Using of Humic Matter from Low Rank Coal to Increase Phosphorous Fertilizer Efficiency and Production of Corn at Oxisol

Abstract

The objective of this research was examined humic matter from low rank coal capability  combined with P fertilizer to adsorp Al and Fe metal, to improve soil fertility, to increase of P fertilizing efficiency and productivity Oxisol, therefore optimalize productivity of corn can be achieved. The experiment was designed using a 3 x 4 factorial with 3 replications in design groups randomly. The 1st factor was 3 way incubating humic matter with P-fertilizer are : I1 = Incubation of humic matter 1 week, then incubation P-fertilizer 1 week; I2 = Incubation of humic matter and P fertilizer directly into the soil for 2 weeks; and I3 = humic matter and P fertilizer mixed for 1 week, then incubation to the soil for 1 week. The 2nd factor was humic matter and P-fertilizer combination are 4 doses H1=400 ppm (0.8 Mg ha-1)+ 100% R; H2 = 400 ppm + 75% R; H3 = 800 ppm (1.6 Mg ha-1) + 100% R; and H4 = 800 ppm + 75% R. The results showed that the best treatment interaction was founded 800 ppm humic matter and 100% R P-fertilizer doses in the first 3 way incubation that is corn  yields increased from 4.53 Mg ha-1 (control) and 5.65 Mg ha -1 (farmer tradition) to 9.21 Mg ha -1.. However, this result is almost the same as 800 ppm humic matter + 75 % R P-fertilizer doses incubation with followed I3 way too. It was concluded that addition of humic matter and I3 incubation could be P-fertilizer save up to 25%.