The irrigation of the cultivation of the potato supposes, approximately, 15% of the total fixed expenses of exploitation, what does that it is of vital importance do a better management of the water, since it has a positive effect on the yields of the exploitation.
The potato is a demanding crop in water, requires constant water availability to ensure the yield and quality of the tubers, but at the same time requires well drained grooves to avoid prolonged puddles.
The yields are conditioned by the lack of water in three critical moments:
– Nascence. The lack of water in this period reduces the formation of stolons and, therefore, tubers.
– Start of tuberization. Tuberization begins approximately one to two weeks before flowering. It is the time of greatest water needs, but the lack of water causes the delay in the formation of the tubers, so that potatoes of smaller size will be produced.
– Tubing. The shortage of water at forty or sixty days after flowering causes less thickening of the tubers, less production and physiological alterations. On the contrary, the lack of water in the maturation period increases the dry matter content and accelerates the maturation, allowing earlier starts.
The cultivation of the potato allows the use of any irrigation system, although it is mostly irrigated by sprinkling, localized or drip irrigation has advantages over others.
– Optimal use of water.
– Better adaptation to fertigation.
– Reduction of the risk of diseases by not wetting the foliage.
– Reduced dependence on climatic factors, especially wind. – Better adaptation to any topography (slope, shape of the plot).
– Easy system automation.
– Reduction of energy expenditure.
– Does not interfere with other tasks. Gravity irrigation is increasingly disused because water consumption is higher and because irrigation modernization plans are replacing this irrigation system with irrigation to demand, more convenient for the farmer and more efficient.
The efficiency of the different methods of irrigation, expressed in percentage of use of the water used to irrigate, is:
– Sprinkler irrigation: 80% theoretical efficiency.
– Cannon irrigation: 70% theoretical efficiency.
– Drip irrigation: 90% theoretical efficiency.
– Irrigation by gravity: 50% theoretical efficiency.
To calculate the irrigation dose and the interval between waterings, a number of factors must be taken into account: water, soil, field capacity, wilting point, evapotranspiration, cultivation coefficients, water needs, efficiency of the irrigation system, etc. so there is always water available for the plant in the profile where there is greater root growth.