chicob

- First of all, urea as a fertilizer is not completely effective, because some of it will be drained. Urea can be treated for slow release, but this requires processing. And even in this case, some of it will just be degraded by bacteria (some bacteria will turn it into compounds that plants can use, but generally urea content will fall with time).

- I used total nitrogen from urea, but in reality a part of that nitrogen does not come as urea.

- I also used average yields, which depend on the usage of more powerful fertilizers. Fertilizing with urea alone will lead to smaller yields.

Let's say that average yield woud drop to 50% and that I would need not 53 bu 80 people's yearly urine. That would mean I would only provide enough corn for 120 people each year, for a input of 80, which gives a ratio of 3:2. Seems good enough. Unfortunately this is not the case.

Human urea is the result of human diet and metabolism, which gets nitrogen from many different protein sources. Self-sustainability means that those 120 people would have to eat only corn and meat from corn-fed livestock, or trade this for other protein sources (which would only externalize this unsustainability: some other people's diet would have to change). Even if it were possible to keep up with the same urea output without severe weight loss, this would not be enough:

- First of all, plants use nutrients to grow many inedible parts, and that is an important drain of nitrogen. This also means all plants, not just the ones we eat.

- Livestock would still need food sources other than corn. The above assumptions assume well-fed cattle.

Finally, as someone already noted in another comment, human urine contains a significant amount of salt, and without its removal this could lead to excess salinization that would render the soil infertile in the long term. And the higher concentrations of urea needed could also worsen the already present problem of eutrophication.

But using urine might still be a great help with local, temporary unavailability of better fertilizers.

I had some stuff stolen in the past, but never fertilizer.

How many people this would feed is hard to tell, because it depends on the kind of corn. Some corn is meant for human consumption, some other for livestock feed (which in turn is meant for human consumption. But as a rough estimate one can add these two to find an order of magnitude.

In 2008, the USDA broke down the usage for maize, with 133,4 Mton (5250 Mbs) for livestock and 8,3 Mton (327 Mbs) for human consumption. That year, the US population was around 303.5 million people, so that gives an average of 467 kg (1030 lb) a person each year.[3][4]

So those 10 ha would produce enough corn for 240 people for a whole year.[5]

[1] Assuming around 15% moisture content.

[2] https://www.dtnpf.com/agriculture/web/ag/crops/article/2021/...

[3] https://en.wikipedia.org/wiki/Maize#Human_food

[4] https://www.populationpyramid.net/united-states-of-america/2...

[5] I ended up doing the calculation in imperial units, to minimize rounding errors.

Let's say I need 200 kg/ha of a 12-6-6 NPK fertilizer for post-sowing 10 ha of some crop, like corn. (This is a little short of 180 lb/ac for a total of ~25 acres. I'm in Europe, and I don't know what would be a typical value for the US).

This fertilizer has 12% w/w of total nitrogen, so for the total area my needs are 240 kg of nitrogen (~530 lb).

An adult will produce an average of 1,4 L (0.37 gal) of urine daily, with a nitrogen content of 8,83 g/L, so this means a total of 12,36 g/day, or 4,5 kg/year (~10 lb/year).[1]

So I'll need the urine that 53 people pee for a whole year for this single crop. A six tower pivot has something around 4 or 5 times that area. And this area can be used twice a year for different crops. The average US farm has 445 ac.[2]

[1] https://en.wikipedia.org/wiki/Urine#Characteristics [2] https://www.statista.com/statistics/196106/average-size-of-f...

And if plausible deniability from senior management would just add insult to injury, plausibly, claiming that things are taken seriously when things are obviously being neglected is just gaslighting.

Isn't adding a superfluous "and we take those seriously" the rhetorical equivalent of pouting?

Every time I read this - after an account suspension, for example - the impression I get is that no, they don't really take those things seriously. They're just improvising or leaving it for the algorithm.

This doesn't seem logical at all. It sounds like sweeping under the rug. I'm assuming that what is obvious here is that these programs reproduce inequity, and are not a cause of it.

[...] As these scholars argue shutting down gifted programs only deepens the inequities for brilliant, underrepresented students of color and adds another barrier to unlocking their genius.

Does one really need scholars for this?

As a farmer, my advice would be:

#1 Analyze you soil for profile, pH, organic matter and macronutrients. Show the results to a professional and ask for advice. Most lab analyses parameters will stand for a couple of years, so it pays off. Besides, doing the wrong thing once can ruin you soil for decades.

#2 Look around. Is the problem uniform for a wide area or is it just you? Are there any water sources or creeks nearby? Cattle grazing? Is there a history you can check?

#3 Choose your crops having in mind the resources you have. Maybe you soil is terrible for a given crop and quite good for another. Maybe you should just let it be, or maybe not.

#4 Don't go online before speaking to a professional. Avoid guru-based farming/gardening, and be skeptical as a rule of thumb. This applies to my own advice as well.

I know a garden isn't a farm. But still, it's about doing things right and achieving results rationally, isn't it?

https://en.wikipedia.org/wiki/Smart_bookmark

For searching in Hacker news, I saved the URL 'https://hn.algolia.com/?query=%s' with the search key 'hn'. So when I want to search something around here, I just type

    hn something

   https://hn.algolia.com/?query=something

If I don't find what I want right away, I usually assume I am not trying hard enough.

The only exception is I can still easily buy a single piece of fruit.

The rest of the article dissipates this confusion rather quickly.

Stepping back a little, how would one react to a title such as "The illusion of medicine", making the same general argument?

The problem the authors have so perfectly characterized has nothing to do with the emphasis on evidence that medicine requires, but on the distortion imposed on the system by large pharmaceutical companies.

The reality of the obstacles standing in the way of rigorous testing for drug or therapy effectiveness does not make evidence-based medicine an illusion.

In fact, the authors actually make a strong argument in favor of evidence-based medicine, by stating the need to acknowledge these biases. And that the reason for all these biases is greed.

I'm trying to get people interested in developing a model for an open, digital, printable, free textbook, that anyone could access online, download, in full or in part, share, or print if necessary.

The general idea is to create dematerialized textbooks, organized in modules: an officially approved minimum basis, and additional optional modules. Redundancy would be allowed for easy adaptation to local needs. Learning and teaching communities could also make contributions.

Bundles could then be customized or made available in presets. Schools could have their own official bundles, and students could get them in print in libraries, online, and the digital versions would, of course, have open formats.

The best example is that of a Math textbook, that allows for direct translation, and which main contents never get old.

So, for example, LaTeX modules would be made available online, and compiled into one document as needed. Indexes would, of course, need to me made universal in some way. And bundles would get their own UID, for easy sharing.

Today, the available digital textbooks are heavily copyrighted walled gardens, and their licenses expire after some time, so they're broken by design. But their contents are, for the most part, already Commons. So what gives?

When I started writing this comment, I had in mind that the Portuguese Ministry of Education had spent around 40 M€ buying textbooks from large publishers that are distributed for free to students in need, in a voucher system. While checking this, I found recent news reporting that this value, in the Portuguese national budget for 2019, had underestimated the cost by 100 M€ (and that year's budget had a surplus of 0,2% of the GDP...). I expect that an annual sum this large would be more than enough to fund a long term project.

I did not focus much on tractors, though, but automatized irrigation systems that allow remote access and configuration. When choosing my own options, and since I never had the information I needed, I always chose the simplest solution, i.e., local manual configuration without remote access.

Around here the public water supply is remotely controlled, but like an Intranet, via optical fiber. I suspect this has to do not only with poor reception in remote locations but also with security. But water meters are accessed via SIM, I think.

Every time I mention any concerns with security, however, these are met with skepticism. The usual inability to foresee third-parties' motivations, in variations of

"Why would anyone want to interfere with my equipment?"

are very common. And I admittedly lack the skills to raise concerns for this issue past saying that ignorance of threats doesn't make them go away. My only hypothetical case is systematic crop failure due to poor irrigation associated with futures markets that depend on yields.

The article acknowledges that Facebook made mistakes, and that its internal reports prove the company knows the harm it can do to vulnerable teenagers. Then these issues are discarded. Apparently, Facebook even had some growth after all...

But lying to advertisers? This is deemed as unacceptable, and flagged as a possible beginning of the end.

I know this is the Economist, but when it comes to reputational points of no return, I think that vulgar remark regarding early users' trust did the job.

https://www.sciencedirect.com/science/article/abs/pii/S00144...

I'm not sure whether to tag this under 'non sequitur' or ' throwing the baby out with the bathwater'.

I have never witnessed the dynamics of reparation policies. The closest thing we have in Portugal, if it could be so called, is the Jewish Law of Return, a bureaucratic shortcut for granting Portuguese nationality to descendants of 15th and 16th century Portuguese Jews that were forced to flee the country, escaping persecution.

In Portugal, the concept of race has been recognized on the fly, and only in terms of the Constitutional Rights of citizens in the case of discrimination. This might change in the near future. As such, I follow this subject in American politics and news, since the USA are an obvious case-study.

As I see it, the fact that the concept of race is meaningless in anthropological terms, as informative as it can be, is not helpful in fighting prejudice in general or racism in particular. A bit like explaining basic geometry to a flat-earther: in most cases, it is pointless. On the other hand, it seems to me that acknowledging the dynamics of the division of people by racial categories (self-reported or not) is a dead end, and one that might betray its very purpose.

At best, this strategy will sustain the social conscience of the issues of race, without eroding the poisonous constructs associated with it. As in other areas of discrimination, like gender, strategies that favour outcome in detriment of opportunity might have some value to it, as this is a kind of social bailout that could just work. In some European countries, positive discrimination works only as a temporary exception.

But unlike social concepts like gender, or nationality, whose fundamental aspects are less troublesome (there being, as far as I know, no equivalent of transgenderness in race) or whose arbitrariness (like geography) can be critically questioned in different fora, race has the problem of been deep rooted in physical appearance and prejudice.

I don't see how a humanist society can deal in a meaningful way with such a stratification without risking to reinforce racist preconceptions. Am I missing something?

Duh I meant fighting insects. B. thuringiensis has nothing to do with fungi.