As early as the late 1800s, scientists recognized differences in crop responses to added lime. Since that time, numerous researchers have substantiated and expanded these findings, by suggesting that both corn and soybean are more acid tolerant than alfalfa. For example, in 1964 Doll in Michigan recommended pH ranges for corn to be 5.5 to 7.5, soybean 6.0 to 7.0, and alfalfa 6.3 to 7.8. When Woodruff (1972) reviewed the Midwestern literature published prior tot he early 1970s, he noted that corn generally did not respond to lime unless the pH was 5.0 or less. Furthermore, Woodruff stated that where lime responses were seen, there did not appear to be a benefit from higher rates of application. This early work did not specifically review any soybean experiments; however, it is clear that like those for corn, responses are soil type and location specific.