scholarly journals Long-term Dynamics of Ammonia Nitrogen Content and Runoff in the muddle Amur Water

Author(s):  

The long-term dynamic of the content and runoff of ammonia nitrogen in the water of the Middle Amur are discussed. There are decreasing of ammonia runoff in 1.4 times in comparison with 1981-2000, and dominance of nitrate nitrogen in runoff of mineral forms in recent years. Trends in runoff changes are due to transformation on the watershed. At present anthropogenic components of runoff is formed by the Songhua River runoff and is more pronounced in the wintertime.

2008 ◽  
Vol 54 (No. 5) ◽  
pp. 197-203 ◽  
Author(s):  
W. Sądej ◽  
K. Przekwas

The present study is focused on the correlation between varied long-term fertilization and changes in soil nitrogen concentrations. It was found that all fertilization systems significantly increased the levels of total, mineral and organic nitrogen in the soil profile. Organic fertilizers (manure and slurry) contributed to a more considerable increase in the concentrations of total nitrogen and nitrogen undergoing hydrolysis in 6M HCl, compared to mineral fertilizers. Ammonia nitrogen dominated over nitrate nitrogen among mineral nitrogen forms. Organic fertilization contributed to nitrate nitrogen accumulation, while mineral fertilization to ammonia nitrogen storage. The highest accumulations of nitrate nitrogen and ammonia nitrogen were observed after the application of slurry and manure, respectively. Hydrolyzable nitrogen content and its proportion in total nitrogen generally decreased with soil depth. An increase in the levels of organic nitrogen forms, i.e. nitrogen contained in amino sugars and amino acids as well as ammonia nitrogen from decomposition of amides, amino sugars and amino acids, was conditioned primarily on the application of organic fertilizers, particularly manure. Amino acid-N dominated among hydrolyzable nitrogen compounds (77%), while amino sugar-N accounted for 5.6% only.


Author(s):  
V. E. Sineshchekov ◽  
G. I. Tkachenko

In a multifactor stationary field experiment on the area of the Elitnoye Holding in the Novosibirsk region (central forest-steppe subzone) in 2002-2018 the seasonal dynamics of nitrate nitrogen in the fields of four full grain-steam crop rotation by steam and grain predecessors against an extensive background (without chemical means) in four versions of the main mechanical treatment of leached black soil was investigated. Along with this, the productivity of grain crops was studied with long-term minimization of the main tillage on extensive and intensive backgrounds. The authors found out that in the central forest-steppe of the Ob river region before sowing grain crops according to the various methods of steam preparation most of all in the meter layer of nitrate soil was found in black steam with plowing (150 kg / ha) and less in variants with soil-protective treatments (132-141 kg / ha ). The lowest level of this element in the soil (124 kg / ha) in spring was noted by the early minimum steam. Before sowing the second wheat after steam, the nitrate nitrogen content in the meter soil layer for plowing (79 kg / ha) was slightly higher than in the options with soil treatment (61-64 kg / ha). In the final field of crop rotation, regardless of the studied soil cultivation systems, the minimum initial amount of nitrogen (56-57 kg / ha) was noted. By the end of the growing season of crops, the nitrate content in the soil was sharply reduced. Before harvesting wheat by steam, the nitrogen content in the upper meter profile was 41-55 kg / ha, for grain precursors even less - 27-33 kg / ha. The steam yield of grain crops on extensive and intensive backgrounds was 3.09-3.21 and 3.96-4.02 t / ha, respectively, and practically did not depend on the methods of its preparation. On repeated sowing the wheat yield in comparison with an extensive background in plowing (1.26-1.79 t / ha) was significantly higher than in the studied options for minimizing the main tillage (1.02-1.55 t / ha). When optimizing the mineral nutrition of plants and the phytosanitary situation of crops, wheat productivity by grain predecessors in crop rotation fields increased 2.0-2.9 times without significant differences in soil treatment options.


Author(s):  

Outputs of studies of current and scenario changes of the river runoff in the Volga and the Don basins probable in the current century first third part under influence of the global climate change and social/economic transformations are presented. Long-term phases of low and high annual and seasonal runoff of the Volga and the Don over the period from late XIX and early XXI centuries and the human factors’ influence on them have been found. Their duration varies in the wide range reaching eighty years and more. Noticeable runoff changes are characteristic for contrast phases. Integral scenario assessment of the river runoff changes on the basis of various climatic scenarios and water consumption has been given. Rather wide range of the probable runoff changes in comparison with the current situation has been obtained on the basis of scenarios of social/economic development and specific water use changes. Expected increase of the Volga water content under the influence of climatic factors will facilitate improvement of the water/economic situation at this river, while there is no chance to expect water content in the Don. At the same time there is a probability that the current phase of climate worming is going to come to an end and to be replaced by the long-term cold phase and this might cause the corresponding hydrological changes.


Author(s):  

The contribution of natural climate and anthropogenic factors in the Volga river runoff changes at Volgograd during the period of instrumental observations (1882–2007). has been revealed. The estimates are based on two independent approaches. One of them is based on the restoration of the annual and seasonal runoff against the riversindicators’ regression dependencies, and the other one is based on the water use statistical data and methods of water balance. The calculations give the total Volga river annual runoff anthropogenic decrease values that are fairly close to each other.


Euphytica ◽  
2021 ◽  
Vol 217 (1) ◽  
Author(s):  
Wenqing Tan ◽  
Di Zhang ◽  
Nana Yuyama ◽  
Jun Chen ◽  
Shinichi Sugita ◽  
...  

2011 ◽  
Vol 250-253 ◽  
pp. 3392-3396
Author(s):  
Yu Jia Song ◽  
Hui Qing Liu

The discharge of urban sewage and agricultural non-point source pollutants is the main reason causing eutrophication in gullies in most cities of northern China. Based on a careful analysis on the ecological structure and ecological characteristics of a gully, this article preliminarily studies the interception and degradation mechanisms of nitrogen pollutants by the gully. Meanwhile, to take gullies in Changchun as the object of the study, this article carries out an experiment on the interception effect of nitrogen pollutants by gullies. This experiment respectively establishes a control section in the upper and lower reaches of a gully, and takes water samples four times in each section from May to August to determine total nitrogen, total phosphorus, nitrate nitrogen, ammonia nitrogen and salinity. The result shows: the gully plays some role in the interception of pollutants; total phosphorus accounts for the largest interception in pollutants in the experimented gully section, with the relative interception rate of 27.46%, followed by ammonia nitrogen, with the interception rate of 21.80%, which is the result of the combined effects of aquatic plants, microorganisms and sediment in the gully.


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