MCQ
Q.
The manure also considered as bio-fertilizer is:
Correct Answer: D
- Is a substance that contains living microorganisms.
- These, when applied to seeds, plant surfaces, or soil, colonize the rhizosphere or the interior of the plant and promotes growth by increasing the supply or availability of primary nutrients to the host plant.
- Biofertilizers add nutrients through the natural processes of Nitrogen fixation.
- Examples: Rhizobium, Azotobacter, Blue-green algae, Azospirilium.
Key PointsBlue green algae:
- Blue-green algae (BGA) is a photoautotrophic, prokaryotic algae.
- They are free-living creatures and also known as Cyanobacteria.
- It fixes the atmospheric nitrogen in moist soils.
- So BGA has been recommended as a biofertilizer.
- The algae include unicellular as well as filamentous species.
- Some of the filamentous forms have specialized cells known as heterocysts.
Important Points
Biofertilizers:
| Free Living |
|
| Symbiotic | Rhizobium, Frankia, Anabaena azollae |
| Associative symbiotic | Azospirillum |
| Endophytic | Gluconacetobacter Burkholderia |
Thus, the manure also considered as bio-fertilizer is Blue green algae.
Additional Information
Compost:
- Composting is a process in which both aerobic and anaerobic micro-organisms decompose organic matter.
- Farm compost is a mass of rotted organic matter made from farm waste like sugarcane trash, paddy straw, weeds and other plants.
- While town compost is a mass of rotted organic matter made from town refuses like night soil, street sweepings and dustbin refuse.
Green Manure:
- Green manures are the crops that are grown primarily for building and maintaining soil fertility and structure.
- Green manure crops should be such that they can be grown quickly.
- Green manure crops include legumes such as vetch, clover, beans and peas; grasses such as annual ryegrass, oats, rapeseed, winter wheat and winter rye and buckwheat.
- Green manure crops provide nitrogen as the major nutrient.
Farmyard Manure:
- It is the decomposed mixture of dung and urine of farm animals.
- It also contains litter and leftover materials from roughages or fodder fed to cattle.