PENGGUNAAN MACAM BAHAN ORGANIK DENGAN KANDUNGAN HUMAT DAN FULVAT BERBEDA DAN PUPUK P TERHADAP KETERSEDIAAN DAN SERAPAN P PADA TANAMAN JAGUNG MANIS

Abstract

Low P availability and high P sorption observed in
Andisols are considered as important limiting
factors for crop production. Hence, efforts made to
improve P availability to crop demand are needed
for management of Andisols. Humic and fulvic
acids derived from organic matters that are added
to soils are able to improve P availability by
reducing P sorption. Objectives of this study was
to elucidate effects of application of the three types
of organic matters containing different humic and
fulvic acid contents on P availability and uptake by
maize. The study was carried out in a glasshouse
of the Faculty of Agriculture, Sebelas Maret
University, from August to November 2005.
Gliricidia sepium pruning having highest content
of humic and fulvic acids played the most
significant role in increasing P availability.
Increased available P due to application of the
three types of organic matters was in the order of
Gliricidia sepium pruning (53.61%), rice straw
(1.18%), and manure (16.13%), compared to
control. The changes in soil chemical properties
(Al, Fe and pH) and increasing P availability,
increased P uptake in the tops of maize