Indian-Origin Scientists at the Washington University in St Louis, Ramesh Raliya, a research scientist, and Pratim Biswas, the Lucy & Stanley Lopata Professor and chair of the Department of Energy, Environmental & Chemical Engineering, both at the School of Engineering & Applied Science, have discovered a way to reduce the use of fertilizer made from rock phosphorus and still see improvements in the growth of food crops by using zinc oxide nano-particles. It is greatly hoped that their use of nano-particles in fertilizers could help increase output without adding further strain on existing natural resources. The nano-particle fertilizers are also expected to be more Eco-friendly than conventional fertilizers.
The scientists also claim that this is the first study to show how to mobilize native phosphorus in the soil using zinc oxide nano-particles over the life cycle of the plant, from seed to harvest.
Traditionally, fertilizers are either applied directly to the soil or are mixed with irrigation water, to provide plants with nutrients to increase their growth and enhance the production of crops. Plants absorb around 42% of the phosphorous from fertilizers. The rest and the un-absorbed move to lakes and rivers where it ultimately pollutes the water.
According to the scientists, “Currently, farmers are using nearly 85 per cent of the world’s total mined phosphorus as fertilizer. At this rate, the world’s supply of phosphorus could run out within the next 80 years. When the enzyme activity increases, you don't need to apply the external phosphorus, because it's already in the soil, but not in an available form for the plant to uptake”.
A nano-particle is an ultra-fine object that has the characteristic of a complete unit in terms. The scientists have experimented with using the zinc nano-fertilizer on mung bean (green gram) plants. The results have been promising. These two scientists have created zinc oxide nano-particles from a fungus around the plant’s root. Zinc, which is an essential nutrient for plants, interacts with three enzymes to break down phosphorus from its complex form to one that the plant can easily absorb. These new fertiliser cum nano-particles could be applied and sprayed directly onto the leaves of the plants. As these particles are extremely small, they are more efficiently absorbed by the plants and hence no residue is left un-absorbed which could further pollute the soil or the water.
The research was recently published in the Journal of Agricultural and Food Chemistry.