Farming without Gasoline or Diesel

Writing about "5 Billion Less People on Earth?" caused me to start thinking about how farming could be done without Gasoline or Diesel on a planetary scale. What I came up with was that if hydroelectric electrical Generating stations and good soil and climate for growing food intersected like it does various places on earth then that would be a plus when there is no more oil  on earth within about 10 to 25 years(depending upon how fast the world uses it up). So, the idea would be to utilize hydroelectric generation by using electrically powered tractors for plowing fields. But one of the problems for this would be really big batteries if the tractor wasn't tethered to a really powerful AC or DC line directly. So, I thought about how this could be done in a practical way. There are two basic ways to do this (or more). One way would be to utilize tractors as they are now and replace the Gasoline or diesel engines with comparable powerful electric motors run by rechargable batteries (or) by building some kind of framework sort of like a light rail system for powering the tractor over the fields.

The second way of doing this might be using something on a very small scale much like a Roomba which has a rechargable battery and automatically vaccums your floor all day while you are at work. So, this device could be rechargable but also might have solar arrays that would automatically fold out when the charge got low so the device could recharge. Such a device would be under 2 or three feet tall and plow the fields and plant and possibly even harvest the food. So, it would replace in a way human plowers, planters and harvesters and basically live in the fields slowly plowing, planting, tending and harvesting the crops. If each device had a solar array to recharge its batteries and this were a relatively sunny climate these devices might work 3 months straight without supervision operating on Artificial intelligence and burning up relatively little power except for power from the sun.

So, if there were no more Gas or diesel on earth we still might grow crops like cane or corn or something else to create ethanol to run tractors to plow and plant as well.

And of course the third alternative that would be used over most of the earth is Horses, cows, water buffalo and anything else that might be trained to pull a plow including humans worldwide.

Later: I also started to think about how Hydroelectric only works if you have enough rain that year or season in the watershed areas of those rivers and or lakes creating enough water pressure to generate electricity hydraulically. So, hydroelectric generation of power worldwide will only work when there isn't a serious drought in that area in progress.

However, as long as most people on earth are aware that there will be NO OIL at all within about 25 years or less this can be dealt with in a more harmonious and less chaotic way through human adaptation.