Phosphorus and Sulphur Biogeochemical Cycles

Rocks are the reservior of sulphur as the sulphur is present in the form of iron pyrites (FeS2)  and gypsum (CaSO4) in rocks.

Phosphorus is primarily found in the Earth's crust in the form of phosphate rocks, which are crystalline in nature. It is released into the ecosystem through the weathering of these rocks.

The phosphorus cycle is considered an imperfect cycle because a significant portion of phosphorus is lost to deep ocean sediments and is not readily recycled back into the biosphere on a short timescale.

Volcanic eruptions release massive amounts of sulfur gases, such as sulfur dioxide, directly into the atmosphere, which significantly impacts and disrupts the global sulfur cycle. Unlike gaseous cycles such as carbon or nitrogen, sulfur has a sedimentary and gaseous phase heavily influenced by geological events like volcanism.

The phosphorus cycle is a sedimentary cycle, meaning its primary reservoir is in the Earth's crust (rocks and sediments) rather than the atmosphere.

There are 4 layers of Earth, namely lithosphere (land), hydrosphere (water), biosphere (living), and atmosphere (air). Lithosphere of Earth makes up the hard and rigid outer layer of the Earth. It is reservoir of phosphorus. The largest reservoir of phosphorus is sediments or sedimentary rocks. Hence, phosphorous cycle represents sedimentary type of nutrient cycle or simply sedimentary cycle.

Sedimentary cycles are those cycles that involve earthbound elements like, calcium, sulfur, phosphorous etc. The phosphorus cycle does not involve the atmosphere, it mainly cycles through water, soil and sediments. 

Sedimentary cycles are those cycles which include the weathering of rocks and erosion of minerals along with its circulation in the environment and back to earth crust. It includes those of iron, calcium, phosphorus and other more earthbound elements. It is the other name of phosphorus cycle. It is because of the sedimentary rocks, as well as the other type of rocks on weathering, gives rise to the cycling of phosphorus.

Sedimentary rocks are the largest reservoir of the phosphorous .Phosphates are removed from the rocks (via weathering) and are distributed throughout both soils and water. Plants take up the phosphate ions from the soil. The phosphates then move from plants to animals when herbivores eat plants and carnivores eat plants or herbivores. The phosphates absorbed by animal tissue through consumption eventually returns to the soil through the excretion of urine and feces, as well as from the final decomposition of plants and animals after death. Hence option B is correct.

Sedimentary cycles involve the transportation of matter through the ground to water; that is from the lithosphere to the hydrosphere. Most phosphates originate as salts in ocean sediments or in rocks. Over time, geological uplift brings these sediments to the surface, and weathering releases the phosphate ions. Plants can then absorb these phosphates from the soil and use it in cellular processes. Phosphate taken up by plants may then be passed on to animals when the plant is consumed by herbivore that, in turn, may be consumed by carnivores. After death, the animal or plant decays, and the phosphates are returned to the soil by way of bacterial decomposition. Runoff from the land may carry leached phosphate back to the ocean, where it eventually enters sediments and is reincorporated into rock.

The sedimentary cycle is one of the  biogeochemical cycles that forms an important factor for the growth and development of a living organism. For the sedimentary cycle, the major reservoir is the lithosphere which releases the  elements through weathering. The mineral elements required by living organisms are obtained  from inorganic sources either from salts dissolved in water or from rocks. The sedimentary cycle is represented  by phosphorous, sulphur and iodine cycles.
Sulphur cycle is the cycle which allows the circulation of sulphur from the source to the various living organism and back to the natural resources in form of salts of sulphur.

• The term biogeochemical cycle is used for the exchange or circulation of biogenetic nutrients between living and nonliving components of the biosphere.
• The nutrient cycle can be a gaseous cycle in which the materials involved in circulation between living and nonliving components are gases or vapors, e.g., carbon, hydrogen, oxygen.
• In sedimentary cycles of matter; the materials involved in circulation between biotic and abiotic components of the biosphere are non-gaseous e.g., phosphorous, calcium, magnesium.
• The reservoir of phosphorous is phosphates present in rocks.
  
  Thus, the correct answer is option B.

Phosphorus is a critical element. In living systems, it occurs in nucleic acids, nucleotides including ATP, bones, teeth, phospholipids etc. It is obtained from the soil as orthophosphates. Organic phosphorous circulates in nature from plants to animals. Phosphate is released by decomposers back to the soil. The reservoir pool for phosphorus is phosphates in rocks from which the phosphorus is slowly transferred to cycling pool.

Phosphorus is obtained from soil as orthophosphate $(PO _{4}^{3-})$. Organic phosphorus circulates in nature from plants to animals. Phosphate is released by decomposers (Phosphatising bacteria) back to soil.

A large amount of phosphate is lost in the sea by sedimentation. This is irretrievable loss.

The phosphorus cycle is a long-term sedimentary cycle. Geological processes, such as tectonic uplift, move phosphorus from the sea floor back to land surfaces over geological timescales.

There are 4 layers of Earth, namely lithosphere (land), hydrosphere (water), biosphere (living), and atmosphere (air). Lithosphere of Earth includes the crust and the uppermost mantle. It makes up the hard and rigid outer layer of the Earth. It is reservoir of phosphorus. The largest reservoir of phosphorus is sediments or sedimentary rocks. Hence, phosphorous represents sedimentary type of nutrient cycle. 

There are 4 layers of Earth, namely lithosphere (land), hydrosphere (water), biosphere (living), and atmosphere (air). Lithosphere of Earth includes the crust and the uppermost mantle. It makes up the hard and rigid outer layer of the Earth. It is reservoir of phosphorus. The largest reservoir of phosphorus is sedimentary rocks. 

There are 4 layers of Earth, namely lithosphere (land), hydrosphere (water), biosphere (living), and atmosphere (air). Lithosphere of Earth makes up the hard and rigid outer layer of the Earth. It is reservoir of phosphorus. The largest reservoir of phosphorus is sediments or sedimentary rocks. Crystalline rocks are sedimentary rocks. They are the natural source of phosphorous.  

Biochemical cycle is also called as biogeochemical cycle or nutrient cycle. Biochemical cycle with gaseous phase includes various cycles like carbon cycle, nitrogen cycle, oxygen cycle. The nitrogen, carbon and oxygen are found in the gaseous form in the atmosphere. Calcium cycle, sodium cycle, phosphorous cycle, iron cycle, magnesium cycle, sulfur cycle are sedimentary cycles.

Biochemical cycle is also called as biogeochemical cycle or nutrient cycle. Biochemical cycle with gaseous phase includes various cycles like carbon cycle, nitrogen cycle, oxygen cycle. The nitrogen, carbon and oxygen are found in the gaseous form in the atmosphere. Calcium cycle, sodium cycle, phosphorous cycle, iron cycle, magnesium cycle, sulphur cycle are sedimentary cycles.

The natural reservoir of phosphorus is rock, which contains phosphorus in the form of phosphates. When rocks are weathered, minute amounts of these phosphates is mixed in soil and are absorbed by the roots of the plants. Herbivores and other animals obtain this element from plants. 

Marine birds plays a unique role in phosphorus cycle. These birds eat marine fish, which is rich in phosphorus . Their excreta are called a guano deposits.

There are 4 layers of Earth, namely lithosphere (land), hydrosphere (water), biosphere (living), and atmosphere (air). Lithosphere of Earth includes the crust, sedimentary rocks and the uppermost mantle. It is reservoir of phosphorus. Hence, weathering of rocks makes phosphorus available to first producers.

Forests play a crucial role in the hydrological cycle by regulating water infiltration, transpiration, and runoff, which helps maintain water balance in receiving regions.

The sulfur cycle is primarily a sedimentary cycle, but it has a significant gaseous component (such as sulfur dioxide and hydrogen sulfide) that allows it to circulate through the atmosphere.

Phosphorus does not have a significant gaseous phase in its natural biogeochemical cycle, unlike carbon, nitrogen, or sulfur.

Sulfur dioxide (SO2) reacts with moisture and oxygen in the presence of impurities to form sulfuric acid (H2SO4), which can damage paper and other materials.

Sulfur dioxide (SO2) is oxidized in the atmosphere in the presence of oxygen and moisture to form sulfuric acid, a primary component of acid rain.

Sulfur and nitrogen oxides react with atmospheric water vapor to form acids, which fall to the Earth's surface as wet deposition, commonly known as acid rain.

Sulfur-rich mineral springs are known for their therapeutic properties, often used in balneotherapy to treat various skin conditions.

Sulfur dioxide (SO2) is a pollutant that can react with the materials in leather, causing it to become brittle and disintegrate over time.

The combustion of fossil fuels, particularly coal in power plants, is the largest anthropogenic source of sulfur dioxide emissions globally.

When smoke (containing sulfur dioxide) interacts with water vapor in the atmosphere, it forms sulfuric acid mist, which contributes to smog and acid rain.

Chemosynthetic microbes, such as sulfur-oxidizing bacteria, derive energy from the oxidation of inorganic sulfur compounds rather than from sunlight.

Sulfur dioxide is a major air pollutant that contributes to the formation of acid rain, which causes the deterioration of materials like leather and paper.

Volcanic eruptions are a significant natural source of sulfur dioxide, releasing large quantities of the gas into the atmosphere.

Statement B is incorrect because low temperatures and anaerobiosis inhibit or slow down decomposition rather than accelerate it. Warm, moist, and aerobic conditions favor rapid microbial decomposition. The other statements regarding humification, lignin-rich detritus, and humus resistance are correct.

Hydrogen sulfide (H2S) is a colorless gas known for its characteristic odor of rotten eggs.

The reduction of sulfur compounds, often by anaerobic bacteria, results in the production of hydrogen sulfide (H2S).