Steve Solomon grows vegetables in an area about 2,000 square feet in size (about 2,700 feet if paths are included) to feed himself and his wife half of their daily calories.  He is currently able to use copious soil amendments and irrigation, and also benefits from gardening in an area where the soil doesn't freeze solid in the winter.  Without those advantages, Solomon estimates that he could need as much as 9,000 square feet to feed his family.  If he wanted to include potatoes and sweet potatoes in his garden to fulfill more of his food requirements, he would add another 1,000 to 1,500 square feet for a total of a tenth to a quarter of an acre to feed two adults.

In addition to this garden area, Solomon sets aside another area of equal size and rotates his entire garden every three to five years.  He argues that if you live in an area where the ground doesn't freeze solid in the winter, disease and insect infestations will build up to a point where your yields begin to decline after a few years, even if you rotate crops.  So he manages a ley equal in size to his current garden, where he grows grass and clover, cutting the greenery a few times a year and letting the clippings rot into the ground to increase the soil's fertility.  After a few years, he tills up the ley and turns it into garden, then sows the old garden into a ley.

This is one of the areas where I wish that Gardening When It Counts went into a little greater depth.  While I agree that people have been letting land lie fallow and rotating vegetables through these areas at intervals for a long time, I wonder whether a permaculture approach could result in a garden ecosystem that was resilient enough to prevent disease and pest outbreaks.  I'll discuss in a later post how Solomon uses a mixture of seedmeal, lime, guano, and kelpmeal as his primary fertilizer and only adds a relatively small amount of compost.  If he added more organic matter to his soil every year, would this whole garden rotation be unnecessary since the plants wouldn't get micronutrient deficiencies and would be healthy enough to resist diseases and pests?  The necessity of tri-annual tilling using Solomon's method turns me off, but I can't say for sure whether my method will be any better since this is only our fourth garden year.