Causes of loss of soil fertility?

Question

Causes of loss of soil fertility?

Answer 1

not plowing under and letin it sit fur a year or two every once in a while and water runoff taking away the top soil.and if you plant by the moon signs then you want git  much more out your  crops i reckon now you hear.you want lots of corn? you wait till its a full moon then wait till its three couters  moon then plant. if in you plant on a full moon it will grow tall and pretty but hardly no corn

Answer 2

Take a different look at farming for a second -- more like mining.  Farms are pulling the nutrients from the ground to grow crops.  Much like miners pull ore from the ground.

This is the key cause of soil nutrient loss.

The three key aspects in soil that are need to produce viable crops are nitrogen, phosphorous, and potassium (this combination is often called the NPK value).  These nutrients also are vital to the soils health.

In the 1930s poor farming practices leached the soil of vital nutrients and the over use of inorganic fertilizer lead to the Great Dust Bowl.  The top soil simply blew away, leaving the farms incapable of producing any crops.

Timothy Egan has written an amazing book about this moment in American history called "The Worst Hard Time: The Untold Story of Those Who Survived the Great American Dust Bowl".  There is a good link about the book below (first one).

Loss of soil fertility can also be caused by sever weather conditions like drought, flooding, poor runoff or water flow conditions, and invasive or invasionary plant growth.

The good news is a new farming method called "Precision Agriculture" is helping stop the collapse of soil fertility.  This includes:

"...the process of breaking farm plots into small sections and analysing them to find out what sections need certain fertilizers and pesticides. Chemical applications are expensive, and if farmers can use more exact amounts of what is required, then farming will be cheaper and less damaging run-off will result."

This also means the land will be treated much better as well and become much more sustainable.

Use of crop rotation and the leaving of crop reside on the fields are still used in Precision Agricultural as well, but now play (and this is helpful) a less key role.

Answer 3

planting the same crop year after year in the same spot, loss of top soil, grubs (doesn't directly affect topsoil, but you will have significant damage

Answer 4

hi causes may be if the soil has  been burn or cropped for so long without cropped rotation and the only solution is by adding ammonium nitrate in it which is fertilizer

                            thanks

Answer 5

The two most significant causes are erosion and over-irrigation, but mostly erosion.

Answer 6

Using chemical fertilisers, which only replace a part of the nutrients which are removed by plants, and don't replace any of the natural structure-forming material that keeps the soil alive.

Using pesticides, which kill the good with the bad, so that the beasties that work in the soil get killed as well.

Not adding fibrous material, so that the soil structure can be maintained.

Overwatering, so that the nutrients get washed out of the soil.

Lots of things