The Amish are terrific farmers, they will readily adopt new farming practices. My rough understanding is the reason they don't want electricity is it requires them to be hooked into the power grid, thereby making them dependant on the outside world, "the English". Things like GM and fertilizers, etc. do not require them to be tied into the rest of us. The Amish are a group of people who can probably survive the total meltdown of technology.
Amish are Germanic anabaptists, sort of cousins to the Mennonites, Hutterites, and Dunkards. My mothers mother was a Mennonite so moms aunts, uncles and many of her cousins are as well. The church they went to Friedenstahl(Peace Valley) became smaller and smaller, so they teamed their local relief effort with a neighboring Amish congregation(Amish don't have church buildings, but both the Amish and Mennonites are big on helping out during disasters, the Mennonite Relief is one of the best run church disaster organizations anywhere). My great aunts and their husbands went to the Friedenstahl church, and while that branch of Mennonites had cars and electricity, they could hardly be called worldly. However, the hierarchy of the Amish church found out the two local congregations were partnering, and banned it, saying the Mennonites were too "worldly".
Some of these groups have sort of an audit, in other words, a church leader comes to your farm and audits your books, then tells you what you will give to the church for a given year. Another one of mom's cousins neighbored with a Dunkard(I think, there is another group whose name escapes me in that anabaptist group) they did things like fill silo etc. During his audit the auditor discovered he was working with a non-Dunkard, and informed him this would no longer be allowed. The neighbor ended up quitting the church over it.
Sometimes though the rules have to be bent. I heard a story of an Amish dairyfarmer whose upright silo unloader was powered by a stationary gas engine and a hydraulic pump, then had about a hundred or so feet of hose running to the top of the silo. Something happened and I can't remember what it was that was going to cause him to have to replace all that hydraulic hose, which was very expensive. He was finally allowed by the church hierarchy to get electricity and hook into the power grid, because of the expense of maintaining the old system.