Judul: Model Lintas Transformasi Unsur Fosfor Tanah Kaolinitik dan Smektitik
Abstrak: Phosphorus (P) is one of essentials needed in a sufficient amount to normal plant growth. The objective of this research was to path modelling caolinitic and smectitic soils P transformations. Path diagrams were able to describe soil P transformations, Its elaboration resulted in structural equation models which were P transformations path models. The models parameters estimated using Partial Least Square (PLS). Bartlett's test and KMO showed not all variables used had multicolinearity. Only P-uptake (X1), Po-NaHCO3 (X5), Pi-NaHCO3 (X6), Pi-NaOH (X7), P-occluded (X8), P-HCl (X9) from caolinitic and P-uptake (X1), Po-NaHCO3 (X5), Pi-NaHCO3 (X6), Pi-NaOH (X7), P-HCl (X9) from smectitic which included in path modelling.
Keyword: smectitic soils, phosphorus transformations, path analysis, partial least square, caolinitic soils

Judul: Perubahan Fraksi Fosfor Cepat Tersedia pada Tanah Tergenang yang Diameliorasi Bahan Organik
Abstrak: Prolong phosphorus fertilization has result in high unavailable P residue in soil. In this condition, further P fertilization will not result in higher plant productivity known as leveling off. P in soil exists in inorganic and organic forms, and in broad-range of availability from freely available to unavailable forms. The objective of this research was to study the effects of organic matter on rapidly available P extracted with 0.5 M NaHCO3 in submerged soil. Organic matter treatments were 0, 500, 750, 1000, 2000, and 5000 kg/ha. Research unit was 200 g soil (105oC ovendry weight) in a 10 cm diameter pot. Everyweek for 5 weeks, subsamples of each research unit was extracted for determining NaHCO3-P fraction following Tiessen and Moir 1993 procedure. The results showed that NaHCO3-P increased with increasing organic matter treatments and submersion time. Some dynamics, however, were found that likely related to redox dynamics in submerged soil.
Keyword: Bogor Agricultural University (IPB), Submerged Soil, NaHCO3-P, P availability, Organic Matter

Judul: Respon Antibodi pada Ayam Broiler yang Divaksinasi Vaksin Rekombinan Infectious Bursal Disease (IBD).
Abstrak: Penelitian ini dilakukan untuk mengevaluasi durasi antibodi asal induk terhadap Avian Influenza (AI) dan mengevaluasi respon antibodi Infectious Bursal Disease (IBD) pada ayam broiler yang divaksinasi dengan vaksin IBD rekombinan. Penelitian ini meggunakan dua kelompok ayam broiler: kelompok divaksinasi dan kelompok kontrol. Kelompok yang divaksinasi menerima vaksinasi herpesvirus of turkey (HVT)-IBD pada usia satu hari dan kelompok kontrol tidak divaksinasi apapun. Sampel serum diambil pada hari ke 3, 6, 9, 12, 15, 19, 22, 26, 29, dan 33. Keberadaan antibodi AI ditentukan dengan uji inhibisi hemaglutinasi (HI), sedangkan keberadaan antibodi IBD ditentukan dengan enzyme linked immunosorbent assay (ELISA). Antibodi AI asal induk pada kedua kelompok terdeteksi dari hari ke 3 hingga hari ke 29, tetapi titer antibodi berada di bawah level protektif 24. Antibodi IBD pada kelompok kontrol, positif dari hari ketiga hingga 33, tetapi rataan titer antibodi turun pada level terendah pada usia 15 hari. Titer antibodi IBD pada kelompok yang divaksinasi positif sampai usia 33 hari. Penelitian ini menunjukkan bahwa keberadaan antibodi AI asal induk tidak dipengaruhi oleh vaksinasi HVT-IBD, dan keberadaan antibodi IBD asal induk tidak memengaruhi keberhasilan vaksinasi HVT-IBD.
Keyword: antibodi, ayam broiler, Avian Influenza, Infectious Bursal Disease, HVT-IBD