scholarly journals Window phase analysis of nutrient losses from a typical rice-planting area in the Yangtze river delta region of China

2020 ◽  
Author(s):  
Shuang He ◽  
Fayong Li ◽  
XINQIANG LIANG ◽  
Hua Li ◽  
Sheng Wang ◽  
...  
Keyword(s):  
Stream Water ◽  
Nutrient Loss ◽  
Nutrient Concentrations ◽  
Self Organizing Map ◽  
Delta Region ◽  
Observation Study ◽  
Total N ◽  
Nutrient Runoff ◽  
Runoff Losses ◽  
Total P

Abstract Background: Rice paddy wetlands may serve as a nutrient source or sink in agricultural ecosystems. However, the pattern of nutrient loss on a watershed scale is not clear. A year-round on-site observation study based on 6-h intervals was conducted. Rainfall, temperature, runoff nutrient concentrations, and adjacent stream water samples were automatically monitored to uncover the temporal changes in the runoff losses of the predominant nutrient proxies (total N and total P) from a typical rice-planting area (120 ha) in the Yangtze delta region of China. Results: A high total N concentration in the rice-planting area was observed during the rice-planting season; however, significant fluctuation in the total P was evident throughout the year. The Δtotal N (drainage minus stream) parameter showed negative values with a mean of −0.25 mg L -1 , while Δtotal P showed positive values with a mean of 0.06 mg L −1 . The annual average N and P runoff from paddy field were 11.6 kg ha −1 and 1.5 kg ha −1 , respectively. The window phases for the total N loss were mainly concentrated in the rice-growing season. However, the window phase for the total P loss was more dispersive throughout the year. No apparent relationships were found between rainfall and N and P concentrations by self-organizing map analysis. Conclusions: The high-resolution monitoring, in this study, suggested that nutrient loss loading rather than nutrient concentration, was strongly related to surface runoff Therefore, fertilization before high-intensity rainfall should be avoided to mitigate the nutrient runoff losses and maintain the rice wetland eco-function.

scholarly journals Window phase analysis of nutrient losses from a typical rice-planting area in the Yangtze river delta region of China

2019 ◽  
Author(s):  
Shuang He ◽  
Fayong Li ◽  
Xinqiang Liang ◽  
Hua Li ◽  
Sheng Wang ◽  
...  
Keyword(s):  
Yangtze River ◽  
Yangtze River Delta ◽  
Nutrient Loss ◽  
The Yangtze River ◽  
Delta Region ◽  
Total N ◽  
Yangtze River Delta Region ◽  
Runoff Losses ◽  
The Yangtze River Delta ◽  
Total P

Abstract Background Rice paddy wetlands may serve as a nutrient source or sink in agricultural ecosystems. However, the pattern of nutrient loss on a large scale is not clear. A year-round on-site observation study based on 6 h intervals was conducted. Rainfall, temperature, runoff nutrient concentrations, and adjacent stream water samples were automatically monitored to uncover the temporal changes in the runoff losses of the main nutrient proxies (total N and total P) from a typical rice-planting area (120 ha) in the Yangtze river delta region of China.Results A high total N concentration in the rice-planting area was observed during the rice-planting season; however, a larger fluctuation in the total P was evident throughout the year. The Δtotal N (drainage minus stream) parameter showed negative values with a mean of −0.25 mg L −1 , while Δtotal P showed positive values with a mean of 0.06 mg L −1 . The window phases for the total N loss are mainly concentrated in the rice-growing season. However, the window phase for the total P loss was more dispersive throughout the year. No clear relationships were found between rainfall and N and P concentrations by self-organizing map analysis.Conclusions This high-resolution monitoring suggested that nutrient loss loading, rather than nutrient concentration, was strongly related to runoff depth, and the avoidance of fertilization before high-intensity rainfall could mitigate the nutrient runoff losses and maintain the rice wetland eco-function.

Erosion and nutrient loss reduction with an alternative planting method for coffee (Coffea arabica).

1969 ◽  
Vol 92 (3-4) ◽  
pp. 153-169
Author(s):  
David Sotomayor-Ramírez ◽  
John Ramírez-Ávila ◽  
Edwin Más ◽  
Gustavo A. Martínez
Keyword(s):  
Puerto Rico ◽  
Coffea Arabica ◽  
Phase 1 ◽  
Nutrient Loss ◽  
Nutrient Concentrations ◽  
Phase 2 ◽  
Nutrient Losses ◽  
Nutrient Runoff ◽  
The Media ◽  
Planting Method

Coffee (Coffea arabica) planting in the interior mountainous region of Puerto Rico is usually performed on steep slopes after vegetation removal. The construction of individual terraces around the tree, such as the "Media Luna" planting method, prior to planting could reduce sediment and nutrient losses and could increase yields by improved on-site water and nutrient retention. Experiments were conducted to test the hypothesis that the "Media Luna" planting technique could reduce sediment, total phosphorus (TP), and total Kjeldahl nitrogen (TKN) in runoff during and after the establishment of a coffee plantation in Puerto Rico. The experiments were conducted on a commercial farm where the predominating soils were Mucara (Dystric Eutrudepts) in Phase 1, and Humatas (Typic Haplohumults) in Phase 2. In Phase 1 (recent plantings), sediment and nutrient runoff losses were similar in the conventional countour planting method and in the "Media Luna" treatments. Nutrient concentrations in runoff increased in events following fertilization. Recently loosened unconsolidated sediment material in the "Media Luna" treatment may be more susceptible to losses during the initial establishment phase. In phase 2 (mature plantings), sediment and nutrient losses were greater from soils planted with the conventional contour planting method than from those with the "Media Luna" treatment. The lower TP concentrations measured during Phase 2 suggests that the "Media Luna" technique could be a beneficial practice for coffee production in some areas of Puerto Rico.

Predicting Cyanobacteria dominance in lakes

2001 ◽  
Vol 58 (10) ◽  
pp. 1905-1908 ◽  
Author(s):  
John A Downing ◽  
Susan B Watson ◽  
Edward McCauley
Keyword(s):  
Field Experiments ◽  
Nutrient Concentrations ◽  
Strongly Correlated ◽  
Total N ◽  
Algae Biomass ◽  
Cyanobacteria Blooms ◽  
Freshwater Resource ◽  
Toxic Blooms ◽  
Total P ◽  
Controversial Concept

A controversial precept of aquatic ecology asserts that low ratios of nitrogen to phosphorus (N:P) lead to noxious and sometimes toxic blooms of Cyanobacteria. Cyanobacteria dominance is a major risk to human and ecosystem health. The stoichiometric control of Cyanobacteria therefore has become central to freshwater resource management. This controversial concept is based on observed Cyanobacteria dominance in lakes with low N:P and the results of lab and field experiments. Here we analyze data from 99 of the temperate zone's most studied lakes and show that this model is flawed. We show that the risk of water quality degradation by Cyanobacteria blooms is more strongly correlated with variation in total P, total N, or standing algae biomass than the ratio of N:P. Risks associated with Cyanobacteria are therefore less associated with N:P ratios than a simple increase in nutrient concentrations and algal biomass.

Field Determination of the Critical Nutrient Concentrations for Cladophora in Streams

1976 ◽  
Vol 33 (1) ◽  
pp. 85-92 ◽  
Author(s):  
S. L. Wong ◽  
B. Clark
Keyword(s):  
Plant Tissue ◽  
Stream Water ◽  
Dry Weight ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Nutrient Concentrations ◽  
P Concentration ◽  
P Content ◽  
Waste Load ◽  
Total P

Many streams in southern Ontario experience excessive seasonal growth of aquatic plants such as Cladophora and Potamogeton. A direct relation, with a regression coefficient of 0.87, was observed between ambient P concentration in the water and P content of plant tissue in six rivers. Critical or growth controlling total P concentration of 60 μg/liter in stream water and 1.6 mg/gram dry weight in plant tissue were determined. Unlike P, no significant correlation was observed between N content of plant tissue and N concentration in water. The correlation of total P with plant growth can be used to estimate the waste load which would result in maximum growth rate of Cladophora.

Nutrient Mass Balance and Fate in Dairy Cattle Lots with Different Surface Materials

2019 ◽  
Vol 62 (1) ◽  
pp. 131-138
Author(s):  
Peter A. Vadas ◽  
J. Mark Powell
Keyword(s):  
Nutrient Loss ◽  
Gas Emissions ◽  
Total N ◽  
Environment Management ◽  
Nutrient Deposition ◽  
P Loss ◽  
High Nutrient ◽  
Surface Materials ◽  
Nutrient Mass Balance ◽  
Total P

Abstract.On dairy farms, outdoor lots where cows spend substantial time can be areas of high nutrient deposition in manure. This represents an inefficient use of farm nutrients, if the nutrients are not recovered, and a potential for nutrient loss to the environment. Management of barnyards to recover nutrients can have environmental and production benefits. We monitored nitrogen (N) and phosphorus (P) fate for five years in dairy heifer barnyard plots constructed with soil, sand, or bark mulch surfaces. The plots were stocked with heifers several times per year for about a week at a time. We monitored N and P loss in runoff (soil plots only), leachate, and gas emissions. Of the total N inputs to the plots through heifer excretion, 6% to 8% of inputs were lost in runoff (~2%), leachate (~3% to 4%), and gas emissions (~3% to 4%) from the soil and mulch plots. Most of the N inputs remained in the surface materials. For the sand plots, more N inputs were lost in leachate (~13%) and gas emissions (~6%), but most of the N remained in the surface material. Of total P inputs to the plots through heifer excretion, 4% to 6% of inputs were lost in runoff and leachate, with most of the P remaining in the surface materials. The results suggest that most of the nutrients deposited by heifers onto barnyards could be recovered and used as fertilizer for crop growth by excavating the surface materials and spreading them on cropland, by including animal holding areas in land used for crop rotation so crops can recover nutrients , or by corralling animals directly on cropland. Keywords: Barnyards, Cattle, Leaching, Nutrients, Runoff.

Nitrogen and phosphorus relationships to benthic algal biomass in temperate streams

2002 ◽  
Vol 59 (5) ◽  
pp. 865-874 ◽  
Author(s):  
Walter K Dodds ◽  
Val H Smith ◽  
Kirk Lohman
Keyword(s):  
Stream Water ◽  
Water Quality Monitoring ◽  
The United States ◽  
Anthropogenic Effects ◽  
Nutrient Concentrations ◽  
Monitoring Networks ◽  
Stream Water Quality ◽  
Nitrogen And Phosphorus ◽  
Total N ◽  
Temperate Streams

Knowledge of factors limiting benthic algal (periphyton) biomass is central to understanding energy flow in stream ecosystems and stream eutrophication. We used several data sets to determine how water column nutrients and nonnutrient factors are linked to periphytic biomass and if the ecoregion concept is applicable to nutrient–periphyton relationships. Literature values for seasonal means of biomass of periphyton, nutrient concentrations, and other stream characteristics were collected for almost 300 sampling periods from temperate streams. Data for benthic chlorophyll and nutrient concentrations from a subset of 620 stations in the United States National Stream Water-Quality Monitoring Networks were also analyzed. The greatest portion of variance in models for the mean and maximum biomass of benthic stream algae (about 40%) was explained by concentrations of total N and P. Breakpoint regression and a two-dimensional Kolmogorov–Smirnov statistical technique established significant breakpoints of about 30 µg total P·L–1 and 40 µg total N·L–1, above which mean chlorophyll values were substantially higher. Ecoregion effects on nutrient–chlorophyll relationships were weak. Ecoregion effects were cross-correlated with anthropogenic effects such as percent urban and cropland area in the watershed and population density. Thus, caution is necessary to separate anthropogenic effects from natural variation at the ecoregion level.

scholarly journals Effects of boron and vermicompost on growth, yield and nutrient content of Chilli (Capsicum annum L.)

2021 ◽  
Vol 6 (1) ◽  
pp. 31-36
Author(s):  
KS Nawrin ◽  
MJ Uddin ◽  
AHMZ Ali ◽  
MK Rahman
Keyword(s):  
Leaf Area ◽  
Growth Yield ◽  
Dry Weight ◽  
Nutrient Content ◽  
Growth And Yield ◽  
Nutrient Concentrations ◽  
Nutrient Accumulation ◽  
Total N ◽  
Capsicum Annum ◽  
Total P

The effects of boron (B) and vermicompost (VC) on growth and yield of Chilli (Capsicum annum L.) and nutrient accumulation in its fruits was examined. The highest plant height (22 cm), leaf number per plant (73), leaf area (502.53 cm2/plant), dry weight (22.27g/plant), fruit length (8.97cm), fruit number per plant (6), fruit yield (11.76 g/plant) were recorded in B0.5 kg/ha + VC5 ton/ha at harvest. The results of growth and yield of Chilli varied significantly (p<0.05) and increased with time. The total nutrient concentrations in the fruits were measured and varied significantly (p<0.05). The highest concentration of total P (0.028 %), K (2.50%), S (0.20 %), Cu (8.0 mg/kg), Fe (410 mg/kg) and Mn (0.80 mg/kg) in the fruit were observed in B0.5 kg/ha +VC5 ton/ha treatment and total N (0.41 %) and Zn (3.50 mg/kg) were found in B1.5 kg/ha + VC5 ton/ha treatment. The overall best growth, yield and nutrient accumulation in the fruits of Chilli was achieved in B0.5 kg/ha + VC5 t/ha treatment. J. Biodivers. Conserv. Bioresour. Manag. 2020, 6(1): 31-36

Nutrient status of Lake Liddel, New South Wales: mass loadings of nitrogen and phosphurus, industrial modification, and trophic state

1992 ◽  
Vol 43 (2) ◽  
pp. 443 ◽  
Author(s):  
RN Royle ◽  
RJ King
Keyword(s):  
Point Source ◽  
New South ◽  
Nutrient Status ◽  
Nutrient Concentrations ◽  
Nitrogen And Phosphorus ◽  
Total N ◽  
South Wales ◽  
Annual Total ◽  
The Mean ◽  
Total P

The concentrations of nitratehitrite-N, Kjeldahl-N and total P in point-source additions to and losses from Lake Liddell (32° 22'S,150° 1'E) were measured fortnightly from September 1987 to September 1988. These data were used in conjunction with flow-rate data to construct a nitrogen and phosphorus budget from Lake Liddell. The annual net point-source loadings of nitrogen and phosphorus were 23 400 and 5700 kg, respectively. There was little relationship between changes in lake nutrient concentrations and fortnightly mass loadings. The mean molar N: P ratio for point source mass additions was 13: 1, whereas that within the lake was 33: 1. These features indicate that within-lake processes were the dominant processes in determining lake nutrient concentrations. Retention in the sediments of a greater proportion of the total P pool than of the total-N pool appeared to be one of these processes. The use of Lake Liddell water in power-station operations resulted in substantial increases in nitrate/ nitrite-N and total-P concentrations in waters returned to the lake. The use of Dillon's model to predict mean annual total-P concentrations from mass loadings indicates that Lake Liddell is on the border between mesotrophic and eutrophic states.

Evaluation of selected soil properties for indicating cattle activity at off-stream watering and river access sites in southern Alberta

2013 ◽  
Vol 93 (3) ◽  
pp. 343-358 ◽  
Author(s):  
J. J. Miller ◽  
T. W. Curtis ◽  
E. Bremer ◽  
D. S. Chanasyk ◽  
W. D. Willms
Keyword(s):  
Soil Properties ◽  
Stream Water ◽  
Calcareous Soils ◽  
Soil Bulk Density ◽  
Soil Test ◽  
Nutrient Distribution ◽  
Total N ◽  
Southern Alberta ◽  
Soil Test P ◽  
Total P

Miller, J. J., Curtis, T. W., Bremer, E., Chanasyk, D. S. and Willms, W. D. 2013. Evaluation of selected soil properties for indicating cattle activity at off-stream watering and river access sites in southern Alberta. Can. J. Soil Sci. 93: 343–358. Off-stream watering troughs may reduce surface water pollution by shifting nutrient distribution from natural watering sites along the river to around artificial water troughs some distance from the river. The objective of our study was to evaluate the suitability of nine soil properties for assessing the impacts of cattle activity adjacent to eight watering sites. Nine surface (0–5 cm) soil properties were evaluated along four 100-m transects at the five off-stream water troughs and three river access sites along the Lower Little Bow River in southern Alberta over 4 yr (2007–2010). The properties included P (total P, soil test P or STP), N (total N, NO3-N, NH4-N), total C, total C:total N ratio (TC:TN), chloride (Cl), and soil bulk density. Soil test P was significantly (P≤0.05) enriched at 65% of site-year comparisons, followed by total C (63%), NO3-N (55%), total P and TC:TN (50%). This suggested that these soil properties were relatively good indicators of cattle activity at the majority (>50%) of watering sites. Chloride was a valid indicator only in non-saline areas (100% of four non-saline sites). Total C and TC:TN ratios were not valid indicators in the calcareous soils at all sites because of possible confounding influence of inorganic C. Overall, we recommend Cl as an indicator of cattle activity at watering sites not affected by soil salinity and high natural Cl levels, and STP as the best overall indicator of cattle activity at off-stream watering sites and river access sites. Certain soil properties were also influenced by distance from watering site, stocking rate, precipitation, and age of water trough.

scholarly journals Effects of copper and vermicompost on growth and yield of cowpea (Vigna unguiculata L.) Walp and nutrient accumulation in its fruits

2020 ◽  
Vol 5 (2) ◽  
pp. 13-18
Author(s):  
AT Sharif ◽  
AHMZ Ali ◽  
MK Rahman
Keyword(s):  
Leaf Area ◽  
Plant Height ◽  
Vigna Unguiculata ◽  
Growth Yield ◽  
Dry Weight ◽  
Growth And Yield ◽  
Nutrient Concentrations ◽  
Nutrient Accumulation ◽  
Total N ◽  
Total P

The effects of copper (Cu) and vermicompost (VC) on growth and yield of cowpea (Vigna unguiculata L.) Walp and nutrient accumulation in its fruits was examined. Eight treatments of Cu and VC were used. The highest plant height (226.67 cm), leaf number per plant (86.33), leaf area (174.12 cm2/plant), dry weight (13.98 g/plant), fruit length (52.4 cm), fruit number per plant (6), and fruit yield (5.65 g/plant) were recorded in Cu0.5 kg/ha + VC5 ton/ha treatment at harvest. The results of growth and yield of cowpea varied significantly (p≤ 0.05) and increased with time. The total nutrient concentrations in the fruits were measured and varied significantly (p≤ 0.05). The highest concentration of total P (0.79%), K (4.14%), S (0.42%), Cu (27 mg/kg), Fe (640 mg/kg) and Mn (59 mg/kg) in the fruits were observed in Cu0.5 kg/ha + VC5 ton/ha treatment and total N (4.29%) and Zn (88 mg/kg) were found in Cu1.5 kg/ha + VC5 ton/ha treatment. The overall best growth, yield and nutrient accumulation in the fruits of cowpea were achieved in Cu0.5 kg/ha + VC5 treatment. J. Biodivers. Conserv. Bioresour. Manag. 2019, 5(2): 13-18

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