soil water and plant relationship 1

Question 1

what is soil?

soil water?

Answer 1

soil is the store house of water or is is the system consisting of four phase such as solid ( mineral and organic matter),liquid(water), gas( soil air) and living organism( bacteria, fungi, protozoa, insects and small burrowing animals.)
The unconsolidated minerals and organic matter in the surface of the earth that serves as the medium for the plant to grow .

soil is the suspended water in the surface of the soil near the aeration zone layer enough to be discharged into the atmosphere by means of evaporation or transpiration

Question 2

physical characteristics of soil affecting soil water

Answer 2

soil is the constituent of minerals(45%), Air(25%), Water(25%) and organic matter(5%).combination of minerals and organic matter is the solid part establishing the soil pores. The soil water and the air are held in the pores.

Question 3

soil texture

Answer 3

proportion of sand, silt and clay in the fine earth(2mm).Fraction of the soil particles are determined by particle size analysis (32%sand, 28 % clay,40 % silt).

group- gravel, sand ,silt and clay
sand, silt and clay are called as soil separates( less than or equal to 2mm)
gravel is greater than 2mm in diameter.

Question 4

size limits of soil separates

Answer 4

very coarse sand 2-1mm
coarse sand 1-0.50 mm ISS 2.00-0.20
medium sand 0.50-0.250mm
fine sand 0.250- 0.100mm ISS 0.20- 0.020

very fine sand 0.100- 0.050mm 0.20-0.002
silt 0.50-0.020mm
clay less than 0.0020mm less than 0.002

Question 5

sandy soils
clay soils
silt soil

Answer 5

sandy soils -simple capillary system
(+ve)large volume of non capillary macro pores- good drainage and aeration
(-ve) low water holding capacity and cation exchange capacity

clay soils-complex granules, large surface area( 10ha/kg of soil)
(+ve) hold more water and cations than sandy soils
slow movement of water- poor drainage and aeration

silt soil-light and moisture retention type of soil with high fertility rate
(+ve) medium size particles, well drained and holds moisture well
(-ve) as the particles are fine, get easily compacted and prone to rain erosion

good proportion of sand silt and clay known as loamy soil is favorable for conditions for plant growth , water retention, aeration and contains good nutrient.