Acidic Precipitation Effects on Crops: A Review and Analysis of Research

Abstract

For more than a century it has been known that vegetative growth is affected by the products of fossil fuel combustion. Recently, the acidic deposition phenomenon has gained increasing attention, especially when implicated as a factor responsible for economic loss. Research has been directed toward quantification of effects; however, limitations in the design of many crop studies restricts the usefulness and applicability of the results. Acidic deposition varies in a number of ways that may affect crop yield (i.e., level of acidity, amount and intensity of rain, S and N doses). The responses to these variables may be nonlinear. To allow comparisons of published acid precipitation effects research, calculations for this review were made (based on information in the literature or from personal communication) to describe the experimental conditions, the various dose parameters, and the responses in comparable units for each investigation.The majority of crop species studied in field and controlled environment experiments exhibited no effect on growth nor yield as a result of simulated acidic rain. The growth and yield of some crops, however, was negatively affected by acidic rain; others exhibited a positive response. This analysis of the current literature concludes that the effects of acidic precipitation on crops appear to be minimal and that when responses are observed, they may be positive or negative. More complex experimental designs and analyses may be necessary in order to examine and describe the possible subtle responses of agricultural systems to acidic precipitation.

Response of Eastern Hardwood Species to Ozone, Sulfur Dioxide and Acid Precipitation

“…The reason for this is unclear and has been reported by other reseachers. 12 Evans and coworkers 13 reported that even the method by which rain is applied can affect the growth response. The proposed mechanisms by which acid rain may affect growth are reviewed by McLaughlin 14 and Morrison.…”

A Collaborative Effort to Model Plant Response to Acidic Rain

“…The Mitscherlich model was explored as an alternative to functions which have been used to model plant response to ozone 8 because the Mitscherlich has natural biological interpretations for its parameters and it has been applied previously to model plant growth response to the supply of nutrients. The Mitscherlich function is intuitively more satisfactory than a plateau-linear model 2 because it does not assume the existence of a sharp break in response. Although the Mitscherlich function is a generalized model that fits many types of data, it would not be appropriate for data that demonstrates a stimulatory effect at low concentrations (quadratic relationship).…”

“…3 ' 4 Nor have the effects of growth conditions on exposureresponse functions been evaluated even though there is reason to believe that environmental conditions change plant response to acidic rain. 6 Disagreement in results between laboratories performing research on acidic rain may be due to many factors 2 and the contribution of different treatment and growing conditions to the divergency of results is not known.…”

Different responses of two Mosla species to potassium limitation in relation to acid rain deposition

“…The negatively charged nitrate and sulphate ions in acid rain may act as "counter-ions," which allow cations such as potassium (K + ), sodium (Na + ), calcium (Ca 2+ ) and magnesium (Mg 2+ ) to be leached from the soil and become unavailable to plants (Ivring, 1983). This will probably lead to nutrient deficiency.…”