3 ms·

If you don't irrigate during the day in hot climates some crops will die, and the yields will be terrible for most.

Jedd 3y ago
> If you don't irrigate during the day in hot climates most crops will die That is clearly not true. Most crops are fine with watering after sunset / before sunrise.
- peterleiser 3y ago
  Fair. I just edited my comment because I combined two concepts and muddled them together. It's more common to suffer a poorer yield than total crop loss. But crops like tomatoes can die from lack of water during high heat days if the heat lasts for several days. Also, irrigating only at night (not just evening, but over night) can contribute to fungal and disease issues with some crops.
  - Jedd 3y ago
    Sure, cucurbits and solanaceous crops and prone to humidity / water induced fungal attacks. Tomatoes are better watered at ground level (refer other thread about drippers) or even just flood irrigation. Tomatoes are actually pretty robust, if you grow them properly. The way I was taught to maximise survival / yield in hot climates is to grow as seedlings for a few weeks, until they're maybe 30cm or so tall. Dig holes ~ 25cm deep, flood / drain / flood / drain - and then take all but the upper few branches off the seedling, and plant, backfill with soil, so about 5m is above-ground. Because they have adventitious rooting you've effectively just given them a massive reservoir of water retention. This is obviously expensive at scale (though not intrinsically infeasible) but works superbly well in hostile, arid climates. I expect the next decade or two will force a lot of changes to the way food is grow in already marginal climates.
fbdab103 3y ago
Doesn't that mean we should stop growing crops in such regions?
- looofooo0 3y ago
  Permaculture maybe possible
- _heimdall 3y ago
  It means that method of farming is a bad fit for that climate, yes. Its a much more complex problem though. Most farms in the US depend on debt and subsidies to get by. That money comes with strings attached, from the yield required to cover expenses to subsidies that require mono-cropped fields that basically sit idle in the off season or when a crop fails. There are different techniques that could be used, but none of them will match the sheer tonnage of yield from a mono-crop drenched in fertilizer, herbicides, and laid out in a way that allows for massive tractors and combines to be used. All of these methods cause huge damage to the land, but again I'd argue we've left those farmers with little to no choice in the matter given how our food system is designed.
- blendo 3y ago
  No, groundwater is renewable in a lot of places, like in much if the Sacramento Valley, where it rain 20-30” a year. But in the Fresno/Bakersfield area of California, with only 5-10” if rain per year, over pumping is making farming uneconomic. See SGMA https://en.wikipedia.org/wiki/Sustainable_Groundwater_Management_Act https://en.wikipedia.org/wiki/Sustainable_Groundwater_Manage...

Jedd 3y ago

> If you don't irrigate during the day in hot climates most crops will die That is clearly not true. Most crops are fine with watering after sunset / before sunrise.

peterleiser 3y ago
Fair. I just edited my comment because I combined two concepts and muddled them together. It's more common to suffer a poorer yield than total crop loss. But crops like tomatoes can die from lack of water during high heat days if the heat lasts for several days. Also, irrigating only at night (not just evening, but over night) can contribute to fungal and disease issues with some crops.
- Jedd 3y ago
  Sure, cucurbits and solanaceous crops and prone to humidity / water induced fungal attacks. Tomatoes are better watered at ground level (refer other thread about drippers) or even just flood irrigation. Tomatoes are actually pretty robust, if you grow them properly. The way I was taught to maximise survival / yield in hot climates is to grow as seedlings for a few weeks, until they're maybe 30cm or so tall. Dig holes ~ 25cm deep, flood / drain / flood / drain - and then take all but the upper few branches off the seedling, and plant, backfill with soil, so about 5m is above-ground. Because they have adventitious rooting you've effectively just given them a massive reservoir of water retention. This is obviously expensive at scale (though not intrinsically infeasible) but works superbly well in hostile, arid climates. I expect the next decade or two will force a lot of changes to the way food is grow in already marginal climates.

fbdab103 3y ago

Doesn't that mean we should stop growing crops in such regions?

looofooo0 3y ago
Permaculture maybe possible
_heimdall 3y ago
It means that method of farming is a bad fit for that climate, yes. Its a much more complex problem though. Most farms in the US depend on debt and subsidies to get by. That money comes with strings attached, from the yield required to cover expenses to subsidies that require mono-cropped fields that basically sit idle in the off season or when a crop fails. There are different techniques that could be used, but none of them will match the sheer tonnage of yield from a mono-crop drenched in fertilizer, herbicides, and laid out in a way that allows for massive tractors and combines to be used. All of these methods cause huge damage to the land, but again I'd argue we've left those farmers with little to no choice in the matter given how our food system is designed.
blendo 3y ago
No, groundwater is renewable in a lot of places, like in much if the Sacramento Valley, where it rain 20-30” a year. But in the Fresno/Bakersfield area of California, with only 5-10” if rain per year, over pumping is making farming uneconomic. See SGMA https://en.wikipedia.org/wiki/Sustainable_Groundwater_Management_Act https://en.wikipedia.org/wiki/Sustainable_Groundwater_Manage...