Interaction of Tillage System and Irrigation Amount on Peanut Performance in the Southeastern U.S

Abstract

Abstract A five-year study to investigate the potential interaction of conservation tillage with reduced irrigation amounts was conducted near Dawson, GA on peanut (Arachis hypogaea L.). Conventional tillage was compared to two conservation tillage programs (wide-strip and narrow-strip tillage) under four irrigation levels (100, 66, 33, and 0% of a recommended amount). Peanut yield did not exhibit a tillage by irrigation interaction as expected, although the main effects of irrigation and tillage were each significant by year due to weather variations. Peanut yield in narrow-strip tillage or wide-strip tillage were individually superior to conventional tillage in three seasons out of five, however only in one year did both conservation tillage systems outperform the conventional system. No detrimental effects on yields could be attributed to conservation tillage. Peanut quality and digging loss were dependent on the tillage by year effect as well as the main effect of irrigation. Irrigation increased total sound mature kernels (TSMK) 2% versus non-irrigated (0% irrigation level); tillage was not significant each year of the study but increased TSMK 2% in three of five years. Digging losses were greater in plots with increased yield potential such as those receiving irrigation. Net economic returns revealed a moderate trend towards sustained profitability under reduced irrigation levels through narrow-strip tillage and to a lesser extent, wide-strip tillage. Under conventional tillage systems, returns decreased with decreasing amounts of irrigation applied.