I understand what water and air are composed of and I more or less understand how fire works. But what is soil? If you put your hands in your garden, you will take out very heterogenous stuff, you will get some twigs and bugs which of course are organic matter, but what’s the general brown stuff? Is it organic? Were does it come from and how is it produced? Also collateral question, if earth is organic matter, when the first living organisms came out of the ocean, which were plants, how did they find nutrients?
In: Planetary Science
Soil is primarily made up of:
-very decomposed organic matter that has either been repeatedly eaten, digested, and pooped out, first by herbivores or carnivores and then by detritovores like worms and springtails, and then finally fungi and bacteria, or dead plant or animal matter that was directly decomposed by fungi and microbes.
-Some less decomposed organic matter, like wood bits
-Sand and rocks, and sometimes clay and other minerals.
-Living organisms. bacteria, fungi, slime molds, amoebas, roots, algae, larger critters.
Plants don’t actually need soil, or rather not all plants need soil. There are a large number of plants on earth today that are known as Epiphytes(grow on other plants, like moss or bark) and Lithophytes(grow on rocks), These plants often look very different from your conventional plants due to unusual survival strategies, but they make it work. Over time as they grow, reproduce, and die, their corpses formed the base for soil. Many of these plants were designed to be very efficient in collecting, absorbing, and either conserving water or surviving a lack of water. They would pry minerals from the rocks or bark they grow on, collect trace nutrients that wash off rocks during rain or blow in as dust.
Some examples of these types of plants include many types of mosses, bromeliads, air plants, a wide variety of orchids such as moth orchids, sempervivums, butterworts, many species of ferns like staghorn ferns, and even some cactus species! Even some Fungi get in on the action, such as Lichens. The earliest land plants would have consisted of Mosses and Liverworts alongside Lichens primarily, growing on weathering rock or gravel that released minerals as it slowly dissolved in water, meanwhile without any plants to hold it back, dry areas of the continents would have kicked up nutrient-rich dust and blown it onto wetter areas for these early plants to absorb.
Latest Answers