DETERMINATION OF UREA-HUMIC ACID DOSAGE OF VERTISOLS ON THE GROWTH AND PRODUCTION OF RICE
ABSTRACT: The main problem of
the use of N fertilizer in paddy soil Vertisols is the low efficiency.
Urea-humic acid applications at certain dosage are believed to increase rice
growth and production. This study was aimed to examine the effect of urea and
urea-humic acid to the amount and form of N-available, N uptake, plant growth,
and the production of rice. Five dosage levels of urea-humic acid were applied
for rice on Vertisols. Results of the research showed that the urea-humic acid
fertilizer could increase the content of N-NH4+ soil at 28 days and N-NO3- soil
at 42 days. The urea-humic acid could improve plant height, number of tillers,
and total dry weight. The highest rice production is achieved by 100% humic
acid-urea, especially on parameters of dry weight effectively harvested and
effectively milled, with 5.56 tons and 4.61 tons per hectare respectively.
Correlation between soil N-NO3- level with soil N-NH4+ level was significant at p = 0.05 (r =
0.871). Efficiency of urea-humic acid fertilizer at 100% recommended dosage
(200 kg urea-humic acid) to the dry weight of
effectively harvested crop with dry weight of effectively milled crop
was 22% compared to the recommended urea fertilizer (200 kg ha-1).
Author: Retno Suntari, Rurini
Retnowati, Soemarno, Mochammad Munir
Journal Code: jppertaniangg150023
