Development of an Automated Linear Move Fertigation System for Cotton Using Active Remote Sensing

Abstract

Optimum nitrogen (N) application is essential to the economic and environmental sustainability of cotton production. Variable-rate N fertigation could potentially help farmers optimize N applications, but current overhead irrigation systems normally lack automated site-specific variable-rate fertigation capabilities. The objective of this study was to develop an automated variable-rate N fertigation based on real-time Normalized Difference Vegetation Index (NDVI) measurements from crop sensors integrated with a lateral move irrigation system. For this purpose, NDVI crop sensors and a flow meter integrated with Arduino microcontrollers were constructed on a linear move fertigation system at the Edisto Research and Education Center in Blackville, South Carolina. A computer program was developed to automatically apply site-specific variable N rates based on real-time NDVI sensor data. The system’s ability to use the NDVI data to prescribe N rates, the flow meter to monitor the flow of N, and a rotary encoder to establish the lateral’s position were evaluated. Results from this study showed that the system could accurately use NDVI data to calculate N rates when compared to hand calculated N rates using a two-sample t-test (p > 0.05). Linear regression analysis showed a strong relationship between flow rates measured using the flow meter and hand calculations (R2 = 0.95), as well as the measured distance travelled using the encoder and the actual distance travelled (R2 = 0.99). This study concludes that N management decisions can be automated using NDVI data from on-the-go handheld GreenSeeker crop sensors. The developed system can provide an alternative N application solution for farmers and researchers.

<strong>Technological Advancements in Cotton Agronomy: A Review and Prospects</strong>

“…By water efficiency, drip irrigation is the best available technology used in cotton and agriculture generally because it applies the minimal amount of water required for optimal plant growth, saves fertilizer through fertigation, increases cotton yield, and saves labor costs [51,52] . Because of their high water-use efficiency, which supports the sustainability drive, there are recent research efforts to utilize these irrigation systems for autonomous variable rate fertigation using low-cost electronics and controllers and to enhance their satisfactory performance and prospects [53] . Also, in China, where they irrigate about 3.33 million ha of farmland with drip irrigation, continuous research studies are being conducted to improve the irrigation technique for durability and higher performance [54] .…”

“…Also, in China, where they irrigate about 3.33 million ha of farmland with drip irrigation, continuous research studies are being conducted to improve the irrigation technique for durability and higher performance [54] . And because most cotton farms are still furrow-irrigated in many countries (especially in developing economies), the combination of these new more water-efficient irrigation systems with machine learning algorithms, biodegradable PM, vegetation indices computed in real-time with remotely sensed data, and modern electronics presents hope/near-term solution for cotton water sustainability drive [53] .…”

A vision of precision agriculture: Balance between agricultural sustainability and environmental stewardship

“…Continuous and uniform water application across long distances, reducing labor and water usage. (Bell et al, 2022) Center pivot irrigation…”