How does agriculture affect the phosphorus cycle

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How does agriculture affect the phosphorus cycle? Explanation: Farmers tend to use excessive amounts of phosphorus. Therefore, runoff from agricultural fields cause phosphorus problem in lakes, reservoirs, streams, ponds.

Farmers tend to use excessive amounts of phosphorus. Therefore, runoff from agricultural fields cause phosphorus problem in lakes, reservoirs, streams, ponds.Aug 31, 2016

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Answer

How do humans affect the phosphorus cycle?

Humans affect the phosphorus cycle mainly by the use of fertilizers and raising livestock, especially hogs. Fertilizers and hog waste are high in phosphorus, which makes its way into the soil (where it is necessary in moderate amounts) and, due to runoff, in water. How is phosphorus cycle disturbed?

Why is phosphorus the limiting nutrient in the phosphorus cycle?

In nature, phosphorus is often the limiting nutrient —in other words, the nutrient that’s in shortest supply and puts a limit on growth—and this is particularly true for aquatic, freshwater ecosystems. The phosphorus cycle is slow compared to other biogeochemical cycles such as the water, carbon, and nitrogen cycles.

How is phosphorus taken up by plants and animals?

When plants and animals excrete wastes or die, phosphates may be taken up by detritivores or returned to the soil. Phosphorus-containing compounds may also be carried in surface runoff to rivers, lakes, and oceans, where they are taken up by aquatic organisms.

How does the phosphorus cycle differ from other biogeochemical cycles?

The phosphorus cycle is slow compared to other biogeochemical cycles such as the water, carbon, and nitrogen cycles. In nature, phosphorus is found mostly in the form of phosphate ions—.

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Why is phosphorus important to agriculture?

Phosphorus (P) is an essential element for plant and animal growth and is necessary to maintain profitable crop and livestock production. It also can increase the biological productivity of surface waters by accelerating eutrophication, the natural aging of lakes or streams brought on by nutrient enrichment.


How does agricultural runoff affect the phosphorus cycle?

Phosphorus and Water Quality When the rainfall or irrigation rate is higher than the soil’s ability to absorb water, the result is runoff. Runoff can transport soluble P, P attached to eroding soil particles, plant residues, and/or any recently applied commercial fertilizers into lakes, ponds, streams, rivers and bays.


What can affect the phosphorus cycle?

Humans greatly influence the phosphorus cycle through the release of mined phosphates into ecosystems, especially in the form of fertilizers, but also from detergents and sewage waste.


Where does the phosphorus come from in agriculture?

Most of the phosphorus used in fertilizer comes from phosphate rock, a finite resource formed over millions of years in the earth’s crust. Ninety percent of the world’s mined phosphate rock is used in agriculture and food production, mostly as fertilizer, less as animal feed and food additives.


What is agricultural runoff?

Agricultural Runoff is water from farm fields due to irrigation, rain, or melted snow that flows over the earth that can absorb into the ground, enter bodies of waters or evaporate.


How phosphorus in fertilizers affect the environment?

Too much phosphorus can cause increased growth of algae and large aquatic plants, which can result in decreased levels of dissolved oxygen– a process called eutrophication. High levels of phosphorus can also lead to algae blooms that produce algal toxins which can be harmful to human and animal health.


How do animals contribute to the phosphorus cycle?

Animals absorb phosphates by eating plants or plant-eating animals. Phosphorus cycles through plants and animals much faster than it does through rocks and sediments. When animals and plants die, phosphates will return to the soils or oceans again during decay.


How does deforestation affect the phosphorus cycle?

Deforestation disrupts the phosphorus cycle by weakening the rate of P deposition, the major mechanism of P input to the system. This effect, combined with the enhancement of mobile P leaching, leads to a less conservative cycling of P and, over the coming decades in the Yucatán, a decline in plant-available P.


How does pollution affect the phosphorus cycle?

Human interference in the phosphorus cycle, such as through phosphorus pollution of water bodies by sewage discharge and drainage from agricultural land, can contribute to the growth of toxic blue-green algae, fish death, reduced quality of affected water bodies.


How does agriculture influence the nutrient cycle?

Furthermore, agriculture also influences the nutrient cycle in another way: agriculture accelerates land erosion — because ploughing and tilling disturb and expose the soil — so more nutrients drains away with runoff (see also soil degradation). And flood control contributes to disrupting the natural nutrient cycle.


What are phosphates in agriculture?

Phosphorus is an essential and major nutrient for both plants and animals. Thus as food is grown on agricultural land and transferred from there to be consumed by animals and people, so the large quantities of phosphorus taken up from the soil by the crops are removed from the field.


How do fertilizers affect the nitrogen and phosphorus cycles?

Nitrogen from fertilizers sinks into soils, often creating conditions that favor the growth of weeds rather than native plants. Nitrogen then washes into waterways, causing a surplus of nutrients, a situation called eutrophication.


What causes soil phosphorus to increase?

Rapid growth and intensification of the livestock industry in certain areas of the U.S. and Europe have created national and regional soil P imbalances. Before World War II, farming communities tended to be self-sufficient, in that they produced enough feed locally to meet livestock requirements and could recycle the manure nutrients effectively to meet crop needs. As a result, sustainable nutrient cycles tended to exist in relatively localized areas (Figure 4).


How does phosphorus behave in soil?

In addition, P is cycled from roots to aboveground parts of the plant and is redeposited in crop residues on the soil surface. This builds up organic material and stimulates biological activity in surface layers. Further, in reduced tillage systems, fertilizers and manures are applied to the soil surface with little or no mechanical incorporation, thus exacerbating P buildup in the top 2 to 5 inches of soil.


What are the forms of phosphorus in soil?

Soil P exists in organic and inorganic forms (Figure 2). Each form consists of a continuum of many P compounds, existing in equilibrium with each other and ranging from solution P (taken up by plants) to very stable or unavailable compounds (the most typical). In most soils, 50 to 75% of the P is inorganic.


How can a field’s risk for phosphorus loss be monitored with soil tests?

Losses of P in surface runoff increase with an increase in soil test P levels. Although studies currently are limited to only a few soil types and situations, they show the scientific basis for establishing soil test P levels at which P losses in surface runoff reach unacceptable levels. In other words, if maximum allowable P concentrations in agricultural runoff are proposed, we can estimate at what soil test P level these concentrations probably will be met or exceeded. More data of this type are needed for different soil types, crop covers, surface runoff volumes, and erosion potentials, so that scientists can develop recommendations for fertilizer and manure use that will be effective for crop production and farm management, yet flexible enough to be workable and economical for farmers.


How does land use affect eutrophication?

Changes in land use can accelerate the eutrophication of lakes and streams. Aging processes that naturally take place over the course of centuries (left column) may occur much more rapidly when agricultural nutrients are added to the water (right column).


What is the role of nitrogen in eutrophication?

Figure 1. Changes in land use can accelerate the eutrophication of lakes and streams.


How does phosphorus reduce runoff?

Phosphorus applications at recommended rates can reduce P loss in surface runoff when they increase crop uptake and cover. Nevertheless, it is of vital importance that we implement management practices that minimize soil test P buildup in excess of crop requirements, reduce surface runoff and erosion, and improve the ease and reliability with which we can identify the fields that are the major sources of P loss to surface waters. In summary: 1 Best management systems should attempt to balance P inputs and outputs. 2 Source and transport controls should be targeted to identified critical source areas of P export from watersheds. 3 Threshold soil P levels that guide manure applications should be linked with site vulnerability to P loss.


How do living things affect the phosphorus cycle?

Plants take up inorganic phosphate from the soil. The plants may then be consumed by animals. Once in the plant or animal, the phosphate is incorporated into organic molecules such as DNA. When the plant or animal dies, it decays, and the organic phosphate is returned to the soil.


What are 3 ways humans have impacted the phosphorus cycle?

Humans have greatly influenced the phosphorus cycle by mining phosphorus, converting it to fertilizer, and by shipping fertilizer and products around the globe. Transporting phosphorus in food from farms to cities has made a major change in the global Phosphorus cycle.


What human activities disrupt the phosphorus cycle?

Human actions—mining phosphorus (P) and transporting it in fertilizers, animal feeds, agricultural crops, and other products —are altering the global P cycle, causing P to accumulate in some of the world’s soil.


How do human activities mainly contribute to the phosphorus cycle?

Humans affect the phosphorus cycle mainly by the use of fertilizers and raising livestock, especially hogs. Fertilizers and hog waste are high in phosphorus, which makes its way into the soil (where it is necessary in moderate amounts) and, due to runoff, in water.


How is phosphorus cycle disturbed?

Humans have altered the P cycle in aquatic systems, directly, by mining P-rich rock, and indirectly, through the manipulation of other element cycles and the alteration of aquatic food webs. Aquatic ecologists are becoming increasingly aware of the importance of these indirect alterations to biogeochemical cycles.


How do humans directly interfere with the phosphorus cycle quizlet?

We as humans impact the phosphorus cycle by mining and using fertilizer. Also by cutting down the rain forest. By using the fertilizer this changes some of the plants which causes the cycle to be unbalanced. Weathered rocks release phosphorus, in the form of phosphate into the soil for plants to absorb.


What significant impacts does phosphorus have on human society?

The impacts of our actions Excessive phosphorus in our water supplies can have negative consequences for humans. It can result in excessive plant growth (including algae). This can in turn clog our water pipes and filters and interfere with human activities (such as swimming and fishing).


How does phosphorus move from the ocean to the land?

Over long periods of time, phosphorus-containing sedimentary rock may be moved from the ocean to the land by a geological process called uplift.


How are phosphates taken up?

When plants and animals excrete wastes or die, phosphates may be taken up by detritivores or returned to the soil. Phosphorus-containing compounds may also be carried in surface runoff to rivers, lakes, and oceans, …


What is the limiting nutrient in aquatic ecosystems?

Phosphorus is often the limiting nutrient, or nutrient that is most scarce and thus limits growth, in aquatic ecosystems. When nitrogen and phosphorus from fertilizer are carried in runoff to lakes and oceans, they can cause eutrophication, the overgrowth of algae. The algae may deplete oxygen from the water and create a dead zone.


How can eutrophication be reduced or prevented?

How can eutrophication be reduced or prevented? Fertilizers, phosphorus-containing detergents, and improperly disposed of sewage can all be sources of nitrogen and phosphorus that drive eutrophication. Using less fertilizer, eliminating phosphorus-containing detergents, and ensuring that sewage does not enter waterways—e.g., from a leaky septic system—are all ways that individuals, companies, and governments can help reduce eutrophication.


What is the cause of eutrophication?

Most fertilizers used in agriculture—and on lawns and gardens—contain both nitrogen and phosphorus, which may be carried to aquatic ecosystems in surface runoff. Fertilizer carried in runoff may cause excessive growth of algae or other microbes that were previously limited by nitrogen or phosphorus. This phenomenon is called eutrophication. At least in some cases, phosphorus, not nitrogen, seems to be the main driver of eutrophication.


Why is eutrophication harmful?

Why is eutrophication harmful? Some algae make water taste or smell bad or produce toxic compounds. Also, when all of those algae die and are decomposed by microbes, large amounts of oxygen are used up as their bodies are broken down. This spike in oxygen usage can sharply lower dissolved oxygen levels in the water and may lead to death by hypoxia—lack of oxygen—for other aquatic organisms, such as shellfish and finfish.


Why is too much nitrogen bad for plants?

more. If too much nitrogen or phosphorus is present in an environment, plant growth is greatly increased . This is due to the fact that both nitrogen and phosphorus are limiting nutrients. While this abundance of nutrients may be fine in your backyard, it can potentially be very harmful.


How does trade affect the P cycle?

International agricultural trade affects our ability to close the human P cycle by shifting the spatial arrangement of crop production, livestock production, and human consumption of crops and animal products. Trade has supported the increased concentration of crop and livestock production to levels that exceed the P assimilation capacity of soils in some regions and depleted soil P resources in other regions. In a globalizing world, it will be increasingly important to integrate biophysical constraints of our natural resources and environmental impacts of agricultural systems into trade policy and agreements and to develop mechanisms that move us closer to a more equitable managing of the global commons. In the case of phosphorus, this will likely include an emphasis on regional food systems, particularly for livestock production, to increase recycling opportunities of this non-renewable resource.


Why are agricultural imports important?

Because most countries currently apply surplus P to agricultural lands, agricultural imports effectively represent avoided P surpluses for importing countries as environmental impacts of production are displaced to source countries . Feed imports also represent displaced P surpluses associated with crop production for importing countries; however, they allow these countries to support high livestock densities, which can result in large P surpluses within importing countries due to manure production that exceeds the land base available to absorb these excess nutrients.


What does the black arrow represent in the P flow diagram?

Diagram of the P flows estimated through agricultural soils associated with crop and livestock imports and exports. Black arrows represent P flows within a country and gray arrows represent imports and exports across international boundaries.

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