The success of drip irrigation depends not only on using quality equipment but also on careful planning, as well as regular operation and maintenance. Byron La Trobe, a technical consultant for Netafim in Southern and Eastern Africa, emphasized the importance of these aspects for achieving higher yields.
When choosing drip irrigation systems, farmers should understand that selecting equipment is only one part of the task. It is critically important to study water quality, soil condition, uniformity of irrigation, and maintain the system in working order to maximize the return on investment.
Before installing a drip irrigation system, farmers must analyze the conditions on their agricultural land. La Trobe recommends knowing both the water quality and the soil characteristics. Water analyses help determine the necessary filtration requirements and suitable water delivery rates through drippers, while soil properties influence the spacing between drippers and the irrigation schedule.
According to La Trobe, conducting such analyses represents a relatively small expenditure compared to the potential costs that may arise from incorrect irrigation system design.
Irrigation uniformity plays a significant role in crop productivity and growth, especially for crops with shallow root systems. Closer placement of drippers promotes better coverage of moist zones, which minimizes dry spots between emitters and ensures a more balanced distribution of water along the rows of plants.
When plants receive the same amount of moisture, root development and nutrient uptake become more stable. However, poor uniformity can lead to some parts of the field being overwatered while others receive insufficient water, causing uneven growth and potentially reducing yield. The stability of water and nutrient supply also contributes to more uniform stem, flower, or fruit development.
Drip irrigation offers a significant advantage during flowering because it concentrates water around the root zone while keeping the surrounding cover and environment for flowers relatively dry. This is especially important when successful pollination is required for a good harvest. La Trobe notes that overhead watering during flowering can create unfavorable conditions for bees, so creating a favorable environment for pollinators should be part of the irrigation strategy.
Water quality can significantly affect irrigation management. Farmers should regularly measure electrical conductivity (EC) in both water and soil, and consult an agronomist if salinization problems arise. Since different crops tolerate salinity differently, the volume of additional water needed to manage salts in the root zone will vary. Additional irrigation also increases pumping costs and raises the risk of fertilizer leaching beyond the root zone. Regular soil and water analysis helps farmers make more informed decisions regarding crop selection and irrigation management.
Given the pressure on fertilizer prices, La Trobe believes that precise fertilization (fertigation) opens up significant opportunities for farmers. Instead of applying fertilizers in large doses at once, nutrients can be supplied over a longer period, ensuring their more constant availability to the crop. Smarter fertigation management also reduces the likelihood of nutrient leaching below the root zone. As La Trobe says: 'Every drop of fertilizer that leaches outside the root zone is a loss of money.'
For suitable crops, thin-walled drip lines can serve as a practical seasonal replacement for thick-walled reusable systems. These lines can be replaced each season, allowing farmers to start with new lines instead of managing accumulated deposits from previous seasons. Nevertheless, proper field preparation is necessary. Farmers must remove prickly weeds, sharp stones, and debris that could puncture the drip lines during installation or during the season. La Trobe also advises considering the use of mechanized equipment for installation and removal to reduce labor costs and prepare fields faster for the next planting.
One of the most common mistakes farmers make is underestimating the importance of filtration. La Trobe warns: 'Never forget the filter.' Poor filtration can lead to clogging of drippers, uneven water distribution, and ultimately, reduced yield. Investing in a proper filtration system from the beginning can prevent costly problems in the future.
La Trobe concludes that success in irrigation boils down to one simple principle: understand your water, understand your soil, and design your system accordingly.