Why doesn't the earth run out of soil?

Question

Farmers grow and harvest millions of tons of crops every year, but how is the soil used to grow the crops replaced.

I understand that the grain is formed by photosynthesis ( carbon dioxide in the air) but what about the rest of the plant?

It takes its nutrients from the soil doesn't it?

Sorry, I know nothing about agriculture.

Answer 1

the nutrients are what is taken from soil. not the muddy dirt. that is why you can't farm in one area for a very long time. the earth runs out of nutrients and plants die. when the plants die though they decay and become the soil again with the nutrients.

Answer 2

Soil is not lost through plant use as was indicated. It is not lost through wind or water erosion, it is just redeposited elsewhere.

What is lost is the use of the soil.  It can be rendered useless by over cropping or removal of too many nutrients which are not replaced.  Soil erosion , even though the soil relocated, can make soil useless for cropping.  Damage can also be done to the water supply by the soil from the erosion.  One of the major ways soils are lost to agriculture in when it is lost to cities, roads, airports, etc.  The soil is still there under all that concrete, but is lost to agriculture.  The loss of our precious soil to agriculture is a big problem.  There is only a given amount of land.

Answer 3

Wow.... I guess you're science-knowledge deficient then.

Answer 4

Because new dirt is made everyday!  We have a garden and a mulch pile.  Whenever we use vegetables we throw the tops, rinds, peels etc  out in there in a pile.  When my husband mowes, he piles it on top.  The sun cooks it and soon after several months or weeks (depending on how hot its been) underneith the insulation of grass clippings, where once were carrot peels and tops, banana peels and  is dark rich earth.

Answer 5

This is why you rotate crops so you do not completely deplete the soil.  Look up composting as well.

Composting, Crop rotation, theory of matter.....

Answer 6

mastermind is right on the moeny.

Answer 7

Soil formation is a continuous process which primarily comes from the rock.Again plant don't use soil directly but uses the minerals and nutrients present in it. The soil which is eroded from a place gets deposited somewhere else.so there is no question of permanent loss of soil.

Answer 8

every plant/tree gives off waste, winds carries debri.every yr there is a layer forming, and also living things turn back to dirt,dust,clay

Answer 9

composting,ashes to ashes dust to dust

Answer 10

In nature weathering of rocks is a continuous process which is the primary source for the formation of soil which is taking place from millions of years and still continuing. It cannot be noticed significantly as it is a time consuming natural activity.Soil is usually relocated through erosion,wind, crop removal,human activities,it still gets ploughed back to earth in one or the other form but the place where it reaches back the soil may vary!.

Answer 11

Plants don't use up soil.  They use up minerals in the soil.  The minerals are replenished through decomposition, rain, turning up new dirt, fertilizer, etc.

Answer 12

millions of acres of topsoil go downstream to the gulf of mexico via the mississippi river due to erosion.

it took millions of years to create the rich soils of the midwest...we'll never be able to replace it.

the best we can do is use careful farming practices and leave as much organic matter behind. synthetic fertilizers and herbicides are of great concern too.

the richest lands of old times were those found within floodplains where new silt and mud replensioned the agricultural landscape...now we do our best to prevent floods...how will the minerals from mountain erosion make it to our farmland is a huge concern!