral N used to be up to ten instances higher beneath legumes however soil mineral N pools were not carefully associated to nitrous oxide emissions. Comparable emissions were viewed under

Legumes are soil-amendment crops with strong benefits on soil health and need to be an essential element of the farming systems [13]. Legumes have positive effects on soil processes such as benefiting agroecosystems, agricultural productivity, soil conservation, soil biology, SOC and N stocks, soil chemical and bodily properties, BNF, nitrous oxide (N2O) emission, and nitrate (NO3) leaching by means of lowering the need for chemical fertilizers. Above all, legumes are now utilized as soil nourishment agents. However, these benefits on soil health need to be quantified, and their mechanisms understood. Thus, incorporating legumes as a section of cropping systems is pertinent to higher soil fitness and

The concentrations rise, it has become an increasing number of necessary to account for losses of CO2 and N2O arising from agriculture. Emissions of these gases may occur either directly as the result of farming activities (e.g., cultivation and harvesting) or circuitously for the duration of the production and transport of required inputs (e.g., fertilizers, herbicides, and pesticides). The plausible function of N2-fixing legumes in lowering GHG emissions via direct effects on CO2 and N2O fluxes in the production of high-protein grain and forage will be in contrast to the functions of fertilizer N in the following sections. CO2 emissions bobbing up from

#### *Role of Legumes in Improving Soil Fertility Status DOI: http://dx.doi.org/10.5772/intechopen.93247*

*Legume Crops - Prospects, Production and Uses*

**3.5 Lower soil pH**

growth and development.

**4. Biological diversity**

**4.1 Legumes and carbon sequestration**

serious consideration in many circumstances [11].

**4.2 Reduction in greenhouse gasoline emissions**

as a "glue" that binds soil together into stable aggregates. This aggregate stability increases pore space and tilth, reducing both soil erodibility and crusting.

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

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.

For a range of years, the practicable importance of legumes in many agroecosystems, but also the restrained extent to which this possible has been realized, has been recognized. Legumes do not just contribute in terms of food, feed and fertility, but are also essential as fuelwood and with admire to carbon (C) sequestration. In this chapter we focal point on the extent to which legumes can contribute to greater C sequestration and the delivery of co-benefits including greater biodiversity and reduced greenhouse fuel (GHG) emissions. We additionally consider briefly the main reasons why legumes are currently underutilized and the possibilities for a larger function in the future. Enhancing C sequestration in the soil is linked to elevated biomass and hence to soil fertility. Raising fertility is perchance the most effective way of rapidly growing carbon sink capacity. Clearly, one way of doing this is through elevated addition of nitrogenous fertilizers. However, caution in the enormous use of nitrogenous fertilizers as a strategy to elevated productivity is excellent for a variety of reasons, consisting of the potential for other emissions. By contrast, the role of legumes in supplying nitrogen (N) through fixation is being increasingly more seen as important as an extra beneficial in terms of common GHG stability than had as soon as been thought. The introduction of legumes and their higher utilization as section of a pasture improvement system are consequently probably to be worthy of

Legumes are also possibly to have a position to play in lowering GHG emissions from ruminant systems. An approach to decreasing methane emissions of current interest and supported by some initial evidence is the use of tannin containing forages and breeding of forage species with greater tannin content. Forage legumes such as *Lotus corniculatus* (birds foot trefoil) and *L. uliginosus* (greater trefoil) possess secondary metabolites acknowledged as condensed tannins in their leaves. They are no longer present on the leaves of white or purple clover but are existing in the inflorescences. Methane production values had been lower in housed sheep fed on

Because inoculated, nodulated legumes acquire their N from the air as diatomic

**20**

purple clover and birds foot trefoil than on a ryegrass/white clover pasture [12]. The emissions of nitrous oxide from soils improved linearly with the quantity of mineral nitrogen fertilizer applied and because structures containing legumes produce lower annual nitrous oxide emissions, alfalfa and different legume vegetation need to be regarded differently when deriving national inventories of GHG from agriculture. The nitrous oxide emissions are from soils with alfalfa and soybean cropping, looking at soil floor emissions in evaluation with perennial grass. Low nitrous oxide emissions have been considered under grass and soil mineral N used to be up to ten instances higher beneath legumes however soil mineral N pools were not carefully associated to nitrous oxide emissions. Comparable emissions were viewed under timothy (*Phleum pratense*) as underneath legumes.

Legumes are soil-amendment crops with strong benefits on soil health and need to be an essential element of the farming systems [13]. Legumes have positive effects on soil processes such as benefiting agroecosystems, agricultural productivity, soil conservation, soil biology, SOC and N stocks, soil chemical and bodily properties, BNF, nitrous oxide (N2O) emission, and nitrate (NO3) leaching by means of lowering the need for chemical fertilizers. Above all, legumes are now utilized as soil nourishment agents. However, these benefits on soil health need to be quantified, and their mechanisms understood. Thus, incorporating legumes as a section of cropping systems is pertinent to higher soil fitness and productivity [14].

### **4.3 The potential for legumes to mitigate climate change**

The concentrations rise, it has become an increasing number of necessary to account for losses of CO2 and N2O arising from agriculture. Emissions of these gases may occur either directly as the result of farming activities (e.g., cultivation and harvesting) or circuitously for the duration of the production and transport of required inputs (e.g., fertilizers, herbicides, and pesticides). The plausible function of N2-fixing legumes in lowering GHG emissions via direct effects on CO2 and N2O fluxes in the production of high-protein grain and forage will be in contrast to the functions of fertilizer N in the following sections. CO2 emissions bobbing up from N fertilizer manufacturing and symbiotic N2 fixation.
