The best modern farm equipment can grow alternate crops in alternate rows. It can be done in a way that is sort of mix between what had historically been done by using seasonal crop rotation and planting trees as wind breaks.
The system works by using a high precision DGPS system so the tractor wheels are in the same spot every year so the rows stay in the same places. The hills can also be mapped so that the side of a hill may get processed first or last in a season and the amount of fertilizer or planting depths of crops can be adjusted for optimum yield or land protection.
Many of the California farming areas were settled after people left the mid-west dust bowl. Most of the dust bowl problems were a result of not using the best farming techniques when a drought worsened and it took lots of time to rebuild those areas. Those areas also get massive amounts of rain from time to time from hurricanes hitting the Gulf of Mexico. California doesn't have that advantage.
Another odd thing is there seems to be some connection between early crop failures in the midwest that predate the dust bowl and those crop failures started screwing with the futures markets which some have claimed was the start of the stock market crash and great depression.