HOw much Nitrogen do you need to grow corn? you'd be surprised....

[JohnWxy]

ONe of the most important techniques to reduce NItrogen use is testing the soil before you apply Nitrogen to determine how much you really need to add. Most farmers don't do this even though it's easy and cheap to do.

A study was done in Iowa see how much NItrogen they really needed to add to their fields with 70 farmers participating. All the farmers tested the soil before applying NItrogen to HOw much difference did it make in terms of NItrogen applied to their fields? On average the farmers reduced their nitrogen application rates by 46% That's no typo forty-six percent. And thats with a very negligible affect on crop yield.

Nitrogen is one of the significant contributors of GHGs in the ethanol production process. cutting Nitrogen application by nearly half would make a significant improvement in the reductions of GHGs by Ethanol compared to gasoline.


They conducted a study in Iowa, with 70 farmers participating. The far

http://www.ewg.org/reports/Nitrate/nitratealts.html

"In the largest test, conducted by 70 farmers participating in an Iowa Natural Heritage Resourceful Farming demonstration project, fertilizer use was reduced by 46 percent, with less than a one percent decrease in yields."

Also, farmers add quite a bit of Lime to counter-act the acidification caused by large doses of NItrogen. So reducing NItrogen use this much would significantly reduce lime application rates too.

[Warpy]

1. Native American farmers generally used

companion planting. Maize was their staple grain, but its ability to leach nitrogen from soil was well known (although they didn't know it was nitrogen). They compensated by growing beans in among the corn plants. The roots of legumes fix atmospheric nitrogen into the nitrates that nourish the corn. The three things you'd find in their fields were their staples of maize, beans and squash.

It's a little more efficient than the 3 field method used in Europe, one field for grain, one for legumes and veggies, and the third fallow, used to pasture an animal whose droppings would supply the nitrogen for the following year's planting. An alternative would be to plant a nitrogen fixing crop like alfalfa in the fallow field and digging it under the next year.

Companion cropping isn't conducive to mechanized planting and harvesting, at least not yet, and field rotation isn't commercially viable for most farmers. As chemical fertilizer becomes increasingly expensive, farmers (including ADM) are going to have to revisit the concepts.

[GliderGuider]

2. Does anyone know if experiments have been done using charcoal?

Tilling in charcoal to create the analog of "Terra preta" as found in the Amazon rain forest can apparently improve the productivity of most soils, some by up to several hundred percent. The charcoal stays in the earth for hundreds and possibly thousands of years, making it an ideal carbon sequestration mechanism as well as a growth enhancer. You could possibly get the whole process of ethanol production to a carbon-negative balance by both eliminating artificial NG-based fertilizers and using charcoal made from fast-growing trees like coppice willows and poplars as the "fertilizer". Since I'm not a fan of ethanol, I'll just say that this technique will work just as well on food crops - reducing the fertilizer requirement while sequestering carbon.

http://www.css.cornell.edu/faculty/lehmann/terra_preta/TerraPretahome.htm

[XemaSab]

3. Interesting idea...

Probably commercial application of nitrogen ultimately depletes the soil by providing extra nutrients for soil microbes which also "eat" carbon.

[JohnWxy]

4. very interesting.

[piedmont]

6. It would add carbon to the soil, which is a good thing, but not nitrogen. nt

[GliderGuider]

7. It does more than just add carbon.

It provides a growth matrix for a whole lot of micro-organisms that condition the soil in different ways.

According to a company called Eprida that is commercializing a combined biofuel/charcoal/fertilizer process:

The Eprida technology uses agricultural waste biomass to produce hydrogen-rich bio-fuels and a new restorative high-carbon fertilizer (ECOSS) ...In tropical or depleted soils ECOSS fertilizer sustainably improves soil fertility, water holding and plant yield far beyond what is possible with nitrogen fertilizers alone. The hydrogen produced from biomass can be used to make ethanol, or a Fischer-Tropsch gas-to-liquids diesel (BTL diesel), as well as the ammonia used to enrich the carbon to make ECOSS fertilizer.

We don't maximize for hydrogen; we don't maximize for biodisel; we don't maximize for char...By being a little bit inefficient in each, we approximate nature and get a completely efficient cycle.

From this link:

Claims for biochar's capacity to capture carbon sound almost audacious. Johannes Lehmann, soil scientist and author of Amazonian Dark Earths: Origin, Properties, Management, believes that a strategy combining biochar with biofuels could ultimately offset 9.5 billion tons of carbon per year-an amount equal to the total current fossil fuel emissions!

This approach seems to hold a lot more promise than marginal technologies such as PV and fusion :think:

[Dead_Parrot]

9. I think piedmont was referring to charcoal

Charcoal and biochar are two different substances (and terra preta is different again). I think the micro-organisms are probably the key (present in terra preta, encouraged by biochar, and not really helped by pure charcoal) but there seems to be scant research on this that I can find.

[piedmont]

11. Yes, I was referring to the charcoal mentioned up-thread

I'll say again: charcoal alone does not add nitrogen.
This bio-char stuff looks promising, but the N content comes from adding ammonia to it. Ammonia requires energy to produce from atmospheric N2. The company says though, that 30% of the H2 produced by the process is enough to provide the energy for the ammonia production. Sounds promising.

[GliderGuider]

12. "Biochar" is just charcoal

From the web site of Johannes Lehmann, who I cited above,

Inspired by the fascinating properties of Terra Preta de Indio, bio-char is a soil amendment that has the potential to revolutionize concepts of soil management. While "discovered" may not be the right word, as bio-char (also called charcoal or biomass-derived black carbon) has been used in traditional agricultural practices as well as in modern horticulture, never before has evidence been accumulating that demonstrates so convincingly that bio-char has very specific and unique properties that make it stand out among the opportunities for sustainable soil management.

The benefits of bio-char rest on two pillars:
1- The extremely high affinity of nutrients to bio-char
2- The extremely high persistence of bio-char

These two properties (which are truly extraordinary - see details below) can be used effectively to address some of the most urgent environmental problems of our time:
1- Soil degradation and food insecurity
2- Water pollution from agro-chemicals
3- Climate change

The addition of nitrogen as advocated by Eprida is useful, but not necessary in order to get a fertilizing effect. The Amazonian aboriginals certainly didn't add nitrogen, they apparently just buried charcoal. Lehmann has a page on Terra Preta that goes into more detail.

[Dead_Parrot]

14. Interesting...

Thanks. I'm still half convinced biochar is different from normal charcoal (I think - or thought - it was 'cooked' at a lower temperature, which left a lot of other compounds intact), but I'll go do some reading... :)

[GliderGuider]

13. Here's some research

http://crops.confex.com/crops/wc2006/techprogram/P16849.HTM

Enhancing the Productivity of Crops and Grasses while Reducing Greenhouse Gas Emissions through Bio-Char Amendments to Unfertile Tropical Soils.

Marco A. Rondon1, Diego Molina1, Maria Hurtado1, Juan Ramirez1, Johannes Lehmann2, Julie Major2, and Edgar Amezquita3. (1) Centro Internacional de Agricultura Tropical - CIAT, A.A. 6713, Cali, Colombia, (2) Cornell Univ, Bradfield Hall, Ithaca, NY 14853, (3) CIAT, A.A. 6713, Cali, Colombia

...

Plots were established by burning native vegetation. Lime was applied (2000 and 500 kg/ha for the crop and pasture plots respectively). One month later, three levels of biochar were applied to the plots: Zero, (control), 8 ton biochar/ha and 20 ton biochar/ha. The biochar was produced locally from wood of mango trees using traditional methods. The biochar was ground to <2mm, broadcasted on the soil surface and then incorporated by disking to 5 cm depth. Four months later, at the beginning of the rainy season, maize (Cultivar H-108) was sown as well as Brachiaria dictyoneura (var Llanero).

...

Results: Additions of even low doses of charcoal (Biochar) to soils results in a net cumulative increase in total biomass of maize, imprioved pasture and native savanna vegetation. Yields of maize were similar in all treatments during the first year but significantly increased by biochar in the two subsequent years. In the third year, yields increased from 5.7 ton/ha (control) to 6.6 and 7.3 ton/ha for the low and high dose of biochar. Forage production from B. dictyoneura increased by 26% and 55% in the second year relative to the control in the low and high biochar plots respectively.

...

During the initial year, annual methane sinks by soils were increased on average 200 mg CH4per square meter in all high biochar plots relative to the controls, while N2O emissions were reduced on average 15 mg N2O per square meter. Most of the applied C in the biochar has long residence times in the soil and consequently constitutes a feasible option to store large quantities of C in the soils on the long term. Overall, the use of biochar results in a net decrease in the integrated Global Warming Potential from the studied soils. The rediscovered use of biochar increases crop and plant yield on very unfertile soils and constitutes a new tool to mitigate climate change.

In my opinion the potential exhibited by the agricultural use of charcoal far exceeds that of biofuels alone, primarily because it additionally addresses two of the most urgent aspects of the looming crisis - rising atmospheric CO2 and declining food production. The fact that it can also be used to produce fuels either through growing biofuel crops or as a by-product of the charcoal-making process means that it hits the trifecta in the solution space. It's also one of the few mitigation proposals that might actually scale up enough to do some good.

[MountainLaurel]

5. I just hit this part of "Omnivore's Dilemma"

Before the U.S. military had so much ammonium nitrate to get rid of, the standard practice for building nitrogen in the soil was to rotate corn crops with legumes.

[NickB79]

8. Yep, many small farmers still do this

My dad usually rotates between corn, alfalfa/oats and soybeans. The alfalfa develops a deep root system that breaks up hard soils and brings up nutrients otherwise unavailable, while the oats act as a cover crop the first year to shade the young alfalfa seedlings. The soybeans have nitrogen-fixing bacteria in their roots to fix atmospheric nitrogen into nitrates. Sometimes he also rotates in millet as a silage crop for the cattle (I don't know if millet fixes nitrogen, but it seems to grow well in marginal soils). The other benefit of crop rotation is that you reduce the number of weed seeds and insect larvae that survive from year to year by constantly changing the crops available to attack. This means less pesticides and herbicides are required.

The main problem with this practice is that modern cash crop farmers working thousands of acres of land will tool up for one or two specific crops that they will grow for years at a time, if not a decade. The issue is that most farm equipment manufactured in the past 50 yrs has become more and more specialized to an individual crop. At the same time, the cost of a new tractor or plow is astronomical; a new tractor can run over $100,000, and new combines twice that much. You can't afford to buy all the necessary equipment to carry out crop rotation between 3 or more different crops. Instead, you farm one or two crops in the same fields for years and throw fertilizers, herbicides and pesticides at the problems that arise. Over time, this destroys the soil. I have seen once-fertile Iowa corn fields that are now essentially wet sand after a decade or more without rotation or fallowing. Without fertilizers, no crops would grow in that stuff.

[JohnWxy]

10. In the study by Farrell of ethanol he mentioned the practice of rotating corn with soy beans.

Apparently it is widely practiced.