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Agriculture and food capacity

Soils on arable lands globally are a resource to society with potential use for food production. Production is ultimately limited by soil type, climate, hydrology, and land management. The native soil type is what has been provided by the land, from centuries or millennia of soil development, typically under mostly natural conditions under native plant vegetation. The effect of human populations may have been to drain land for cultivation (affecting hydrology), to modify the landscape, build structures, and to remove native vegetation. Some modifications have aided with food production. Others have had unintended consequences of causing land degradation, such as salinization, topsoil erosion, compaction, pollution, desertification, or depletion of soil nutrients.

Some of these issues are of serious concern in developing countries where oversight and regulations protecting the land may not be in place. For instance, overgrazing and rapid deforestation of the land, and generally poor land management, can lower the organic matter content of surface soils, thus lowering fertility and increasing the likelihood of topsoil erosion due to removal of the protective vegetative covering. As the world's population continues to increase, we will need to find ways to continually increase (or more effectively utilize) food production capacity from an essentially fixed amount of arable land worldwide. As population density has increased, crop yields and the numbers of acres in production have been continually increasing, with technological advances and more land in agriculture. This is not a sustainable trend, though, since the land area on earth is finite. In fact, some prime farmland is even being removed from production in developed countries as urbanization and land development occur on the ever-expanding edges of population centers. Efforts will need to be made to preserve enough high yield farmland to be sustainable for future generations.

Soil compaction, tillage, and sustainable practices

In modern agricultural practices, heavy machinery is used to prepare the seedbed, for planting, to control weeds, and to harvest the crop. The use of heavy equipment has many advantages in saving time and labor, but can cause compaction of soil and disruption of the natural soil biota. Much compaction is reversible and some is unavoidable with modern practices; however, serious compaction issues can occur with excessive passage of equipment during times when the soil has a high water content. The problem with soil compaction is that increased soil density limits root penetration depth and may inhibit proper plant growth.

Current practices generally encourage minimal tillage or no tillage in order to reduce the number of trips across the field. With proper planning, this can simultaneously limit compaction, protect soil biota, reduce costs (if performed correctly), promote water infiltration, and help to prevent topsoil erosion (see below). Tillage of fields does help to break up clods that were previously compacted, so best practices may vary at sites with different soil textures and composition. Crop rotation can also help to reduce bulk density with planting of crops with different root depth penetration. Another aspect of soil tillage is that it may lead to more rapid decomposition of organic matter due to greater soil aeration. Over large areas of farmland, this has the unintended consequence of releasing more carbon and nitrous oxides (greenhouse gases) into the atmosphere, thereby contributing to global warming effects. In no-till farming, carbon can actually become sequestered into the soil. Thus, no-till farming may be advantageous to sustainability issues on the local scale and the global scale.

Questions & Answers

What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Sustainability: a comprehensive foundation. OpenStax CNX. Nov 11, 2013 Download for free at http://legacy.cnx.org/content/col11325/1.43
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