外文翻譯--希臘有機(jī)土壤的凈氮礦化培養(yǎng)試驗(yàn)（英文）

1、Incubation Experiments on Net Nitrogen Mineralization in Organic Greek SoilsAthanasios Charoulis and Theodore KaryotisNational Agricultural Research Foundation, Institute for Soil Mapping and Classification, Larissa, Gre

2、eceJohn MitsiosDepartment of Agronomy, University of Thessaly, N. Ionia, Volos, GreeceAbstract: Aerobic incubation experiments were conducted in organic surface samples collected from arable soils of Philippoi, in Northe

3、rn Greece. Laboratory experiments were carried out to investigate the nitrogen (N) mineralized from soils and sugar beet residues incorporated into the soils. Cumulative mineralization of N, potentially mineralizable nit

4、rogen (N0), and mineralization rate constant k were estimated after 30 continuous incubation weeks at 358C. Total N content of soils ranged between 6.6 and 19.2 g kg21, total soil carbon from 119 to 309 g kg21, soil orga

5、nic carbon ranged from 119 to 308 g kg21, and the C : N ratio varied from 13.5 to 18.3. The cumu- lative net mineralized N ranged between 132 and 426 mg kg21 for nonamended soil and between 165 and 586 mg kg21 for residu

6、e-amended soil. Nitrate was the main form of mineralized N, although appreciable amounts of ammonium were measured. Poten- tially mineralizable nitrogen (N0) varied between 254 and 1067 mg kg21 for non- amended soil and

7、311–1465 mg N kg21 in residue-treated soil. The mineralization constant k was between 0.052 and 0.068 (week21). Close relationships between total soil N and soil organic carbon, and between cumulative mineralization and

8、total soil N were found. Mineralization occurred rather rapidly, although the amount of miner- alized N per week was reduced in the later weeks of incubation. Variation in net mineralization among soil samples can be att

9、ributed to soil organic matter content, origin, and state of decomposition, as well as differences in management histories,Address correspondence to Athanasios Charoulis, National Agricultural Research Foundation, Instit

10、ute for Soil Mapping and Classification, 1 Theophrastou Str., Larissa 41335, Greece; E-mail: haroulis@lar.forthnet.grCommunications in Soil Science and Plant Analysis, 36: 231–240, 2005 Copyright # Taylor & Francis,

11、Inc. ISSN 0010-3624 print/1532-2416 online DOI: 10.1081/CSS-200043052Downloaded by [University of Manitoba Libraries] at 02:00 04 July 2014 with distilled water, dried at 608C for 48 h, and then pulverized. Soil pH value

12、s were measured in a 1 : 1 soil to H2O suspension (11). Soil carbonates were determined by the volumetric calcimeter method (12). Total soil carbon and total nitrogen were determined by LECO Elemental Analyzer (Model CNS

13、- 2000). Organic carbon content was estimated as the difference between total and inorganic form. Homogeneous subsamples were obtained from each air-dried soil sample, and nitrogen mineralization was estimated under cont

14、rolled conditions by the incubation method of Stanford and Smith (13). The incubation procedure involved the addition of triplicate 15 g air-dried soil samples mixed with equal quantity of quartz sand (20 mesh). Treatmen

15、ts for all soil samples were (1) nonamended soil and (2) soil amended with dried sugar beet residue. For soils receiving residue, dried and pulverized sugar beet leaves (0.2 g) were added to each incubation tube and mixe

16、d thoroughly. Soil tubes were placed to the incubator in vertical position in the dark. Soil water content was monitored by weighing the samples three times a week and adding water up to field water capacity (excess wate

17、r was removed under vacuum 60 cm Hg) (13). The temperature during the period of incubation was kept at 358C, and N mineralization was determined at time intervals of 2, 4, 7, 10, 14, 18, 24, and 30 weeks. Leaching was pe

18、rformed by adding 100 mL of 0.01 M CaCl2 followed by 25 mL of N-free nutrient solution. The leachates were collected in glass beakers of 100 mL, and the total volume was measured. After each incubation, NO3-N and NH4-N w

19、ere deter- mined by a FIAstar 9000 Analyzer (FOSS TECATOR, Sweden). The nitrogen mineralization potential (N0) was estimated from the equation Nt ¼ N0Figure 1. Simplified map of northern Greece.Incubation Experiment