Sunday, October 25, 2015

Biochar: naturally increasing soil fertility, sequestering carbon

Increasing evidence suggests that biochar—the residue of burning plant matter in an oxygen-starved environment—can be extremely important in improving fertility of poor soils.

Hawai`i researchers have worked on ways of producing the material from macadamia husks and other local products, including sewage sludge. It comes out as shards, splinters, chunks and powder that some have called agriculture’s black gold.

More and more, that evidence is coming down on the side of char. University of Hawai`i researcher Michael Antal has a great deal of information at this website.

Biochar has been promoted as a valuable soil amendment for any farming system, including organic, backyard, third world, conventional and more. 

The US Department of Agriculture reports extensively on biochar, and says that studies with numerous crops showed significant increases in production with many of them. 

Field tests in the African nation of Burkina Faso have shown that soils treated with biochar produce heads of lettuce that weigh more than those grown in untreated soils, all other things being equal. The Urban FoodPlus project, outlined in the magazine Rubin, showed that not only was the soil better at growing crops, but the biochar locked up carbon in the soil, serving to counter CO2 buildup in the atmosphere.

Biochar may help with water retention and may also promote better nutrient uptake. It also sequesters carbon, reduces soil acidity.

A lot of the early work on biochar in soil is built on the discovery in the Amazon area of vast areas of dark soils called terra preta, in which early peoples have introduced charcoal into the soil, ostensibly to improve crop potential.

But there are caveats with this process. One of them involves the availability and loss of the plant materials that are burned to produce biochar. Some researchers are working on other feedstocks for biochar, including livestock manure and even sewage.

Spanish researchers at the University of Madrid used cattle, pig and chicken manure to produce biochar.

Another group used sewage sludge, and had good results. “The obtained results so far are quite encouraging as they show how the addition of biochar to soil can enhance its quality (for example, its ability for moisture retention, pH or biological activity) and therefore, to enhance crop yields,” wrote Science Daily on the work.  

The International Biochar Initiative celebrates the benefits of this material. On its website, the IBI crows about Brazilian soils into which the biochar was introduced hundreds of years ago: “These soils continue to ‘hold’ carbon today and remain so nutrient rich that they have been dug up and sold as potting soil in Brazilian markets.”

The IBI website has extensive information on how to go about the process.

For Hawai`i-specific information see and

© Jan TenBruggencate 2015

Monday, October 12, 2015

Organic farming in Islands up 60 percent since 2008

Organic farming in Hawai`i is going gangbusters, according to a new federal organic survey.

The 2014 Organic ProductionSurvey of the U.S. Department of Agriculture reports that there are now 166 organic farms in the Islands, and that they’re tilling 3,505 acres.

Hawai`i State Statistician Kathy King has worked through the national numbers.

If you’ve been under the impression that most organic farmers are selling at farmers’ markets or directly to local consumers, you’d be wrong. It’s a much bigger business than that. 

Only about a third sell directly to consumers. Another third sells to retailers, and the third group to wholesalers. (The actual percentages are 28 consumer, 37 retail and 35 wholesale.)

It appears that if you like local food, organics are pretty significant players in that market. But they also have a big export role.

The survey shows that 49 percent of organic products are sold within 100 miles of the farm—which pretty much means on the same island as where they’re grown. Another 16 percent are sold within the state of Hawai`i. 

That said, a big proportion, 35 percent of organic crops, are shipped out of state. (The 35 percent breaks down to 30 percent shipped within the country and 5 percent internationally.)

Most of the value in organics is in vegetables, although more growers are producing organic fruits. Sixty-one farms produce $8.7 million in vegetables. One hundred twenty-six farms produce $3.4 million in organic fruits. That makes the industry worth $12.1 million.

And that’s a big increase since a survey in 2008, when the total was $7.6 million. That represents a 60 percent increase in organic farming value over six years.

In addition to crops sold fresh, 44 of the islands’ 166 farms made value added products, which had a total value of $1.8 million.

A release from the National Agricultural Statistics Service Hawaii Field Office reviews some of the production practices of the organic farmers of the Islands:

“The majority of organic farmers in Hawaii used the following production practices: organic mulch/compost, green or animal manures, no-till or minimum till, maintained buffer strips, and water management practices. 

“Other production practices utilized were biological pest management, maintaining beneficial insect or vertebrate habitat, selecting planting locations to avoid pests, releasing beneficial organisms, choosing pest resistant varieties, and planning plantings to avoid cross-contamination.”

An overview of Hawaii anagriculture as a whole finds that there are 7,000 farms in the Islands, covering 1.12 million acres. 

Coffee has the highest value at $54.3 million, followed by macadamia nuts at $40 million, bananas at $11.8 million and papayas at $11.3 million. 

Taro stands at $1.9 million and avocado at $1.6 million.
Perhaps the most significant numbers are about the primary operators of Hawaiian farms. Only 52 percent, 3,642 of 7,000 of Hawaiian farmers do it full-time. And of those farmers, 2,666 are 55 or older. Of those, 1,445 are 65 years old or older.

© Jan TenBruggencate 2015

Monday, October 5, 2015

Kapa plant Wauke confirms Polynesian migration theories

When Polynesians cane across the Pacific, a 5,000-year migration, they brought familiar products with them.

A new paper tracks genetically one of those products, paper mulberry, which is known in Hawai`i as wauke (Broussonetia papyrifera). 

(Image: An indication of the wide range of the wauke plant, this one was photographed within the volcanic crater of Rano Kau on Rapa Nui or Easter Island. Credit: Kuo-Fang Chung.)

And its genetic makeup in different locations across the ocean confirms modern theories of  migration from the island now known as Taiwan, through New Guinea, and eventualy into the Eastern Pacific and Hawai`i.

The paper, entitled “A holistic picture of Austronesian migrations revealed by phylogeography of Pacific paper mulberry,” was written by by Taiwan and Chile researchers Chi-Shan Chang, Hsiao-Lei Liu, Ximena Moncada, Andrea Seelenfreund, Daniela Seelenfreund and Kuo-Fang Chung.
The paper was printed in the Proceedings of the National Academy of Sciences

Various theories start the migration of the people who would be the Polynesians in South China, Taiwan, Vietnam or elsewhere in southeast Asia. 

“We test these propositions by studying phylogeography of paper mulberry, a common East Asian tree species introduced and clonally propagated since prehistoric times across the Pacific for making barkcloth, a practical and symbolic component of Austronesian cultures,” the authors write.

Wauke, whose inner bark was converted into bark cloth for clothing, ornament and other uses, may be the most widely distributed fiber product of early prehistory, the authors write.

“We demonstrate a tight genealogical link between its populations in South China and North Taiwan, and South Taiwan and Remote Oceania by way of Sulawesi and New Guinea, presenting the first study, to our knowledge, of a commensal plant species transported to Polynesia whose phylogeographic structure concurs with expectations of the “out of Taiwan” hypothesis of Austronesian expansion,” they write.

A commensal relationship is one in which two different things—in this case humans and wauke—work together to the benefit of both. Humans got clothing, and the paper mulberry got to dramatically expand its range.

The authors studied 600 or so samples of wauke tissue collected from across the Pacific, and looked at genetic variation in them. They were able to track the migration of the wauke, and thus the Polynesians, across the ocean. 

Separately, they were able to show that the earliest Taiwan residents may have brought a predecessor plant from southeast China.

© Jan TenBruggencate 2015