摘要:

The persistence of the effects of four nitrification inhibitors (2‐ethynylpyridine, nitrapyrin, etridiazole, 3‐methylpyrazole‐l‐carboxamide) on nitrification in soil was assessed by measuring the ability of two soils to nitrify NH4+[added as (NH4)2SO4] after they had been treated with 5 μg inhibitor g‐1soil and incubated at 10, 20, or 30°C for 0, 21, 42, 84, 126, or 168 days. The soils used differed markedly in organic‐matter content (1.2 and 4.2% organic C). The data obtained showed that the persistence of the effects of the inhibitors studied decreased markedly with increase in soil temperature from 10 to 30°C and that, whereas the initial inhibitory effects of the test compounds on nitrification were greatest with the soil having the lower organic‐matter content, the persistence of their effects at 20 or 30°C was greatest with the soil having the higher organic‐matter content. The inhibitory effects of 2‐ethynylpyridine and etridiazole on nitrification were considerably more persistent than those of nitrapyrin or 3‐methylpyrazole‐l‐carboxamide and were significant even after incubation of inhibitor‐treated soil at 20°C for 168 days.

ISSN:0010-3624    

DOI:10.1080/00103629009368259

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Removal of moisture from soil is of great importance in research, and any attempt in improving the existing soil drying techniques would be desirable. Evaporation rates of water from six soil samples of varying organic matter content were determined gravimetrically while exposed simultaneously to bipolar ions produced by corona electrodes and a thallium‐204 beta‐ray source. These devices produced ion fluxes of 2.63 × 1012positive and 2.68 × 1012negative ions cm‐2s‐1in air at the soil surface. Argon (A), dry air, and nitrogen (N) gases were used as ionization media for moisture loss studies. The rate of moisture loss was found to be the lowest in N. The water vapour fluxes from the exposed soil samples were enhanced by a factor of at least three compared to control samples under ambient conditions.

ISSN:0010-3624    

DOI:10.1080/00103629009368260

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

ISSN:0010-3624    

DOI:10.1080/00103629009368248

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor