science test 3 terán andrea

HOW SOIL FORMS

BY: TERÁN ANDREA

7 “C”

MONDAY, NOVEMBER 24,2014

WHAT IS SOIL?

• SOIL IS THE MIXTURE OF MINERALS, ORGANIC MATTER, GASES, LIQUIDS, AND THE MYRIAD OF ORGANISMS THAT TOGETHER SUPPORT PLANT LIFE. IT IS A NATURAL BODY THAT EXISTS AS PART OF THE PEDOSPHERE.

HOW DOES SOIL FORM?

• SOIL FORMS AS ROCK IS BROKEN DOWN BY WEATHERING AND MIXES WITH OTHER MATERIALS ON THE SURFACE. IT IS CONSTANTLY FORMED WHEREVER BEDROCK IS EXPOSED.

• SOIL FORMATION CONTINUES OVER A LONG PERIOD, AND GRADUALLY SOIL DEVELOPS LAYERS CALLED HORIZONS.

WHAT TYPES OF SOILS ARE THERE?

• CLAY SOIL PARTICLES ARE VERY SMALL AND COMPACT. GARDENS WITH THESE TYPES OF SOIL PARTICLES DON’T WORK WELL BECAUSE THE AIR HAS A HARD TIME GETTING TO THE ROOTS.

• SANDY SOIL PARTICLES ARE LARGE. THE WATER AND NUTRIENTS (PARTICULARLY NITROGEN) QUICKLY DRAIN AWAY FROM THE PLANT ROOT ZONE. SANDY SOIL IS THE OPPOSITE OF CLAY SOIL.

• SILT SOIL IS MADE UP OF FINE PARTICLES. LIKE CLAY THE SOIL HOLDS WATER BUT DOESN’T HAVE GOOD AERATION AROUND THE ROOTS.

IS THE LIFE LINKED TO THE SOILS? WHY?

YES, THE SOIL IS IMPORTANT FOR ALL THE LIVING ORGANISMS, BECAUSE THEY DEPENDS OF SOIL.

• IN A BALANCED SOIL, PLANTS GROW IN AN ACTIVE AND VIBRANT ENVIRONMENT.

• WITHOUT THE ACTIVITIES OF SOIL ORGANISMS, DEAD MATTER WOULD ACCUMULATE AND LITTER THE SOIL SURFACE, AND THERE WOULD BE NO FOOD FOR PLANTS.

• ALSO THE ANIMALS DEPEND OF SOIL BECAUSE THEY EAT THE PLANTS THAT GROW IN THE SOIL.

• THE HUMANS ALSO DEPEND OF THE SOIL BECAUSE WE NEED TO EAT THE VEGETABLES AND FRUITS THAT GROW IN THE SOIL.