Add a little P, get a load more Poo! Part 5: P reserves and productivity!!

More on the reserves of P!

Van Vuuren et al.’s (2010) highlights predicted use of P from 1970 to 2100. Clearly they think that P reserves are going to last a while; they come to the conclusion that:

• There are no signs of short-term to medium-term depletion
• In the longer term, the depletion of low-cost and high-grade resources will have consequences for future production trends
• Given the impact of resource uncertainty on the assessment of risks associated with P depletion, it is important to pay more attention to data on P resources. Uncertainty was found to play a role in data on P production,
• Phosphate rock depletion may lead to concentrating production to a few countries, thus increasing production costs.
• Major reductions in the use of fertiliser P can be achieved by improving plant nutrition management, better integrating of animal manure and recycling P content in human and/or animal excreta

What is most interesting about the article is that it highlights the different scenarios of P depletion; the figures show their findings:

Cordell et al. (2009) also look at the geopolitics; inequality; economics and relative irony of it all – peak oil has received a lot of attention and it is only necessary for energy and cars (I know hear me out!) whilst P is integral to crop growing, and that ever vital necessity that is food.

The figures below (taken from Cordell et al. 2009) include a pretty graph showing Phosphorous sources over time; it just shows how dependant, or as Cordell et al. puts it ‘addicted’ (2009, 292). 

With high grade P reserves being depleted (Cisse and Mrabet, 2004), and our addiction (Cordell et al. 2009), the debate as to where the next lot of P will come from, which just adds to increased food insecurity and environmental degradation due to a potential in greater mining; this leads to:

• Greater energy use – fossil fuels and GHG emissions.
• Greater waters usage and wastage – particularly in countries where safe water supplies are already an issue.
• Rising prices – of P, fertilisers, agriculture and fundamentally the cost of food).

Inorganic fertiliser alone is not sufficient in restoring soil organic carbon (SOC) that forms through decomposition in situ of organic materials , and attaining the highest yields in crop production  (Su et al, 2006; Liu et al., 2010). SOC is an integral part to the soil and provides plants with capacity to grow due to its properties or absorbing water and nutrients. Fertilisers cannot provide that level of SOC; just another benefit of using manure and other waste material to fertilise the soil.

Turnerand Leytem (2004) looked into phosphorous compound sequestration from, of all things, urine. Their success in fractionating the compounds in two steps furthers the research in attaining P from readily available resources, excrement. Admittedly, this is a much more energy intensive way as well as poorly cost-effective; but it opens the doors to greater utilisation and indeed valuation of what we all poop and pee out.

So a variety of sources point to manure and other forms of excreta as a sustainable and beneficial source of P; not to mention an eventual necessary source!

Happy New Year!!! Lets hope there are a lot less cows farting this year!

Add a little P, get a load more Poo! Part 4: P reserves and losses!

Cordell et al. (2009)’s paper on the story of phosphorous is a MUST READ! 

It is packed full of information on the subject… but I will try my best to extract the useful information. Being half Moroccan (half Italian), I can’t help but rub my hands with glee… the largest stores of P are locating in the country (regardless of what anyone says, Western Sahara does not exist in Morocco; we call the southern provinces… moving swiftly on…!) as shown in the figure below from Elser and Bennet (2011). 

This is however a big problem in terms of global securities and power balances. With turmoil in north Africa and the apparent ‘revolutions’ reaching their 1^st birthday, it is more important than ever that food and the fertiliser used, does not fall into the same fate as it did 3-4 years back with the large prices rises in grains (Elser and Bennet, 2011). 700% price rise in P coupled with the price rise signalled a warning light to governments worldwide. However, as Cordell et al. (2009) and Elser and Bennet (2011) note, the world still is not reacting to this train wreck; they can’t even pull their act together on gas emissions and the Kyoto agreement (COP Durban 2011 round of talks).

One thing is for sure is that if we use less, costs will go down and we are less dependent on another out-sourced commodity that everyone needs. If we all became vegetarian, then we would require significantly less P than a meat based diet, and most of the crop can easily be returned to the soil as residue, recycling most of the P used as a fertiliser. Even so; the largest wastage of P originates in the poor application of fertilisers to soils (8 million tonnes, MT). Leeching of the synthetically produced nutrients results in massive inefficiencies in P management; contaminating ground, surface and coastal waters with high levels of nutrients had led to vast amounts of eutrophication.

Eutrophication is when nutrients (either via leeching direct from fertilisers or poor waste management) added to water bodies causes the growth of organisms; algal blooms are a common example of added nutrients altering the natural ecology of a body of water (lake, sea, estuary, etc.). (Smithand Schindler, 2009) The blooms photosynthesis at high rates, starving most other organisms of oxygen (increased when the blooms die and decompose); creating a hypoxic environment.

Please read more on eutrophication in these sites:

• http://rtseablog.blogspot.com/2011/03/eutrophication-mapping-first-steps-that.html
• http://feastingonnaturalresources.blogspot.com/ This blog, by Megan Smith is great! She also talks about agriculture and environmental issues surrounding the wider debate. I highly recommend her post on Coastal Eutrophication – The impact of Agriculture in Chesapeake Bay

Back to wastes of P and as the figure above (Cordell et al. 2009) suggests, 14/17.5 MT of P go to agriculture; of that only 3 MT make it to our forks. 8 MT is wasted through poor application, and of the 3 MT we consume as food, 1 MT is wasted as spoiled food. By just eating within our means we save 1 MT. through better fertiliser management techniques with save an extra 8 MT. It is easier said than done, but through accurate monitoring of soil nutrient levels, we can guage whether or not the land needs to be fertilised, saving energy, money and effort as well as P. Using more natural fertiliser we can solve some of the problems, by no means is sh… poo a panacea for eutrophication/power insecurities/commodity prices/waste management/agricultural productivity and the like, but it is a step in the right direction!

Reserves of P aren't well documented globally, in fact many researches, scientists, geologists and mad hatters disagree as to how much P there is under ground. Cordell et al. (2009) explores this using a number of different scenarios showing just how long it would take, depending on how much P we need, to finally hit the last nail on the head of the coffin that would be global inorganic P reserves. 

Next part coming soon!

Add a little P, get a load more Poo! Part 2: Video time!

This video summarises the main arguments around P, and it's in green (my favourite colour!). I particularly like the part about doing your part whilst sitting...just one letter away from what you're actually doing!

Meat the truth! Documentary Time!

This documentary, presented by a Dutch MP (Dutch Party for the Animals - might be a little biased) explores the role livestock plays in GHG emissions; pretty much what this blog is designed for!

The whole documentary is a great watch, please do!

To eat or not to eat meat… That is the question! Part 1: is it all demand?

When people debate the issue around livestock and the negatives of increasing production of meat and livestock associated products many say we should reduce meat consumption.

REALLY?!?

Now sure, one way we COULD reduce emissions from livestock is to cut down on our sausages, chicken legs and kebabs; after all, less cows and sheep farting, less direct methane emissions. But there are other issues around more animals on the planet that feed our hunger for meat. This paper by McApline et al. 2009 looks at environmental degradation in Colombia, Brazil and Australia due to expanding beef production and the deforestation it causes.

A big issue around emissions from livestock is the fact that there are large indirect GHG emissions from forest clearance and land use changes. The paper looks at factors that have increased beef production and surprisingly, in some countries like Brazil, it is not supply and demand which dictate beef production and emissions; its land prices. Land policy in Brazil has made it more profitable to clear once natural rainforest and keep it clear than let it be. The cheapest way to keep vegetation from establishing again is to regularly cut regrowth… cows are surprisingly good at turning grass into milk, meat, leather and other useful products for human consumption. This not only has a dramatic effect on local ecosystem services and physiography; the global consequences include depletion of the capacity for natural carbon sequestration.

Meat is big business. Curtailing meat production will directly affect the economies which rely mainly on agriculture and the primary sector. This is a controversial topic as if a country is able to utilise its natural resources within its territory for economic means and development ‘at the expense’ of the environment, who are we to judge? We chopped down our ‘oak’ forests centuries ago to fight wars with continental Europe. With the specific driver of meat production in this context being land management, economical profitability and natural lawn mowers; there is an assumption that if the main driver of livestock (beef) expansion being the one stated, then whether you eat the meat or not, there still will be emissions from it, albeit highly inefficient per capita of digestion. In the case of Australia, land management reform in the favour of protecting old growth forests has reduced the profitability in expanding cheap, subsidised (through tax incentives) cattle ranches. This protection has worked, again regardless of whether Sheila or Russell eat steak or love veggie burgers.

However, with all business, it is fundamentally based on a market; therefore demand. If demand for meat (whatever the reason) decreases; then production and emissions would – economically speaking – decrease too.

I will explore more arguments around decreasing dependence on livestock as a food source. However, I am guessing it isn’t as straight forward as I think it’s going to be!

Welcome!

Welcome!

This blog is to inform, amaze, inspire and of course explain the many uses of poo… Now please do not adjust your screens or refresh the page, I did just write poo.

Before we indulge ourselves in the wonders of excretion, understanding of the past is vital to analysing potential solutions of present problems for the future. In this context, methane (CH4) is a significant greenhouse gas (GHG), 20 times more potent than carbon dioxide (CO2) and one way that it is emitted is in the form of cow (and other animal) farts, and the anaerobic decomposition of organic materials, like manure. 

But before all of that! Here is a video that makes light of the fundamental argument that I am making.

Enjoy and I will post again soon!