Why Are Service Providers Slow to Adopt Crop Sensors for Nitrogen Management?

Recently, we have seen important discussions about key aspects of precision agriculture. One of these articles, about the value in variable rate nutrition, explains how there is no easy recipe or universal method to do it successfully, even more so when talking about variable rate application of nitrogen. The dynamics of nitrogen in soil and crop response to nitrogen fertilizers is quite complex, varying from place to place and year to year, making it a challenge to apply the optimum rate.

In another article, the author raises general questions about some missing pieces in precision agriculture. Among the questions, there is a discussion about how complex the prescriptions for variable rate application should be. Simple prescriptions, based only on soil testing, for example, are cheaper to implement and easy to understand, but may not account for important factors related to crop response to fertilizers. Recommendations that are more complex will need more knowledge of the area and some local calibration of algorithms.

For nitrogen, time is also very important. Ideally, topdressing applications should consider in-season data to better account for temporal variability, and for that, we need a workflow of data collection, data processing, decision making, and application usually within one week. Scientists have been developing remote sensing tools to make this feasible. Active crop canopy sensors, usually known as NDVI sensors, are the state-of-the-art remote sensing technologies. These sensors have been available for some time, mostly focused on real-time variable rate application of nitrogen. However, there is still low adoption of this technology by farmers. This raises an important question: if conventional methods are not good enough to make variable rate prescriptions for nitrogen application, why haven’t service providers and farmers adopted crop canopy sensors as a better alternative?

A recent paper published in Field Crops Research journal by Colaço and Bramley provides some insights to answer this question. The paper is a review on the use of crop sensors to improve nitrogen management in grain crops. Overall, the studies using crop sensors to guide variable rate nitrogen reported fertilizer savings of 5%-45% with little effect on grain yield. Economical evaluations reported impacts on profit usually ranging between losses of US$ 30 ha−1 and profits of US$ 70 ha−1, with an average profit of US$ 30 ha−1. The lack of consistent evidence of economic benefits is one factor that limits adoption by farmers. About 25% of studies reported economic losses from sensor-based nitrogen applications, but there are some concerns with the methodology used that may explain the results. The following paragraphs include a summary of the authors’ comments plus some personal opinions.

The strategies for using the sensors are divided in two groups: real-time prescription based on sensor values and a local reference; and real-time redistribution based on sensor values and a pre-defined average rate. In the first one, the concept of reference strips is used to determine the deficit of nitrogen in plants that received a normal rate of nitrogen when compared to plants that received nitrogen fertilizer in abundance. In this group, the algorithm includes two variables, the adjustment of the average rate as a function of crop response in that specific place and conditions, and the variable rate application according to field spatial variability.

The second concept is simpler to implement by using a virtual reference concept, which is obtained as the sensor performs readings in the area. Despite the advantage of not needing the N-Rich reference strips, this strategy assumes that the planned average rate is optimum, and only redistributes the fertilizer in the field. In both scenarios of using crop sensors, the shape of the algorithm used to convert sensor values into prescription rates depends on crop type, development stage, and assumptions of underlining limiting factors. All of this will influence the results obtained with variable rates.

What is observed in many studies is that the greatest gains in the use of sensors have come from the better estimate of the average optimum rate, rather than from the variable rate itself. In this scenario, the use of other tools like predictive models of crop response based on historical data and weather forecasts can enhance the chances of success.

Real-time variable rate application of topdress nitrogen fertilizer in cotton and the vegetation index variability map obtained by crop canopy sensors.

Regarding the limitations in methodologies used, most experiments are carried out in small plots, which makes it difficult to evaluate the effects of spatial variability. The allocation of reference strips within the field is also a problem because field variability must be considered. Better results can be obtained using on-farm-trials and management zones, so that reference strips can be replicated in strategic locations, using rates close to the optimum recommended by modeling tools rather than very high rates as sometimes used in N-Rich strips.

One thing that sometimes seems to be forgotten is that the ROI of using variable rate technology is strictly related to the magnitude of spatial variability. There is still no widely used precision agriculture opportunity index to compare how variable are the experimental fields used. Most researchers fail to describe and consider this. In relatively homogeneous fields the improvement of nitrogen management using crop sensors can be expected to be much less important than applying the optimum average rate. In fields with large variations, nitrogen may not be the more important yield limiting factor, therefore the use of a single algorithm is unlikely to provide good results.

In conclusion, there is still a lot to be learned about nitrogen management in each situation and this is an area of research that can be improved by new technologies such as big data and machine learning. It is evident that more data including historical information and multiple sensors, coupled with complex models, are needed to describe crop response to nitrogen application. Moreover, this needs to be simple to use, otherwise the technology will not be adopted.

Leave a Reply

One comment on “Why Are Service Providers Slow to Adopt Crop Sensors for Nitrogen Management?

Sensors/IoT Stories
Sensors/IoTThe Answer to Agriculture’s Daunting Challenges – Soil Sensors
September 20, 2018
According to the United Nations, 9.6 billion people will live on planet Earth by 2050. Feeding these mouths will require Read More
Sensors/IoTSentera Gimbaled Quad Sensor Optimizes Crop Health Data Capture
August 7, 2018
Sentera’s Quad sensor is now available in an integrated gimbal-stabilized package for DJI Inspire and Matrice drones. Featuring four fully-customizable Read More
Industry NewsRanch Systems, IoT Provider Aeris Announce Collaboration Agreement
July 25, 2018
Aeris, a technology provider in the Internet of Things (IoT) space, said today it is collaborating with Ranch Systems of Read More
Data ManagementAgriculture’s Next Breakthrough: New Technologies Are Driving Efficiency, Data Insights
July 3, 2018
We live in an exciting time in agriculture. Not only is technology advancing rapidly, but the understanding and comprehension of Read More
Trending Articles
Data ManagementAre You Using Your Soil to Its Full Potential?
September 14, 2018
Harvest is progressing across most parts of the U.S. and those growers who aren’t already harvesting are gearing up to Read More
Imagery/SensingAgtech: 10 Things I Hate About You!
September 4, 2018
Before you get bent out of shape from the title, remember if you’ve read my articles before you know I Read More
Kansas State University
Industry NewsKansas State University, Topcon Form Precision Ag Research Partnership
August 30, 2018
Kansas State University and Topcon Agriculture are collaborating to develop tools and systems to advance precision agriculture and support farmers. Read More
Blockchain building block graphic
Specialty CropsIs Blockchain the Future of Food Safety?
August 24, 2018
When the Internet Protocol Suite (TCP/IP) was standardized in 1982, permitting the worldwide proliferation of interconnected networks and eventually the Read More
WinField’s Joel Wipperfurth On Empowering Data-Driven Decisions
InfoAg ConferenceOne on One with Joel Wipperfurth, Winfield United
August 15, 2018
Winfield United's Joel Wipperfurth discusses ag technology trends and topics during last month’s InfoAg Conference. Read More
Industry NewsUrtheCast to Acquire Geosys from Land O’Lakes in $20 Million Deal
August 15, 2018
UrtheCast Corp. and Land O’Lakes, Inc. today announced they have entered a binding term sheet for the purchase of Geosys Read More
Latest News
Business ManagementIvy Tech, Farmers Partner to Help Precision Ag Educatio…
September 20, 2018
Harvest time has taken on a new meaning for some Wabash Valley farmers, and Bobbi Hunt-Kincaid hopes her family’s first Read More
Sensors/IoTThe Answer to Agriculture’s Daunting Challenges – Soil …
September 20, 2018
According to the United Nations, 9.6 billion people will live on planet Earth by 2050. Feeding these mouths will require Read More
Data ManagementRainfall Revisited: Accurate Observations and Beyond
September 18, 2018
As a provider of weather analysis and forecast services to the agricultural industry, one of the most common questions I Read More
Business ManagementWhy Is Funding a Challenge for Women-Led Agtech Compani…
September 17, 2018
When it comes to women-led agtech companies the funding discussion never seems to cease. In June after the The New Read More
Mobile Phone in field
Decision Support SoftwareWhy Are 570 Million Farmers Not Yet Using Agricultural …
September 17, 2018
Until recently, using agricultural apps and software was a rare practice among growers. This is now changing. The mass adoption Read More
Data ManagementAre You Using Your Soil to Its Full Potential?
September 14, 2018
Harvest is progressing across most parts of the U.S. and those growers who aren’t already harvesting are gearing up to Read More
Grower Services & SolutionsDeere-Granular Collaboration Produces New Profit Maps T…
September 14, 2018
The newest development from the ongoing John Deere-Granular product development and marketing collaboration is Profit Maps, now available to farmers Read More
DronesOpinion: Combining Two Pluses with the WingtraOne UAV
September 13, 2018
For the every-day consumer interested in UAVs, there is an ocean of products from which to choose. This includes the Read More
AsiaShould Agri-Input Manufacturers Outsource E-Commerce to…
September 12, 2018
Editor’s note: Venky Ramachandran is a contributing writer for PrecisionAg.com’s sister site, AgriBusinessGlobal.com. This article was originally published on LinkedIn. Now, Read More
Industry NewsValley Irrigation Adds Remote Irrigation Management Opt…
September 11, 2018
Valley Irrigation, an industry leader in smart irrigation solutions, has announced enhancements to its remote management technologies. Multi-Year Licensing In Read More
Variable Rate ApplicationVariable Rate Fertigation System Expands with Mobile Co…
September 10, 2018
Building on the success of its Reflex Variable Rate Fertigation system, Agri-Inject has taken fluid injection to the next level Read More
Industry NewsTeralytic Earns Ag Data Transparent Certification
September 10, 2018
Soil analytics company Teralytic has completed the Ag Data Transparent certification, affirming that their data use is private, secure, and Read More
Business ManagementTop 20 Two-Year Colleges for Precision Agriculture
September 10, 2018
Earlier this year, I compiled a list of the 25 best colleges for precision agriculture. It was quite the process. Read More
Industry NewsRaven, Topcon Announce Slingshot API Agreement
September 6, 2018
Raven Industries and Topcon Agriculture announced today a licensing agreement for Topcon Agriculture’s use of the Slingshot Application Programming Interface Read More
Tablet Grower
Data ManagementThe Power of Predictive Analytics in Agriculture
September 5, 2018
Years ago if we would have been told computers, data, and technology would be scattered around every farm there may Read More
DronessenseFly Launches eBee X Drone, Breaks Through 1,000 ac…
September 5, 2018
senseFly today reportedly sets a new standard in mapping tools with the launch of the eBee X. Launched with the Read More
AmericasOn The Scene: 2018 Farm Progress Show Wrap Up
September 5, 2018
Former Monsanto President (now Bayer CropScience Chief Operating Office) Brett Begemann’s opening salvo during his first appearance at a Farm Read More
EventsAg Experts Discuss Big Data Challenges in Agriculture
September 5, 2018
Agricultural experts at a Houston conference praised the advancements in unmanned aerial vehicles, sensors, and data-collecting technology used in precision Read More