Rhizoma peanut responses to fertilizer treatments on a Louisiana coastal plain soil

Abstract

Responses of rhizoma perennial peanut (Arachis glabrata Benth.) to rates of phosphorus (P), potassium (K), and a commercial product containing K, magnesium (Mg), sulfur (S), and boron (B) were evaluated on a Louisiana Coastal Plain soil. Although even the highest rate of ? failed to maintain the initial high level of soil P, no response in forage production to ? fertilization was obtained. Annual forage production with ? fertilization of 75 or 150 kg/ha/yr averaged 7,470 kg/ha compared to 6,100 kg/ha of forage for the control. Although yields were similar at the above two rates of K, the 150 kg/ha/yr rate maintained the initial soil ? level, while the 75 kg/ha/yr rate resulted in a decrease in soil ? from 40 to 30 mg/kg over three years. Lack of a response to the commercial product containing Mg, S, and ? at 110 or 220 kg/ha/yr of product indicated that soil levels of these nutrients were adequate for rhizoma peanut under the conditions of this experiment. Unexplained, non‐treatment differences in soil Ca and pH among plots produced negative correlations with forage yield, suggesting possible sensitivity of rhizoma peanut to reduction in availability of a micronutrient with increasing pH. Under the relatively fertile conditions of this 3‐year field experiment, rhizoma perennial peanut produced positive yield responses to ? fertilization at 75 and 150 kg/ha/yr, but forage production was not increased by ? or a source of Mg, S, and B.