Soil Texture Explained Leaving Cert Agricultural Science Soil

Soil Texture - Explained Leaving Cert. Agricultural Science

Soil texture refers to composition of a soil in terms of Mineral Particles. Mineral particles are those derived or created from the breakdown of rock. Sand, Silt, and Clay The % of each will determine a number of characteristics.

Composition The more sand in a soil the better it’s drainage. More sand means the soil has better aeration, higher temperatures, and can therefore be sowed earlier and seeds will germinate earlier. The more clay in a soil the poorer its aeration and drainage. It has a higher chance of being waterlogged. This includes more leaching, poaching, etc. Why? It’s all to do with pore space – the spaces between soil particles.

First of all, check out the relative sizes of each particle Remember the drawings are 2 D, but the particles are 3 D

Question – How many of each could you get into this container?

Sand? How many doesn’t necessarily mean much… But the idea of taking these large spheres, think of them as basketballs… And putting them into a container, what do you notice between the particles/basketballs?

Sand? Pore spaces! Really big ones too… The bigger the pores the more air and water can Pass through freely. The less water in those pores The quicker it is to heat. It also means the soil is more prone to drought!

How about the others? Silt Clay

The smaller the particle… The less pore space there is. If sand is a basketball, silt is a tennis ball, clay would be a very small marble. Imagine a container full of small marbles, there would be next to no space between them. Therefore, clay soils have very poor aeration, drainage and waterlog so easily