Drip on maize: Measure and manage for more
by Marike Brits, Netafim South Africa
In an agricultural environment that is posing more challenges by the day, there are factors that the producer cannot control. These factors pose numerous risks. However, by taking full command of every factor that he or she can in fact control, the producer can mitigate many of the risks posed.
This can be done through several positive actions:
- Ensuring optimised soil conditions, improving water and nutrient uptake,
- Reducing weed pressure,
- Improving disease control to create an ideal growth environment which in turn supports higher plant populations and promotes higher yields.
Precision Irrigation to the Rescue
As our industry knows best – well-managed, precise irrigation is a tool with massive potential to manage risk and equip producers for challenges in agricultural production. The advantages of precision irrigation are crystal clear: in short, the achievement of higher yields while saving time and money by delivering the correct amount of water and nutrients at the correct time and in the right place with no waste. The excellent advantages of precision irrigation apply to a myriad of varying topographies, climates, and many other factors.
A look beyond
In Southern Africa, irrigating maize and its rotation crops with drip irrigation is not yet a common practice. However, as we check in with our counterparts at Netafim USA, it is easy to get excited about the potential impact of drip irrigation in the Southern African grain industry.
According to Netafim USA market segment leader for maize, soybean and hemp, Jim Hunt, drip irrigation can be implemented in many different circumstances to deliver a massive positive impact on efficiency and yield. “The easy wins are often on fields with lower quality soil and where decent quality water is easily available.
If you have these circumstances on your farm, you should be considering drip irrigation. The potential impact is, however, in no way limited to these farms.”
Tim Wolf, agronomist at Netafim USA, explains that they will consider water availability, soil type and other factors to determine how drip irrigation can fit into an operation. “Another important factor in success will be the producer’s commitment to maximising the impact of the system. Fact is, if you use drip irrigation to its full potential and you are finely tuned into the needs of the plants, efficiency and yield will increase and return on investment will be rapid,” says Tim.
The team is often approached by producers who have hit a “yield barrier”. The producer needs to get more from his land and resources, cannot expand his land investments and has done all he can to maximise output. “Our recommended solution will be drip irrigation and fine management of the drip system.”
Benefits of drip irrigation
Michael Esmeraldo, Netafim South Africa’s Northern sales manager, reminds us that the precise application made possible by sub-surface or surface drip irrigation can not only limit water stress in crucial growth phases of maize production, but can also ensure optimal nutrient application and bring many other benefits.
“It is important to understand that drip irrigation is more than an irrigation method. It is a management tool that allows producers to ensure precise water application, improve control of fertilizer application, eliminate run-off and evaporation and drive consistently higher yields through improved plant health. As a total field management tool, drip irrigation provides producers with precise control over the root zone environment during the plant’s critical growth stages. Maintaining optimal, uniform soil moisture levels with outstanding aeration while delivering precise quantities of nutrients and water directly to each plant’s root zone,” says Michael.
The team from Netafim USA reiterates this. “To yield the maximum potential of drip irrigation, we must look at drip not only as an irrigation system, but rather a fertigation system or total delivery system. Farmers often ask us what they would need the system for in a high rainfall year. The answer is precise nutrient application and fine-tuned crop management,” says Jim.
The benefits of delivering nutrients through drip irrigation include:
- Delivering well-timed nutrients throughout the season.
- Precise delivery of nutrients to the root zone.
- Lower occurrence of fertiliser leeching.
- The ability to adapt the fertiliser program during the season when necessary.
- Daily access to the plant’s root zone when needed.
A wider range of nutrients can be delivered through drip compared to other irrigation systems.
“Many studies prove the impact of well-timed and structured nutrient application. Understanding when the crop needs which nutrients and delivering those nutrients at exactly the right time is key,” says Tim. It is, moreover, necessary to know how your crop is doing throughout the season. “Do tissue sampling, monitor soil moisture and adjust the irrigation and fertigation plan accordingly,” recommends Tim.
Balance in the Soil
Soil is the “storage” from which plants extract water. If too much water is applied, the storage reservoir will overflow, and water will run off or percolate below the active root zone of the crop. If the storage reservoir drops too low, the plants will be stressed, and yield reduced.
“An ideal point of balance between water and oxygen at which plants will thrive exists for each soil and crop. When farmers irrigate, their aim should be to manage the root zone with precision in order to maintain the perfect soil-water balance to ensure that stress and runoff is avoided. A subsurface or surface drip irrigation system is the perfect tool to manage water application with this in mind,” says Michael.
He emphasises that maize production is extremely weather dependent, which is why fluctuating yields is one of the major risks faced by grain farmers. “By implementing drip irrigation, you can stabilise yields and remove one uncertainty from the equation. This is as it will allow you to ensure that the maize plant has exactly what it needs during specific growth stages.”
It is proven that both irrigation depth and frequency have a significant effect on grain yield. Experts therefore agree that it should be a priority to take control by limiting water deficits in the crucial growth stages when the plant is sensitive to water stress. The need for adequate water during pollination is well documented, but yield is also negatively affected by disease pressure up to and during pollination. A subsurface or surface drip irrigation system helps reduce disease pressure by keeping foliage dry during this critical period. Finally, the yield potential of the pollinated ear is realised during grain filling. During this stage, adequate water application is critical.
The right approach
According to Michael, the conversation in the grain industry must not be focussed on higher yields alone. “We must talk about ways to ensure that farms can be financially sustainable. This is where Netafim believes drip irrigation can help the industry. Through drip irrigation you can increase water-use efficiency to maintain yields in drought circumstances, increase yield per hectare or to irrigate more hectares with the water available to you.”
Jim explains that the exact management approach will differ from farm to farm, and even from field to field. ‘Any approach will however boil down to keeping the soil profile as full as possible at the beginning of the season and throughout the season, as well as delivering the necessary nutrients throughout the season just ahead of when the plants need it.’
The water used by the plant is replaced daily. This allows the producer to maintain the perfect air-water balance in the soil to create a better growing environment. Being able to keep all the necessary nutrients in the plant at a balanced amount is key to high yield and high efficiency.
“What I have learned about crop management through drip irrigation, has made me a better irrigator and fertigator – even with my pivots.” The team at Netafim USA say they very often receives this comment as feedback.
“Many of our customers who adopt drip, already use pivot irrigation. They implement drip irrigation on lower producing fields, or fields where the shape and topography do not allow for pivot irrigation. The adoption of drip tunes them into a higher level of management which helps them out in the rest of their operation,’ says Jim.
Of course, agronomic support and training form a massive part of the success of drip irrigation on these farms. Across the globe, the Netafim team believe that it is not only about the installation, but also offering agronomic and technical support plus training. The Netafim field support model creates the opportunity to help producers become even better at what they do and pay better attention to what the plants need. “These farmers are making significant investments in our systems and they deserve our support in making the system work for them,” says Jim.
“The better drip is managed and the greater the effort towards measuring, the greater the effect of the drip irrigation system will be. We believe the effort and cost of these activities are massively outweighed by the beneficial impact of the information gained.”