WASHINGTON, D.C. — Technological changes have allowed farmers and ranchers to be more productive, with inventions such as tractors, irrigation and pesticides, but the innovation has not stopped there.

Technology’s impact on agriculture and its surrounds was the focus of the Conference on Agricultural Productivity and the Environment, hosted by the USDA, Farm Foundation and Global Harvest March 11-12. “Technological change benefits agriculture … growth has an impact on the environment,” said Mary Bohman, administrator for USDA’s Economic Research Service.

She said some of the consequences of improved technology are negative, but there are benefits, too. “We’re producing more with fewer resources,” she said – and releasing fewer greenhouse gases.

At the same time, she said technological improvements cause people to undervalue the environment and a natural ecosystem.

In addition to the direct impact it has had on agriculture, new technology has made it easier to measure the impact of ag on the environment, said Stephen Polasky, a regent’s professor and the Fesler-Lampert Chair of Ecological/Environmental Economics at the University of Minnesota.

“We know that markets and prices provide incentives and clear signals of value for goods and services. But there are some things you can’t define – ecosystem. (A) farmer gets paid for producing corn … and not for clean water,” he said.

He has been involved in a project to reduce phosphorus in the watershed to Lake Pepin, Minn., by 50-80 percent. When he first heard the goal, he thought it would be a nearly impossible task.

“We need to estimate benefits and costs associated with alternative ways to improve water quality,” he said. “I’m focusing on water, carbon and farming.”

He said soybeans and corn are the primary crops grown in the region. He needed to obtain data on how different tilling practices, manure and chemicals affected water quality. Then he needed to study different ways to improve water quality.

He explored if different crops were grown in the area, or the crop rotation was changed, as well as increasing grasslands to determine the consequences. “We had to go outside of the expected approach because it wasn’t thorough enough,” Polasky said.

He accessed a variety of data made available from the Soil Water Assessment Tool and water quality to determine where phosphorus was used and where was it found in nature. There were low-cost solutions to reduce phosphorus, but the changes were not enough to obtain the 50 percent reduction goal, he reported.

To reach that goal, more expensive measures need to be taken, making it unlikely farmers and ranchers would volunteer to participate in programs, he said. By determining the value of better water quality on the region, a 20 percent improvement to phosphorus levels could be made in water with little cost change, Polasky added.

“If you have low price for crops, water quality is a much better deal. But when you have high costs of crops, it’s not as good a deal,” he pointed out.

Tim Benton, with the United Kingdom’s Global Food Security Programme, said having a diverse ecosystem around farms allows them to produce more crops than current farming practices alone.

“If you’re just measuring farm ... one little pocket of pasture in intensive cropland, you’re not going to have much biodiversity,” he said. He said work has been done to reduce carbon emissions from cows, but now there are more cows on farms.

“If you look at it per cow, it looks like a good thing, but it’s not. I think the end result is that we have to think about demand. Only with change in demand will we ever crack this issue.”

He also said about 30 percent of all food purchased is wasted. “If we reduce our consumption of meat by 50 percent, it would … allow the environment to come back in,” he said.