Biofertilizers (Biology)

Cyanobacteria or blue-green algae is an example of biofertilizer, which helps in fixing atmospheric nitrogen. Blue-green algae are mainly used as biofertilizer in the crop paddy.

Azolla, anabaena, nostok, blue-green algae etc. promote nitrogen fixation in paddy harvesting. They work as organic fertilizers. Rhizobium leguminasarum in pea and azotobacter wheat promotes nitrogen fixation. Generally azolla is not used for nitrogen fixation in maize. Thus the correct answer is option (d).

Azolla is an aquatic fern. It gives a good biofertilizer when mixed with blue-green algae (BGA) or cyanobacteria and contributes in supplying nitrogen to rice fields. In addition, they also bring about directly or indirectly a number of changes in the physical, chemical and biological properties of the soil and soil-water interface in rice fields.

Azolla is an aquatic fern. It gives a good biofertilizer when mixed with blue-green algae (BGA) or cyanobacteria and contributes in supplying nitrogen to rice fields. In addition, they also bring about directly or indirectly a number of changes in the physical, chemical and biological properties of the soil and soil-water interface in rice fields.

Azolla is an aquatic fern. It gives a good biofertilizer when mixed with blue-green algae (BGA) or cyanobacteria and contributes in supplying nitrogen to rice fields. In addition, they also bring about directly or indirectly a number of changes in the physical, chemical and biological properties of the soil and soil-water interface in rice fields.

Azolla is an aquatic fern. It gives a good biofertilizer when mixed with blue-green algae (BGA) or cyanobacteria and contributes in supplying nitrogen to rice fields. In addition, they also bring about directly or indirectly a number of changes in the physical, chemical and biological properties of the soil and soil-water interface in rice fields.

Azolla is an aquatic fern. It gives a good biofertilizer when mixed with blue-green algae (BGA) or cyanobacteria and contributes in supplying nitrogen to rice fields. In addition, they also bring about directly or indirectly a number of changes in the physical, chemical and biological properties of the soil and soil-water interface in rice fields.

Azolla is a floating aquatic fern that grows in temperate climates that are ideal for paddy cultivation. It is commonly used as bio-fertilizer in the water-logged rice field. Azolla pinnata is high in nitrogen, making it a perfect biofertilizer.

Rhizobium, Blue-green algae (Cyanobacteria) and Azolla help in nitrogen fixation, while Vascular Arbuscular Mycorrhiza (VAM) helps in uptake of phosphorus by the plant and hence, it is a phosphate bio-fertilizers.

VAM fungi benefit their host plant by improving the uptake of water, minerals and particularly the poorly mobile ion phosphorus in the soil. It also increases the plant's resistance against pathogens and improves plant tolerance to environmental stresses such as drought.

Biochar is a stable, carbon-rich form of charcoal that is applied to the soil. It is produced from heating organic materials like crop waste, grass, woodchips and manure in a high temperature, low oxygen process known as pyrolysis.

Biochar can be used as a part of the growing medium in vertical farming. Adding biochar to soil increases its carbon content and can mitigate greenhouse gas emissions. Some biochars can improve soil fertility, water holding capacity and crop productivity.

Research shows that biochars derived from grasses or crops appear to have the best balance of agricultural benefit and carbon stability. Some studies also show that increasing the application rate of biochar has a positive feedback on biological nitrogen fixation (BNF) and soil microbial biomass.

The extremely porous nature of biochar is found to be effective at retaining both water and water-soluble nutrients, and it is very much suitable as a habitat for many beneficial soil microorganisms. From the above explanation, all of the given statements are correct.