Nitrogen studies on black soils form the Darling Downs, Queensland. I. Seasonal variations in moisture and mineral nitrogen fractions

1956 ◽  
Vol 7 (3) ◽  
pp. 169 ◽  
Author(s):  
AE Martin ◽  
JE Cox

A study of the equilibrium levels of moisture, nitrate nitrogen, and ammonium nitrogen is reported on two representative black soils (developed from basaltic colluvium and alluvium respectively) from the Darling Downs for the years 1952-1954 inclusive. Both soils were under native grassland in 1952; a portion of the sampling area at each site was cultivated early in 1953 and left fallow for the rest of the sampling programme. The moisture contents of surface (0-6 in.) grassland and fallow plots varied directly with rainfall. Subsoil under grass showed low moisture contents which increased only after heavy rain but decreased thereafter, probably owing to transpiration. Under fallow, subsoil moisture was higher and showed significant fluctuations, suggesting that losses occurred by slow liquid flow or vapour movement a t moisture contents between field capacity and the wilting point. Ammonia-nitrogen contents at the surface were lower than for comparable soils in temperate regions and showed a significant decrease with depth; values for the corresponding fallow plots were similar in amount and varied similarly with depth. Surface soils showed minor fluctuations with season, being higher in summer. Under incubation conditions at 25°C, ammonia nitrogen rarely fell below 1.0 mg/kg oven-dry soil, which suggests that this is the minimum threshold concentration of ammonia nitrogen in these soils for the nitrification process. Nitrate nitrogen showed a significant rise in summer on the colluvial basaltic soil under grass. The soil developed on basaltic alluvium showed no such seasonal trend and contained uniformly low amounts of this fraction. Cultivation resulted in a sharp rise in nitrate nitrogen in both soils, the wetter alluvial soil showing a longer time lag. There was some evidence of nitrification in the 6-12 in. depth a t one site, but below this rises in nitrate nitrogen, which were correlated with rainfall and increases in moisture content, could be accounted for by leaching. Incubation tests gave rise to highly variable nitrate nitrogen contents and such tests were found unreliable in these soils, probably owing to imperfect aeration of the laboratory sample. Analyses for total nitrogen of several alluvial black soils from the same area showed a progressive decline in this constituent with increasing periods of cultivation; in the first 26 years of cultivation about 0.8 per cent. of the total nitrogen is lost per annum. This value agrees with the nitrate nitrogen accession in fallow subsoil, suggesting that leaching of nitrate formed at the surface is a major factor determining losses in total nitrogen. The implications of these findings are discussed.

2011 ◽  
Vol 374-377 ◽  
pp. 498-503
Author(s):  
Jin Lan Xu ◽  
Lei Wang ◽  
Jun Chen Kang ◽  
Ting Lin Huang ◽  
Yu Hua Dong

Abstract: Active barrier system (ABS) capping zeolite with large surface area and strong adsorption ability is an effective way to control eutrophication of lake since it can remove ammonia in the lake released by sediment. Influence of the initial nitrogen concentration on eliminating nitrogen load of europhia sediment capping with active barrier system (ABS) were studied through an investigation of the repairment results of serious pollution period (total nitrogen concentration up to 25.33 mg/L), moderate pollution period (14.39 mg/L) and the slight pollution period (3.47 mg/L) of the ancient Canal of Yangzhou. The results showed that: (1) zeolite F1 inhibition effect is stronger than zeolite F2. More TN were removed as the initial TN concentration increased and longer rapid inhibit period were presented with the increased initial TN concentration. (2) The ammonia nitrogen in sediment could be rapidly released into the overlying water, and with lower initial TN concentration in source water, more ammonia would be released from the sediment. Long time treatment was necessary to inhibit the release of ammonia completely if the water showed a high initial TN concentration. (3) After covering zeolite, the total nitrogen in the overlying water were removed mainly through nitrification and denitrification. At the initial TN concentration of 3.47 mg/L, 14.39 mg/L, 25.88 mg/L, 61%, 45% and 52% of TN were removed by the conversion of ammonia to nitrogen gas, however, others left in water as nitrate nitrogen and nitrite residues, and 90% was nitrate nitrogen.


2013 ◽  
Vol 807-809 ◽  
pp. 2059-2065 ◽  
Author(s):  
Wen Yu Hsiao ◽  
Kao Long Gu ◽  
Yih Ming Weng

A traditonal soy sauce (S1) and two types of Monascus-fermented soy sauces (S2 and S3) were prepared. Biochemical changes during the aging of soy sauce mash were examined. During a 180-day fermentation period, titratible acidity, pH, brown color, total nitrogen, formaldehyde nitrogen, ammonia nitrogen, and amino nitrogen were determined. After the 180-day fermentation, the final total acidities for S1, S2 and S3 were 2.52, 2.52 and 2.65 g lactic acid/100 mL, respectively; the pH values for S1, S2 and S3 were 5.0, 5.0 and 4.9, respectively. The final total nitrogen contents for S1, S2, and S3 were 1.84%, 1.84% and 1.85%, respectively. The final amino nitrogen contents in soy sauce S1, S2 and S3 were 0.56, 0.56 and 0.57 g/100 ml. The amino acid composition of glutamic acid content in three soy sauces S1, S2 and S3 were 10.88, 11.0, and 11.37 mg/mL.


2017 ◽  
Vol 76 (2) ◽  
pp. 396-412 ◽  
Author(s):  
Su-jin Lu ◽  
Jian-huan Si ◽  
Chuan-ying Hou ◽  
Yu-si Li ◽  
Meng-meng Wang ◽  
...  

To provide a theoretical basis for alpine source lake protection, ten samples were taken from each lake annually from 2012 to 2015. Each year, the various species of nitrogen and phosphorus nutrients were measured. The average contents of nitrate nitrogen, ammonia nitrogen, nitrite nitrogen, total phosphorus, and total nitrogen in the four lakes are 0.195–0.0 mg/L, 0.038–0.143 mg/L, 0.004–0.168 mg/L, 0.006–0.740 mg/L, and 0.050–0.547 mg/L, respectively. The total phosphorus contents in Eling Lake, Longbao Lake and Sea Star were higher than Class I water quality standards, and the total nitrogen contents in Eling Lake, Sea Star and Zhaling Lake were higher than Class I water quality standards as well. The concentration contour maps of the nitrate nitrogen, ammonia nitrogen, nitrite nitrogen, total phosphorus and total nitrogen showed that the indicators of the four lakes in the east, the west, and the center of the lake did not have the same trend. From 2012 to 2015, each of the measured nutrients showed a rising trend year by year. The four lakes are polluted by both endogenous and exogenous pollution, and it is necessary to limit the exogenous pollution and protect the alpine lakes immediately.


Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1467 ◽  
Author(s):  
Tao ◽  
Wang ◽  
Guan ◽  
Xu ◽  
Chen ◽  
...  

Agricultural drainage plays an effective role in preventing waterlogging and salinity disasters and also is the main transport pathway for agricultural non-point source pollutants into rivers and lakes. Hence, the water quality of agricultural drainage should be a point of focus. In this paper, nitrogen and phosphorus loss under improved subsurface drainage with different filter materials (gravel, layered sand-gravel, mixed sand-gravel, straw) were studied by a three-year field experiment (2016–2018) compared with the conventional subsurface drainage. The pH values, total nitrogen, ammonia nitrogen, nitrate nitrogen, total phosphorus and soluble reactive phosphate were considered. The results showed that the nitrogen and phosphorus concentrations of drain outflow under improved subsurface drainage with gravel filter were larger than that with layered sand-gravel filter and mixed sand-gravel filter. The improved subsurface drainages with layered sand-gravel filter and mixed sand-gravel filter had an effect on reducing the ammonia nitrogen, total phosphorus and soluble reactive phosphate concentrations of the outflow. Meanwhile, the characteristics of nitrogen and phosphorus loss under the improved subsurface drainage with straw filter were different from that with layered sand-gravel filter and mixed sand-gravel filter. For the improved subsurface drainage with layered sand-gravel filter outflow, the ammonia nitrogen, total phosphorus, and soluble reactive phosphate concentrations were about 13%–78%, 38%–63%, 40%–68% less, and total nitrogen, nitrate nitrogen concentrations were 24%–80%,18%–96% more than that under conventional subsurface drainage. Meanwhile, for the improved subsurface drainage with straw filter outflow, compared with conventional subsurface drainage outflow, the percentage changes of the total nitrogen, nitrate nitrogen, ammonia nitrogen, total phosphorus and the soluble reactive phosphate concentrations were about −76%–62%, −77%–78%, −152%–−274%, −103%–−400% and −221%–−291%, respectively. Additionally, in the outflow of all subsurface drainage patterns, there were much higher total nitrogen and nitrate nitrogen concentrations which should be focused on and the agricultural water management should be adopted.


2018 ◽  
Vol 37 (2) ◽  
pp. 137-154
Author(s):  
John K. Kayima ◽  
Aloyce W. Mayo ◽  
Joel K. Nobert

The capacity of the Lubigi wetland to reduce nitrogen and faecal coliform pollution entering Lake Kyoga in Uganda was investigated. Three transects with 5 sampling points in each, were established in the wetland. Wetland plants samples were collected from the specific locations along the transects, and laboratory tests and analyses were carried out for plants biomass and nitrogen contents determination. Samples of wetland sediments were also collected, and laboratory tests and analyses were done for determination of nitrogen content in the sediments. Wetland water samples were taken from the main wetland inlet and the main outlet from the wetland main study area. At the same time, wetland water pH, dissolved oxygen and temperatures were measured in-situ. Laboratory tests and analyses for ammonia-nitrogen, nitrate-nitrogen, total Kjeldahl nitrogen, total nitrogen and faecal coliforms were carried out on the wetland water samples. The results indicate that the Lubigi wetland received about 16 to 173 mg/l of total nitrogen, largely in form of organic- nitrogen (64.7%) and ammonia-nitrogen (35.2%). Nitrate-nitrogen and Nitrite-nitrite accounted for only 0.1% of the total nitrogen in the inlet. The wetland removed about 24.9% of this nitrogen, which is equivalent to removal of about 1,672 tons of nitrogen annually. About 67.5 gN/m2 and 0.30 gN/kg of dry sediments were sequestered in the wetland plants biomass and the benthic layer respectively. The Lubigi wetland main study area also receives faecal coliform concentrations with the wetland inlet mean value of 653,509 CFU/100ml and its outlet mean value is 218,676 CFU/100ml. These values give a faecal coliform (FC) overall removal efficiency of approximately 66.5%. It was thus concluded that the Lubigi wetland has considerable capacity to buffer and protect Lake Kyoga, by reducing nitrogen and faecal coliform pollution entering the lake.


Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 21
Author(s):  
Ilaria Piccoli ◽  
Giuseppe Virga ◽  
Carmelo Maucieri ◽  
Maurizio Borin

Constructed wetlands (CWs) represent a green technology for digestate liquid fraction (DLF) treatment. However, previous research has warned about their performance when treating wastewater with high suspended solid and organic loads. In addition, the high NH4-N concentration typical of this wastewater can compromise vegetation establishment and activity. In view of this, a digestate pretreatment is needed. This study aimed to test the performance of filters filled with recovery materials, such as brick and refractory material, for DLF pretreatment. The effect on DLF physical (electrical conductivity, pH, dissolved oxygen, and temperature) and chemical (total nitrogen, ammonia–nitrogen, nitrate–nitrogen, total phosphorus, soluble phosphorus, and chemical oxygen demand) characteristics was monitored during eight weekly cycles. The effect of filtration on total nitrogen and ammonia–nitrogen removal began after about one month of loading, suggesting that an activation period is necessary for bacteria. For effective N removal, the presence of multiple digestate recirculations per day through the filters appears mandatory to guarantee the alternation of nitrification and denitrification conditions. For P removal, filling material particle size appeared to be more important than its composition. Unclear performances were observed considering chemical oxygen demand. Further studies on filling media and microbial community interactions, and the long-term efficiency of filters, are desirable.


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.


1995 ◽  
Vol 3 (3) ◽  
pp. 167-174 ◽  
Author(s):  
Mark W. Young ◽  
Donald K.L. MacKerron ◽  
Howard V. Davies

Oven dried samples of leaf stem and tuber material taken from a nitrogen field experiment were analysed by Dumas combustion when fresh and by near infrared (NIR) then, and in the next two years, by a number of operators who made estimates of nitrogen concentration, [N]NIR, with differing degrees of error. The errors differed between years in the case of the one operator who made estimates in two years. Leaf, stem and tuber material of high and low nitrogen concentration were treated to produce samples at various moisture contents. These samples were scanned by NIR and the spectral data were examined. Higher moisture was found to decrease the reflectance at all the wavelengths used and would, therefore, introduce error into [N]NIR estimates. The NIR calibration used was found to be applicable to cultivars in a range of maturity classes. Several recommendations are made that will help to minimise the error introduced into [N]NIR estimates from various sources.


2019 ◽  
pp. 119-124
Author(s):  
Brigitta Simon ◽  
Tamás Kucserka ◽  
Angéla Anda

In lakes and wetlands, leaf litter input from the coastal vegetation represents a major nutrient load and plays a basic structural and functional role in several ecosystems. In Hungary, at the banks of lakes and wetlands, Salix and Populus trees are the most common species. In an experiment in Lake Balaton and Kis-Balaton Wetland between 16 November 2017 to and 3 June 2018, the decomposition rates and leaching dynamics of Salix, Populus and mixed leaves (50% Salix and 50% Populus) were investigated. Total nitrogen and phosphorus content of biomass samples were measured at the beginning and end of the experiment for the leaching dynamics experiment. We found that litter mass losses (Salix, Populus and mixed leaves) were not significantly different between the two mesh size litterbags and between Lake Balaton and Kis-Balaton Wetland. Different amounts of the total nitrogen and phosphorus leaching from Salix, Populus and mixed leaves were detected. The total nitrogen contents of the plant samples were around 8-18% at the end of the investigated period. Slightly higher values were measured compared to phosphorous (27-29%).


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