Loss of nitrate nitrogen in the soil surface layer in Japanese grassland during the heavy rainfall season and its enhancement by the root mat

1980 ◽  
Vol 55 (1) ◽  
pp. 147-151
Author(s):  
N. Ae
2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Kantamla Biseke Mafuru ◽  
Tan Guirong

This study analyses the spatial and temporal distribution of heavy rainfall events (HREs) and its associated circulation anomalies over Tanzania during March to May (MAM) rainfall season of 1980–2010. A total of 822 HREs were revealed, concentrated over the northern sector (NS) of the country. Years with anomalous HREs are associated with low-level westerly convergence, advection of moisture from both the Indian Ocean and Congo basin, an upper warm temperature anomaly (UWTA), intensified and well-positioned Intertropical Convergence Zone (ITCZ), and pronounced rising motion since the ascending limb of the Walker type of circulation is centered over Tanzania. The analysis of the UWTA in this study has brought a key factor in exploring the possible likely cause and improved early warning system for the HREs during the MAM rainfall season in Tanzania. Making use of the thermal wind equation and the velocity divergent form of the continuity equation (DFCE), we found that the UWTA results into an upper-level horizontal wind divergence which significantly accelerates vertical ascent, deepening the surface low pressure for an enhanced convective process and HREs formation.


Atmosphere ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1195
Author(s):  
Vladimir Kalchikhin ◽  
Alexey Kobzev ◽  
Petr Nagorskiy ◽  
Mariya Oglezneva ◽  
Konstantin Pustovalov ◽  
...  

The electrical state of the surface atmosphere changes significantly under the influence of cloudiness and atmospheric phenomena, including atmospheric precipitation. These features can be used for possible diagnostics of precipitation and improvement of their characteristics based on variations of atmospheric-electrical quantities in the surface layer. Studies of variations of meteorological and atmospheric-electrical quantities in the surface layer were carried out during the heavy rainfall associated with the cumulonimbus (Cb) clouds passage. Meteorological and atmospheric-electrical observations in the Geophysical Observatory of the Institute of Monitoring of Climatic and Ecological Systems are presented in this paper. Precipitation data are used to identify periods of heavy rainfall ≥ 5 mm/h. Information of weather stations and satellites is used to separate the heavy rainfall events by synoptic conditions like thunderstorms and showers of frontal or internal air masses. We find that rains associated with the frontal Cb clouds produce more abrupt changes in negative electrical conductivity in comparison with the Cb clouds in internal air masses. The significant increase in negative electrical conductivity (more than two times vs. normal values) occurs typically during the passage of frontal Cb and heavy rain with droplet size greater than 4 mm.


2005 ◽  
Vol 85 (2) ◽  
pp. 307-317 ◽  
Author(s):  
Francis J. Larney ◽  
Olalekan O. Akinremi ◽  
Reynald L. Lemke ◽  
Vasile E. Klaassen ◽  
H. Henry Janzen

Changes in soil properties reflect the success or failure of reclamation practices on abandoned wellsites. We examined the effect on soil properties of four (0, 50, 100 and 150%) topsoil replacement depths (TRD) and five amendment treatments [compost, manure, wheat (Triticum aestivum L.) straw, alfalfa (Medicago sativa L.) hay, check] aimed at reclaiming three wellsites (Strathmore, Hesketh and Rosedale) in southcentral Alberta. TRD treatment differences were consistent across all wellsites, with 30 to 32% higher soil organic carbon (SOC) on the 150% TRD compared to the 0% TRD. Initially, the alfalfa treatment showed higher levels of nitrate-nitrogen (e.g., 26 mg kg-1 vs. 3 to 7 mg kg-1 for the other amendment treatments in the 15- to 30-cm depth at Strathmore in fall 1998), which was related to its rapid breakdown and mineralization of organic N. After 40 mo (June 1997-October 2000), the average amounts (n = 3 wellsites) of added C conserved near the soil surface were: compost (65 ±10% SE) > manure (45 ±16% SE) > alfalfa (28 ±11% SE) > straw (23 ± 6% SE). Our results show that organic amendments play an important role in improving soil properties related to long-term productivity of reclaimed wellsites, especially where topsoil is scarce or absent. Key words: Wellsite reclamation, topsoil depth, organic amendments, soil quality


2014 ◽  
Vol 28 (2) ◽  
pp. 169-176 ◽  
Author(s):  
Majid Mahmoodabadi ◽  
Elina Heydarpour

Abstract Soil organic carbon is one of the most important soil components, which acts as a sink for atmospheric CO2. This study focuses on the effect of different methods of organic matter application on the soil organic carbon sequestration in a 4-month experiment under controlled greenhouse conditions. Three rates of straw residue and farmyard manure were added to uncultivated and cropland soils. Two treatments of straw residue and farmyard manure incorporation were used into: a soil surface layer and 0-20 cm soil depth. The result showed that the application of organic matter, especially the farmyard manure incorporation led to a significant increase in the final soil organic carbon content. Higher amounts of soil organic carbon were stored in the cropland soil than in the uncultivated soil. On average, the soil surface layer treatment caused a higher sequestration of soil organic carbon compared to the whole soil depth treatment. If higher rates of organic matter were added to the soils, lower carbon sequestration was observed and vice versa. The result indicated that the carbon sequestration ranged farmyardmanure > strawresidue and cropland soil > uncultivated soil. The findings of this research revealed the necessity of paying more attention to the role of organic residue management in carbon sequestration and prevention of increasing global warming.


2021 ◽  
Vol 11 (02) ◽  
pp. 267-283
Author(s):  
Lovina Peter Japheth ◽  
Guirong Tan ◽  
Ladislaus Benedict Chang’a ◽  
Agnes Lawrence Kijazi ◽  
Kantamla Biseke Mafuru ◽  
...  

2018 ◽  
Vol 5 (4) ◽  
pp. 149-154 ◽  
Author(s):  
O M Fediuk ◽  
N O Bilyavska ◽  
E K Zolotareva

In the natural conditions early-spring period development of Galanthus nivalis L., the leaves germination from bulbs was carried out in the soil surface layer, mainly, covered with snow, so the leaves were exposed to low soil temperatures. It was found, that at the leaf germination stage, when exposed to minus soil temperature, the mitochondria were predominantly elongated, that is, functionally active. Under the influence of positive temperature, the mitochondria form changed to a round one, which indicates their transition to low functional activity. A similar tendency was manifested even during the budding stage, in particular, when the soil temperature was lowered to an average of –3.47 °C, the mitochondria changed their form to an elongated one, that is, they passed into an active functional state. Wherein, the temperature of the leaves was higher by 3.84 °C compared to the soil. At the stages of germination and budding of G. nivalis under natural conditions, a direct correlation was found between the soil surface layer temperature and the leaves temperature, and at the flowering stage this relation was reverse. During the flowering stage, despite the influence of predominantly positive soil temperatures, leaves growth was significantly slowed, and their temperature was only slightly higher by 0.38 °C compared to the soil. At the same time, the mitochondria changed their shape to a round one. Thus, the increase in their long axis at different stages in spring development, are aimed at adapting to influence low temperatures of the soil surface layer.


2013 ◽  
Vol 61 (4) ◽  
pp. 328 ◽  
Author(s):  
James D. Woodman

The population dynamics of the Australian plague locust, Chortoicetes terminifera, are strongly linked to the timing and distribution of heavy rainfall events in semiarid and arid environments. While the effects of insufficient rainfall on survival are relatively well understood, little information exists on the effects of excessively wet conditions. This study aimed to quantify the survival of first-instar C. terminifera nymphs to a range of water-immersion periods and temperatures. Results show that survival is strongly dependent on immersion temperature whereby survival times ranged from time to 50% mortality (LT50) = 8.12 ± 0.26 h at 15°C to 4.93 ± 0.30 h at 25°C. Nymphs entered a coma-like state within 2 min of immersion. Post-immersion recovery times were greater for longer immersion periods and longer at higher temperatures for immersion periods of >3 h. These findings suggest that first-instar nymphs would be able to survive most instances of transient, localised pooling of water associated with heavy rainfall in the field. However, flooding that could trap individuals for >5 h (including nymphs still underground within the egg pod before emergence to the soil surface) has the potential to cause high mortality, particularly during summer and early autumn when water temperatures may be high.


1907 ◽  
Vol 90 (3) ◽  
pp. 438-441 ◽  
Author(s):  
Jaime F. Caárdenas-García ◽  
Haigen Yao ◽  
Siding Zheng ◽  
Richard E Zartman

1983 ◽  
Vol 101 (1) ◽  
pp. 253-255 ◽  
Author(s):  
A. C. Armstrong ◽  
K. Shaw ◽  
S. J. Wilcockson

Public concern continues to be expressed about the quality of water discharged from agricultural lands. High concentrations of nitrate nitrogen are often blamed on modern agricultural practice in general and to land drainage in particular (Royal Commission on Environmental Pollution, 1979, para. 4.38). However, undrained land also discharges water by flow within the soil and across the soil surface and it may discharge significant quantities of solutes.


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