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US corn yields between 1950 and 2008 (blue dots) with projected yield to 2030 (black line) and target yield to achieve a 50% increase between 2005 and 2030 (red square). Historical data from USDA, 2009.
In 2005 the US Department of the Environment and the US Department of Agriculture released an influential report claiming that by 2030 US farms could produce almost a billion tons of biomass for conversion to biofuel each year. More than half would come from annual crops, and the rest from perennial crops and manure.
A key assumption of the report is that grain yields will increase by 50% by 2030. Established yield trends suggest that we won’t reach that target.
Global distribution of annual average onshore wind power potential (W/m2) for 2006 (Lu et al. 2009; click image to go to source).
A new study of the global potential for wind-generated electricity (Lu et al. 2009) concludes that windmills can meet the world’s energy demand with plenty of power to spare.
The open access paper in the Proceedings of the National Academy of Sciences claims that a global network of windmills operating at 20% of capacity could produce 2,470 exajoules (EJ) — about five times the current commercial energy consumption of the planet (~500 EJ). The latest estimate is much higher than the first evaluation of global wind power (Archer and Jacobson 2005), which estimated a similar network’s output at 443 EJ.
Weed management with hand tools (Benjamin Austin, foreground) and a tractor (Tony Silvernail, background).
At the beginning of July 2008 I posted pictures of the farm scale study at Kentucky State University. Here are some pictures of the same study, repeated in 2009. The plot diagram that I posted in 2008 is identical for 2009, except that we have rotated the crops:
- Last year’s soybean rows are this year’s corn.
- Last year’s corn is this year’s sweet potato.
- Last year’s sweet potato is this year’s sweet sorghum.
- Last year’s sweet sorghum is this year’s soybean.
To get the crops off to a good start we are focussing on weed management.
SNAP is the new name for the federal Food Stamp Program. It stands for the Supplemental Nutrition Assistance Program
According to the USDA’s Food and Nutrition Services web site, the USDA’s largest program, SNAP, serves more then 28 million low-income individuals every month. This massive program has the potential to be a tremendous tool in the quest to provide everyday food security and nutritious food to low-income families across America. In fact, the new name change from the federal Food Stamp Program to SNAP (Supplemental Nutrition Assistance Program) was intended to “reflect the mission to provide food assistance and increased nutrition for the health and well being of low-income people.” The SNAP program is a huge part of the USDA’s Food and Nutritional Service Programs budget. Needless to say, a massive amount of energy in various forms goes into this program. read more…
The Science Barge is supposed to demonstrate sustainable urban farming using technology that could grow vegetables on New York City rooftops. It was designed by engineering firm New York Sun Works, whose website describes the project with an audacious claim:
The Science Barge is a prototype, sustainable urban farm and environmental education center. It is the only fully functioning demonstration of renewable energy supporting sustainable food production in New York City. The Science Barge grows tomatoes, cucumbers, and lettuce with zero net carbon emissions, zero chemical pesticides, and zero runoff.
The Science Barge is a well-intentioned, but unsuccessful, attempt to demonstrate sustainable urban agriculture. Docked in Manhattan in 2007 and Yonkers since 2008, it has attracted thousands of school children and considerable media attention but promotes a form of agriculture that could dramatically increase energy consumption and greenhouse gas emissions.
The EPA estimates that agriculture is responsible for one-third of all domestic methane emissions yet federal policy makers continue to underestimate the role of industrial agriculture in climate change legislation.
On Thursday, June 11, the House Agriculture Committee held a hearing on H.R. 2454, the American Clean Energy & Security Act of 2009.
H.R. 2454 does not include agriculture as a sector that would be required to reduce greenhouse gas (GHG) emissions but does leave agriculture as a sector that could provide offsets for other GHG emitters by reducing GHG emissions or sequestering carbon in agricultural operations. The major issue addressed at the hearing was whether EPA or USDA would determine what agriculture practices and systems could be used for offsets.
According to the National Sustainable Agriculture Coalition, the clock is “ticking” on climate change legislation. House leaders have indicated that legislation must come to the floor before the July 4th congressional recess because health care legislation will take over the agenda after the recess.
Rainfall at KSU Research Farm between May 1 and June 11, 2009. Dark bars show daily rainfall (left axis); light area shows cumulative rainfall (right axis). Suitable planting windows shown in gold.
Kentucky has had a wet spring. Since the beginning of May we have had just 11 days suitable for planting. The most severe rainstorms came on June 10th and 11th, with more than 2.5 inches of rain in a 24 hour period.
That much rain on bare soil can lead to erosion. We do our best to protect our soil with cover crops between main crops, but the soil is bare and vulnerable around planting time.
With some trepidation we went out yesterday morning to survey the damage. Would our freshly-sown seed be washed away? Did our newly-transplanted sweet potatoes survive the onslaught?
We transplanted sweet potatoes by hand into biointensive and market garden plots and used a water wheel planter pulled behind a tractor for small farm plots. This video shows the different methods used at each farm scale.
Moises Hernandez (foreground) and Brian Geier transplant sweet potato starts into a biointensive plot. All management in the biointensive plots is conducted by hand.
Almost all of our crops are in the ground for the second year of our farm scale study. Kentucky has had a wet spring, so everything is growing like mad, but soggy soil has delayed some planting.
Last year we had relatively poor establishment of our direct-seeded crops in the biointensive plots. This year we transplanted everything into the biointensive plots. The soil preparation in the biointensive plots was conducted with hand tools. We cut the cover crop with scythes, and incorporated it, along with some aged horse manure, using spading forks and a broadfork. The manure was not composted according to organic requirements, so we will have to wait 120 days after its incorporation to harvest the sweet potatoes, and 90 days to harvest the other crops.
Total greenhouse gas emissions associated with food production and distribution in the United States. The production phase accounted for 83% of emissions. (From Weber and Matthews 2008. Click image to go to source).
A 2008 study (830 KB pdf) from Carnegie-Mellon University, now freely available online, estimates that the production and distribution of food emits 8.1 metric tonnes of carbon dioxide equivalents per US household. That translates to 3.2 tonnes per person, or about 16% of US greenhouse gas emissions.
The study raises several interesting points:
- The estimate that the food system accounts for 16% of greenhouse gas emissions is very similar to an estimate of 15% that I recently posted to this blog;
- Eliminating red meat and dairy products from the diet for one day each week could have the same climate impact as buying all food locally for a year;
- The average food item travels 4 times as far as the distance from the farm to the consumer. The average “farm to fork” distance in this study was 1,250 miles, but the food had to travel 5,120 miles to get there;
- Even with all that travelling, transportation accounted for just 11% of food system greenhouse gas emissions.
