10 February 2008

Optimistic About Topsoil

Optimists tend to be more productive than pessimists. While the media is full of pessimistic voices about "global warming disaster", "peak oil catastrophe", "water shortages", "topsoil depletion", etc., the media does not bother to look for solutions to all of these "problems." Finding solutions is for optimists, who are not afraid to get their hands dirty.

Take dirt, for example. Soil--topsoil to be more specific. While whining "environmentalists" and journalists waste forests of paper telling everyone how hopeless the situation is, individuals more in contact with the real world set about to find ways to build new topsoil, and make it more fertile. One approach to soil fortification is "biochar:"
Biochar or agrichar is a fine-grained charcoal substance made from biomass that has been heated in the absence of air. When used as a soil amendment in combination with sustainable production of the biomass feedstock, biochar effectively removes net carbon dioxide from the atmosphere while providing energy....Biochar can remain in the soil for several hundreds to thousands of years, creating virtually permanent soil sinks. Biochar and bioenergy co-production from urban, agricultural and forestry biomass can help combat global climate change by displacing fossil fuel use, by sequestering carbon in stable soil carbon pools, and by dramatically reducing emissions of other greenhouse gases from soils, such as N2O

...Biochar in soils has been shown to:

* Improve soil health
* Increase crop yields and productivity (by up to 800% when combined with mineral fertilizer in highly weathered acidic tropical soils; by 200 and 300% in advanced agricultural systems that are already at the limit of intensification)
* Reduce soil acidity; acid soils make up about half of the world's potential arable land
* Reduce N2O emissions from soils
* Improve water quality
* Reduce nutrient and chemical leaching and run-off, and
* Reduce the need for chemical and fertilizer inputs___Biopact

Other methods of building topsoil include composting in raised beds, using the essential ingredients:
There are six essential ingredients for soil formation.

1. Minerals
2. Air
3. Water
4. Living things IN the soil (plants and animals) and their by-products
5. Living things ON the soil (plants and animals) and their by-products
6. Intermittent and patchy disturbance regimes

* For soil to form, it needs to be living (4)
* To be living, soil needs to be covered (5)
* To be covered with healthy plants and decomposing plant litter, soil needs to be managed with appropriate disturbance regimes (6)

There is little information available as to how to increase the levels of air, water and organic materials in soil. For this reason, components 5 and 6 of the soil building checklist tend to be overlooked. That may explain why many people believe that new topsoil cannot be formed.

One has to wonder, how did all the topsoil get here in the first place? We know how quickly we lose it when we ignore the fundamental importance of components 5 and 6. To turn things around, we need to encourage soil building processes every day in our land management.___Source

Here is an online book detailing the use of the earthworm for topsoil formation. And this US Patent describes the use of water-based drilling mud for building topsoils. Most creative.

Tropical soils are a bit different, but an intelligent selection of cover crops can make all the difference in building tropical topsoils.

The topic of topsoils is more down to earth than most topics covered at Al Fin. Yet a more intelligent approach to topsoils would go a long way toward improving crop yields and food supplies in much of the world. Certainly a more sustainable approach to topsoils in the industrial world would result in less expenditures on chemical fertilizers and less damaging agricultural runoffs into the water table.

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Blogger Snake Oil Baron said...

It has been stated that Amazonian natives used biochar to make the jungle horticulture productive in the absence of topsoil. Rather than slash and burn techniques, the biochar holds water and nutrients in the porous structure whereas ash from normal burning would get washed away. They supplemented it with fish processing waste from their river catches which made the stuff extremely rich. (As an aside, fish processing "waste" might be produced closer to the agricultural source if land based aquaculture becomes wide spread)

I have also heard about using hydrophilic/hygroscopic proteins from seaweeds to make agriculture in dry regions better able to hold on to water and minimizing soil evaporation. It would be interesting if these techniques could be combined.

Further research is being done to green deserts by taking advantage of what little water there is and constructing an environment to use it effectively. Now, some of the people who support this are overly idealistic and have a far more negative view of the modern agriculture system that have resulted if vast productivity gains but unlike the "organic foods" racket, some of these innovations look like they have potential and using a combination of biochar, modern agriculture and desert reclamation schemes might very well increase the trend towards using less land for agriculture and returning some of it to prairie, savanna and forest while making deserts become productive.

Sunday, 10 February, 2008  
Blogger al fin said...

I agree. The potential for improving the vitality and fertility of soils worldwide, has only just begun to be explored and developed.

The claim that we are "irrevocably losing topsoil" betrays an appalling ignorance of science.

Monday, 11 February, 2008  
Blogger SwampWoman said...

Not to mention that any western farmer knows how to take care of and improve the soil. If the land is rented on a year-to-year contract, however, the incentive to improve the soil may not be there.

The desert soils seem to be a bigger challenge due to salinization. My family has always farmed/ranched in non-desert conditions. I suppose if I had grown up with dry soil, I'd consider salinization from irrigation more manageable.

Monday, 11 February, 2008  

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“During times of universal deceit, telling the truth becomes a revolutionary act” _George Orwell

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