Imagine driving a tractor through a field, spraying chemicals to protect crops, only to realize you've wasted gallons of herbicide on areas that didn't need it. Or worse, discovering that uneven application has left parts of your field vulnerable to pests. For decades, farmers have struggled with inefficiencies like these—until with precision spraying solutions these days.
Among those precision spraying innovations available on the market, the precision magic lies in real-time nozzle dosage adjustment and automatic section control on/off, two cutting-edge technologies transforming crop protection in modern agriculture. In this blog, by taking FJD ATS Precision Spray Autosteering System as an example, we'll break down how these two technologies work, their benefits, and why they're important for precise spraying.
Real-Time PWM Nozzle Dosage Adjustment
The core idea of pulse width modulation (PWM) is to regulate flow by rapidly switching nozzles on and off while maintaining constant pressure. The PWM controller sends electrical pulses to the nozzle's solenoid valve. Each pulse cycle has a duty cycle (percentage of time the nozzle is "on" vs. "off"). For example, a 50% duty cycle means the nozzle is open half the time and closed half the time. By varying the duty cycle, the system adjusts the average flow rate without changing the spray pressure.The FJD ATS system applies the PWM-based nozzle dosage adjustment. This means it can achieve a smaller overlap in any area by adjusting the duty cycle of the inner and outer nozzles for turning compensation. By varying the width of the pulses sent to the nozzle's solenoid, the system adjusts the amount of liquid that is released during each pulse, achieving a consistent rate in all areas for efficient pesticide applications.
You can think of real-time nozzle dosage adjustment as a "smart thermostat" for crop spraying. Just as a thermostat adjusts room temperature based on real-time data, this technology fine-tunes the amount of chemicals (fertilizers, pesticides, herbicides, etc.) at each nozzle sprayed onto crops using live field data. Here is how it works in the FJD ATS system:
GNSS Positioning and Sensors
The GNSS receiver maps the field and collects precise location data, and based on this geo data, FMS (a farm management system from FJD) creates a detailed "prescription map" for where and how many chemicals to apply. Then, the ATS system import the precription map from FMS and enables georeferenced spraying together with ISOBUS-Geo, ensuring every drop of spray goes to the right places.In addition, sensors mounted on agricultural sprayers collect real-time data on multiple variables: vehicle speed (to calibrate flow rates), soil moisture (preventing over-application), crop health (via chlorophyll sensors), pest hotspots (using AI cameras), and micro-weather conditions like wind direction. This integrated data stream enables dynamic nozzle control—automatically adjust spray patterns, droplet size, and chemical volume—to precisely match field requirements across variable terrain.
Variable Rate Technology (VRT)
Based on positioning information and sensor data, the PWM controller adjusts nozzle output on the fly. For example, if a part of the field has nutrient-rich soil, the system reduces fertilizer flow. When nutritionally poor plots are detected, it increases fertilizer dosage. This ensures the optimal chemical dosage for each part of the field.Adaptive to the tractor's operational speed, the PWM controller updates the duty cycle of each nozzle to deliver the precise amount. If the sprayer speeds up, nozzles increase their duty cycle to spray more pesticides per second. Upon slowly entering a headland, the duty cycle drops to stop applying chemical use.
Nozzles respond instantly as the sprayer moves, ensuring each plant gets exactly what it needs—no more, no less. By maintaining constant pressure via the PWM technology, the FJD ATS ensures consistent droplet size and spray pattern even as flow rates change.
PWM-Based Spraying vs. Traditional Spraying
PWM-based spraying offers a blend of efficiency, precision, versatility, and performance that makes it a preferred choice over traditional systems in spray applications. Here is a quick comparison to demonstrate its advantages:| Non-PWM Spraying | PWM-Enabled Spraying |
| Flow rate adjusted by changing pressure, leading to inconsistent droplet size | Flow rate adjusted via duty cycle; pressure stays constant |
| Slow response to field variations | Instant, real-time adjustments |
| Higher risk of over/under-spraying | Precise dosage for every square foot |
| More chemical waste | 10%–30% reduction in chemical use |
Automatic Section Control On/Off
Automatic section control is a technology used in sprayers to automatically turn individual boom sections on or off in real time, ensuring chemicals are applied only where needed. This prevents overlapping sprays (reducing waste) and avoids missing unsprayed areas (improving coverage). It’s especially critical for irregularly shaped fields, curved rows, or when making turns at the end of passes.Section control acts like a "smart sprinkler system" for farms. It automatically shuts off sprayer sections when they pass over areas that don't need treatment, such as already-sprayed zones, waterways, or field boundaries. It uses GNSS tracking and geofencing to activate/deactivate boom sections based on the sprayer's position. Here's how it works step by step:
Field Setup
Before spraying, the operator defines the field boundaries using GNSS/GPS or imports a pre-existing field map. The sprayer's boom is divided into sections (e.g., 12 sections, each 3 meters wide). With the FJD ATS, you can control up to 30 spraying sections. That's a big advantage because other brands like ARAG, Tecomec, and Raven only let you control around 13 to 16 sections.
Real-Time Position Tracking
As the sprayer moves across the farmlands, the GNSS receiver pinpoints its exact location within the field. The controller compares this position to the field map and tracks already-sprayed areas and wait-to-spray areas. The FJD ATS also tracks sprayed areas in real time for record-keeping.Section Activation/Deactivation
When the sprayer enters an unsprayed zone, all sections are active. If the sprayer approaches already sprayed areas (overlap) or no-spray zones (e.g., field edges, obstacles), the controller instantly shuts off the relevant solenoid valves. Taking the FJD ATS for example, in a U-shaped field, the inner boom sections turn off during tight turns to avoid double-spraying. At the end of a row, outer sections deactivate to prevent overspray beyond the field boundary.Dynamic Adjustment
The ATS system continuously updates based on sprayer speed, boom height, and obtacle detection. Specifically, faster speeds require quicker valve responses. Based on the height of the spraying boom, the system adjusts timing to account for spray drift. Upon detecting objects such as rocks, trees, or waterways, the ATS turns off the section to stop spraying.Section Control: Manual vs. Automatic
Below is a quick comparison between manual section control and automatic section control:| Manual Section Control | Automatic Section Control |
| Operator toggles sections manually via switches | Sections activate/deactivate automatically via GNSS |
| High risk of human error (overlap or missed spots) | Precision accuracy (±2.5 cm with RTK) |
| Inefficient for complex field shapes | Optimized for curves, contours, and odd geometries |
| Requires constant attention | Hands-free operation |
For a better understanding of automatic section control, imagine a 24-meter boom divided into 8 sections (3 meters each). The sprayer begins a pass along the edge of a rectangular field, with sections 1–8 fully active (green light). When the sprayer reaches the end and starts a U-turn, sections 1–4 (left side) automatically turn off to avoid spraying outside the field, with only sections 5–8 (right side) remaining active to cover the unsprayed area. As the sprayer completes the turn and aligns with the next row, all sections then reactivate.
Better Together: Synergy of Both Technologies
While each technology is powerful alone, their combined use unlocks next-level precision. A sprayer equipped with both technologies can reduce herbicide flow (via nozzle adjustment) and turn on/off sections (via section control) when navigating curved rows or irregularly shaped fields. This dual approach ensures every square inch of the field gets optimal treatment.Many farmers using the FJD ATS systemreported a 10%–30% reduction in chemical costs for weed control and pest management. By adopting precision spraying, they have seen better crop health and yield increases. As governments around the world increasingly penalize chemical runoff, these precision spraying systems help farms stay compliant. This also helps food growers meet consumer demand as eco-conscious buyers prefer food grown with minimal chemical use.
The Bigger Picture: Sustainable Farming
Real-time nozzle adjustment and section control are no longer futuristic concepts—they're technologies farmers are using today to grow more food with fewer resources. As climate change and population growth pressure the agriculture industry, adopting precision spraying systems like the FJD ATS is essential. Whether you're a small family farm or a large agribusiness, the question isn't if you should invest in precision spraying—it's when!Ready to upgrade your spraying operation? Click here to contact us for a tailored solution or feel free to consult our local authorized dealers in your region!