Dietary shift to potatoes could cut staple crop emissions in China by 25%

The authors keep in mind that it stays to be seen whether such a significant dietary shift can be carried out on a big scale. And, they warn, if the greater potato production isnt matched by domestic demand, the climate benefits will be balanced out by the requirement for rice imports from neighbouring countries.

The research study, released in Nature Food, examines the land use, water usage and greenhouse gas emissions associated with growing four staple crops: rice, wheat, maize and potatoes. It discovers that a massive dietary shift towards potatoes, combined with much better growing methods, could minimize the greenhouse gas emissions of these staples by approximately 25%.

In addition to the emissions reductions, the researchers find that incorporating more potatoes into the diet plan would cut the overall land used for staple-crop agriculture by about 17% by 2030– even when accounting for the countrys growing calorific need.

A dietary shift from rice to potatoes might “notably minimize” the climate and ecological effects of staple crop agriculture in China, according to a new research study.

Potatos comparative advantage

For the final situation (S2) a “strategic siting” strategy was enacted on top of the other policies. This linear-regression model reallocates the crops to reduce greenhouse gas emissions while making “just slight adjustment [s] to the planting areas of the other staples. Taken in mix with the other modifications, S2 results in a 25% reduction in emissions, a 17% decrease in land use, a 17% decrease in water use and a 19% increase in calorific yield.

The chart below shows the projected land usage (left), emissions (middle) and water usage (right) for each of the 3 circumstances. The bars in each figure are broken down to reveal the relative contributions of rice (blue), wheat (green), maize (red) and potatoes (orange).

Liu, B. et al. (2021) Promoting potato as staple food can lower the carbon-land-water impacts of crops in China, Nature Food, doi:10.1038/ s43016-021-00337-2.

The very first circumstance (” S0″) presumes no dietary or production modifications. The researchers determined that in order to fulfill the calorific demand, the amount of land utilized for farming would need to increase by about 17%. Moreover, they discovered, the greenhouse gas emissions and water use connected with staple crop agriculture would each boost by about 20% by 2030.

” Creating that bridge in between these two different stories, I think thats really crucial. And its not the sort of thing that Ive seen before.”.

Fertiliser application, which has actually increased in China by over 300% over the last 3 years, is another major source of agricultural emissions in the type of nitrous oxide. Almost half of the 128MtCO2e attributed to fertilisers is due to maize farming..

( Another recent Nature Food study revealed that more than one-quarter of food produced in China is squandered yearly, nearly one-half of which is due to handling and storage after the crop is gathered.).

Worldwide, the production, processing, transport and usage of food are accountable for about one-third of human-driven greenhouse gas emissions. Discussion of lowering farmings impact generally only focuses on decreasing intake of beef, dairy and other red meats..

Sharelines from this story.

For each of four staple crops, a province-by-province breakdown of (leading to bottom): overall land usage, land-use intensity, overall emissions, emissions intensity, total water usage and water-use intensity. “Intensity” is computed on a calorific basis. Darker colours suggest greater overalls and intensities; all data are from 2015. Source: Liu et al. (2021 ). Please note: These maps are produced by Liu et al. The classifications employed and the discussion of the product within them do not imply the expression of any opinion whatsoever on the part of Carbon Brief worrying the legal status of any country, area, city or area or of its authorities, or worrying the delimitation of its frontiers or boundaries.

Persuading a whole country to alter its diet is no small feat, Yang admits. Due to the fact that of this, he states, the policy is “most likely lagging behind” the targets it at first set out. Beijing News reported last year that potato yields had actually just a little enhanced which usage patterns in the country had not substantially altered considering that the policy was exposed.

There is also, Kear states, “a lot of room for enhancement” in selecting or reproducing higher-yield varieties than those that are presently planted.

In order to assess the prospective results of the policy, the researchers took a look at 3 circumstances utilizing designs of crop demand, yield growth and land use. Each situation developed on the previous one and consisted of the forecasted increase in calorific demand for staple crops (expected to rise by over one-third in China by 2030).

In S1, both the yield and the usage of potatoes boosts. In S2, the enhancements of S1 are preserved and potatoes are planted tactically in locations where they could have the biggest effect. Colours indicate the four different staple crops.

” We can compare rice production in China versus rice production in those other countries. It turns out that rice production in China is extremely efficient, whereas in those other nations, yields are lower. In this case, were kind of leaking our problem to other countries.”.

One is that potatoes spoil more quickly than other staples such as rice, Scherer says. In order to be successful, she tells Carbon Brief, changes require to be made “at various stages in the value chain”– not simply on the production side, but in regards to customer behaviour, food storage and how processed food are made..

And that does not truly modify the flavour of the noodles you consume. And that can, to some level, help this policy or aid in promoting potatoes.”.

Virtually all of the greenhouse gas emissions from staple-crop planting in China can be found in the type of methane discharged as a result of rice farming– more than 150m tonnes of CO2e (MtCO2e) in 2015..

To name a few targets, the method required 30% of potatoes to be taken in as staples by 2020. While the root acts as a staple in some areas of China, in many parts of the nation, it is used as an active ingredient for vegetarian or meaty dishes that are consumed along with a staple.

GlossaryCO2 equivalent: Greenhouse gases can be expressed in regards to co2 equivalent, or CO2eq. For an offered quantity, various greenhouse gases trap various amounts of heat in the environment, a quantity called the international warming capacity. Co2 equivalent is a way of comparing emissions from all greenhouse gases, not simply carbon dioxide.CloseCO2 equivalent: Greenhouse gases can be expressed in terms of co2 equivalent, or CO2eq. For a given quantity, various greenhouse gases trap various quantities of heat in the environment, a quantity referred to as … Read More.

Potatoes have numerous agronomic benefits over other staple crops. When Yang and his associates evaluated the ecological impact of each of the four staples, they discovered that potatoes have a lower impact in several ways. Potatoes also used less water than each of the other staples and needed less land than maize or wheat.

Dietary shift is tough.

Room for enhancement.

Potato yields in China lag behind these high-yield nations for a number of reasons, Dr Philip Kear, a plant breeder and geneticist and a nation intermediary scientist at the International Potato Center, who was not associated with the research study, tells Carbon Brief..

One key to effectively executing the policy will be closing the “yield gap” with other countries, Yang tells Carbon Brief. The average yield of potatoes in China was 15% listed below the world average in 2015 and 65% below that of “high-yield” countries such as the US, New Zealand and Belgium..

Potatoes have several agronomic advantages over other staple crops. They are more drought-resistant and more geographically versatile, making them more resistant to a changing environment. Potatoes also contain higher levels of specific micronutrients, such as potassium and vitamin C, than maize, wheat and rice..

Collecting potatoes in the Red Fields of Kunming Dongchuan Red Land, China. Credit: Danita Delimont/ Alamy Stock Photo.

Potatoes just account for 4.5% of the 267MtCO2e produced from the agricultural production and transportation sectors. This, the researchers note, is “relatively smaller sized than its share of cultivated land” because potato farming does not require as much diesel and electrical power as farming other staples.

The paper thinks about three main contributors to greenhouse gas emissions in staple crop farming: crop planting, fertiliser application and production and transportation.

Although China is a major supplier of staple crops– producing around one-quarter of the worlds rice, maize and potatoes and nearly one-fifth of its wheat– potatoes only take up 6% of the nearly 1m square kilometres of cropland devoted to staple crops in the country..

The chart below shows the total land usage, greenhouse gas emissions and water use for each of the 4 staple crops studied– from rice in the left-hand maps through to potatoes on the right– along with the intensity of land use, emissions and water use (specified as the usage or emissions on a per-calorie basis). The darker shading indicates higher overalls and strengths throughout Chinas provinces.

Under the second scenario (S1) Potato-as-Staple-Food strategies to enhance potato production were accounted for. These include the adoption of high-yield potato ranges and increasing the relative proportion of calories sourced from potatoes. They predict increasing potato yields by 125% and utilizing potatoes to fulfill the space between yield and demand of the other staples. This, the authors find, would result in a 14% decrease in greenhouse gas emissions, a 10% decrease in overall land growing, an 11% reduction in water usage and a 10% increase in the mean calorific yield of the staples by 2030..

” Very little research has been done on whats the environmental ramifications of this policy? And why it may matter is that various crops have different ecological footprints. Thats extremely clear to those people who have studied farming systems, but not always clear to the policymakers.”.

Taken together, the authors compose, these figures show “potatos comparative benefit” amongst staple crops in decreasing greenhouse gas emissions.

In spite of the possible gains, there are likewise risks connected with the policy that could negate some of its environmental benefits..

Kear tells Carbon Brief that the research study is “quite helpful and rather helpful” in considering both the dietary advantages and the ecological impacts of the Potato-as-Staple-Food policy. He adds:.

Potatoes are typically grown on “marginal land” in China, where soils are poorer or water is more scarce, Kear discusses. And since farming in China is predominantly carried out by little farmholders, he adds, the degree of mechanisation on farms is much lower than in other places in the world..

Yang tells Carbon Brief:.

These include the adoption of high-yield potato ranges and increasing the relative proportion of calories sourced from potatoes. They predict increasing potato yields by 125% and utilizing potatoes to satisfy the space in between yield and need of the other staples.

This focus on meat can miss out on out on other areas where modification might help minimize emissions, says Prof Laura Scherer, a commercial ecologist and ecological researcher at Leiden University who was not involved in the study.

When Yang and his colleagues analysed the environmental impact of each of the four staples, they discovered that potatoes have a lower effect in several methods. Compared to rice, wheat and maize, potatoes produce substantially lower amounts of greenhouse gases on a per-calorie basis. Potatoes also utilized less water than each of the other staples and required less land than maize or wheat.

One way to make potatoes more palatable is by replacing them in for other staples in processed foods, such as buns or noodles. Yang discusses:.

The authors likewise caution that an increase in potato production without an accompanying modification in usage patterns could end up negating the benefits of changing out other staples for potatoes. This is since if domestic rice production falls however need is sustained, China will have to import rice from neighbouring countries.

And because the Chinese policy is concentrated on food security and nutrition, there has actually been less interest in evaluating the environmental impacts of such a large-scale dietary shift, Prof Yi Yang, a commercial ecologist at Chongqing University, says. Yang, who is one of the authors of the brand-new study, informs Carbon Brief:.

In 2015, the Chinese federal government carried out a nationwide method referred to as the “Potato as Staple Food” policy. Its stated aim is to enhance food security– the nations ability to feed its own population without dependence on imports– by increasing both production and intake of potatoes throughout China..