Research Update: Cover Crops, Soil Conservation, and Prevented Planting Acres

Author: Kristy Borrelli

Editor: Leigh Bernacchi

Each ton of soil eroded in the Pacific farm production region has a negative economic impact of $0.53.                –David Steury

As many of you and your clients consider crop insurance purchases before the sales closing date, here is some REACCH research, conducted by Professor of Agricultural Economics Kate Painter and her 2013 University of Idaho REACCH summer intern David Steury, on the dilemma of prevented planting acres and soil conservation.

The region’s highly erodible soils suggest that cover crops would be an ideal alternative to summer-fallow. Cover crops can conserve erodible soil and slow or reverse some of the impacts caused by intensive farming practices. The USDA-Natural Resource Conservation Service estimates that 4 to 5 tons of soil per acre can be retained using cover crops compared to fallow.

Spring precipitation is expected to increase by 5 to 15% over the next 40 to 70 years in the inland Pacific Northwest (Figure 1). Wetter springs could delay plantings and impede yields of spring crops. In such instances, farmers often rely on prevented planting coverage, which allows the parcel of land to be kept fallow or planted to a cover crop.

Figure 1. Projected percent change in the frequency of wet springs (Mar through May) for 2031 through 2060 as compared to contemporary climate (averaged from 28 climate models run under experiment RCP 8.5). Wet springs were defined as being among the wettest 20% of springs. The models hint at more frequent wet springs in a changing climate. No change would correspond to a value of 0. Blue indicates an increase in frequency of wet springs: orange/brown indicate a decrease.
Figure 1. Projected percent change in the frequency of wet springs (Mar through May) for 2031 through 2060 as compared to contemporary climate (averaged from 28 climate models run under experiment RCP 8.5). Wet springs were defined as being among the wettest 20% of springs. The models hint at more frequent wet springs in a changing climate. No change would correspond to a value of 0. Blue indicates an increase in frequency of wet springs: orange/brown indicate a decrease.

Cover crops have great potential to serve as a conservation option to cereal farmers, especially during wet springs. However, prevented planting coverage restricts growers from harvesting crops until November 1 or later, without reducing their benefits by half. Because the November 1 date is too late to eliminate a cover crop and plant a winter crop, farmers often choose to leave their ground fallow instead.

Historically, prevented planting claims have been strongly correlated to high springtime precipitation. The expected increase in precipitation over the next several decades then suggests that prevented planting claims will also increase. Because soil erosion is a costly alternative, conservation strategies that reduce natural resource losses (e.g. cover crops) should be considered in insurance policies. Combatting soil degradation from weather events will help ensure long-term productivity and profitability.

Figure 2. Winter erosion after winter wheat harvest, direct seed versus conventional tillage.
Figure 2. Winter erosion after winter wheat harvest, direct seed versus conventional tillage.

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Originally posted on the REACCH website in September 2014.