Dr Sabine Reinsch tells us more about a UK-China research collaboration which aims to tackle agricultural over-fertilization and connected soil health issues...
China's population, presently around 1.39 billion, continues to grow. Current agriculture struggles to provide food and to meet the demands of the changing diets of the Chinese population today. Even though population growth is estimated to stagnate by 2030, food will need to be produced from the same land for an additional 60 million people by that time. On top of the challenge to provide more people with food, the Chinese government requires that fertilizer use doesn't increase after 2020. Thus, a change in land-management is needed to avoid starvation.
Between 1975 and 1995, fertilizer factories were built and inorganic fertilizers were introduced to Chinese agriculture to overcome the poor nutrition of soils and to increase yields. Crop yields increased rapidly. However, intensive land-management, pollution and industrial waste left ~20 % of China's arable land contaminated. In addition, the overuse of chemically produced fertilizers has caused soil pH to decrease. Low soil pH immobilizes plant available nitrogen and mobilizes heavy metals. Acid rain caused by high air pollution also increases the risk of lower soil pH.
The UK-China Virtual Joint Centre for Improved Nitrogen Agronomy (CINAg) collaboration studies the effect of chemical (NPK fertilizer) and organic (manure) fertilizers on soil properties in connection to soil functioning.
Soil properties determine:
- Water quality
- Greenhouse gas emissions
- Carbon storage.
Second CINAg project meeting in Beijing with the UK team (Bangor University, CEH and Rothamsted Research) in April 2017.
The CINAg research team aims to decrease soil nitrogen loss in the form of water-soluble nitrogen or nitrogen gases. The retained soil nitrogen can then be used by plants for biomass (= food) production. Fewer fertilizers are needed to produce the same amount of food, and soil acidification may be slowed down or even stopped. Rothamsted Research and Bangor University are testing novel enzymes designed to slow down the transformation of fertilizer nitrogen to plant available nitrogen. In this way, more nitrogen can be used by plants over time.
CINAg scientists visiting experimental stations in the Quonzho province. Research posters are presented by Chinese students.
Besides the soil chemical composition - often with a focus on nitrogen, phosphorus and potassium - soil physical and biological properties are important for a healthy soil. For example, the availability of soil nutrients changes with soil moisture. Soil nutrient availability also changes with soil pH, different soil microbes and compaction.
Researchers from the Centre for Ecology & Hydrology, Bangor University and Rothamsted Research explore how soil properties affect multiple soil functions. Our aim is to develop a closer link between commonly measured soil functions such as yields, nutrient and carbon stocks, and water quality, with soil properties. Texture is an inherent soil property; especially soil clay content determines the capacity of soils to store carbon and retain nutrients. Clay minerals are charged, and their interactions with organic matter and water are crucial for aggregate formation and stability; thus the stability of soils in the future. However, land-management techniques, like tilling and the use of heavy machinery, change the stability of our soils.
"Our aim is to develop a closer link between commonly measured soil functions such as yields, nutrient and carbon stocks, and water quality, with soil properties."
Visiting local farmers and a novel farming-research integration programme (Science and Technology backyards) in which masters students identify local farming problems and help in solving them.
As part of the CINAg project, we want to identify crucial soil properties that benchmark soil functioning and health.
The CINAg project is funded by the BBSRC-Newton Fund for Virtual Joint Centres with Brazil, China and India in Agricultural Nitrogen.