|Fertigation - a modern agrotechnique that combines water and fertilizer application through irrigation - provides an excellent opportunity both to maximize yield and to minimize environmental pollution.
Fertigation enables application of the nutrients exactly and uniformly, and only to the wetted root volume, where the active roots are concentrated. This remarkably increases the efficiency of fertilizer application and so enables reduction of the amount of fertilizer applied. This not only reduces the production costs but also lessens the potential for groundwater pollution by leaching of the fertilizer.
Fertigation enables the farmer to adapt the amounts and concentrations of the applied nutrients to meet the actual nutritional requirement of the crop throughout the growing season. In order to achieved correct planning of the nutrients supply to the crop according to its physiological stage, so as to achieve the maximum yield and best quality we must know the daily nutrient requirements throughout the growing cycle. These parameters are specific for each crop and climate. The optimal curve of consumption of nutrients defines the minimal application rate of a certain nutrient that is required to maintain a constant nutrient concentration in the soil solution. These data constitute the basis of the fertigation programs for different crops.
Other advantages of fertigation are: (1) the saving of energy and labor; (2) the flexibility in application scheduling (nutrients can be applied to the soil when crop or soil conditions would otherwise prohibit entry into the field with conventional equipment); (3) convenient use of compound and ready-mix nutrient solutions, and those containing small concentrations of micronutrients which are otherwise very difficult to apply accurately to the soil; and (4) the supply of nutrients can be better regulated and monitored. When fertigation is applied through the drip irrigation system, the crop foliage can be kept dry, thus avoiding leaf burn, and delaying the development of plant pathogens.
Drip and microirrigation differ from other irrigation methods, in that fertigation is not optional but is, in fact essential; it provides the only good way to apply fertilizers to the crop root zone. On high-value drip-irrigated crops, such as lettuce, tomatoes, and peppers, fertigation ensures a superior standard of management, for achieving high yields and good quality, than can be provided with other irrigation methods.