The definitive reference for farmers, seed buyers, researchers, and students working with sesbania and tropical legume agriculture.
✓ 50+ Terms✓ Expert Reference✓ Seed Trade Ready
Who Is This Glossary For?
Whether you are a smallholder farmer exploring green manure options, a commercial seed buyer negotiating international contracts, an agricultural researcher studying nitrogen fixation, or a student encountering tropical legume science for the first time, this glossary gives you clear, practical definitions grounded in real-world sesbania cultivation.
Every term below includes a plain-language definition and a context note showing how it applies specifically to sesbania species and the seed trade. Use the alphabetical navigation to jump to any letter.
Farmers seeking to understand soil health and green manuring practices
Seed buyers and importers needing trade and quality-testing vocabulary
Agronomists and researchers referencing technical terminology
Students and extension workers building foundational knowledge
A
Agroforestry
A land-use management system that integrates trees and shrubs with crops or livestock on the same plot. Agroforestry improves biodiversity, reduces erosion, and creates diversified income streams for farmers.
Sesbania grandiflora is one of the most widely planted agroforestry trees in Southeast Asia, providing shade, fodder, and nitrogen-rich leaf litter to companion crops.
Alley Cropping
A form of agroforestry where food crops are grown in the alleys between rows of trees or shrubs. The woody species are periodically pruned and the cuttings are applied as mulch or green manure to the cropping rows.
Sesbania sesban rows planted at 4-metre intervals create productive alleys where maize or rice can benefit from nitrogen-rich prunings incorporated into the topsoil.
Azolla
A small aquatic fern that forms a symbiotic relationship with the nitrogen-fixing cyanobacterium Anabaena azollae. Azolla is used as a biofertilizer and green manure in flooded rice paddies.
In integrated rice systems, azolla is sometimes combined with sesbania dhaincha as a dual green manure strategy, with azolla covering the water surface and dhaincha growing above it before incorporation.
B
Biofertilizer
A substance containing living microorganisms that, when applied to seeds, plant surfaces, or soil, colonize the rhizosphere and promote growth by increasing the availability of nutrients. Unlike chemical fertilizers, biofertilizers work through biological processes.
Rhizobium-based biofertilizers are often applied as seed inoculants to sesbania before sowing, ensuring rapid nodulation and maximum nitrogen fixation from the earliest growth stages.
Biomass
The total mass of living organic material produced by a plant or crop, typically measured as dry weight per unit area. High biomass production is critical for effective green manure crops.
Sesbania bispinosa (dhaincha) can produce 15 to 25 tonnes of fresh biomass per hectare within 45 to 60 days, making it one of the highest-yielding green manure crops in tropical agriculture.
Bispinosa
The species epithet for Sesbania bispinosa, commonly known as dhaincha. It refers to a fast-growing annual legume native to the Indian subcontinent, recognized for its exceptional green manure properties and gum production potential.
Bispinosa seeds are among the most traded sesbania varieties globally, with major demand from rice-growing regions in India, Bangladesh, and Southeast Asia. Learn more about dhaincha seeds.
Bradyrhizobium
A genus of slow-growing, nitrogen-fixing bacteria that form symbiotic root nodules with certain legumes. Bradyrhizobium strains are distinguished from Rhizobium by their slower growth rate in laboratory culture.
Some sesbania species, particularly Sesbania rostrata, can form nodules with both Bradyrhizobium and Azorhizobium, giving them unusual flexibility in nitrogen fixation across different soil conditions.
Broadcasting
A sowing method in which seeds are scattered uniformly across the soil surface, either by hand or with a mechanical spreader. Broadcasting is faster than row planting but can result in uneven spacing.
Dhaincha seeds are commonly broadcast at a rate of 40 to 60 kg per hectare in flooded rice fields, where precision spacing is less critical because the entire crop will be incorporated as green manure.
C
C:N Ratio (Carbon-to-Nitrogen Ratio)
The ratio of the mass of carbon to the mass of nitrogen in a substance. In soil science, C:N ratio determines how quickly organic matter decomposes; materials with low C:N ratios (below 25:1) break down faster and release nitrogen more readily.
Sesbania green manure has a C:N ratio of approximately 15:1 to 20:1, which means it decomposes rapidly after incorporation and releases plant-available nitrogen within two to three weeks.
Certified Seed
Seed that has been produced, processed, and tested under an official seed certification program. Certified seed meets minimum standards for genetic purity, physical purity, germination rate, and freedom from seed-borne diseases.
When purchasing sesbania seeds in bulk, buyers should request certified seed lots accompanied by official test certificates indicating germination rate, purity percentage, and moisture content.
Cover Crop
A crop planted primarily to protect and improve the soil between main cropping seasons, rather than for harvest. Cover crops prevent erosion, suppress weeds, and add organic matter when terminated.
Sesbania sesban serves as an effective cover crop in tropical orchards, where its dense canopy shades out weeds while its root nodules continuously enrich the soil with biologically fixed nitrogen.
Cross-Inoculation
The ability of a rhizobial strain isolated from one legume species to form effective nitrogen-fixing nodules on a different legume species. Cross-inoculation groups help agronomists select appropriate inoculants.
Sesbania species belong to a specific cross-inoculation group, and inoculants formulated for other legumes like soybeans or clovers may not effectively nodulate sesbania roots.
Crop Rotation
The practice of growing different types of crops in the same field across sequential seasons. Rotation breaks pest and disease cycles, improves soil structure, and balances nutrient demands.
Inserting a sesbania green manure crop into a rice-wheat rotation is a proven strategy to restore soil nitrogen levels depleted by successive cereal harvests.
D
Dhaincha
The common name (from Hindi and Urdu) for Sesbania bispinosa, one of the most important green manure legumes in South Asia. Also spelled "dhancha" or "daincha" in different regions.
Dhaincha is the backbone of green manure programs in Indian rice agriculture. Millions of hectares are sown with dhaincha seeds each monsoon season, then ploughed under before transplanting rice seedlings.
Dormancy
A state in which a viable seed fails to germinate even when provided with adequate moisture, temperature, and oxygen. Dormancy is an evolutionary survival mechanism that prevents premature germination.
Sesbania seeds exhibit hard-seed-coat dormancy, where an impermeable testa prevents water absorption. Scarification (mechanical or chemical) is used to break this dormancy before sowing. Learn how to germinate sesbania seeds.
Dryland Farming
Agricultural production carried out in arid or semi-arid regions without supplemental irrigation, relying entirely on natural rainfall. Dryland farming requires drought-tolerant crop varieties and moisture-conservation practices.
Sesbania sesban is valued in dryland farming systems across sub-Saharan Africa because its deep taproot can access subsoil moisture, enabling the plant to survive and fix nitrogen even during prolonged dry spells.
F
FOB (Free On Board)
An international trade term (Incoterm) indicating that the seller delivers goods on board the vessel at the named port of shipment. Once goods cross the ship's rail, risk and cost transfer to the buyer.
Sesbania seed export contracts from Pakistan are typically quoted FOB Karachi, meaning the price includes all costs up to loading the container onto the vessel at Karachi port.
Fodder
Any agricultural product used as livestock feed, including leaves, stems, pods, and processed feed materials. High-protein fodder crops are especially valuable in tropical and subtropical livestock systems.
Sesbania grandiflora leaves contain 25 to 30 percent crude protein, making them an excellent supplemental fodder for dairy cattle and goats in regions where commercial feed is expensive or unavailable.
Foundation Seed
Seed produced from breeder seed under carefully controlled conditions. Foundation seed is the source material used to produce certified seed for commercial distribution. It represents the second generation in the formal seed multiplication chain.
National seed agencies maintain foundation seed stocks of improved sesbania varieties to ensure that certified seed reaching farmers retains the genetic purity and performance characteristics developed by plant breeders.
G
Galactomannan
A natural polysaccharide (plant gum) composed of a mannose backbone with galactose side groups. Galactomannans are extracted from the endosperm of certain legume seeds and used as thickeners, stabilizers, and emulsifiers in industrial applications.
Sesbania bispinosa seeds are a commercial source of galactomannan gum, which is used in the food, textile, paper, mining, and oil-drilling industries as a cost-effective alternative to guar gum.
Germination Rate
The percentage of seeds in a sample that successfully sprout under controlled testing conditions within a specified time period. Germination rate is one of the most critical quality parameters in the seed trade, directly determining field establishment potential.
Premium sesbania seed lots typically carry a germination rate of 80 percent or higher. Buyers should always request a recent seed test certificate before placing bulk orders to verify this figure.
Green Manure
A crop grown specifically to be ploughed back into the soil to improve its fertility and organic matter content. Green manure crops are typically fast-growing legumes that fix atmospheric nitrogen, enriching the soil when incorporated.
Sesbania is one of the world's most effective green manure crops. A 45-day sesbania green manure crop can add 80 to 120 kg of nitrogen per hectare, reducing or eliminating the need for urea in the following rice crop.
Grandiflora
The species epithet for Sesbania grandiflora, a fast-growing softwood tree reaching 8 to 12 metres in height. Known for its large, showy flowers (white or red) and multiple agricultural uses.
Grandiflora is cultivated across India, Indonesia, the Philippines, and Myanmar for its edible flowers, high-protein leaves, and exceptional nitrogen-fixing capacity. Explore grandiflora seeds.
H
Hard Seed Coat
A physically impermeable seed coat (testa) that prevents water and gas exchange, thereby inhibiting germination. Hard seed coats are a form of physical dormancy common in many legume species.
Up to 50 percent of freshly harvested sesbania seeds may have hard seed coats. Mechanical scarification or soaking in hot water (80 degrees Celsius for 3 minutes) is recommended to improve germination uniformity.
Hectare
A metric unit of area equal to 10,000 square metres or approximately 2.47 acres. The hectare is the standard unit used globally in agriculture for measuring field areas, crop yields, and seed application rates.
Sesbania seed rate recommendations are typically expressed per hectare. For dhaincha green manure, the standard broadcast rate is 40 to 60 kg of seed per hectare.
Humus
The stable, dark-brown organic component of soil formed by the long-term decomposition of plant and animal matter. Humus improves soil structure, water-holding capacity, and cation exchange capacity.
Regular incorporation of sesbania green manure builds humus levels over successive seasons, progressively improving soil tilth and reducing the compaction problems common in intensively cropped rice paddies.
I
Inoculation
The process of applying nitrogen-fixing bacteria (rhizobia) to legume seeds or soil before planting. Inoculation ensures that the correct bacterial strains are present to colonize root nodules and begin fixing atmospheric nitrogen.
First-time sesbania growers should inoculate seeds with a sesbania-specific Rhizobium culture, particularly when planting in fields that have never grown sesbania before, as the correct rhizobial strain may not be present in the native soil.
Intercropping
The agricultural practice of growing two or more crops simultaneously in the same field. Intercropping maximizes land use, reduces pest pressure, and can improve total system productivity compared to monoculture.
Sesbania sesban is intercropped with maize in parts of East Africa, where the sesbania fixes nitrogen and provides stakes for climbing beans after being coppiced.
L
Legume
A plant belonging to the family Fabaceae (Leguminosae), characterized by fruit borne in pods and the ability to form symbiotic nitrogen-fixing relationships with rhizobial bacteria. Legumes are fundamental to sustainable agriculture worldwide.
All sesbania species are legumes. Their capacity to fix 80 to 200 kg of atmospheric nitrogen per hectare per season makes them among the most valuable legumes for soil improvement in tropical farming systems.
Lopping
The practice of cutting branches from a standing tree, usually to harvest fodder, fuelwood, or green leaf manure while keeping the tree alive. Lopping is common in agroforestry management.
Sesbania grandiflora trees tolerate heavy lopping and can be pruned every 6 to 8 weeks during the growing season, yielding protein-rich leaf biomass for livestock fodder without killing the tree.
M
Moisture Content
The amount of water present in a seed sample, expressed as a percentage of the total weight. Moisture content is a critical factor in seed storage, viability, and trade, because excess moisture promotes fungal growth and accelerates seed deterioration.
Sesbania seeds should be dried to a moisture content of 10 percent or below before storage or export. Seed lots exceeding 12 percent moisture risk mould development during transit in shipping containers.
Mulch
Any material, organic or inorganic, spread over the soil surface to conserve moisture, regulate temperature, suppress weeds, and improve soil health as it decomposes. Organic mulches include straw, leaves, and crop residues.
Sesbania prunings laid as mulch around fruit trees decompose within weeks, releasing nitrogen and potassium into the root zone while suppressing competing weeds.
Mycorrhiza
A symbiotic association between a fungus and the roots of a plant. Mycorrhizal fungi extend the effective root surface area, dramatically improving the plant's uptake of phosphorus and other nutrients from the soil.
Sesbania plants can form dual symbioses with both rhizobial bacteria (for nitrogen fixation) and mycorrhizal fungi (for phosphorus uptake), maximizing nutrient acquisition in low-fertility tropical soils.
N
Nitrogen Fixation
The biological process by which atmospheric nitrogen gas (N2) is converted into ammonia (NH3) or related nitrogenous compounds in the soil. In agriculture, this process is carried out by symbiotic bacteria living inside root nodules of leguminous plants, making nitrogen available to the host plant and subsequent crops.
Nitrogen fixation is the primary reason sesbania is grown as a green manure. A well-nodulated sesbania crop can fix 80 to 200 kg of nitrogen per hectare in a single season, equivalent to 175 to 435 kg of urea fertilizer.
Nodulation
The formation of specialized structures (nodules) on the roots of leguminous plants, where nitrogen-fixing bacteria reside. Effective nodulation is indicated by pink or red nodule interiors, caused by the presence of leghemoglobin.
Sesbania rostrata is unique among legumes in that it can form nodules on both its roots and its stems, enabling it to fix nitrogen even in waterlogged soils where root nodulation is suppressed.
NPK
An abbreviation representing the three primary macronutrients essential for plant growth: nitrogen (N), phosphorus (P), and potassium (K). NPK values on fertilizer labels indicate the percentage by weight of each nutrient.
Incorporating a sesbania green manure crop before rice significantly reduces the NPK fertilizer requirement, typically cutting nitrogen application by 50 to 75 percent while also adding organic phosphorus and potassium to the soil.
O
Organic Matter
The fraction of soil composed of decomposed and decomposing plant and animal residues, microbial biomass, and humus. Soil organic matter is critical for nutrient cycling, water retention, and maintaining soil biological activity.
Sesbania green manure is an effective strategy for rebuilding organic matter in degraded tropical soils. A single crop can add 3 to 5 tonnes of dry organic material per hectare, lifting soil organic carbon levels over successive seasons.
P
Purity Percentage
The percentage by weight of pure seed of the desired species in a given seed lot, excluding inert matter, weed seeds, and other crop seeds. Purity percentage is determined by laboratory analysis and is a key quality metric in seed trade contracts.
Export-grade sesbania seed lots are expected to have a purity percentage of 98 percent or higher. Lower purity indicates contamination with soil particles, broken seeds, or seeds from other plant species.
Phytoremediation
The use of living plants to remove, degrade, or stabilize contaminants in soil, water, or sediment. Phytoremediation is an environmentally friendly alternative to conventional excavation and chemical treatment of polluted sites.
Sesbania species have shown promise in phytoremediation research, particularly for absorbing heavy metals like lead and cadmium from contaminated agricultural land and industrial wastewater.
R
Rhizobium
A genus of nitrogen-fixing bacteria that forms symbiotic nodules on the roots of leguminous plants. Inside these nodules, Rhizobium converts atmospheric nitrogen into ammonia, which the plant uses for growth.
Sesbania-specific Rhizobium strains are commercially available as seed inoculants. Applying the correct strain at sowing ensures rapid nodule formation and maximizes the amount of nitrogen fixed during the growing season.
Rostrata
The species epithet for Sesbania rostrata, a tropical legume unique for its ability to form nitrogen-fixing nodules on both stems and roots. Originally native to West Africa, it has been studied extensively for rice-based green manure systems.
Rostrata is particularly suited to flooded rice paddies because its stem nodules remain active above the waterline, continuing to fix nitrogen even when root systems are submerged and anaerobic.
Rotation
See Crop Rotation. In the seed trade context, rotation also refers to the practice of rotating seed stock to ensure that older inventory is sold first, maintaining overall lot viability.
Seed warehouses storing sesbania follow a first-in-first-out rotation policy, because germination rate declines with storage age, especially if moisture and temperature controls are suboptimal.
S
Scarification
Any treatment that weakens, opens, or otherwise alters the seed coat to permit water absorption and initiate germination. Scarification methods include mechanical abrasion, hot water soaking, acid treatment, and exposure to temperature fluctuations.
Soaking sesbania seeds in hot water at 80 degrees Celsius for three minutes, followed by immediate cooling, is the most practical scarification method for field-scale planting. Full germination guide.
Seed Rate
The quantity of seed required to plant a given area, usually expressed in kilograms per hectare. Seed rate depends on species, sowing method, seed size, germination rate, and intended plant population density.
The recommended seed rate for sesbania dhaincha as a green manure is 40 to 60 kg per hectare when broadcast, or 25 to 30 kg per hectare when drilled in rows at 25 cm spacing.
Sesban
The species epithet for Sesbania sesban, a versatile perennial or semi-perennial legume shrub native to tropical Africa and Asia. Also known as Egyptian sesban or common sesban, it is widely used for green manure, fodder, and soil improvement.
Sesban is the most geographically widespread sesbania species, cultivated from sub-Saharan Africa to South and Southeast Asia. View sesban seed specifications.
Silage
Fermented, high-moisture animal fodder produced by storing green crop material under anaerobic conditions. The fermentation process preserves the nutritional value of the forage for use during dry seasons or winter months.
Sesbania grandiflora leaves and tender stems can be ensiled with maize or sorghum to create a protein-enriched silage that improves milk production in dairy cattle compared to cereal-only silage.
Soil Amendment
Any material added to soil to improve its physical, chemical, or biological properties. Unlike fertilizers, which primarily supply nutrients, amendments focus on enhancing overall soil health and structure.
Sesbania biomass incorporated as a soil amendment improves clay soil drainage and sandy soil water retention simultaneously, because the organic matter it contributes enhances aggregate stability in both soil types.
T
Topsoil
The uppermost layer of soil, typically the top 15 to 30 centimetres, which contains the highest concentration of organic matter, microorganisms, and plant nutrients. Topsoil quality directly determines crop productivity.
Sesbania green manure protects and enriches topsoil by adding fresh organic matter, stimulating microbial activity, and reducing erosion during fallow periods between cash crops.
Tropical Legume
A legume species adapted to tropical and subtropical climates, typically requiring warm temperatures (above 20 degrees Celsius), adequate rainfall, and frost-free conditions for optimal growth. Tropical legumes are essential for sustainable farming in equatorial regions.
Sesbania species are among the most productive tropical legumes, thriving between latitudes 30 degrees north and 30 degrees south in regions with mean annual temperatures above 22 degrees Celsius and rainfall above 500 mm.
V
Viability
The capacity of a seed to germinate and produce a normal seedling under favourable conditions. Viability is often tested using tetrazolium (TZ) staining, which identifies living tissue in seeds that may be dormant but still alive.
Sesbania seed viability can remain above 80 percent for three to five years when stored at moisture contents below 10 percent and temperatures below 25 degrees Celsius in airtight containers.
Vigor Test
A seed quality assessment that goes beyond germination rate to evaluate the speed, uniformity, and strength of seedling emergence under stress conditions. Vigorous seeds establish more reliably in the field than seeds that merely pass a standard germination test.
Accelerated aging and cold germination vigor tests are used to predict how well a sesbania seed lot will perform under suboptimal field conditions such as cold soil, excess moisture, or soil crusting.
W
Waterlogging Tolerance
The ability of a plant to survive and continue growing in saturated or flooded soil conditions where oxygen supply to the roots is severely limited. Waterlogging-tolerant species develop morphological and physiological adaptations such as aerenchyma tissue.
Sesbania bispinosa (dhaincha) is renowned for its waterlogging tolerance, which is why it thrives as a green manure in flooded rice paddies where most other legume species would die within days of submersion.
Windbreak
A linear planting of trees or shrubs established to reduce wind speed, protect crops from wind damage, decrease soil erosion, and create favourable microclimates on the leeward side.
Fast-growing sesbania grandiflora trees are planted as temporary windbreaks in coastal areas, providing effective wind protection within 12 to 18 months while also enriching the soil through leaf litter and nitrogen fixation.
Frequently Asked Questions
What is the most important term to understand when buying sesbania seeds?
Germination rate is the single most important term. It tells you the percentage of seeds that will actually sprout and grow. For sesbania seeds, a germination rate of 80 percent or higher is considered good quality. Always request a seed test certificate showing germination rate, purity percentage, and moisture content before placing a bulk order. Understanding these three metrics protects you from low-quality lots that result in poor field establishment and wasted investment.
What is the difference between sesbania sesban, grandiflora, and bispinosa (dhaincha)?
These are three distinct species within the Sesbania genus, each with different growth habits and primary uses. Sesbania sesban is a multi-stemmed shrub widely used for green manure and nitrogen fixation in tropical agriculture. Sesbania grandiflora is a fast-growing tree valued for its edible flowers, high-protein fodder, and agroforestry applications. Sesbania bispinosa (commonly called dhaincha) is the most popular species for green manuring in rice paddies and is also a commercial source of galactomannan gum used in industry.
How does nitrogen fixation work in sesbania plants?
Sesbania plants form a symbiotic relationship with nitrogen-fixing bacteria (Rhizobium or Bradyrhizobium) that colonize specialized structures called root nodules. Inside these nodules, the bacteria convert atmospheric nitrogen gas (N2) into ammonia (NH3), a form that plants can absorb and use for growth. A healthy sesbania crop can fix 80 to 200 kg of nitrogen per hectare per season, which is equivalent to 175 to 435 kg of urea fertilizer. This biological process significantly reduces the need for synthetic nitrogen inputs, lowering costs and environmental impact. Visit our research page for detailed data on fixation rates by species.
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