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ARS Home » Midwest Area » Columbia, Missouri » Cropping Systems and Water Quality Research » Research » Publications at this Location » Publication #226624

Title: Development of a Motorized Digital Cone Penetrometer

item CHUNG, S
item JUNG, I
item HONG, Y
item JUNG, K
item Sudduth, Kenneth - Ken

Submitted to: International Conference on Precision Agriculture Abstracts & Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 5/2/2008
Publication Date: 7/21/2008
Citation: Chung, S.O., Jung, I.K., Hong, Y.K., Jung, K.Y., Sudduth, K.A. 2008. Development of a Motorized Digital Cone Penetrometer. In. Proceedings of the 9th International Conference on Precision Agriculture, July 20-23, 2008, Denver, Colorado. 2008 CDROM.

Interpretive Summary: Precision agriculture aims to minimize costs and environmental damage caused by agricultural activities, and to maximize crop yield and profitability, all based on information collected at within-field locations. Soil strength, an indication of compaction, is a factor that can vary considerably within fields and can also greatly affect crop yields. Because of this, farmers and researchers need a quick and inexpensive way to measure compaction. Engineers in the US and Europe have developed automated sensors to meet this need, but these sensors will not work well in the small fields found in Korea and much of the rest of Asia. In this research, we developed an automated digital cone penetrometer to improve the efficiency of compaction data collection in these small fields. The unit was small enough to be moved and operated by a single person, and included features important for collecting accurate data efficiently. Compared to the hand-operated penetrometers currently used, this new device provided more accurate data which would provide better information on which to make soil management decisions. This research will be useful to scientists, crop advisors, and farmers who need to accurately measure soil compaction in small areas.

Technical Abstract: Quantification and management of variability in soil strength, or soil compaction, is an important issue in Korea, but tractor mounted on-the-go sensors that have been developed in the USA and European countries are not practical, due to the small size of typical Korean fields. Therefore, hand-operated digital penetrometers have been widely used in Korea, but maintaining a standard penetration rate and a vertical insertion angle is difficult. In this study, a motorized digital cone penetrometer that could penetrate up to 50 cm was developed. The penetrometer was small and light enough to be transported manually to allow movement on wet-paddy fields and narrow greenhouse inter-rows. The penetrometer included 3 cone tips to reduce data collection time, an electrical motor to push the cone tips into the soil, an encoder to measure penetration depth, a frame and rubber wheels, and a central processing unit to control the motor and to log sensor data and DGPS position. The prototype sensor detected vertical CI variations and peaks similar to a hand-operated commercial unit. Data from the prototype contained fewer errors, represented actual soil strength levels better, and reduced nugget variances significantly, due to its ability to maintain a stable penetration rate and angle.