Effects of Simulated Acid Rain on Yield Response of Two Soybean Cultivars

Abstract

An important component of the effects of acid rain on our ecosystem is its impact on the yield of agricultural crops. Field experiments were conducted for 3 yr to determine the effects of simulated acid rain on seed yield of two soybean [Glycine max (L.) Merr.] cultivars, 'Amsoy 71' and 'Williams 82'. Soybeans were grown on a Flanagan silt loam (fine, montmorillonitic, mesic Aquic Argiudoll) and protected from ambient rainfall by movable rain exlusion shelters. Plants were treated biweekly with simulated rain of pH 5.6,4.6,4.2, 3.8,3.4, and 3.0. For Amsoy 71 there was a linear decrease in yield with increasing rainfall acidity for 1 of 3 yr but no significant effects for the other two. Thus acid rain appears to reduce the yield of some soybean cultivars slightly but this effect is not consistent from year to year. Amsoy 71 and Williams 82 soybean treated with the most acidic rain, pH 3.0, resulted in average yields for the 3 yr of the study of approximately 3 and 4% lower than the average yields for the other treatments, respectively. However, calculations from the response functions developed have shown that at current levels of rainfall acidities the effects on yield are very small. With an increase in rainfall acidity of 50°7o in Illinois the predicted yield decrease for Amsoy 71 and Williams 82 soybean would be less than 1%. Similarly the expected increase in yield of these cultivars would be 1% or less if acidity in the rainfall were reduced by 50%. While there may be beneficial effects of reduced S and N oxide emissions, these results suggest the resultant lower rainfall acidities are not likely to produce noticeable changes in yield of soybean. Additional index words: Glycinemax (L.) Merr., Rain exclusion shelters, Grain yields, pH, Sulfate, Nitrate. Porter, P.M., W.L. Banwart, J.J. Hassett, and R.L. Finke. 1987. Effects of simulated acid rain on yield response of two soybean cultivars. J. Environ. Qual. 16:433-437.

Physiological response of two soybean cultivars to simulated acid rain

“…Such sensitivity could limit pbotosynthate production or utilization, resulting in increased pod abortion. In our study, however, neither yields nor final pods per plant were significantly affected by acid rain (Porter et al 1987(Porter et al , 1989.…”

“…Because sample sizes were small, caution should be used in interpreting the seed yield data. Complete yield data are reported elsewhere (Porter et al, 1987). In 1983, abscised leaf eight of Amsoy 71 increased with decreasing rain pH indicating accelerated leaf abscission at rain pH 3-0 and 4-2.…”

“…reported that simulated acid rain of The geographic region of the United States between pH 31 did not effect soybean yield components. Illinois and southeastern Ontario is a major soybean Similarly, recent reports (Porter et al, 1987(Porter et al, , 1989 \Glycine max (L.)] producing area that has been concluded that simulated acid rain had minimal subject to rainfall with a mean annual acidity of effects on yield or yield components for soybean approximately pH 42 to 4-6 for at least 10 years including dry matter production and pods per plant. (NADP, 1987).…”

Riverine Response of Sulfate to Declining Atmospheric Sulfur Deposition in Agricultural Watersheds

“…Early on in NAPAP it was recognized that acidic deposition had little impact on crop production, and studies in Illinois on corn and soybeans ended quickly (Banwart et al, 1987; Porter et al, 1987). However, S is an important macronutrient in plants (Dick et al, 2008), and decreasing atmospheric deposition of S has led to concerns about S deficiencies in crop plants in the midwestern United States (e.g., Dick et al, 2008; Fernández et al, 2012; Sawyer et al, 2011).…”