Abstract
Field experiments were conducted during the wet seasons of 1983-84 and 1984-85 to evaluate the effectiveness of farmyard manure (FYM) and FYM plus lime on maize growth and on pH and exchangeable Al of an acid Oxic Paleustalf with initial pH values of 3.9 to 4.3 and exchangeable Al of 1.3 cmol (+) kg-1. Lime at 3 t ha-1 and 6 t ha-1 was applied only at the beginning of the 1983-84 season while FYM at 30 t ha-1 was applied every season. Lime alone significantly reduced exchangeable Al, but it had only a small effect on increasing soil pH and was ineffective in increasing maize growth and yield. Higher reductions in exchangeable Al (at least 50% above the values obtained with lime alone) and an increase of one unit in the pH of the top soil were obtained by application of FYM alone, or in combination with 3 t ha-1 of lime. FYM alone and FYM plus lime significantly increased plant growth and yield compared to lime only. This study has shown that application of FYM alone may provide a rapid method of overcoming soil infertility and increasing crop yield in acid Alfisols where lime by itself may not be an effective amendment.
