Getting Ahead: 4^E

Visualizzazione post con etichetta 4^E. Mostra tutti i post

22.4.16

Innovation in modern farming Class4

11.3.16

Grammar Revision Modal verbs Class4°

Browse the following links and do the exercises

MUSTN'T /DON'T HAVE

MUST/MUSTN'T/ DON'T HAVE/NEEDN'T

OBLIGATION

DEDUCTION

DEDUCTION WEB EXERCISES

3.3.16 What is a NURSERY?

HOW are plants propagated ?

Asexual propagation of plants refers to producing more plants by budding, grafting, or layering from existing plants.

To know something more about grafting and budding read
this interesting paper Plant_Propagation_Methodologies.pdf

Grafting

With the term grafting we mean some different techniques in which a section of a stem with leaf buds is inserted into the stock of a tree.

It is used to reproduct other cultivars, repair injured trees or for topworking an esthablish trees to one or more different cultivars.

Budding

A single bud is used as a SCION.

Budding is the most commonly method used for fruit tree reproduction.

It is done in summer.

Layering

It is the technique in which a portion of an aerial stem grows roots while still attached to the parent plant.

To learn how to reproduce a new plant with layering watch the video below.

26.2.16 COULD

MUST

4.2.16

Fertilisers Class 4

To learn about the damages of over-fertilization on the enviromen click on the word: EUTROPHICATION

And to strenghten your knowledge watch this video:

17.12.15 Soil Structure

Soil structure refers to the arrangement of soil particles separated into units called soil aggregates.

An aggregate is made of solids and pore spaces.

The arrangement of soil aggregates into different forms gives a soil its structure.

The natural processes that aid in forming aggregates are:

1) wetting and drying,

2) freezing and thawing,

3) microbial activity that aids in the decay of organic matter,

4) activity of roots and soil animals, and

5) adsorbed cations.

The wetting/drying and freezing/thawing action as well as root or animal activity push particles back and forth to form aggregates.

Decaying plant residues and microbial byproducts coat soil particles and bind particles into aggregates.

Aggregates are described by their shape, size and stability.

Balance of large and small pores provides for good soil aeration, permeability and water-holding capacity.

Tillage, falling raindrops and compaction are primarily responsible for destroying aggregates

SOIL HORIZONS

Structure is one of the defining characteristics of a soil horizon.

A soil exhibits only one structure per soil horizon, but different horizons within a soil may exhibit different structures.

All of the soil-forming factors, especially climate, influence the type of structure that develops at each depth.

Granular and crumb structure are usually located at the soil surface in the A horizon.

The subsoil, predominantly the B horizon, has subangular blocky, blocky, columnar or prismatic structure.

Platy structure can be found in the surface or subsoil while single grain and structureless structure are most often associated with the C horizon.

References:http://passel.unl.edu/pages/informationmodule.php?idinformationmodule=1130447039&topicorder=1&maxto=10&minto=1

You can see and feel the texture of a soil rubbing a small sample of soil between fingers.

Soil texture varies from CLAY that is fine, through SILT that is medium, to SAND that is coarse.

LOAMY SOIL contains a large amount of organic matter which retains water and provide nutrients to the plants.
SAND AND CLAY SOILS have less organic matter and have drainage problems.

Clay soil is defined heavy
Sandy soil is defined light

Now watch the video and then fill in the chart below.

Sand soil ____________________________________________________________

Loamy sand__________________________________________________________

Clay loam____________________________________________________________

Clay_________________________________________________________________

Sandy loam____________________________________________________________

Silt loam_______________________________________________________________

Loam_________________________________________________________________

Sandy clay loam_______________________________________________________

Silty clay loam________________________________________________________

Sandy clay____________________________________________________________

Silty clay_________________________________________________________________

Now watch this second video and learn how to use the Texture Triangle

30.10.15

The Present Perfect- Class 4

If you want to revise the use of the Present Perfect Tense you can watch the videos (blue tags), refresh your memory about the grammar rules ( red tags) and practice doing exercises ( green tags)