Landscape pattern at the class level regulates the stream water nitrogen and phosphorus levels in a Chinese subtropical agricultural catchment

2020 ◽  
Vol 295 ◽  
pp. 106897 ◽  
Author(s):  
Ji Liu ◽  
Xinliang Liu ◽  
Yi Wang ◽  
Yong Li ◽  
Yuexi Jiang ◽  
...  
Keyword(s):  
Landscape Pattern ◽  
Stream Water ◽  
Nitrogen And Phosphorus ◽  
Class Level ◽  
Phosphorus Levels

scholarly journals Nitrogen and Phosphorus Addition to Soil Improves Seed Yield, Foliar Stomatal Conductance, and the Photosynthetic Response of Rapeseed (Brassica napus L.)

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 483
Author(s):  
Esmaeil Zangani ◽  
Kamran Afsahi ◽  
Farid Shekari ◽  
Eileen Mac Sweeney ◽  
Andrea Mastinu
Keyword(s):  
Stomatal Conductance ◽  
Quantum Yield ◽  
Photosystem Ii ◽  
Chlorophyll Content ◽  
Seed Yield ◽  
Nitrogen Application ◽  
Flowering Stage ◽  
Nitrogen And Phosphorus ◽  
Brassica Napus L ◽  
Phosphorus Levels

The effects of nitrogen and phosphorus levels on the physiological traits, yield, and seed yield of rapeseed (Brassica napus L.), were studied in a farm research project of Zanjan University. Three levels of nitrogen (0, 100, and 200 kg/ha) and three levels of phosphorus (0, 75, and 150 kg/ha) were considered. The results showed that an increase in nitrogen level caused an increase in the leaf chlorophyll content so that the application of 200 kg/ha of nitrogen increased the chlorophyll content of the leaves until the mid-grain filling stage. Nitrogen application lowered leaf stomatal conductance in the early flowering stage whereas the stomatal conductance was increased during the late flowering stage. Nitrogen application (100 and 200 kg/ha) also increased the quantum yield of photosystem II. On the other hand, with the application of 150 kg/ha and 75 kg/ha of phosphorus, the leaf stomatal conductance and the quantum yield of photosystem II in the early flowering stage increased respectively. The results showed that the application of 200 kg/ha of nitrogen and 75 kg/ha of phosphorus significantly increased seed and oil yield compared to the control. In addition, the number of siliques per plant and the weight of 1000 seeds showed an increasing trend that was affected by nitrogen and phosphorus levels. This study demonstrated that nitrogen enhanced the chlorophyll content, leaf area, and consequently, the quantum yield of photosystem II. Nitrogen also augmented the seed filling duration, seed yield, and oil yield by increasing gas exchange. As a result, the application of 100 kg/ha of nitrogen together with 75 kg/ha phosphorus showed the greatest effect on the qualitative and quantitative yield of rapeseed. However, the application of 200 kg/ha of nitrogen alone or in combination with different levels of phosphorus did not significantly increase many of the studied traits.

Catchment soil characteristics predict organic carbon, nitrogen, and phosphorus levels in temperate lakes

2021 ◽  
Author(s):  
Margot Sepp ◽  
Toomas Kõiv ◽  
Peeter Nõges ◽  
Tiina Nõges ◽  
Silvia Newell ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Characteristics ◽  
Temperate Lakes ◽  
Nitrogen And Phosphorus ◽  
Phosphorus Levels

scholarly journals Evaluating the Impacts of Agriculture to Groundwater Pollution in a Shallow Aquifer in Eastern Croatia

2011 ◽  
Vol 68 (2) ◽  
Author(s):  
Vilim FILIPOVIĆ ◽  
Dragutin PETOŠIĆ ◽  
Ivan ŠIMUNIĆ ◽  
Ivan MUSTAĆ ◽  
Zlatko SVEČNJAK ◽  
...  
Keyword(s):  
Groundwater Pollution ◽  
Agricultural Land ◽  
Shallow Aquifer ◽  
Nitrogen And Phosphorus ◽  
Potential Threat ◽  
Investigation Area ◽  
Groundwater Samples ◽  
The Mean ◽  
Phosphorus Levels ◽  
Observation Period

Agricultural activities are frequently associated with groundwater pollution. In this study, the goal is to evaluate the nitrate and phosphorus levels and it's impact to the groundwater. The investigation was located in the Eastern Croatia in the area of 6.600 ha of mainly agricultural land. Groundwater quality in the countertop part of the soil profile to 4.0 m depth was monitored by 40 installed hydropedological piezometers. Sampling water from piezometers was carried out every 60 days. In the groundwater samples nitrate, nitrite, ammonia and orthophosphate were analyzed. According to the indicators it was confirmed that at all locations during the observation period mean concentrations of NH4-N, NO3-N, total nitrogen (N) and phosphorus (P) in the groundwater from piezometers occasionally exceeded the value of maximum allowable concentration (MAC) which is prescribed by the Regulations. The mean concentrations of NO3-N were consistent and varied in the range from 2.42 to 4.61 mg NO3-N/l, the mean concentrations of nitrogen from ammonia exceed the permissible value (NH4-N) throughout the year, the average being higher than MAC (0.50 mg NH4-N/l) and were within the range of 0.57 mg NH4-N/l in to 1.21 mg NH4-N/l. The maximum concentration of phosphorus in groundwater were in the range of values from 0.40 to 1.11 mg P/l. Observation of traditional agricultural production in the investigation area with emphasis on leaching of nitrogen and phosphorus shows that it represents a potential threat to the future pollution of groundwater with nitrogen with phosphorus.

Nitrogen and phosphorus levels in the Yazoo River Basin, Mississippi

Ecohydrology ◽  
2009 ◽  
Vol 2 (3) ◽  
pp. 270-278 ◽  
Author(s):  
F. Douglas Shields ◽  
Sam Testa ◽  
Charles M. Cooper
Keyword(s):  
River Basin ◽  
Nitrogen And Phosphorus ◽  
Yazoo River Basin ◽  
Phosphorus Levels

Post-fire water-quality response in the western United States

2018 ◽  
Vol 27 (3) ◽  
pp. 203 ◽  
Author(s):  
Ashley J. Rust ◽  
Terri S. Hogue ◽  
Samuel Saxe ◽  
John McCray
Keyword(s):  
United States ◽  
Water Quality ◽  
Stream Water ◽  
Western United States ◽  
Change Point Analysis ◽  
Quality Data ◽  
Stream Water Quality ◽  
Nitrogen And Phosphorus ◽  
Water Quality Data ◽  
Quality Response

Wildfires are increasing in size and severity in forested landscapes across the Western United States. Not only do fires alter land surfaces, but they also affect the surface water quality in downstream systems. Previous studies of individual fires have observed an increase in various forms of nutrients, ions, sediments and metals in stream water for different post-fire time periods. In this research, data were compiled for over 24 000 fires across the western United States to evaluate post-fire water-quality response. The database included millions of water-quality data points downstream of these fires, and was synthesised along with geophysical data from each burned watershed. Data from 159 fires in 153 burned watersheds were used to identify common water-quality response during the first 5 years after a fire. Within this large dataset, a subset of seven fires was examined further to identify trends in water-quality response. Change-point analysis was used to identify moments in the post-fire water-quality data where significant shifts in analyte concentrations occurred. Evaluating individual fires revealed strong initial increases or decreases in concentrations, depending on the analyte, that are masked when averaged over 5 years. Evidence from this analysis shows significant increases in nutrient flux (different forms of nitrogen and phosphorus), major-ion flux and metal concentrations are the most common changes in stream water quality within the first 5 years after fire. Dissolved constituents of ions and metals tended to decrease in concentration 5 years after fire whereas particulate matter concentration continued to increase. Assembling this unique and extensive dataset provided the opportunity to determine the most common post-fire water-quality changes in the large and diverse Western USA. Results from this study could inform studies in other parts of the world, will help parameterise and validate post-fire water-quality models, and assist communities affected by wildfire to anticipate changes to their water quality.

Effects of soils, fertilizers and stocking rates on pastures and beef production on the Wallum of south-eastern Queensland. 3. Relation of liveweight changes to chemical composition of blood and pasture

1973 ◽  
Vol 13 (64) ◽  
pp. 537 ◽  
Author(s):  
RF Thornton ◽  
DJ Minson
Keyword(s):  
Plasma Concentrations ◽  
Inorganic Phosphorus ◽  
Nitrogen And Phosphorus ◽  
The Difference ◽  
Treatment Comparisons ◽  
Mineral Levels ◽  
Induced Changes ◽  
Stocking Rates ◽  
Phosphorus Levels

During the concluding phase of a six-year grazing trial a study was made of the steers and the pasture material from paddocks annually fertilized with 125 kg ha-1and 250 kg ha-1of superphosphate. Plucked pasture samples from the low and high superphosphate treatments contained 0.11 and 0.15 per cent phosphorus, 0.83 and 0.91 per cent nitrogen and 0.12 and 0.12 per cent sulphur, respectively. The N: S ratio of these samples were 6.8 and 7.6 and the in vitro digestibilities were 41.6 and 44.9 per cent. There were marked seasonal patterns in the concentrations of all components with minimum values in the winter months when liveweight gain was lowest. Greater superphosphate application increased mean liveweight gain (0.29 to 0.41 kg head-1day-1), mean plasma concentrations of both urea-nitrogen (6.3 vs 5.0 mg 100 ml-1) and of inorganic phosphorus (6.7 vs 6.3 mg 100 ml-1). The mean blood sulphate-sulphur concentration of 28 �g ml-I was not influenced by treatment. Comparisons of the levels of nutrients in pasture and blood with published requirements indicated that neither sulphur nor phosphorus were deficient in either treatment. However, the between treatment differences in both nitrogen and phosphorus levels could not be ignored as possible reasons for the difference in animal production between the two levels of superphosphate application. Improved animal performance associated with increased application of superphosphate was probably influenced more by the induced changes in the organic components rather than the mineral levels of the pasture material.

Polyhydroxyalkanoate (PHA) storage within a mixed-culture biomass with simultaneous growth as a function of accumulation substrate nitrogen and phosphorus levels

2015 ◽  
Vol 77 ◽  
pp. 49-63 ◽  
Author(s):  
Francesco Valentino ◽  
Lamija Karabegovic ◽  
Mauro Majone ◽  
Fernando Morgan-Sagastume ◽  
Alan Werker
Keyword(s):  
Mixed Culture ◽  
Nitrogen And Phosphorus ◽  
Simultaneous Growth ◽  
Phosphorus Levels
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