Judul: Evaluation of Chicken Manure Rate in Andisols Wonokitri Based on Phosphorus Sorption And Fractionation Dynamics
Abstrak: Andisols have problems with the low efficiency of phosphorus (P) fertilization due to the high retention of P. Phosphorus in Andisols can accumulate in unavailable form. Farmers in Andisols generally applied organic matter such as chicken manure in high doses to reduce these problems, therefore it is necessary to evaluate the dynamics of P sorption and P fraction after the addition of chicken manure. This research is needed to increase fertilizer efficiency and reduce the potential for environmental pollution. This research was conducted in February-November 2022. The soil sample was collected from Wonokitri Village, Tosari District, Pasuruan Regency, East Java Province. Laboratory analyzes were conducted at Soil Chemistry and Fertility Laboratory, Soil and Environmental Biotechnology Laboratory, Department of Soil Science and Land Resources, Faculty of Agriculture, IPB, and at Agricultural Instrumentation Standardization Agency (BSIP) of the Indonesian Ministry of Agriculture. This research was used a completely randomized design (CRD) which consisted of 5 rates of chicken manure addition in Andisols Wonokitri, namely without added chicken manure (PM0), 10 t ha-1 (PM10), 20 t ha-1 (PM20), 30 t ha-1 (PM30), 40 t ha-1 (PM40). Each treatment was repeated 3 times to obtain 15 experimental units. The treated soil was put in a jar, and watering with distilled water until reaches 85% of field capacity and incubated for 2 weeks, then analyzed to determine the soil properties. Greenhouse experiment was carried out using wheat (Triticum spp.) for 14 days. The observed parameters were P sorption, P release, P sorption kinetics, P fractionation and P uptake by plants. Analysis of variance was performed at 95% confidence intervals followed by Tukey test at 95% confidence interval. The results showed that the P content in Andisols Wonokitri was at very high level, which caused by high rates and continuous application of inorganic and organic fertilizers. The Langmuir isoterm simulation showed that the chicken manure addition at rate of 10-40 t ha-1 significantly reduced the values of P bonding energy (k) in Andisols Wonokitri, although not reduced the sorption maxima (b). The sorption experiment simulated with Langmuir isoterm reveal two sorption sites and showed a decreasing value of k along with increasing rates of chicken manure. PM40 had the lowest k value in all sorption sites compared to all treatments, however PM40 was not significantly different with PM20 in second sorption site. In the P desorption experiment, showed only one sorption site and PM40 was not significantly different from PM10. The sorption-desorption simulation using the Freundlich isotherm showed that the sorption constant value (K) decreased along with increasing a rate of chicken manure addition. The P sorption kinetic experiment showed that the application of chicken manure decrease the P sorption rate constant (k), however there was no significant difference in PM20-PM40. The P fractionation analysis showed the application of chicken manure increase the P resin, NaHCO3-Pi and NaOH-Pi along with increasing rate of chicken manure. The addition of chicken manure did not decrease the HCl-Pi and Residual-Pi fractions. The increased levels of available-P fractions (P resin and NaHCO3-Pi) due to the addition of chicken manure correlated with an
Keyword: Amorf, Bahan Organik, Efisiensi, Eutrofikasi, Pemupukan