Demonstration of Management and Tillage Options for CRP,

The citizen advisory committee of the Northeast Iowa Demonstration Project recommended BMP tillage and management demonstrations for lands previously in the Conservation Reserve Program (CRP), (about 150,000 A. in the 4 northeast Iowa counties) as high priority for water quality protection. Many of the CRP acres are among the most fragile in the highly erodible land classification in this area of karst topography, sinkholes, warm- and coldwater streams.

Visitors to demonstration plots can take a "self-guided tour" with information provided in a rural mailbox.

The objective of the demonstrations was to provide sound, locally-appropriate agronomic and economic information about sustainable options for productive use of CRP. Uses of local interest were examined, including crop production and forage management/improvement.

Wildlife foodplot areas within larger CRP fields were used to establish replicated corn (6-row) and small forage plot treatments. Corn plots were conducted for four years, each year in a different county, while two years' information was collected for forage plots at the same site. Demonstrations provided a basis for recommendations on corn following CRP, including herbicide management, tillage operations, planting (including no-till and strip-till) and economical nitrogen rates. Demonstrations also provided data for recommendations on the economics of retaining CRP as pasture; varying nitrogen rates and application dates and a legume interseeding option were evaluated by harvesting replicated plots on a "grazing schedule" to determine forage quantity and feed quality.

In northeast Iowa, CRP fields can be converted to corn production without yield loss or excessive erosion using no-till or strip-till planting techniques. A reduced rate, fall-applied herbicide program was more effective than a full rate spring-applied program and had less potential for environmental impact. Lower than anticipated nitrogen rates were adequate for corn following CRP, especially on soils with organic matter above two percent. Use of CRP for hay or grazing was not profitable without additional nitrogen to enhance yields. Interseeding clover using frost seeding techniques was a more profitable alternative than application of nitrogen, with the additional benefit of a more desirable distribution of the forage supply during the grazing season.

The long term environmental benefits of CRP can be maintained on much of northeast Iowa's present contract acres with the use of no-till corn production practices and refined nutrient and pest management. On the most fragile CRP acres, grass and clover pasture for cattle are a profitable option if intensive grazing practices are used for forage harvest.

A field day at CRP conversion demonstration site.

Demonstration of Management and Tillage Options for released CRP acres in Northeast Iowa