Is a rainfall simulator useful for estimating phosphorus runoff from pastures — a question of scale-dependency?

2002 ◽  
Vol 42 (7) ◽  
pp. 953 ◽  
Author(s):  
P. S. Cornish ◽  
R. Hallissey ◽  
E. Hollinger

Research on management practices that aim to reduce phosphorus in runoff from agricultural land has been hampered by the need to study large catchments over relatively long time periods to account for both the temporal and spatial effects of scale. The concentrations of pollutants such as phosphorus in runoff, similarly to suspended sediment, may diminish with increasing catchment scale. However, the runoff from well-covered dairy pastures contains predominantly soluble rather than particulate phosphorus. This paper examines the hypothesis that the concentration of soluble phosphorus in runoff from dairy pastures is insensitive to scale, and that small-plot rainfall simulators can be used to estimate concentrations of phosphorus in runoff at the farm or subcatchment scale.Over 2 years and 9 runoff events, the mean concentration of soluble phosphorus in runoff from a 140 ha dairy farm (0.95 mg/L) was not significantly different from a 4 ha representative subcatchment (paddock) within the dairy farm (0.66 mg/L). Relative concentrations from the 2 sources varied between events, depending on the duration of the runoff event. This variation was attributed to changes in the relative importance of different source areas as events progressed; runoff from the more distant parts of the larger catchment area, typically in higher positions in the landscape, apparently increased in importance in longer events.A hand-held rainfall simulator, with plots of only 1 m2, provided a quick, useful estimate of soluble phosphorus concentration in runoff. The mean concentration of soluble phosphorus in runoff from simulated rainfall at 9�locations in the 4 ha paddock (0.64 mg/L) was very similar to the value obtained from the paddock over a 2-year period (0.66 mg/L). We conclude that the concentration of soluble phosphorus in runoff from dairy pasture does depend on scale, and other variables, but the effect of scale was small for the catchment studied. A rainfall simulator may be used, with adequate replication, to estimate the soluble phosphorus concentrations in runoff that could be expected from dairy pastures over much larger areas.

1997 ◽  
Vol 35 (2-3) ◽  
pp. 131-138 ◽  
Author(s):  
Pirjo-Riitta Rantala ◽  
Hannu Wirola

The aim of the study was to determine if solid, slightly soluble compounds can be used as nutrient source in activated sludge treatment plants instead of liquid phosphoric acid. Four different solid materials were tested in lab-scale solubility tests to find compounds which are least soluble. Two materials were chosen for further studies: apatite and raw phosphate. The use of apatite and raw phosphate as nutrient source was studied in lab-scale activated sludge reactors along with a control reactor where phosphorus was added in liquid form. The phosphorus dosage, measured as elementary phosphorus, was the same for all three reactors. The reactors were fed with pre-clarified chemi-thermomechanical pulp mill (CTMP) wastewater. There were no significant differences in the reductions of organic matter between the three reactors. The mean effluent concentration of total phosphorus was 3 mg P/l in the control reactor and less than 1 mg P/1 in the other two reactors. The soluble phosphorus concentration was more than 2 mg P/l in the control reactor and less than 0.5 mg P/l in the other two. Apatite was an even better nutrient source than raw phosphate. Further lab-scale tests were conducted using two different grain sizes of apatite. No significant differences were found between the studied grain sizes (<0.074 mm and 0.074 mm-0.125 mm). Apatite was then used in full-scale at a CTMP-mill two different times. The experiments showed that the mean concentrations of phosphorus can be reduced radically by using apatite as a nutrient source instead of liquid phosphorus. Solid phosphorus compounds are a viable alternative to reduce the phosphorus load from forest industry wastewater treatment plants.


Author(s):  
Karolina Sawa ◽  
Leszek Hejduk ◽  
Johannes Deelstra ◽  
Lillian Øygarden

Nutrient output from rural areas on the example of two catchments Skuterud and Zagożdżonka In this paper, two rural catchment - the Zagożdżonka catchment in Poland and the Skuterud catchment in Aas, Akershus county in Norway are compared. In addition to the general description, more in particular information, runoff, N-NO3 load, P-PO4 load, total phosphorus and total nitrogen concentrations in streams are compared. The data compared are from 1993 to 1995 in Zagożdżonka catchment and from 1994-1996 from Skuterud catchment. The average concentration of N-NO3 in Zagożdżonka River in the period was 0.85 mg·l-1 and the mean concentration of P-PO4 was 0.13 mg·l-1. In the stream in Skuterud catchment the average concentration of N-NO3 was 4.95 mg·l-1 and the mean concentration of P-PO4 was 0.04 mg·l-1. For both catchments the same data were also compared for the 2008. In Skuterud catchment the highest concentration of nutrients occurred in November, March and April, which was connected to the higher runoff from agricultural areas during the snowmelt period. In Zagożdżonka catchment the highest concentration of nutrients was noted in March, April and in summer time, which was connected to periods with high amounts of precipitation. Comparison of the two rural catchments showed many differences in applied measurement methods for water sampling, water measurement, discharge measurement, runoff amounts and management practices, which had an effect on results of monitoring program. The compared data can be useful to predict the development of future environmental conditions for example water quality. It can also be useful for predict how nutrient runoff will be in future. What is more the different conditions for runoff in Skuterud and Zagożdżonka then different measures are needed.


2020 ◽  
Vol 13 (1) ◽  
pp. 232
Author(s):  
Susanta Das ◽  
Proloy Deb ◽  
Pradip Kumar Bora ◽  
Prafull Katre

Soil erosion from arable lands removes the top fertile soil layer (comprised of humus/organic matter) and therefore requires fertilizer application which affects the overall sustainability. Hence, determination of soil erosion from arable lands is crucial to planning conservation measures. A modeling approach is a suitable alternative to estimate soil loss in ungauged catchments. Soil erosion primarily depends on soil texture, structure, infiltration, topography, land uses, and other erosive forces like water and wind. By analyzing these parameters, coupled with geospatial tools, models can estimate storm wise and annual average soil losses. In this study, a hilly watershed called Nongpoh was considered with the objective of prioritizing critical erosion hazard areas within the micro-catchment based on average annual soil loss and land use and land cover and making appropriate management plans for the prioritized areas. Two soil erosion models namely Revised Universal Soil Loss Equation (RUSLE) and Modified Morgan–Morgan–Finney (MMF) models were used to estimate soil loss with the input parameters extracted from satellite information and automatic weather stations. The RUSLE and MMF models showed similar results in estimating soil loss, except the MMF model estimated 7.74% less soil loss than the RUSLE model from the watershed. The results also indicated that the study area is under severe erosion class, whereas agricultural land, open forest area, and scrubland were prioritized most erosion prone areas within the watershed. Based on prioritization, best management plans were developed at catchment scale for reducing soil loss. These findings and the methodology employed can be widely used in mountainous to hilly watersheds around the world for identifying best management practices (BMP).


2008 ◽  
Vol 58 (9) ◽  
pp. 1797-1802 ◽  
Author(s):  
Richard Grayson ◽  
Paul Kay ◽  
Miles Foulger

Diffuse pollution poses a threat to water quality and results in the need for treatment for potable water supplies which can prove costly. Within the Yorkshire region, UK, nitrates, pesticides and water colour present particular treatment problems. Catchment management techniques offer an alternative to ‘end of pipe’ solutions and allow resources to be targeted to the most polluting areas. This project has attempted to identify such areas using GIS based modelling approaches in catchments where water quality data were available. As no model exists to predict water colour a model was created using an MCE method which is capable of predicting colour concentrations at the catchment scale. CatchIS was used to predict pesticide and nitrate N concentrations and was found to be generally capable of reliably predicting nitrate N loads at the catchment scale. The pesticides results did not match the historic data possibly due to problems with the historic pesticide data and temporal and spatially variability in pesticide usage. The use of these models can be extended to predict water quality problems in catchments where water quality data are unavailable and highlight areas of concern.


1993 ◽  
Vol 28 (3-5) ◽  
pp. 529-538 ◽  
Author(s):  
S. Rekolainen ◽  
M. Posch ◽  
E. Turtola

This paper summarizes the results of recent studies concerning the agricultural nutrient load to surface waters in Finland and possible management practices for reducing nutrient losses from agricultural land. Both the nitrogen and the phosphorus load exceed the loads from municipal and industrial sources together, thus being mainly responsible for the eutrophication of surface and coastal waters. 25% of the total agricultural phosphorus load is bioavailable dissolved reactive phosphorus, and 5% of the paniculate phosphorus load is available for algae. Reduced tillage, filter strips and permanent grassland on the set-aside land are means investigated for reducing erosion and nutrient losses. Based on experiments and model simulations, it is estimated that a wide adoption of all these practices would reduce total phosphorus load by about 40%. Soluble phosphorus and nitrogen losses can be reduced by adjusting the amount and timing of fertilization and manure application to the actual needs of plants. If the whole set-aside area was under permanent grassland, the nitrogen loss would decrease by about 17%, but the effect of cover or undersown crops in Finnish conditions is still unknown. More investigations are also needed of the effects of all these management practices on the soluble phosphorus load.


2007 ◽  
Vol 11 (1) ◽  
pp. 96-107 ◽  
Author(s):  
P. E. O’Connell ◽  
J. Ewen ◽  
G. O’Donnell ◽  
P. Quinn

Abstract. Over the past fifty years, significant changes in UK land use and management practices have occurred, driven by UK and EU agricultural policies. There is substantial evidence that modern land-use management practices have enhanced surface runoff generation at the local scale, frequently creating impacts through "muddy floods". Such local impacts can be avoided or mitigated through the adoption of better land management practices and/or small scale surface runoff control measures. There is little evidence that local scale changes in runoff generation propagate downstream to create impacts at the larger catchment scale. This does not imply that impacts do not exist, but the very few studies in which evidence has been sought have not produced any conclusive findings. Multiscale catchment experimentation, linked to new developments in modelling, is needed which can lead to a better understanding of how small scale changes to runoff generation propagate to larger catchment scales. To facilitate the tracking of changes from the local to the catchment scale, a new modelling approach is demonstrated which allows a downstream flood hydrograph to be mapped back onto its source areas, thus presenting impact information to users in a useful and comprehensible form.


Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 582
Author(s):  
Jerónimo Salinas ◽  
David Meca ◽  
Fernando del Moral

The short-term responses of soil quality indicators are important for assessing the effects of new management practices and addressing threats to crop yields in greenhouses. The aim of this study was to assess, during three consecutive cropping seasons, the effect of a sustainable management package (CRTMP)—which includes the on-site reuse of greenhouse crop residues and tillage—in comparison with conventional management, based on fertigation only (CMP), on certain biochemical soil quality indicators and crop yields. CRTMP significantly increased (p < 0.05) the values of total organic carbon (TOC), particulate organic carbon (POC), light fraction (LF), water soluble organic carbon (WSOC), and dehydrogenase (DH) and β-glucosidase (GL) activities at a depth of 0–15 cm, as well as the mean concentration of nitrates in the soil solution. In addition, a significant Pearson’s correlation (p < 0.01) found between the indicators suggested a balanced improvement of soil biological activity and nutritional soil state. Nonetheless, the significant (p < 0.05) increases in the mean concentration of chlorides in the soil solution and electrical conductivity (p < 0.05) increased the risk of salinization, which may have affected the concentration of nitrates in the petiole sap and total production in CRTMP, which were significantly lower than in CMP. Nevertheless, the proportion of premium product was significantly higher in CRTMP, while the proportion of non-commercial production decreased.


2021 ◽  
Vol 37 (1) ◽  
pp. 8-20
Author(s):  
Manju Loura ◽  
Suman Ghalawat ◽  
Joginder Singh Malik ◽  
K.K. Kundu ◽  
K.K. Yadav ◽  
...  

India contributes the largest to the world milk production. The main objective of the study is to investigate the different technologies adopted by dairy farmers in Haryana. Primary data was collected from 200 dairy farmers from different places in Haryana state. The study was conducted in Haryana study revealed that among all the good dairy practices animal health practices was followed by majority of the dairy farmers and the corresponding mean value was 1.75 and the rank was 1st, followed by management practices (corresponding mean value 2.02 and rank 2nd), hygiene milking practices (corresponding mean value 2.12 and rank 3rd), animal wellbeing (corresponding mean value 2.23 and rank 4th), nutrition (corresponding mean value 2.56 and rank 5th), and environment practices with corresponding mean value 2.57, were least preferred or we may say least adopted by dairy farmers hence environment practices was given rank 6th.Poor animal health is one of the principal constraints to increasing small-scale dairy productivity, as it results in high morbidity and low production. Overcoming this constraint could significantly improve productivity and results in real and direct benefits for producers. The IBM SPSS22 software was used to calculate the mean score of the statements based on Likert 5-point scale.This study gives us an idea about how we start a dairy farm and what management practices should be adopted.


1983 ◽  
Vol 22 (05) ◽  
pp. 246-250 ◽  
Author(s):  
M. Al-Hilli ◽  
H. M. A. Karim ◽  
M. H. S. Al-Hissoni ◽  
M. N. Jassim ◽  
N. H. Agha

Gelchromatography column scanning has been used to study the fractions of reduced hydrolyzed 99mTc, 99mTc-pertechnetate and 99mTc-chelate in a 99mTc-glucoheptonate (GH) preparation. A stable high labelling yield of 99mTc-GH complex in the radiopharmaceutical has been obtained with a concentration of 40-50 mg of glucoheptonic acid-calcium salt and not less than 0.45 mg of SnCl2 2 H2O at an optimal pH between 6.5 and 7.0. The stability of the complex has been found significantly affected when sodium hydroxide solution was used for the pH adjustment. However, an alternative procedure for final pH adjustment of the preparation has been investigated providing a stable complex for the usual period of time prior to the injection. The organ distribution and the blood clearance data of 99mTc-GH in rabbits were relatively similar to those reported earlier. The mean concentration of the radiopharmaceutical in both kidneys has been studied in normal subjects for one hour with a scintillation camera and the results were satisfactory.


1967 ◽  
Vol 55 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Benno Runnebaum ◽  
Josef Zander

ABSTRACT Progesterone was determined and identified in human peripheral blood during the preovulatory period of the menstrual cycle, by combined isotope derivative and recrystallization analysis. The mean concentration of progesterone in 1.095 ml of plasma obtained 9 days before ovulation was 0.084 μg/100 ml. However, the mean concentration of progesterone in 1.122 ml of plasma obtained 4 days before ovulation was 0.279 μg/100 ml. These data demonstrate a source of progesterone secretion other than the corpus luteum. The higher plasma-progesterone concentration 4 days before ovulation may indicate progesterone secretion of the ripening Graafian follicle of the ovary.


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