The physical properties of the soil are related to the capacity that this has to offer different uses that are of benefit for the human being. For good use, conservation, management and recovery of the soil resource, it is necessary to know the fundamental fundamentals of the physical characteristics of the soil. The productivity of a soil depends not only on its nutritional content, but also, on the physical conditions of the soil, conditions that are sometimes not determined. It must be remembered that the development of the aerial part of a plant depends on the development of the root, which, in turn, will depend on the soil having a good balance of aeration and humidity.

This manual aims to be a guide for students and academics that require the analysis of some physical properties of soils. Therefore, the analytical procedures to estimate and determine, in the field and in the laboratory, the main physical properties of the soil

• Do not throw the floor in the laundry or tarjas. The soil must be emptied in waste containers to be later taken outside.

• Ensure that instruments are calibrated and standardized at their reference point.

• make sure the scales are level.

Help elements in case of emergencies (spills, splashes, spills, etc.). They must be kept in good condition and within reach so that they can use it as quickly as required, as well as properly marked.

Collective protection equipment most common in the laboratory

The laboratory has a series of safety performance elements that are described below and must be correctly marked.

> eyewash

It is a system that must allow the rapid and effective decontamination of the eyes and that is constituted by twice the sprinklers or nozzles capable of providing a stream of potable water to wash the eyes or the face, a battery of provision of an appropriate system , of a system of fixation to the ground or the wall and one operated of foot (pedal) or of elbow. The jet received by the nozzles should be low pressure so as not to cause unnecessary pain or damage.

 

> fire safety equipment

Alarms

The repairs are intended to alert you of the danger that all personnel working in the laboratory and all those who should be familiar with the exact location of the fire alarm that is near your laboratory.

Fire extinguishers

If it is not feasible to control the small fires that occur in the laboratory, due to its location, characteristics, persistence or extension, with fire retardant blankets or wet textiles, it is necessary to resort to fire extinguishers. Extinguishers are apparatuses that contain an agent or extinguishing substance that can be projected and directed on fire by the action of an internal pressure. Since there are many types of fire, which are classified according to the liquid, liquids, gases or metals, they must decide in each case the suitable extinguishing agent: water spray or a jet, powder, polyvalent powder, foam or CO2.

Then, make a series of recommendations, which should be followed systematically in the laboratory.

> Personal habits and clothing:

- It is the responsibility of the laboratory personnel to ensure the proper use of the equipment, instruments, reagents, solvents, samples, tools and materials that are being used by this

-It is advisable to wear long pants and, in general, clothing that prevents substances that may fall from entering the footwear or come into contact with the skin of the legs or feet.