In collaboration with researchers at Nanjing Agricultural University, Dr Tony Miller from the John Innes Centre has developed rice crops with an improved ability to manage their own pH levels, enabling them to take up significantly more nitrogen, iron and phosphorous from soil and increase yield by up to 54 percent.
Rice is a major crop, feeding almost 50 percent of the world’s population and has retained the ability to survive in changing environmental conditions. The crop is able to thrive in flooded paddy fields – where the soggy, anaerobic conditions favour the availability of ammonium – as well as in much drier, drained soil, where increased oxygen means more nitrate is available. Nitrogen fertilizer is a major cost in growing many cereal crops and its overuse has a negative environmental impact.
The nitrogen that all plants need to grow is typically available in the form of nitrate or ammonium ions in the soil, which are taken up by the plant roots. For the plant, getting the right balance of nitrate and ammonium is very important: too much ammonium and plant cells become alkaline; too much nitrate and they become acidic. Either way, upsetting the pH balance means the plant’s enzymes do not work as well, affecting plant health and crop yield.