Studies have shown that adding biochar to soil can improve soil fertility, increase nutrient utilization in plants, improve soil water-holding capacity, increase crop yield and reduce emission of greenhouse gases.
However, if you are a potato farmer, your joy may be short-lived. Biochar and potatoes do not go very well together – at least not if you are aiming at saving water, according to results from Aarhus University in Denmark.
During her PhD studies, Caixia Liu from the Department of Agroecology, Aarhus University, investigated the effect of adding biochar produced from wood on potato growth, yield, nutrient uptake and water utilization when three other factors were also taken into consideration: irrigation methods, phosphorus fertilization and inoculation with a certain class of beneficial fungi. The aim was to investigate the interactions between biochar and the fungi on the growth of potatoes.
Caixia Liu found that inoculation of potatoes with a certain type of beneficial fungi – arbuscular mycorrhizal fungi (AM fungi) can improve potatoes’ utilization of phosphorus, make utilization of water more efficient, and increase potato yield in crops that are stressed due to drought or phosphorus deficiency.
The question was what happens when you combine biochar and inoculation with AM fungi. Would there be a double win? The answer was no.
Caixia Liu carried a series of studies with various combinations of irrigation (either full irrigation or alternating partial root zone dehydration), phosphorus fertilization (none or 0.11 mg P/g soil), inoculation with AM fungi (inoculation or no inoculation) and addition of biochar (addition or no addition).
If the crop is irrigated fully, the soil is given no phosphorus at all, and the potatoes are not inoculated with AM fungi, then addition of biochar can increase potato yield. This was the only case in the studies; in all other cases, addition of biochar to the soil had the opposite effect.
The negative effect on potato growth was especially pronounced when phosphorus was added, alternating partial root zone drying irrigation was used, and the potatoes were inoculated with AM fungi. Addition of biochar inhibited the growth and vigour of young potato plants – some of the young potato plants even died.
Source: Aarhus University
Imagine a substance with the potential to fight cancer, Aids, osteoporosis and heart disease, as well as curing ulcers, healing wounds and killing drug-resistant bacteria.
Scottish agricultural scientists are investigating the possibility of extracting the compound, called solanesol, from the leftover leaves of potato harvests, which are usually burnt off or dumped. The chemical is already a key component in the manufacture of coenzyme Q10, which is used in beauty products to combat the appearance of ageing.
Now studies are under way to establish its full powers. Solanesol is found in plants from the family that includes tobacco, peppers, aubergines – and potatoes.
Professor Derek Stewart and Dr. Mark Taylor, from the James Hutton Institute, believe solanesol production could revolutionize Scotland’s potato sector, providing a valuable new income stream for farmers while also helping to cut wastage.
Professor Stewart, head of plant chemistry, says solanesol has been researched for a few years now but China is the major source. “There is an awareness that it may have properties in its own right, like antibacterial, anti-inflammation, anti-ulcer, so its end uses are fairly wide.
“It’s also looking like it may have some ability to reverse things like antibiotic resistance or for sensitising tumour cells, so that targeted treatments work even better – a double whammy,” notes Stewart. “Other derivatives have come into focus with regard to treatments for cardiovascular disease, wound healing and osteoporosis. Currently its biggest use is in the cosmetics industry because it has a certain skin-smoothing effect and therefore an anti-ageing effect.”
More than 25,800 hectares of potatoes were grown on 2,600 farms in Scotland last year, bringing in around £167 million for the Scottish economy.
Potato plants produce more than five tonnes of stems and foliage per hectare, with an estimated solanesol content of around 40 kg.
Depending on its purity, solanesol can command huge prices. Conservative estimates suggest it could be worth at least £156,000 per hectare.
Source: The Scotsman
In their efforts to improve the food security and livelihoods of farmers around the world, potato breeders at the International Potato Center (CIP) strive to develop marketable, resilient varieties with resistance to viruses and late blight that can be grown in an array of environments.
An excellent example of the potential of such a potato is CIP variety No. 392797.22, a high-yielding clone that can be found in fields all over China and is grown in several other countries.
Originally developed in Peru in the 1990s, the variety was selected from a cross of CIP No. 387521.3 and ‘Aphrodite’, from CIP’s lowland tropics virus resistant population. It was field tested in Peru’s lowlands and mountains and was first released to farmers in 1998 by the National University San Luis Gonzaga, Ica under the name ‘UNICA’. Field trials showed that it has a stable, high yield in varied environments, is resistant to viruses, and tolerates drought. It also produces quality potatoes with red skin and yellow flesh that are good for fresh consumption and have the qualities needed for French fry production.
UNICA was introduced to China from CIP in 2001 by the Qinghai (Provincial) Academy of Agriculture and Forestry Sciences. Following evaluation by the Qinghai Crop Variety Assessment Committee, it was released as a provincial variety in Qinghai in 2006 with the name ‘Qingshu 9’ – Qing referring to the Qinghai Academy and shu being the Chinese word for potato. After assessment at a national level, Qingshu 9 was released as a national variety in 2011, and over the next five years, it came to be planted in China’s main potato production regions. At the same time, the variety has been introduced to Kenya, Rwanda, Ethiopia, Vietnam, Tajikistan and Uzbekistan, and is slated for release in Bangladesh in 2017.
Local experts estimated that more than 150,000 hectares in China were planted with Qingshu 9 in 2015. Given an average yield of 30 tons per hectare, compared to a national average of 20 tons per hectare, it is estimated that Chinese farmers produced approximately 4.5 million tons of Qingshu 9 potatoes in 2015.