Hmm, well from personal perspective, being in close contact with farmers who rent my land, I can pretty much assure you bumper crops in grains in this age have more to do with science and hybrids than weather. Sure, fields can be ruined by drought and temperature, but we make up for that pretty easily with mandated maintenance and proper use of chemicals.
Yes and no? I mostly know corn and soybeans, but I think they extrapolate accurrately, to some degree, across the industry. Hybridization. Accuracy. Irrigation.
Hybridized corn is bogglingly robust. Take the corn we planted in the 1950s. Then make it grow taller, faster, with greater stalk strength*, with better root strength, with the capacity to put on more kernels per plant, and the ability to put on some kernels when stressed instead of none. You wind up with plants that will yield more when everything is good, and plants that will resist without total loss a dry year, plants that are still standing after a moderate windstorm. Which is why farmers, particularly ones 60 years old plus are so cynical when people take potshots a seed companies because hybridized corn doesn't plant well year after year like legacy seeds did. It hasn't since the 1950s. It's one of the costs of selective corn breeding. And legacy corn, to put it mildly, sucks. Complaining about kill genes and hybrid vigor is mostly a sign of ignorance of the alternatives.
Herbicide and insecticide controls, be they chemical or GMO, are far more accurate than they used to be. Fertilization is as well. GPS mapping and tracking by computer allows you to identify(probably not every year, that's too expensive) what parts of the soil are low on what minerals. You can then add how much fertilizer you need, where you need it. Remember that adding too much can sometimes be worse than adding too little. Being able to spot map your field is a huge benefit over bigger blanket guesses. I mean, there's still a hell of a lot of guess work and generalization in a given year, but this takes some of that out. The herbicide and insecticide controls reduce effectively the crop's primary competition from weeds as well as its prime predators. Effective control of the European Corn Borer, for example, then plays not only into yields being higher due to lack of damage, but wind resistance as well. Since a plant that has been heavily damaged by that insect is going to either fall over on its own, or fall over in a stiff breeze.
All this stuff does raise average yields, year over year. But as much as we can control insects and weeds that can turn a stressed plant into a non-productive or dead one, as much as we can custom tailor individual strains of crops to the average growing season of a quarter state, as much as we can get closer to providing each plant an optimal soil for growth - you still need the weather. If your spring is muddy and you can't get in the fields in time, yields suffer. If your fall is muddy and you can't get your corn harvested, ears drop. If it's scorchingly hot the week your pollen is tossing, that sucks. Drought resistant is only drought resistant. Not immune. If you don't get any moisture, the crop isn't growing.
Here's really the kick. The plants are strong. They can probably take one or two things going wrong and still come out decent. They can be a little short on rain and have a little insect damage. They can be a little short on nitrogen and the year can be a little windy. It's when you start compounding these stresses on the plants that they fail. Which is why there is so much effort spent on consistency.
While the high-tech stuff sounds the coolest, and gets much of the attention, it's debatable if it is the primary mover of this consistency.
Irrigation very well might be. We've taken millions of acres of fruits, grains, you name it, which are
marginal acres because yearly rainfall is dangerously inconsistent - and we've irrigated them. We can splice genes, but pumping water out of the ground is still perhaps more effective for the raw numbers, year after year after year. And it's going to be a
big problem one of these years. Irrigation is going to have to be tempered in some regards, and we're going to need to make tough decisions around if productive soil or massively unsustainable cities developed in deserts are priorities.
*harvested corn stubble now actually has the nasty habit of destroying combine tires. Those now cost more than they did a couple years ago because they have to be aged before they're sold and mounted. Fresh, unaged, combine tires get destroyed disturbingly quickly.
