Judul: Dinamika Air Dalam Tanah Dan Hubungannya Dengan Sifat-Sifat Struktur Tanah Pada Latosol Semplak
Abstrak: Water in soil is important for plant growth as nutriment, nutriment solvent, and nutriment dissolve flow in soil. Volume and water distribution in soil affected by some factor. The factor e. g : soil structure. Soil structure related with soil pore distribution, which is affected water flow and distribution water in soil. In fact, soil structure has many variant both spatial and temporal. Many variant of soil structure caused the high variant pore distribution. Variant of soil structure could happen because of the different land cultivate. The aim of this research are to the dynamics of water in soil at ex-rice field land and dry land and the ationship with soil structure characteristics. This research starting with soil selection which have different soil stucture characteristic (aggregate stability, aggregate distribution, and pore distribution), taking soil sample, soil analysis at the laboratory, experiment and measurement in spacious, and analyse data. Soil moisture ex-rice field land always higher than dry land. Soil moisture ex-rice field land and soil moisture dry land will be higher at deeper soil layer above layer. Dynamics of change soil moisture beetwen ex-rice field land and also dry land caused by different of rain distribution also soil physical characteristic. Relation link among of soil physical characteristic to soil moisture dynamics seen different each other. Soil aggregate stability index have negative correlation with soil moisture. Excelsior soil aggregate satibility index, make soil moisture decreased, and conversely. Total porosity and micropore have positive correlation with soil moisture. Excelsior total porosity and micropore, make soil moisture increase. But the correlation of macropore to soil moisture on ex-rice field land differ from dry land, that is increase of macropore to dry land the degrade soil moisture, whiel on the ex-rice field land raising of macropore can be raise soil moisture.
Keyword: 

Judul: Karakteristik Fisik Tanah dan Dinamika Kadar Air Tanah pada Berbagai Penggunaan Lahan (Studi Kasus : Kebun Percobaan Cikabayan)
Abstrak: The water supply in dryland agriculture relies on rain water. Erratic rainfall which is often compounded by high intensity of sun light causes a high evapotranspiration, so that soil water is significanly decrease. Changes in soil water levels is variable depending on land use type and is affected by various factors. The dynamic of soil moisture content is then strongly influenced by rainfall pattern and physical characteristic of soil, where the soil characteristic itself is influenced by land use type. This study aims to determine physical characteristic of soil and dynamic of soil water in various land use and rainfall in The Experiment and Research Garden of Cikabayan, IPB, Dramaga, Bogor. Each land use has different permanent wilting point and soil water level due to difference in density of canopy or the depth of soil layer. The field soil moisture content under oilpalm is still higher than the permanent wilting point although no rain for eight days. It may be caused by the dense canopy of palm trees which can reduce the rate of evaporation. The field soil moisture content under citrus fall below the wilting point at the sixth day after rain (on 10-30 cm layer) and the eighth day after rain (30-50 cm layer), while soil under annual crop is still possibly providing water supply even though no rain for eight days .
Keyword: 

Judul: Pengujian Virus Newcastle Disease Gen VII Isolat Lapang Sebagai Virus Standar Pada Uji Tantang Vaksin
Abstrak: This study was conducted to determine the standard of Newcastle disease virus Gene VII field isolate as a virus challenge to vaccine test. A virus suspension that has previously been tested by HA test then titrated with EID50 using 30 Specific Pathogen Free (SPF) of 10 day old chicken embryonated eggs. In addition, chicken lethal dose50 (CLD50) test were used to determine the virus titer that could cause 50% death of the chicken population. The CLD50 test was used 25 day-old-chickens (DOC) divided into 5 groups. The virus was diluted from 10-1 to 10-8. The 104 to 10-8 dilution of NDV was infected to every group of chicken via eyedrop and intranasal with 0.1 ml/chicken dosage. Haemagglutination test showed that the allantoic fluid were contain high titers of NDV is 512 HAU. The infective NDV that had been titrated by EID50 test showed the virus titers is 109 EID50/0.1 ml or 1010 EID50/ml and the virus titers of CLD50 test e.i 106.48 CLD50/0.1 ml or 107.48 CLD50/ml. These results can be concluded that the NDV Gene VII field isolates were most appropriate to be used as a standard virus to vaccine test
Keyword: Newcastle Disease Virus Gene VII, HA tes, EID50 test, CLD50 test