Development of a variable-rate seeding control system for corn planters Part II: Field performance

Abstract

Variable-rate seeding (VRS) is a precision agricultural technology that can properly and accurately adjust the seeding rate according to factors such as soil nutrients, light, and water storage capacity, which can not only greatly increase the crop yield, but also reduce the amount of seed used. Existing VRS control systems, however, are expensive and not suitable for use with a Chinese seed meter. A control system for VRS specifically for China has not yet been developed. This study was undertaken to develop a VRS control system for corn planters that offers flexible planter-unit expansion, is low cost, and suitable for use with a Chinese seed meter. Detailed information about the design and laboratory experiments on the VRS control system were provided in Part I of this study, whereas this part reports the field performance of the system. The field experiments indicated that the developed system, employing a compensation algorithm of seeding lag, can obtain a shorter lag distance (LD); our results showed an average LD of 0.57 m. The seeding accuracy value varied between 96.62 and 99.07%, with an average value of 97.64%. The values of the seeding coefficient of variance ranged from 0.45% to 1.56%, with an average value of 1.04%. The value of the variation of lag distance for zones having 3 boundary shapes (convex, concave, and convex-concave), which assesses the performance of the VRS control system for varying the seeding rates of individual planter units, varied between 0.07 and 0.63%. Compared with systems that control the seeding rate of each row simultaneously, the developed system in this study, which controls the seeding rate of each row independently, had greater precision when seeding in field zones with irregular boundaries.