It's not easy, any more. The ag industry is dying. Formerly, you would go to work washing airplanes, loading chemical, flagging at the ends of fields. You might get a few minutes here and there spraying out a few gallons of rinsate, and after several seasons, you might get a regular or backup seat in a Pawnee.
With so many turbine airplanes being used, fewer seats are available. With the restrictions on the uses of chemicals, less spraying is being done. With the more widespread use of other types of chemical administration (irrigation, ground rigs, systemic agents at the time of planting, etc), less air spray work is required.
With the increases in insurance, it's getting harder and harder to find a seat.
Most places will want to see at a minimum one thousand hours of dedicated ag time. That's aerial application, not just low level, or some kind of flying related to ag. Crop dusting. Getting hired with less than that is possible, of course, but difficult...hard to find.
Regular seats may fly hundreds of hours in a season, but I know operators who are doing in the order of 30-150 hours a season...very hard to get any significant "time" that way.
The overall age of the ag pilot population is increasing. Many pilots won't accept a hot cockpit with little ventilation, the chemicals, the hazards, the lack of benifits, the uncertainty, the seasonality. Ag aviation is a working segment of aviation. There isn't any natural progression in it, or into it. Freight, passengers, scheduled, charter, corporate...all really the same thing with some minor rule changes. But ag is a completely different world, and regardless of your background, plan on starting all over, at the bottom of the pile. There isn't really any other way.
You can buy into an ag business, but the truth is that most farmers are very reluctant to give business to someone they haven't dealt with for at least 20 years. I'm not kidding. Talk to an operator who's been in the area for about ten years, and find out of the locals don't still call him the "new kid." That said, moving into a business (there are plenty for sale: just pick up a copy of Trade A Plane) is only a matter of money...but getting farmers to pay you is another matter.
Crop liability insurance is staggering: many operators won't carry it. One drift claim can kill you. And that drift claim can be miles away. You spray on winter wheat, but five miles west Ms. Peasley's strawberry plants don't look well...a claim goes in. Small thing, but your insurance goes up. Next Mr. Adams claims his trees are sick, also about six miles west...another claim. Your insurance gets cancelled, or you get sued, and the game is over. You lose your home, your airplanes, your business.
Or Ed Gruberman strings an illegal power tap to his tool shed. The same shed that's been sitting in the same barley field you've been spraying the same way for the last ten years. Only he just put it up, and of course didn't tell you (after all, it's illegal). You learn quickly the dynamics of unsupported power lines...they don't snap, but have a lot of give for a long time (two seconds or so) before taking your horizontal stabilizer off or turning you upside down ninety yards away.
You spray Bill Hocking's field, but he doesn't pay you. You got six 55 gallon drums of dimethoate to do his wheat, and he decides to withold the pay. It wouldn't be so bad, but he wanted Asana XL in it, and you already had to pay the Co-Op for both. It doesn't take more than a time or two of this before you're hurting financially...now how do you put a new jug on the airplane, or pay for a new set of brakes or tires? Common, every day stuff for an ag operator. Thin profit margin, praying you make enough to survive the slow season.
How about finding work? You can't put out resumes. Nobody will read them. You need to get in your car, and drive. Keep driving and asking every spray operator you come to, until one hires you. That's what I did. I ended up broken down in a little town in Kansas with two flat tires and a car that wouldn't start, and I had just enough money for a little gas, or some junk food at the local corner store. The spray operator in town hired me and I went to work...put me up in a spare bedroom, else I probably would have starved and been sleeping in a field.
The first season, we lost an airplane and pilot, and each neighbor and competitor was killed. I was eighteen years old, and got thrown into it faster than expected, and it was an eye opener!
As for flying south of the border, the preference is for folks without a blue passport. Certainly with ample ag time. The pay is good, there are some great folks, and what it boils down to is an ag job. It's crop dusting. It involves spraying illicit crops with herbicides in legal doseages. It involves spraying crops for farmers who do not want their crops sprayed. It involves spraying in areas that are not populated by particularly friendly people, who do not have your best interests at heart.
The aircraft are protected. The pay is good. The schedule is great. INL is very particular about who flies for them. Of all the requisites, spanish, etc, the primary one is ag experience. Some retired military personnel with prior experieince in type find an application instructing, but the bottom line is working the airplane, and that requires ag experience...and that's what gets hired.
You can be taught spanish. But INL is not in the business of teaching you to crop dust. Consequently, to have a remote shot, be experienced before applying.
