Menu

New Sensor Will Help Predict Yield in Bioenergy Crops

A “look-ahead” sensor that converted the bending load of napiergrass to a measure of yield was one of four yield-sensing approaches developed by University of Illinois researchers. The study was conducted in Lorida, Florida and funded by the Energy Biosciences Institute (EBI).

Napiergrass, also known as elephant grass, resembles sugarcane in stature and in methods of propagation. The grass is emerging as a candidate bioenergy crop, but there are limited studies available for napiergrass yield sensing, a technology that could play an important role in implementing precision agriculture and reducing harvesting cost. Alan Hansen, a professor in the U of I Department of Agricultural and Biological Engineering, and Sunil Mathanker, a postdoctoral researcher in the department, worked with colleagues from John Deere and BP Biofuels to field test the four yield-sensing approaches and document their correlation to napiergrass yield.

In this study, a stem-bending yield sensor was developed to fit a John Deere 3522 sugarcane billet harvester. Four load cells were fitted between two parallel pipes to form a push bar. The push bar was installed between the crop dividers about 1.2 meters above the ground and 1.5 meters ahead of the basecutter. The study also investigated the hydraulic pressures of basecutter, chopper, and elevator drives as indicators of yield. Three pressure sensors were fitted to the inlets of the hydraulic motors operating the basecutter, chopper, and elevator on the John Deere harvester.

The sensor that measured stem-bending force was the most accurate among the four methods tested. “What’s particularly good about this sensor,” said Hansen, “is that you’re able to measure yield at the point of entry. This is somewhat unique. In combine harvesters, for instance, you’re monitoring a yield sensor at a point much farther along in the flow of material, where the grain is about to enter the tank at the top of the combine. The delay between when the grain comes in and when it reaches the point of measurement creates a potential for error, and we have to come up with an estimate in relation to the time lag. So having this look-ahead sensor right up front is of significant value.”

While the look-ahead sensor showed the best correlation with yield, Mathanker said there are issues, such as crop lodging, harvester speed, and the ability of critical components to respond to sudden changes in ground speed, that pose a challenge for this sensing approach. Varietal characteristics, harvest time, moisture content of the stems, soil conditions, sensor height, and physical properties of the stems could also influence the bending force experienced on a push bar.

Among the three hydraulic pressure-sensing approaches, the chopper pressure showed the highest correlation with yield. A reasonable correlation was found between the basecutter pressure and yield, although in addition to yield, it was expected that the basecutter pressure would depend on cutting height. Chopper and elevator pressures were less affected by factors other than yield compared to basecutter pressure.

“Based on the results of this study,” Mathanker said, “the stem-bending yield sensor showed potential for real-time napiergrass yield prediction. It can also be used to control operating parameters of the harvester [such as travel speed] and to generate yield maps for precision agriculture. We believe this stem-bending force sensing approach can be extended to other thick-stemmed crops.”

Hansen and Mathanker published their findings in Computers and Electronics in Agriculture 111 (2015). Co-authors of the paper were H. Gan (Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign), J.C. Buss (John Deere, Thibodaux, LA), and J.F. Larsen (BP Biofuels North America, Houston, TX.)

The Energy Biosciences Institute is a public-private collaboration in which bioscience and biological techniques are being applied to help solve the global energy challenge. The partnership, funded with $500 million for 10 years from the energy company BP, includes researchers from the University of California, Berkeley; the University of Illinois at Urbana-Champaign; and the Lawrence Berkeley National Laboratory. Details about EBI can be found on the EBI website.

Source: University of Illinois

Recent News

Disaster Avoided? Reviewing the 2019 Grain Ending Stocks Situation
11/19/2019

Grain markets in 2019 had a familiar feel – a late June rally that faded as concerns about the U.S. corn and soybean crops subsided (see futures prices for corn here, soybeans here). This was especially frustrating for producers hoping for a substantial price improvement after spring planting challenges and record prevented planting acreage. Given Mother Nature’s […]

Soybean Crush Prospects
11/19/2019

The release of the NOPA soybean crush estimates last Friday indicated crush levels picked up substantially in October.  Driven by a moderate export pace for soybeans and a decent crush margin, soybean crush appears back on track for the 2019-20 marketing year For the 2019-20 marketing year, the USDA projects soybean crush at 2.105 billion […]

USDA to Extend Flexibility on Crop Insurance Program
11/15/2019

The U.S. Department of Agriculture’s (USDA) Risk Management Agency (RMA) today announced it will continue to defer accrual of interest for 2019 crop year insurance premiums to help the wide swath of farmers and ranchers affected by extreme weather in 2019. Specifically, USDA will defer the accrual of interest on 2019 crop year insurance premiums […]

Your browser is out-of-date!

Update your browser to view this website correctly. Update my browser now