- no-tillage alone is not sufficient to prevent water pollution from agricultural nitrate pollution
- study suggests that no-till needs to be complemented with other techniques, such as cover cropping and intercropping or rotation with perennial crops, to improve nitrate retention and water-quality benefits.
- study found the adoption of no-till resulted in increased nitrate loss via leaching due to the frequent occurrence of macropores, such as those created by dead roots and earthworm burrows, in soils that have been under long-range no-tillage management
September 22, 2017 Indiana University Read full ScienceDaily article here
A new study answers a long-debated agricultural question: whether no-tillage alone is sufficient to prevent water pollution from nitrate. The answer is no……The study suggests that no-till needs to be complemented with other techniques, such as cover cropping and intercropping or rotation with perennial crops, to improve nitrate retention and water-quality benefits.
After studying concentration of nitrate — nitrate amount per water volume unit — and nitrate load, or total amount of nitrate, researchers found surface runoff from no-till fields to contain a similar nitrate load to surface runoff from conventional tillage fields.
In contrast, nitrate load via leaching was greater with no-till fields than with conventional tillage fields.
…No-till leaves crop residue on the soil surface and limits soil disturbance except for small slits to add fertilizer. An estimated 20 percent of all croplands in the U.S. are under no-till management. It reduces soil erosion by avoiding tilling year after year, which leads to soil getting washed away into lakes and rivers. Because reducing soil loss reduces nutrient loss, it was assumed that no-till would reduce water pollution, Wang said….
Stefani Daryanto, Lixin Wang, Pierre-André Jacinthe. Impacts of no-tillage management on nitrate loss from corn, soybean and wheat cultivation: A meta-analysis. Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-12383-7