[steve_adams_86]

There was an Oxygen and Nitrogen (I think) injection project here in BC which was attempting to burn out phosphorous from silt during seasonal turnover of the water columns. I recall that it never showed a positive effect on the body of water, though occasionally it was negative. Lots of fish died at one point. After several years the measurements of P in the silt were hardly any lower, but still too high.

I guess the trouble was only what to do with the algae. They expected it leave the lake, bringing the excess nutrients with it. How would you harvest it?

[GeekyBear]

A good way to get rid of excess nutrients is to pick a water plant with ridiculous growth rates (for example, duckweed), harvest and compost it for use in agriculture. Compost will certainly remain in agricultural fields longer than chemical fertilizers do.

[steve_adams_86]

Composted materials also help hold moisture in place!

The trouble is that distributing compost is extremely expensive and it doesn’t release into the soil quickly.

You can truck out tons of dry fertilizer and irrigate with it, getting immediate results through a system you already have on farms. Your nutrient to dollar ratio is far better (in the short term).

You might know this already. My main intent of mentioning that is that I suspect that way of thinking is actually totally misguided. The externalities seem to be far too severe, and damage to soils seems unsustainable as well. I have a feeling if we sucked up the cost of distribution and application of natural fertilizers, in the not-so-long term we might actually see major turn around on several issues related to crops and fertilizer run off.

There is plenty of evidence for it, but the scale of fertilizer needed is insane. No idea how we’d make that shift. Dry fertilizers are incredibly dense forms of nutrients, and they’re so easy to get from factory to plant.

US universities have published a lot of research showing natural fertilizers do yield good crops with better disease resistance, but any farm using them would need to put more money and time into fertilizing and could expect smaller yields. If everyone plays that game, okay… But if a farmer independently decides to, they need to find a market willing to pay more. That’s exceedingly rare.

We need to collectively value this investment, otherwise it’s very hard for farmers to afford the shift. At least, this is based on my limited hobby gardening/researching understanding. Someone in agriculture would know better.

[colechristensen]

Yup, my whole idea is to find a body of water already suffering from overgrowth of one of these organisms, do what you can to accelerate that growth, and continually harvest it.

[lostlogin]

Pretty much every river in New Zealand needs help. Thanks Fonterra.

[colechristensen]

I’m sure someone could come up with an efficient harvesting / filtering strategy. Pick a species that fit the requirements.

After harvesting do something similar to the process in the post. Dry it, pyrolyze, separate carbon goo from ash, bury one, use the other as fertilizer or another useful purpose.