Farmers may mistakenly believe that no-tilling alone will retain crop nutrients in fields. The topic came up yesterday during break sessions of the Innovating Policy for Chesapeake Bay Restoration conference in Cambridge, Md.
No-till does help reduce nitrogen losses and prevents sediment erosion losses. But as Doug Goodlander, program coordinator for Pennsylvania State Conservation Commission, pointed out, "It may not reduce soluble or dissolvable phosphorus losses if there's run-off.
"No-till builds up soil phosphorus levels in the top couple inches of soil," he explained. "In a run-off event, soluble P losses can be substantial. That's why the practice still needs to be matched with other conservation practices such as buffer zones and cover crops, Goodlander noted.
Pictured are two examples from the same field:
Left: No-till field still has runoff after a heavy rain.
Right: Same no-till field, but with a cover crop, after the heavy rain.