Daniel Berglund, a rice farmer for almost 40 years, climbs into his green-and-yellow 2014 John Deere model 8335R tractor in early May, turns on the ignition, and begins his day. As the tractor—which he bought used to save money—rumbles to life, the computer screen to the right of the large black steering wheel lights up, revealing a map of the 100 acres he leases in Wharton County, a sleepy place southwest of Houston’s sprawl. On the map are GPS-generated contour lines indicating where he should create this year’s dirt levees.