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Remote sensing for nitrogen: Protect your crops and the bottom line

When it comes to the long list of nutrients that help corn grow, nitrogen is a heavyweight. It helps a plant develop protein and amino acids and helps boost chlorophyll production.


In fact, nitrogen is the most yield limiting nutrient in corn production.


Establishing an effective nitrogen management plan is critical. Adjusting that plan based on your yield potential and what you are actually getting from your fertilizer, soil, or other sources in the environment is even more critical.


Traditionally, much of this planning has been based on farmers’ gut feelings, what’s worked in the past, or nitrogen models/algorithms. Most of those algorithms (usually from university extension offices) aren’t tailored to each field’s unique potential, though.


But with better technology, farmers can use data to adjust and optimize their nitrogen application strategy during the growing season. Imagery is an increasingly important piece of that technological puzzle. As the quality of remote sensing for nitrogen continues to improve every day (especially for use in agriculture), it can be an effective tool for nitrogen monitoring and management.


But first… why is it important to monitor crops’ nitrogen status?


Without appropriate levels of nitrogen, your crops will struggle. When there’s not enough nitrogen, you could be looking at discoloration of plant leaves, thin stands, and stunted growth. But too much nitrogen in the soil, and plants could be more susceptible to certain diseases or pests. Too much nitrogen can also burn plants or harm microbial communities in the soil.


So, keeping an eye on nitrogen levels is crucial for any farmer who wants to maximize their yields and their profits. (And we don’t know many farmers who aren’t in the business of maximizing yields and profits.) Monitoring nitrogen levels means you can more effectively disperse fertilizer when and where it’s needed to keep crops healthy.


Different fields within the same farm might also need different levels of nitrogen, so it’s also important to monitor on a field-specific level.


How do you monitor crop nitrogen availability?


Sending samples to a lab is the most common method for monitoring nitrogen in the soil. This can look like either soil or tissue sampling:

  • Pre-sidedress nitrate/nitrogen test: This test is becoming more common, and involves taking a soil sample before sidedress to inform the rate of application. Some farmers also sample throughout the season, but it’s rare.

  • Leaf tissue sampling: In this common strategy, farmers collect plant leaf tissue and send it to a lab for results.

However, when relying on a lab, you could be waiting multiple days for answers. Shipping is often slow, and the actual turnaround time at the lab isn’t fast enough. By the time you get results, a potential nitrogen deficiency could have escalated beyond repair and resulted in unrecoverable yield loss.


In addition, soil and tissue sampling aren’t proactive. They don’t include techniques for actually getting ahead of problems in the nitrogen cycle or predicting what’s happening in the plant. This is where the growing field of satellite imagery and remote sensing for nitrogen can be a game-changer.


How can imagery be used for nitrogen management?


When corn plants are nitrogen deficient, they have a lowered ability to photosynthesize at maximum capacity, may struggle to build biomass, and have less energy to put into reproduction.


These symptoms are often impossible for farmers to actually notice. There’s no flashing sign in your field telling you a plant’s photosynthesis rate is down. But what if you had a bird’s-eye view over your whole operation that could tell you that information?


That’s exactly what satellite imagery can do. Imagery can quickly detect changes in photosynthetic rates, which correlate to nitrogen status. With this imagery data in your hands, you can make more accurate — and proactive — decisions about which pieces of your field might need a little more love (nitrogen) or where you might need to dial back your applications.

Rather than wait for leaf tissue sampling results from a lab, growers with N-Time™ can use satellite imagery as shown above to monitor the nitrogen status of their fields. This allows them to anticipate a nitrogen deficiency and react quickly with timely application.

Benefits of using imagery for nitrogen management


More and more farmers are turning to satellite imagery to help them make decisions about their operation — including when to apply nitrogen fertilizer.


Using imagery (instead of just relying on test strips or labs) means:

  • Minimal labor for the farmer: No more collecting soil samples, pulling leaves, or mailing packages to the nearest lab.

  • Faster updates: Imagery is being updated in real time — and won’t make you wait days for data.

  • Higher precision: With faster updates comes more accuracy. And with more accurate info at hand, farmers can make better decisions for their field and their bottom line.

  • More proactivity: Imagery can help you recognize when a nitrogen imbalance is becoming a problem — up to a week before the crop even shows any symptoms. It doesn’t just alert you after it’s already causing issues to your crop.

How fertigation uses imagery for nitrogen management


Fertigation—which involves applying fertilizer (most often nitrogen) from an irrigation system—is already an efficient process. But imagery can optimize your nitrogen management even further.


With combined shipping and wait times of multiple days at soil or tissue sampling labs, conditions may have already changed when you get results back. And by the time you receive that data and go to fertigate based on it… it might not even be the best route anymore.


When nitrogen recommendations are based on real-time imagery, you can trust those recommendations are still accurate by the time you get them.


This is exactly what we do at Sentinel Fertigation: turn satellite imagery into insights about nitrogen management. Then we help farmers turn that insight into action — when, where, and how much to apply with the script to make it happen.


Sentinel’s N-Time™ software analyzes imagery in real time, quantifies nitrogen status of your crops, and identifies areas of potential concern. So you get to stay one step ahead of crop nutrient needs (without actually having to sift through the imagery data yourself).


Farmers using N-Time™ have saved up to $40/acre in nitrogen costs — translating to hundreds or thousands of dollars in savings, depending on the size of your operation.


If you’re ready to use the power of imagery on your farm, reach out to our team today to learn how N-Time™ can optimize your nitrogen management plan and your bottom line.

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