ISOLASI DAN UJI POTENSI ISOLAT BAKTERI PELARUT FOSFAT DAN BAKTERI PENGHASIL HORMON IAA (Indole Acetic Acid) TERHADAP PERTUMBUHAN KEDELAI (Glycine max L.) PADA TANAH KUNING
Abstract: Biofertilizer is a safe alternative
fertilizer instead of
various chemical fertilizers
for increasing plant productivity which can
minimize the ecological damage. There
are plant symbiotic-soil bacteria
which can solubilize phosphate or
produce IAA. The objectives of this research are to determine the best soil
bacteria in producing IAA or solubilizing phosphate and to know their roles in
promoting plant growth in unfertile soil. As
many as 8
isolates of phosphate
solubilizing bacteria and
5 isolates of IAA
producing bacteria were found. Among those isolates, there were
2 potential isolates (P2 & P4) that were able to solubilize phosphate and 1
potential isolate (I3) that was able to produce IAA. Isolate P4 produced
holozone as wide as 1.45 cm and isolate P2 was 1.3 cm. Meanwhile, isolate I3
produced the highest concentration of IAA compared to the other isolates, that
was 33.3 ppm. These isolates were applicated further on unfertile soil (yellow
soil) as a medium for soybean growth. Soybeans have been grown for 10 weeks to
observe the effect of those potential isolates
on plant growth
and productivity. The
result showed that
application of isolate
I3 was able
to promote plant growth and increase plant productivity better than the
other isolates as well as controls (fertile and unfertile soil). It promoted
the soybean growth such as plant height was 58,8 cm; plant fresh weight was 3.5
g; plant dry weight was 1.55; pod fresh weight was 1.23; pod dry weight was
1.03; the amount of the pod was 3 and the number of the seed was 7.
Keywords: Phosphate
solubilizing bacteria, IAA producing bacteria, biofertilizer, soybean
Penulis: Dessy Merry Silitonga,
Nunuk Priyani dan Isnaini Nurwahyuni
Kode Jurnal: jpbiologidd130003
