Re: Beginner Looking for some help with simple Tracking Robot
If there will be a PC on whatever it is that is connected/supporting the seed planting gantry, and this PC has an internet connection and an available USB port, then (unless you want to build your own) an Arduino (or older version) with a Motor Driver Shield would probably be the quickest and cheapest way to get going. The L298 dual H-bridge motor driver IC on the motor shield can provide up to 2 amps for each motor and there should be many different code examples online for using the shield with an Arduino. Basically, you would program the Arduino to control the motors based on sensor input and a serial data stream from the PC (TTL UART on the Arduino to USB via the onboard FT232RL or ATmega8U2 depending on Arduino model). The sensor feedback (if any) would hopefully prevent malfunctions and could easily be sent back over the serial line to the PC to be sent to the remote control station. You also can easily control hobby servos via PWM channels on the Arduino (plenty of code examples online).
If you do not have a PC to access, you could instead use the TXD and RXD of the UART on the Arduino (broken out to the header) to connect to a radio transceiver module with a TTL UART (XBee being very popular but requiring level conversion from the Arduino's 5V to the Xbee's 3.3V, with some very long range/low baudrate versions available).
Please pardon the pedantry... and the profanity... and the convoluted speech pattern...
"You have failed me, Brain!"