Impact of pig slurry on soil properties, water salinization, nitrate leaching and crop yield in a four-year experiment in Central Spain     

J.A. Díez  P. Hernaiz  M.J. Muñoz  A. de la  Torre A. Vallejo 《Soil Use and Management》2004,20(4):444-450

Abstract. The repeated application of pig slurry to agricultural soils may result in an accumulation of salts and a risk of aquifer pollution due to nitrate leaching and salinization. Under Mediterranean conditions, a field experiment on a sandy loam soil (Typic Xerofluvent) was performed with maize (Zea mays) in 1998, 1999 and 2001 to study the effects of applying optimal (P1) and excessive rates (P3) of pig slurry on soil salinization, nitrate leaching and groundwater pollution. The rate of pig slurry was established considering the optimal N rate for maize in this soil (170, 162 and 176 kg N ha^?1 for 1998, 1999 and 2001, respectively). Pig slurry treatments were compared to an optimal N rate supplied as urea (U) and a control treatment without N fertilizer (P0). The composition of the slurries showed great variability between years. Mean NO₃^? leaching losses from 1998 to 2001 were 329, 215, 173 and 78 kg N ha^?1 for P3, P1, U and P0 treatments, respectively. The amount of total dissolved salts (TDS) added to the soil in slurry application between 1998 and 2001 was 2019 kg TDS ha^?1 for the P1 treatment and 6058 kg TDS ha^?1 for the P3 treatment. As a consequence, the electrical conductivity (EC) of the slurry‐treated soils was greater than that of the control soil. The EC correlated significantly with the sodium concentration of the soil solution. Over the entire experimental period, 2653, 2202 and 2110 kg Na ha^?1 entered the aquifer from the P3, P1 and P0 treatments, respectively. The P3 treatment did not significantly increase grain production in 1999 and 2001 compared with that achieved with the optimal N rate treatment (P1). This behaviour shows the importance of establishing application guidelines for pig slurry that will reduce the risk of soil and groundwater pollution.  相似文献   

Factors associated with Malassezia colonization in the ear canals of healthy dogs     

C. A. Reme 《Veterinary dermatology》2004,15(S1):15-15

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Input and output controls in fisheries management: a plea for more consistency in terminology     

A. K. Morison 《Fisheries Management and Ecology》2004,11(6):411-413

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Fixed nitrogen in sustainable farming systems: a symposium examining factors influencing the extent of biological nitrogen fixation and its role in southern Australian agricultural systems. Setting the scene     

J.A Baldock 《Soil biology & biochemistry》2004,36(8):1191-1193

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Practice relevant rapid tests for milk progesterone in cattle compared with a laboratory-connected routine method     

A Sobiraj  K I Arnstadt  R Scheibner  B Lehmann 《Tier?rztliche Praxis》1989,17(1):21-25

Four commercially available semiquantitative milk progesterone tests (Ovucheck-Praxistest: Cambridge Veterinary Science/Smith Kline), Progestassay-Milchprogesteron (Pitman-Moore/Janssen), Reprostrip-Progesteron-Schnelltest (Noctech/Albrecht), Enzygnost-Milchprogesteron (IQ, 'Bio' UK/Hoechst Veterin?r) were examined for their accuracy by using them for the determination of progesterone levels of 64 milk samples, i.e. 1556 single assays. Several test series were performed, using codified samples and changing sequences. Three or four test persons respectively, performed the tests independently and classified the samples semiquantitatively. These test results were then compared to the results acquired by measuring the progesterone levels of the same samples by means of an approved quantitative, labor-bound progesterone test (Hormonost: Biolab). These control tests were performed at a specialized routine labor, by different personnel and at a different location. Lastly, in 48 out of the 64 sampled animals the reproductive status could be evaluated clinically and was taken into account as well. Samples yielding high progesterone levels, i.e. greater than or equal to 9 ng/ml were classified correctly in 84.4 to 96.5% of the cases, whereas samples with low levels (less than or equal to 2.5 ng/ml) were classified correctly in 68.8 to 90.0% of the cases only. Samples ranging between this spectrum (greater than 2.5 less than 9 ng/ml) were classified correctly only in 42.1 to 52.6% of the cases. However, this range appears to be of the most interest for the veterinary practitioner since cows in proestrus or early interestrus tend to have mild progesterone levels within these values. On the other hand, clinical findings are often insufficient for a proper diagnosis just in these animals.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Recent advances in filtered-air positive-pressure (FAPP) housing for the production of disease-free chickens     

B W Mitchell  C W Beard  H W Yoder 《Avian diseases》1989,33(4):792-800

Design and performance information on a filtered-air positive-pressure (FAPP) housing system for disease-free poultry flocks is presented. The system includes many special features that result in excellent biological security, easy cleanup and maintenance, efficient control of environment, and a centralized alarm in the event of problems. The system has now housed eight flocks without any major problems. Based on its performance thus far, it should be useful as a reliable housing system for disease-free poultry.  相似文献   

A new virus disease of watercress in England1     

J. A. WALSH  C. M. CLAY  A. MILLER 《EPPO Bulletin》1989,19(3):463-470

In 1983 plants showing symptoms typical of watercress chlorotic leafspot agent (WCLSA) were found in Kent (GB). Later, plants showing similar symptoms were found in Dorset (1986) and Hampshire (1987), the main watercress-producing regions of England. These plants, unlike those infected with WCLSA, contained virus particles which were isometric with diameters of 37-38 nm. An antiserum to the virus was produced, with a titre in immunodiffusion tests of 1/128 and this gave good results in immunosorbent electron microscopy (ISEM) and ELISA tests on crude plant sap. Purified preparations of the virus reacted positively in ISEM and immunodiffusion tests with an antiserum to watercress yellow spot virus, a partially described virus occurring in France. Tests suggest that the crook root fungus Spongospora subterranea f.sp. nasturtii is probably the vector of this virus but other means of transmission cannot be excluded. Virus incidence within watercress beds varied, with little or no infection in the water inlet region of the bed where there are also low levels of crook root infection, higher levels in the central region and highest levels at the outlet region where crook root infection is also highest.  相似文献   

Construction and Development of the Dagangshan Forest Ecosystem Research Station     

WANG Bing ZHAO Guangdong CUI Xianghui BAI XiulanResearch Institute of Forest Ecology. Environment  Protection Chinese Academv of Forestry. Beiiins . China 《中国林业科技(英文版)》2002,(4)

Established by the former Ministry of Forestry in 1986, Dagangshan Forest Ecosystem Research Station is one of the 14 national key sites in the field of ecosystem research. In this paper, the basic situation of Dagangshan Forest Ecosystem Station is described, including geographic location, natural conditions, biological resources, research conditions, instruments, achievement, prospects etc.  相似文献   

Efficacy of anthelmintics in horses     

H Manners 《The Veterinary record》1989,125(23):584-585

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Prevalence of bovine tuberculosis among trade cattle in Southern Nigeria     

S. N. Wekhe  N. A. Berepubo 《Tropical animal health and production》1989,21(2):151-152

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