Response of Peanuts and Other Crops to Fertilizers and Lime in Two Long Term Experiments¹

Two long term fertility experiments on a Dothan fine sandy loam (Plinthic Paleudult) included peanuts for short periods. Peanuts were in a rate of N-P-K experiment during 1973-75 and 1981-83. They did not respond to N. Mehlich-1 extractable soil test P dropped from 30 mg/kg in 1954 to 11 mg/kg by 1983. No yield response to P was found for any crop. The soil test K level of 44 mg/kg remained about the same over the 30 years. Cotton yield was doubled by the addition of 37 kg/ha of K, which also increased the soil test level to 56 mg/kg. Peanut and corn yields were increased by 19 kg/ha K, with no further response to higher rates. The addition of lime produced large yield increases from all three crops.

A 2-year rotation experiment from 1929 through 1983 included cotton, corn, soybeans, and wheat at different periods until 1982 and 1983, when the crops were peanuts and grain sorghum. Soil test P in 1929 was 33 mg/kg. No response to P was found on summer crops in over 50 years, and soil test P decreased to only 21 mg/kg during this period. Plots that received no K maintained a constant soil test K level of about 36 mg/kg for 54 years. Annual applications of 28 kg/ha increased the level to around 60 mg/kg. Cotton and grain sorghum produced maximum responses to this rate of K. When peanuts were planted in this experiment for the first time in 1982 and 1983, they produced no response to K. All crops except wheat responded to lime.