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Page 2 TEFL 1C
<br />Summer 1999
<br />...continued from page 1 these BMPs. Further, his land is being considered by
<br />nitrate levels. This condition results from nitrate's the State Agriculture Department as a demonstration
<br />chemical conversion to nitrate, which reduces the site for potato best management practices. "I've
<br />capability of infant's blood to carry oxygen. changed the way I farm," said Wojtanowicz. "Ten years
<br />ago no one thought that nitrogen may be leaching into
<br />"This looks like a classic case of a conflict in user the groundwater. Today, I put less nitrogen on the land.
<br />needs," explained Dan Lais, area hydrologist for the Also, I apply it only when the plants can use it the
<br />Department of Natural Resources. "On the one hand, most. None of the irrigation wells have high nitrate
<br />we have a good, conscientious farmer who depends levels." He added that irrigation is tuned to the recom-
<br />upon water to make aliving - a living that provides mendations of his agronomist as well as highly sophis-
<br />food for people to eat and ticated crop monitoring
<br />jobs locally and regionally. equipment. "The basic
<br />On the other hand, nearby „~~ ~~~ ®llG l'lc'317C~ I/V0 %7c3V£' a concept is to have water for
<br />residents have a right to safe 9 your crops without filling
<br />drinking water." ~00C~9 C0/1SC%E.J'/'~f%Otls ~c3f @1:..011 the soil profile. That way, if
<br />~l1L Ofl1E'1' }1?11C/, 110c~1`~~ f~S%C~L'11fS it rains, you don't have a
<br />The broad issue at play l1aVe s'] 1'%~l'P
<br />here -the impact of fertilizer
<br />and nitrogen applications on
<br />groundwater supplies - is
<br />under increasing scrutiny by
<br />faun and environmental officials. This is happening
<br />because there is little long-term scientific data on
<br />irrigation and related farm management activities. It is
<br />known, however, that water can move from the top of
<br />certain sandy farm fields to an underground aquifer in
<br />less than a year.
<br />f ~'O Sc~~0 ~1'%11%CI11~ leaching situation. Still, if
<br />1Al~~E'B' „ you get a 3-inch downpour,
<br />that's when your nitrogen
<br />disappears."
<br />"The key issue we are dealing with is 'Should we be
<br />issuing irrigation permits for a practice that might
<br />increase nitrate levels in the groundwater?' "said Lais.
<br />"In the past, we have denied or limited permits only if
<br />an irrigation system interfered with someone else's
<br />water quantity. Today, because of nitrate leaching, we
<br />have entered into discussions about water quality issues
<br />as well. As a result, we are working with Mr.
<br />Wojtanowicz and others to identify issues and seek
<br />solutions."
<br />One issue, Lais said, is that traditional potato man-
<br />agement has long involved. practices that, in combina-
<br />tion with heavy rains, periodically flush fertilizer into
<br />the groundwater, thereby elevating nitrate levels. To
<br />address this, the Minnesota Department of Agriculture
<br />and the University of Minnesota. Extension. Service
<br />have taken a hard look at potato farming. Specifically,
<br />crop and water experts have developed and adopted
<br />best management practices for growing irrigated
<br />potatoes. The BMPs recommend realistic yield goals,
<br />proven water management strategies, and specific
<br />nitrogen application rates. Wojtanowicz is following
<br />Several monitoring wells have been drilled on the
<br />Wojtanowicz farm. More aze planned. John Hines,
<br />supervisor of the Monitoring and Assessment Unit of
<br />the State Agriculture Department, said the purpose of
<br />these wells is to collect information that will have
<br />practical applications for other potato farmers and
<br />irrigators. "Agriculture that doesn't impact groundwater
<br />-that's our mission," said Hines. "Research indicates
<br />that the new potato BMPs should work. However, we
<br />won't really know this until we have collected more
<br />data from actual farm sites."
<br />Hines said the potato BMPs were developed, in
<br />part, because of the rapid increase in potato production
<br />in Minnesota, especially in Benton, Morrison, Otter
<br />Tail, Wadena and other counties that have light, sandy
<br />soils. A large percentage of Minnesota's potatoes are
<br />shipped to the RDO/Lamb-Weston processing plant at
<br />Park Rapids, Mn. This plant, when at full capacity, is
<br />designed to produce one-seventh of the world's french
<br />fries, he said. "The potato is a high value crop that
<br />requires intense management," said Hines. "As a result,
<br />some citizens see all the fertilizing and field activity
<br />and assume it is having a negative impact. That may or
<br />may not be the case. Monitoring will provide the
<br />answer."
<br />Wojtanowicz said he isn't sure what inforration the
<br />monitoring wells will net but that accurate data itself is
<br />continued on page 16...
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