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Irrigation

• 02-08-2022

It is the technique or set of techniques that allow the artificial application of water: it essentially aims to replace the water consumed by plants in the process of perspiration/evaporation, commonly called evapotranspiration. Plants need a balance of soil, water, air and light.

Watering or Irrigation

It is the technique or set of techniques that allow the artificial application of water:
it essentially aims to replace the water consumed by plants in the process of perspiration/evaporation, commonly called evapotranspiration. Plants need a balance of soil, water, air and light.

The purpose of irrigation is to create optimum soil moisture conditions.

Advantages of irrigated agriculture

• Guaranteed production, not dependent on rain;
• Higher production per unit area.

Possible disadvantages of irrigated agriculture

• Intense cultivation may endanger soil fertility;
• Possible flood damage;
• Salinization hazard;
• The irrigation and drainage channels take up space;
• Costs involved;
• Leaching of nutrients by deep percolation.

Factors that determine the amount of irrigation water:

• Precipitation (Pr).
• Crop Water Needs (CWN) or Crop Evapotranspiration (ET).

 

Irrigation Methods

An irrigation system must take into account:

• the amount of water required for washing salts;
• losses in the transport of water from the source to the field and in the field;
• the water needed for the initial moisture replacement.

 

 

 

 

 

 

 

 

 

Distribution energy	Methods	Procedures
Gravity	Drainage	Level watering Tilted watering Inclined planes Lanes
	Submersion	Beds Basins
Pressure	Infiltration	Furrows Underground irrigation Localized irrigation - drip irrigation - mini-sprinkler
	Sprinkling	Sprinkling (center pivot, hydraulic cannon, flop, etc.)

 

 The choice of one of these systems/methods/processes depends on:

• the quantity and cost of available water;
• the size and topography of the land;
• particularities of the crop to be irrigated;
• climatic conditions of the region in which the irrigation area is located.

Furrow irrigation

• main irrigation system used in our country;
• reduced irrigation efficiency (50 to 60%);
• tomato, maize, sunflower, soybean, tobacco crops, etc.
• bedside flow, adaptation of the terrain to the crop, slope and length of the furrows.

Basin irrigation

• Used in rice cultivation;
• Reduced irrigation efficiency (20 to 40%);
• It is important to consider the sizing and orientation of the basins, irrigation channels and drainage ditches.

 

Sprinkler irrigation

It has gained increasing importance. Each sprinkler distributes a flow of >500 l/h with a watering efficiency of 70 to 80%. The alternatives:
 • fixed or conventional sprinkler
 • center pivot
 • traveler
 • cannon

Center pivot

• preferred alternative for large areas (circular or semicircular);
• Irrigation and fertilization automation (nocturnal);
• Flexibility of operation in different situations (soils and slopes);
• Possible association between center pivot and fixed sprinkler for better use of the area.

Drip irrigation

• The drip irrigation (1 to 12 l/h) and the mini-sprinkler (20-150 l/h) systems have become particularly relevant in tomato crops;
• There is a foreseeable expansion to maize crops;
• Very high watering efficiency =90%;
• Significantly improves the efficiency of water and nutrient use.