### id261664833 crop rotation took a long time to discover > how environmental factors can hamper innovation. Take crop rotation for instance. The core idea of crop rotation is that if you grow the same crop every year, and haven’t invented fertilizer yet, your crops will use up nitrogen in the soil. Next year’s crop is bad, the one after that is worse, and eventually the soil is no longer fertile. The easiest way to fix this is to let fields lie fallow, which means growing no crops to give time for the land to recover. Alternatively, you can plant legumes like clover, which replenish nitrogen thanks to their symbiotic relationship with nitrogen-fixing bacteria. > > Now, imagine you are a generic human around 10000 BC. You’ve just discovered the basics of farming, and have reached an uneasy level of food security. Some bozo is saying you should leave a perfectly good field alone for long term sustainability. Are you going to listen to them? Keep in mind that you don’t know the chemistry, you have no way of learning the chemistry because the right tools don’t exist yet, crop experiments have a long delay to payoff, and you have limited experimentation budget because messing up crops means people go hungry. It’s easy to see why we don’t have evidence of two-field crop rotation until 6000 BC, and four-field crop rotation wasn’t invented until around the [17th century](https://en.wikipedia.org/wiki/British_Agricultural_Revolution). - [View Highlight](https://read.readwise.io/read/01fqpcys627srv7rm9kv3ktdms) - [[Review How To Invent Everything by Alex Irpan#id261664833 crop rotation took a long time to discover|View in Vault]]