Scientists test biofertilizer that could end agricultural ‘dead-zones’

Every year an agricultural ‘dead-zone’ the size of Massachusetts sprawls across the Gulf of Mexico caused by excess nutrient pollution from human activities.

To tackle the problem, scientists at Harvard University are testing a new biofertilizer that relies on engineered bacteria – and it won’t wash into water supplies.

The new treatment uses hydrogen from water splitting and combines it with nitrogen in the air to produce ammonia, which the plants can then absorb into their routes.

Since other fertilizers give plants more nitrogen and phosphorous than they can use at one time, the excess often gets washed out into our rivers and oceans.

The biofertilizer stays safe within the plants’ roots and can then be stored for future use.

The innovative fertilizer is also carbon-negative by absorbing carbon dioxide from the air.

Dilek Doguton, a principal research scientist in the Nocera Group said: ‘Using the new biofertilizer methods across the U.S. we could remove significant amounts of CO2 per year by sequestering the carbon in the soil.’

Ms. Dogutan and her team will perform large-scale tests of the fertilizer from the winter of 2020, but with an earlier grant from Harvard’s innovation fund, she has already planted two small test plots.

Ms. Dogutan and Daniel Loh, a PhD student in the Department of Chemistry at the Graduate School of Arts and Sciences cleared two parking spot size gardens to test the biofertilizer.

Loh planted radishes, turnips, and spinach in each plot and then every week he fertilized one with 100 millimeters of the biofertilizer and water and the other with as much water but with no fertilizer.

From April to August, Loh monitored the plants and collected data.

His measurements showed that not only did the biofertilizer help the plants grow larger, but the bacteria did not leak into the surrounding plants.

‘This is still very new research, we are still trying to figure out the details, the loading, the sequence, maybe we need to design the bacteria in a different way,’ Ms. Dogutan said.

‘But once they complete their research, they hope to encourage all Harvard campuses to consider switching to the biofertilizer as a way to improve the University’s commitment to sustainability and eventually to win wider acceptance and perhaps end ‘dead zones.’

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