With increasing pressure on farmers to optimise water usage, drip irrigation is gaining popularity, especially in citrus farming. Recent innovations, such as reducing dripper emitter delivery rates, offer new avenues for improving irrigation efficiency by minimising water waste while ensuring crops remain well-watered.
The Concept of Low Flow Drip Irrigation
Low flow drip (LFD) irrigation systems, where dripper delivery rates are less than 1 litre per hour, have been widely adopted in South Africa’s citrus industry. These systems aim to reduce water drainage and enhance water retention within the root zone, promoting efficient water usage. By lowering the emitter delivery rate by up to 70%, LFD maximises water retention in the soil, preventing water loss through deep drainage. This improves irrigation efficiency without compromising crop health.
Trial Insights: Evaluating Water Balance
A detailed study in a ‘Nadorcott’ mandarin orchard in Nelspruit sought to quantify how lowering the dripper emitter rate influences water balance and irrigation efficiency. The trial examined five different treatments, each with varying delivery rates ranging from 2.3 L/h to 0.7 L/h. Results from this trial clearly demonstrated that lower delivery rates significantly decreased drainage below the root zone and increased the amount of water retained in the active root zone. For instance, the 0.7 L/h treatments displayed higher average water content in the root zone, reaching up to 92% compared to 87% for conventional drip systems, indicating that LFD stored more water where the plant roots could access it, improving overall water efficiency.
Wetted Area and Soil Moisture Distribution
The distribution of soil moisture plays a crucial role in determining how effectively water is utilised by crops. The trial showcased that reducing the delivery rate resulted in a larger wetted area within the root zone. For example, the LFD system (0.7 L/h) showed 59% of the root zone had plant-available water compared to only 51% for conventional systems (2.3 L/h). This expanded wetted area translates to more efficient water use and less waste, as water is stored closer to the plant roots where it can be absorbed more effectively.
Maintaining Yield and Crop Health
One of the most notable findings of the trial was that despite the different delivery rates, no treatments showed signs of stress, demonstrating that even with reduced water delivery
rates, LFD systems provided sufficient moisture for optimal plant growth. Farmers can, therefore, adopt LFD irrigation without worrying about compromising the quality or yield of their crops, making it a reliable and efficient option for citrus farming.
In Conclusion
Lowering dripper emitter delivery rates offers an effective strategy for improving irrigation efficiency. By reducing drainage and, in turn, increasing water availability in the root zone, LFD systems present a viable option for farmers aiming to optimise their water usage. As the demand for sustainable agriculture grows, embracing such technologies will help secure the future of farming, ensuring crops are well-watered while conserving precious water resources.
For further information, visit Citrii Software or book a consultation: + 27 76 449 3891
