Paper · 2026 · Journal of Degraded and Mining Lands Management

Path analysis of “new” humic acid derived from water hyacinth on phosphorus dynamics in P-deficient Inceptisols and chili response under intensive cultivation

Emma Trinurani Sofyan; Mega Kartika Hermawan; Rija Sudirja; et al.

4
claims
5
verbatim quotes
0
citations
2
research areas
✓
Open access · cc-by-nc

Abstract

Phosphorus (P) deficiency in intensively cultivated Inceptisols is a persistent problem, not only because of low P reserves but also because of ongoing soil degradation, which reduces fertilizer use efficiency and is characteristic of degraded soils. This study aimed to develop a “new” humic acid from water hyacinth biomass (WHL) through accelerated aerobic decomposition using lignocellulolytic microorganisms and to evaluate its effectiveness in improving soil P dynamics and chili growth responses. The experiment was conducted on P-deficient Inceptisols of the Jatinangor series characterized by low P availability and high metal content. Water hyacinth collected from local reservoirs and rivers was aerobically decomposed with selected microbial starters to enhance humification. WHL was applied in combination with inorganic P fertilizer (SP-36), and its effects on soil P availability, phosphorus dynamics, and chili pepper growth and yield were evaluated using path analysis. The results showed that WHL significantly improved P dynamics mainly through an indirect mechanism involving increased P availability and reduced P fixation, thereby improving chili growth and yield. Application of WHL at a rate of 30 kg ha?¹ combined with SP-36 at a rate of 250 kg ha?¹ produced responses comparable to those obtained with commercial humic acid. These findings indicate that WHL has strong potential as a renewable and cost-effective alternative source of humic acid to improve phosphorus efficiency, restore soil chemical function, and reduce dependence on inorganic P fertilizers in degraded Inceptisols under intensive cultivation.

Abstract from the paper’s OpenAlex record; open copy licensed cc-by-nc. Read at the source ↗

The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.

Claims 4

Intervention effectobservedoriginal resultpositivesignificant (as stated)measured

Claim · model-written summary

Water-hyacinth humic acid significantly increased soil phosphorus availability.

Taxon
chilie0
Treatment
WHLe0
Outcome
P availabilitye0
Direction
increasede0

Not reportedComparator

Verbatim

e0

“WHL significantly improved P dynamics mainly through an indirect mechanism involving increased P availability and reduced P fixation, thereby improving chili growth and yield”

✓ located verbatim in the source · abstract, characters 1011–1185 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

Water-hyacinth humic acid reduced soil phosphorus fixation.

Taxon
chilie0
Treatment
WHLe0
Outcome
P fixatione0
Direction
reducede0

Not reportedComparator

Verbatim

e0

“WHL significantly improved P dynamics mainly through an indirect mechanism involving increased P availability and reduced P fixation, thereby improving chili growth and yield”

✓ located verbatim in the source · abstract, characters 1011–1185 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

Water-hyacinth humic acid improved chili growth and yield.

Taxon
chilie0
Treatment
WHLe0
Outcome
chili growth and yielde0
Direction
improvinge0

Not reportedComparator

Verbatim

e0

“WHL significantly improved P dynamics mainly through an indirect mechanism involving increased P availability and reduced P fixation, thereby improving chili growth and yield”

✓ located verbatim in the source · abstract, characters 1011–1185 · show in text ↑
Intervention effectobservedoriginal resultmeasured

Claim · model-written summary

The WHL and fertilizer combination gave responses comparable to commercial humic acid.

Taxon
chilit0
Treatment
WHL at a rate of 30 kg ha?¹ combined with SP-36 at a rate of 250 kg ha?¹e0
Outcome
responses comparablee0
Direction
comparablee0
Comparator
commercial humic acide0

Verbatim

e0

“Application of WHL at a rate of 30 kg ha?¹ combined with SP-36 at a rate of 250 kg ha?¹ produced responses comparable to those obtained with commercial humic acid”

✓ located verbatim in the source · abstract, characters 1187–1349 · show in text ↑
t0

“chili”

✓ located verbatim in the source · title, characters 116–121 · show in text ↑