Evaluation of nitrogen status of agricultural soils in Java,Indonesia

Abstract

To evaluate the content of nitrogen (N) fractions of agricultural soils in Java, Indonesia, in relation to soil type and land use, 46 surface soil samples, 23 from paddy and 23 from upland, were collected throughout Java to include various types of soils. Soil N was separated into four fractions according to form and availability: inorganic extractable nitrogen (Iex-N), fixed ammonium nitrogen (Ifix-N), organic mineralizable nitrogen (Omin-N) and organic stable nitrogen (Osta-N). The total-N content was determined by the dry combustion method. The Iex-N content was determined by extraction with a 2 mol L^?1 potassium chloride (KCl) solution and the Ifix-N content by extraction with an hydrofluoric and hydrochloric acid (HF-HCl) solution after removal of organic-N. The Omin-N content was evaluated as the potentially mineralizable N based on a long-term incubation method. The Osta-N content was calculated as the difference between the contents of total-N and the three other fractions. The total-N content was 2.06 g kg^?1 on average. The contents of Iex-N, Ifix-N, Omin-N and Osta-N were 25.8, 99.1, 103 and 1,832 mg kg^?1, respectively, and corresponded to 1.3, 4.8, 5.0 and 88.9% of the total-N. Hence, available (Iex-N and Omin-N) and stable (Ifix-N and Osta-N) fractions accounted for 6.3% and 93.7% of the total-N, respectively. Correlation analysis indicated that the contents of total-N and Osta-N had positive correlation with (Alo + 1/2Feo) as an index of amorphous minerals (p < 0.01), suggesting strong influence of volcanic materials for the accumulation of organic matter in Java soils. The content of Ifix-N had a positive correlation with nonexchangeable potassium (K) content (p < 0.01), suggesting the contribution of 2:1 clay minerals which can fix both ammonium (NH₄⁺) and K⁺ in their interlayer sites. On the contrary, Omin-N did not have any significant correlation with soil properties, implying the importance of management for the improvement of the available N level in soils, rather than intrinsic soil properties. Soil N status further showed strong topographical trends depending on the elevation where soil developed. The contents of total N, Iex-N, Ifix-N, Omin-N and Osta-N in Java soils were on average 80, 69, 90, 65 and 80% of those in Japanese soils, respectively, suggesting that the soil N level in Java was lower than that in Japan, probably due to accelerated decomposition of organic matter, especially degradable fractions, reflecting high temperature, but that the level was relatively high for tropical soils due to the effect of volcanic materials. In conclusion, these results should be taken into account for the sustainable management of soil N in agricultural fields in Java, Indonesia.     

There is more than chitin synthase in insect resistance to benzoylureas: molecular markers associated with teflubenzuron resistance in Spodoptera frugiperda

Journal of Pest Science - Chitin synthesis inhibitors are successfully used in pest control and an excellent option for integrated pest management programs due to their low non-target effects....     

Immunochemical Comparison Between sera from the Primary and Secondary Circulations in a Salmonid Fish,Sakhalin Taimen (<Emphasis Type="Italic">Hucho perryi</Emphasis>)

Fish has a unique, non-respiratory vascular system called secondary circulation, which forms capillary networks to the internal and external body surfaces. We compared protein composition in serum from the secondary circulation with that from the primary (blood) circulation. Chromatographic and electrophoretic patterns of sera from the two circulations were essentially same. Immunochemical analysis using specific antibodies against albumin-like protein (α1-protein), immunoglobulin M (IgM), transferrin, vitellogenin and choriogenin (precursor to eggshell protein) revealed that these major blood serum proteins in the primary circulation are present in the secondary circulation. Total protein concentrations in the secondary circulation were lower than those in the primary circulation. α1-Protein levels in the secondary circulation relative to the primary circulation were similar to those of total protein. IgM, however, had significantly lower relative levels in the secondary circulation than total protein. Despite some differences in the protein composition between the primary and secondary circulations, the presence of major blood serum proteins in the secondary circulation suggests that the secondary circulation plays a role in transporting them from the primary circulation to the body surfaces.     

Bt cotton and the predator Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) in the management of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) resistance to lambda-cyhalothrin

Journal of Pest Science - This study sought to provide relevant information for developing effective programs to manage Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) resistance to...     

Effects of hyaluronic acid on Ca(2+) influx, lactate dehydrogenase activity, and cyclic AMP synthesis in canine ejaculated sperm during In Vitro capacitation

The effects of hyaluronic acid, which comprises the cumulus intercellular matrix, on Ca(2+) influx, lactate dehydrogenase (LDH) activity, and cyclic AMP synthesis in canine sperm during capacitation was investigated. Ejaculated sperm were collected from 10 Beagle dogs and the sperm were incubated for 4 hr in Eagle's MEM containing 10 microg/ml of hyaluronic acid. The percentages of actively motile sperm, hyperactivated sperm (HA-sperm), acrosome-reacted sperm (AR-sperm), and sperm labeled with fluoresceinated Ca(2+) indicator (Ca(2+)-labeled sperm) were evaluated to assess Ca(2+) influx into the sperm. LDH activity and cAMP concentration were measured in homogenized sperm. The mean percentages of motile sperm, HA-sperm, and Ca(2+)-labeled sperm in the MEM containing hyaluronic acid were higher than in the control medium (P<0.05, 0.05, and 0.01, respectively), but there was no difference between the percentages of AR-sperm. Mean LDH activity and mean cAMP concentration were also significantly higher than the control values (P<0.05). The percentages of HA-sperm correlated with those of Ca(2+)-labeled sperm (r(2)=0.810). The results indicate that hyaluronic acid increases Ca(2+) influx, LDH activity, and cAMP synthesis in canine ejaculated sperm during capacitation in vitro.     

Ultrasonographic monitoring of nuclear transferred fetal weight during the final stage of gestation in Holstein cows

Dystocia or stillbirth accompanied by Large Offspring Syndrome (LOS) occurs rather frequently in Holstein nuclear transferred calves. In regard to prophylaxes, nuclear transferred Holstein fetuses were monitored with ultrasonography during the final stage of gestation. Fetal weight was estimated weekly based on the fetal metacarpal width using ultrasonography. Fourteen Holstein cows pregnant with Holstein nuclear transferred fetuses were the subjects of this experiment. The fetal weight was estimated by measuring the fetal metacarpal width during the last month of gestation according to the expected date of parturition. Measurements were performed on a weekly basis. The ultrasound-estimated metacarpal width and body weight of 13 of the fetuses in the last week of gestation (30.2+/-2.2 mm, 50.0+/-4.7 kg) were similar to the actual measurement immediately after birth (30.0+/-2.1 mm, 51.2+/-5.5 kg). These results indicate that ultrasonographic monitoring within a week of parturition to is accurate for estimating fetal weight. Prediction of LOS with ultrasonography contributes to reliable a diagnostic method that minimizes syndrome-related gyneco-obstetric complications at parturition with the aid of appropriate treatments.     

A pathological study of the salivary glands of rabid dogs in the Philippines

Rabies is a zoonotic disease caused by the rabies virus. While the salivary glands are important as exit and propagation sites for the rabies virus, the mechanisms of rabies excretion remain unclear. Here, we investigated the histopathology of the salivary glands of rabid dogs and analyzed the mechanism of excretion into the oral cavity. Mandibular and parotid glands of 22 rabid dogs and three control dogs were used. Mild to moderate non-suppurative sialadenitis was observed in the mandibular glands of 19 of the 22 dogs, characterized by loss of acinar epithelium and infiltration by lymphoplasmacytic cells. Viral antigens were detected in the mucous acinar epithelium, ganglion neurons and myoepithelium. Acinar epithelium and lymphocytes were positive for anti-caspase-3 antibodies and TUNEL staining. In contrast, no notable findings were observed in the ductal epithelial cells and serous demilune. In the parotid gland, the acinar cells, myoepithelium and ductal epithelium all tested negative. These findings confirmed the path through which the rabies virus descends along the facial nerve after proliferation in the brain to reach the ganglion neurons of the mandibular gland, subsequently traveling to the acinar epithelium via the salivary gland myoepithelium. Furthermore, the observation that nerve endings passing through the myoepithelium were absent from the ductal system suggested that viral proliferation and cytotoxicity could not occur there, ensuring that secretions containing the virus are efficiently excreted into the oral cavity.