Mats of unincorporated organic matter under irrigated pastures

1966 ◽  
Vol 17 (3) ◽  
pp. 327 ◽  
Author(s):  
CR Kleinig

A mat of partially decomposed organic matter which forms on the surface of solls carrying irrigated pastures is described. It was found under both annual and perennial irrigated pastures on soil types ranging from sandy loams and loams (red-brown earths) to heavy clays (grey and brown soils of heavy texture). Mat weights ranged from 8 000 to 92 000 lb/acre, and the amounts of nitrogen held in them from 85 to 1 240 lb/acre, for 8- to 15-year-old pastures. Age of pasture was not significantly correlated with either mat weight or mat nitrogen content, but it was significantly correlated with the total nitrogen content of the mat and surface soil. The distribution of accumulated nitrogen between the mat and surface soil varied considerably under annual pastures on heavy-textured soils. Carbon/nitrogen ratios indicate considerable decomposition of the organic matter In the mat, and up to 0.60 in, of water available to the pasture was retained in this layer after irrigation. The significance of the mat under irrigated pastures is discussed in terms of water and nitrogen relationships.

2013 ◽  
Vol 864-867 ◽  
pp. 2565-2568
Author(s):  
Jin Xia Wu ◽  
Yan Xia Wang ◽  
Qi Bo Chen ◽  
Zhi Long Tong

Took the Pinus yunnanensis forest as the research object, and took planted forest for control, carried on a research in soil physicochemical properties of different forest ages of Pinus yunnanensis. The results show that: For secondary forests at different ages, (1) middle-aged forest has the smallest soil bulk density and largest soil natural water content. Compared with the same age planted forest, secondary forest has smaller soil bulk density and larger soil natural water content.(2) Middle-aged forest has the smallest soil pH value, and the tallest total nitrogen content and soil organic matter in the 0-20cm soil layer. Compared with the same age planted forest, secondary forest has smaller pH value. While its soil organic matter and total nitrogen content are more than planted forest significantly.(3)There is an extremely significant negative correlation among pH value, soil organic carbon and total nitrogen content; while an extremely significant positive correlation between soil organic carbon and total nitrogen content.


2017 ◽  
Vol 18 (3-4) ◽  
pp. 5-20
Author(s):  
V. L. Samokhvalova ◽  
A. O. Khristenko ◽  
L. O. Shedey ◽  
P. A. Samokhvalova ◽  
O. V. Karatsuba

The method for prediction of productive functions of soils, according to their macronutrient status, is grounded on the example of the total concentrations of nitrogen as biogenic macronutrient in different soil types of Polesie, Forest-Steppe and Steppe climatic zones of Ukraine including soils contaminated by heavy metals and fertilized (organic-mineral, organic and mineral system of fertilizer) soils. In the elaborated methodical approach the productive function (fertility) of different genesis soils forecasts by establishing new relationships of total nitrogen content with a humus calorific value, the energy reserves of the soil in layer up to 20 cm, the application of mathematical-statistical analysis. For example, according to the total nitrogen content as a biogenic macronutrient in accordance with the fixed gradations, with a further extension of the method algorithm for different soil types of climatic zones by the influence of technogenic pollution and technological load. The technical result of the elaborated method is to improve the known method of soil fertility prediction, considering their macronutrient status, by the selective choice of the most correlation associated, diagnostics capable of integral indicators of the energy and nitrogen status of the soil, which enhances the informativeness, accuracy and quick speed forecasting of production and ecological functions of different genesis soils with the identification of differences in ecological condition of soils for prediction and regulation of their quality. The elaborated methodological approach may find application in the assessment and ecological standardization of soil quality by chemical elements content, regulation of loads (technogenic, technological) on a soil system, in agroecology by investigating the question of soil fertility monitoring, lands certification of different purpose and use; organic farming, bioenergy and energy of soil formation; diagnosis, evaluation, determination of quality of humus and the state of the chemical elements; in environmental management of soils both for background conditions and different anthropogenic impacts and in research practice – investigating the biogeochemistry and nutrient macronutrients of the soil cover. Distinctive features and advantages of the proposed elaboration in comparison with known methods and approaches are: 1) express obtain of the accurate by predicted levels of total nitrogen content as a nutrient in the soil with the improving of the soil diagnosis accuracy by establishing some interconnected diagnostically suitable indicators of soils humus substances and nitrogen systems functioning, the direction of the mobilization and immobilization of nutrients (C, N) processes, the humification-mineralization and energy intensity of soils, including the negative impacts of anthropogenic pressures and degradation processes; 2) providing the opportunity for increasing effectiveness of predicting data on the functioning of the nitrogen systems of different genesis soils, environmental and energy state of soil and level of their potential fertility due to the background conditions, the application of different fertilization systems, and risk the availability of heavy metals pollution while minimizing the consumption of material resources; 3) expansion of the user’s ability to determine the total nitrogen content in the soil without long-term chemical analytical research due to the choice of regression equations obtained on the basis of the use of baseline soil properties of a certain type and subtype, according to available information; 4) versatility due to suitability of installed dependencies of the proposed method for all soil types and subtypes, climatic zones and contaminants.


OENO One ◽  
2000 ◽  
Vol 34 (2) ◽  
pp. 75 ◽  
Author(s):  
Cornelis Van Leeuwen ◽  
Philippe Friant ◽  
Jean-Pierre Soyer ◽  
Ch. Molot ◽  
Xavier Choné ◽  
...  

<p style="text-align: justify;">Five indicators of vine nitrogen status were compared for their accuracy to differentiate two levels of nitrogen fertilization (0 and 45 kg N / ha) : petiole total nitrogen content, leaf blade color intensity measured by a device called “N-tester”, grape juice total nitrogen content, grape juice assimilable nitrogen content and grape juice ammonium content. Differences in must total nitrogen content and must assimilable nitrogen content were highly significant between fertilization levels. They can be considered as two powerful tools to assess vine nitrogen status. Levels of must total nitrogen content and must assimilable nitrogen content were highly correlated.</p><p style="text-align: justify;">Mineralizing must in order to measure its total nitrogen content is difficult, mainly because of the presence of large amounts of sugar. This operation can take more than 12 hours and it can fail because of caramelization and the appearance of foam. We propose mineralizing must by means of microwave. Complete mineralization was obtained in only one hour. No foam or caramelization was observed on any of the samples mineralized.</p><p style="text-align: justify;">Vine nitrogen uptake is likely to vary to a considerable extend with soil parameters, even if no nitrogen fertilization is applied. Figuring among those parameters are: soil organic matter content, organic matter C/N ratio and soil organic matter turnover. The latter depends mainly on soil temperature, soil aeration, soil pH and soil moisture content. Differences in vine nitrogen status depending on the soil type were clearly evidenced by measuring must total nitrogen and must assimilable nitrogen at ripeness. Limited nitrogen uptake, as a result of particular soil conditions, can limit vine vigor and be a quality enhancing factor in red grape production. This emphasizes the role of moderate environmental stress in the production of high quality potential grapes.</p>


2019 ◽  
Vol 52 (30) ◽  
pp. 270-276
Author(s):  
Xiangqian Yao ◽  
Wei Yang ◽  
Minzan Li ◽  
Peng Zhou ◽  
Zhen Liu

1992 ◽  
Vol 25 (4-5) ◽  
pp. 203-209 ◽  
Author(s):  
R. Kayser ◽  
G. Stobbe ◽  
M. Werner

At Wolfsburg for a load of 100,000 p.e., the step-feed activated sludge process for nitrogen removal is successfully in operation. Due to the high denitrification potential (BOD:TKN = 5:1) the effluent total nitrogen content can be kept below 10 mg l−1 N; furthermore by some enhanced biological phosphate removal about 80% phosphorus may be removed without any chemicals.


2020 ◽  
Vol 63 (5) ◽  
pp. 407-417
Author(s):  
Lim Wai Yin ◽  
Lim Phaik Eem ◽  
Affendi Yang Amri ◽  
Song Sze Looi ◽  
Acga Cheng

AbstractWith the potential adverse effects of climate change, it is essential to enhance the understanding of marine ecosystem dynamics, which can be driven by the co-evolutionary interaction between autotrophs and herbivores. This study looked into the autotroph-herbivore interactions in Malaysian waters, mainly to determine if autotroph nutritional quality significantly influences herbivore consumption rates. We documented the relative consumption rate of a generalist herbivore (Chanos chanos Forsskål) obtained from the Straits of Malacca through multiple feeding trials using 12 macroalgal species collected from different coastal areas of the Straits of Malacca, the Straits of Johor, and the South China Sea. The herbivore fed selectively on the tested macroalgal species, with the most and least consumed species having the lowest and highest total nitrogen content, respectively. Besides total nitrogen content, the least consumed species also had the highest total phenolic content. Interestingly, we observed that the herbivore generally preferred to consume filamentous macroalgae, especially those collected from the South China Sea. Overall, our findings demonstrated that the feeding behaviour of a generalist herbivore could be influenced by the nutritional quality of the autotrophs, which may depend directly or indirectly on other factors such as autotroph morphology and geography.


2014 ◽  
Vol 602-605 ◽  
pp. 2445-2448
Author(s):  
Fu Quan Jia ◽  
Zhu Jun Tian

NIPGA technology is used in order to detect the total nitrogen content in sewage quickly. D-D neutron generator is used as the neutron source and BGO detector is used to detect gamma rays of nitrogen. The simulated result of MCNP shows the nitrogen’s limit of detection is 0.2 mg/L and the total nitrogen in V-type water can be detected. So this method can be used to detect the total nitrogen content in sewage quickly.


2019 ◽  

<p>In order to study the chemical parameters of the soil after sub-irrigation with wastewater, a system was installed in one of the greenhouses of the Agricultural University of Athens. Wastewater was applied subsurface into the soil mass of the pots were used. Three treatments were used: Untreated wastewater (U), Treated wastewater (T) and tap water (W) as control. Two different types were used: Soil (a) characterized as Sandy loam and soil (b) characterized as Loamy sand. Moreover, in order to investigate the change of total Nitrogen and organic matter concentrations at the point where the emitter was placed, the soil mass was divided into two zones. The upper (zone I) and the lower one (zone II). The total nitrogen content, ammonia nitrogen (NH4-N), nitrogen nitrate (NO3-N) and the percentage of organic matter, were determined in the soil samples. Statistically significant differences (p &lt;0, 05) were observed in the organic matter and the total N%, only for soil (b). For soil (a), organic matter percentage was increased in zone (I) (irrigation with treated wastewater at 20 cm depth). For soil (b), total N% was increased in zone (I), while nitrate and ammonium were increased in zone (II) (irrigation with untreated wastewater at 20 cm depth).</p>


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