Pesticides and Nutrients In Southern U. S. Shallow Ground Water and Surface Runoff

Nutrient and pesticide concentrations in shallow groundwater (3m) and surface runoff were determined for conventional-till (CT) and no-till (NT) soybean watersheds. Groundwater NO3N concentrations were similar for both tillage systems, averaging about 7-8 ppm, but exceeded 10 ppm for some storms. Annual mean groundwater NO3N concentrations were only 0.34 ppm in a riparian zone downslope from the CT watershed. Higher nutrient concentrations in NT surface runoff reflected surface residue leaching. Runoff from both watersheds, 2 days after a broadcast application of 0-20-20, had high nutrient concentrations that decreased during subsequent storms. Pesticide concentrations in groundwater of the NT watershed were as high as 250 ppb at a depth of 1.5 m within 1 week after application (1st rainfall). Concentrations beneath the CT watershed were < 10 ppb maximum. One month after application, pesticide concentrations in groundwater beneath both watersheds had decreased to about 10% of their respective 1-week values. Similar total pesticide losses in runoff occurred for both tillage systems. NT reduced sediment loss but increased pesticide movement into the soil profile. Results of companion studies with corn at another site indicated similar trends for nutrients and pesticides in shallow groundwater. Within 11 months after application, herbicides were still detectable at very low concentrations (<1 ppb). Soil insecticides, applied at planting, were not found in groundwater. Herbicides and insecticides were detectable in both the water and sediment phases of runoff for 5 months after application. At the 1.5-m depth, the mean NO3N concentration in groundwater for conventional-, reduced-and no-till corn was 4.78 ppm compared with 6.96 ppm at the 3-m depth.

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Localization of calcium and zinc in the sperm storage tubules of chicken, quail and turkey using X-ray microanalysis

Reproduction ◽

10.1530/reprod/118.2.331 ◽

2000 ◽

pp. 331-336 ◽

Cited By ~ 9

Author(s):

L Holm ◽

H Ekwall ◽

GJ Wishart ◽

Y Ridderstrale

Keyword(s):

Calcium Concentration ◽

Sperm Storage ◽

X Ray ◽

Elemental Concentrations ◽

Low Concentrations ◽

Intracellular Content ◽

Wet Weight ◽

The Mean ◽

Sperm Storage Tubules ◽

Scanning Electron

Sperm storage tubules from the utero-vaginal junction of chickens, quails and turkeys were analysed for calcium and zinc using X-ray microanalysis of ultra-rapidly frozen tissue in a scanning electron microscope. This technique enabled the tubular fluid surrounding the stored spermatozoa and the intracellular content of the cells of the sperm storage tubules to be analysed separately and, by using standards with known concentrations, their elemental concentrations were estimated. The mean (+/- SEM) concentration of calcium in the tubular fluid from chickens, quails and turkeys was 17 +/- 3, 19 +/- 3 and 17 +/- 4 mmol kg(-1) wet weight, respectively. The intracellular calcium concentration of the cells of the tubules did not differ significantly from these values and was also similar in the mucosal epithelial cells of the utero-vaginal junction. Zinc was localized in the cells of turkey sperm storage tubules and tubular fluid, but at low concentrations. No zinc could be detected in corresponding structures from chickens and quails. The concentration of calcium in the tubular fluid is within the range known to inhibit the motility of spermatozoa, supporting this function for calcium during storage. Zinc is known to depress turkey sperm metabolism and it may also be involved in inducing quiescence of spermatozoa during storage in this species.

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Crop Yields and Phosphorus Loss with Surface Runoff as Affected by Tillage Systems and Phosphorus Sources

10.31274/farmprogressreports-180814-604 ◽

2010 ◽

Author(s):

Antonio P. Mallarino ◽

Mazhar Ul Haq ◽

Matthew J. Helmers ◽

Ryan Rusk

Keyword(s):

Surface Runoff ◽

Crop Yields ◽

Tillage Systems ◽

Phosphorus Loss ◽

Phosphorus Sources

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Nutrient Concentrations in Soil Solution in an Alfisol under Grapefruit Production

HortScience ◽

10.21273/hortsci.33.3.498d ◽

1998 ◽

Vol 33 (3) ◽

pp. 498d-498

Author(s):

Z.L. He ◽

A.K. Alva ◽

D.V. Calvert ◽

D.J. Banks ◽

Y.C. Li

Keyword(s):

Soil Solution ◽

Fine Sand ◽

Drainage Water ◽

Tree Canopy ◽

Nutrient Concentrations ◽

Sour Orange ◽

Parallel Study ◽

Ph Measurements ◽

The Mean ◽

N Rates

A field experiment was conducted in a Riviera fine sand (Alfisol) with 25-year-old `White Marsh' grapefruit trees on Sour orange rootstock to monitor the downward transport of nutrients from fertilization practices. Fertilizer was applied as either dry granular broadcast (three applications/year) or fertigation (15 applications/year) at N rates of 56, 112, 168, and 336 kg/ha per year using a N:P:K blend (1.0:0.17:1.0). Soil solution was sampled bi-weekly from suction lysimeters, installed under the tree canopy, about 120 cm from the tree trunk, at two depths representing above (120 cm) and below (180 cm) the hard pan. The concentrations of K, Ca, and Mg were greater at the 180- than at 120-cm depth, whereas, the converse was true with respect to the concentration of P in soil solution. Over a 2-year period, the mean concentrations of P and K varied from 0.031-0.976 and 150-250 mg·L–1, respectively. Increased rate of fertilization also appeared to increase the concentrations of Ca and Mg in the soil solution. This could be due to effects of slight acidification of the soil with increased rates of ammonium form of N. A parallel study on pH measurements has shown evidence of soil acidification, under the tree canopy, with increased rates of ammonium fertilization. In a bedded grove, the soil solution above the hard pan is likely to seep into the water furrow, which is discharged into the drainage water.

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Nutrient Input and Trophic Status of the “Neue Donau”, a High-Water Control System along the River Danube in Vienna, Austria

Water Science & Technology ◽

10.2166/wst.1990.0021 ◽

1990 ◽

Vol 22 (5) ◽

pp. 137-144 ◽

Cited By ~ 3

Author(s):

M. T. Dokulil ◽

G. A. Janauer

Keyword(s):

Water Quality ◽

Control System ◽

Trophic Status ◽

High Water ◽

Nutrient Concentrations ◽

Nutrient Input ◽

Water Control ◽

Trophic Conditions ◽

River Danube ◽

High Nutrient

The system “Neue Donau” functions as a control system for high waters of the river Danube and is an important recreational area for many people. Water quality and trophic status of the water body is thereforeof prime importance. The high nutrient concentrations of the river Danube (P-tot 238±41µg/l, N-tot 2.53±0.78 mg/l) reach the system via groundwater seepage. Present conditions in the basin of Neue Donau are,as a result of this nutrient in-flux,eutrophic to hypertrophic. Average values during the summer period have declined from 366 µg/l total phosphorus to 78 µg/l, and from 86 µg/l chlorophyll-a tol7µg/l between the years 1985 and 1988. However, a dam which is planned in the river at Vienna will permanently raise the water level of the river thus increasing the the groundwater flow in the direction to the Neue Donau and therefore the nutrient input which will enhance trophic conditions in the impoundment. Since macrophytes play an important role in one part of the system macrophyte management together with measures along the river are some of the suggested strategies to keep the system Neue Donau at acceptable trophic conditions and good water quality.

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Competitive attributes ofA. sativa, T. aestivum, andH. vulgareare conserved in no-till cropping systems

Weed Science ◽

10.1017/s0043174500091384 ◽

1999 ◽

Vol 47 (6) ◽

pp. 712-719 ◽

Cited By ~ 3

Author(s):

Anne Légère ◽

Yuguang Bai

Keyword(s):

Hordeum Vulgare ◽

Avena Sativa ◽

Growth Parameters ◽

Cropping Systems ◽

Seedling Emergence ◽

Biomass Accumulation ◽

Tillage Systems ◽

Area Index ◽

No Till ◽

Lower Test

The robustness of competitive attributes of cereals such as rapid and uniform seedling emergence, tillering, early biomass accumulation and canopy closure, and height advantage over weeds have not yet been tested under environmental conditions typical of no-till (NT) cropping systems. Our objective was to evaluate the effects or NT practices on growth and productivity ofAvena sativa, Triticum aestivum, Hordeum vulgare, and associated weeds. The experiment was conducted on a Kamouraska clay at La Pocatière, QC, in 1994, 1995, and 1996.Avena sativa, T. aestivum, andH. vulgarewere grown under tilled and NT practices. Cereal growth parameters were measured six (1994) or seven (1995) times between planting and the 11th week after planting but only once in 1996. Grain yields and yield components were determined at crop maturity.Avena sativaandH. vulgarepopulations were little affected by tillage, whereasT. aestivumpopulations were reduced by 16 to 20% in NT systems. Growth in height in NT systems was either similar or greater than in tilled systems in all three cereals. Cereal leaf area index (LAI) and biomass accumulation was also comparable between tillage systems, except forT. aestivumLAI in 1994, which was greater in tilled plots on two sampling dates. Response of annual dicots to tillage was inconsistent in all crops. Annual monocots dominated in some but not all NT systems. Perennial dicots dominated in NT systems, whereas perennial monocots were more abundant in tilled systems in all three cereals.Avena sativaandT. aestivumyields in NT plots were comparable or greater than in tilled plots, in spite of having either lower test weights (A. sativa) or lower 1,000-grain weights (T. aestivum). NTT. aestivumproductivity was maintained in spite of reduced plant establishment.Hordeum vulgareyields were also similar across tillage systems, except in 1995, when yields in tilled plots were greater than in NT plots. The height advantage observed for NTH. vulgaredid not result in improved yields. All three cereals, and particularlyA. sativa, appeared well suited to NT systems, despite the pressure provided by different weed groups, compared to tilled systems. However, results suggest that NT production of cereals could benefit from improved attention to perennial dicot control and crop seedling establishment, particularly forT. aestivum.

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Assessment of heavy metals contamination and associated risks in shallow groundwater sources from three different residential areas within Ibadan metropolis, southwest Nigeria

Applied Water Science ◽

10.1007/s13201-021-01414-4 ◽

2021 ◽

Vol 11 (5) ◽

Author(s):

Saheed Adekunle Ganiyu ◽

Abimbola Temitope Oyadeyi ◽

Azeem Adedeji Adeyemi

Keyword(s):

Heavy Metals ◽

Cancer Risk ◽

Urban Area ◽

Ecological Risk ◽

Water Samples ◽

Risk Index ◽

Shallow Groundwater ◽

World Health ◽

Southwest Nigeria ◽

The Mean

AbstractThis study has been conducted to appraise the concentrations of selected heavy metals and total dissolved solids (TDSs) in the drinking water from shallow wells in parts of Ibadan metropolis, southwest Nigeria. Fifteen (15) water samples were collected from three representative residential locations [traditional core area (TCA), peri-urban area (PUA), and urban area (UA)] for geochemical analysis. Heavy metals and TDS were analyzed with the aid of atomic absorption spectrophotometer and calibrated meter, respectively. The mean concentration (mg/L) of Zn, Pb Mn, Fe, and Cd has been 3.930, 0.658, 0.0304, 1.698, and 0.501, respectively, and as a consequence, the order of abundance of studied metals was Zn > Fe > Pb > Cd > Mn. Concentrations of Zn, Fe, Pb, and Cd were higher than recommended standards in 60%, 86.7%, 100%, and 100% of groundwater samples, respectively. However, at all points tested, the mean concentrations of Mn and TDS in water samples lie within the safe limits set by World Health Organization. The evaluation of geoaccumulation index (Igeo), enrichment factor (EF), and contamination factor suggests that representative water samples were low-to-moderate contamination. The potential ecological risk index advocates low-to-moderate ecological risk in TCA and PUA, while it demonstrated exclusive “moderate” risk in UA. Further, the range of pollution load index (PLI) (0.55–1.32) in both TCA and PUA shows nil-to-moderate pollution status, while PLI values > 1 in UA indicate moderate contaminated state. The degree of contamination in groundwater showed the following trends: UA > TCA > PUA in the study area. Moreover, the results of EF and quantification of contamination of analyzed metals in water samples indicate geogenic and anthropogenic inputs. The contribution of studied metals to the incidence of non-cancer risk via oral intake within the residential sites follows the order: cadmium > lead > zinc > iron > manganese. The hazard index as a result of ingested heavy metals for the three population classes surpasses the acceptable range in the order of infant < child < adult. Cadmium and lead made considerable impact to the estimation of cancer risk in the study area for the three human population categories. Factor analysis extracted only one component that explained 94.64% of the entire variance, while cluster analysis identified three distinct groups based on similar water quality characteristics. Based on the findings of the study, awareness programs toward protecting the shallow groundwater sources should be launched, encouraged, and sustained. Moreover, the study suggests better hygienic practices and pre-treatment of contaminated water before consumption.

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Effect of Tillage Systems on Soil Organic Carbon and Soil Quality in a Purple Paddy Soil

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.183-185.1190 ◽

2011 ◽

Vol 183-185 ◽

pp. 1190-1194

Author(s):

Jun Ke Zhang ◽

Qing Ju Hao ◽

Chang Sheng Jiang ◽

Yan Wu

Keyword(s):

Organic Carbon ◽

Soil Quality ◽

Paddy Soil ◽

Conventional Tillage ◽

Water Infiltration ◽

Purple Soil ◽

Tillage Systems ◽

Field Station ◽

No Till ◽

The Impact

The impact of conservation tillage practices on carbon sequestration has been of great interest in recent years. This experiment analyzed the organic carbon status of soils sampled at depth increments from 0 to 60 cm after 20 years in a purple paddy soil. The tillage experiment was established in the Key Field Station for Monitoring of Eco-Environment of Purple Soil of the Ministry of Agriculture of China, located in the farm of Southwest University (30°26′N, 106°26′E), Chongqing. In this paper, five tillage treatments including conventional tillage with rice only system (DP), conventional tillage with rotation of rice and rape system (SL), no-till and ridge culture with rotation of rice and rape system (LM), no-till and plain culture with rotation of rice and rape system (XM) and tillage and ridge culture with rotation of rice and rape system (LF) were selected as research objectives to measure SOC storage and stratification ratio of SOC (CSR). The SOC storage under different tillage systems was calculated based on an equivalent soil mass. The CSR can be used as an indicator of soil quality because surface organic matter is essential to erosion control, water infiltration, and the conservation of nutrients. Results showed that in soil under no-till SOC was concentrated near the surface, while in tilled soil SOC decreased equably with the increase of soil depth. The difference of SOC contents between the five tillage systems was the largest in the top soil and the lowest in the bottom soil. The order of SOC storage was LM (158.52 Mg C•ha-1) >DP (106.74 Mg C•ha-1) >XM (100.11 Mg C•ha-1) >LF (93.11 Mg C•ha-1) >SL (88.59 Mg C•ha-1), LM treatment was significantly higher than the other treatments. The CSR of 0-10/50-60 cm was 2.65, 2.70 and 2.14 under LM, XM and LF treatments, while 1.54 and 1.92 under DP and SL treatments. We considered CSR>2 indicate an improvement in soil quality produced by changing from tillage to no-tillage, as well as changing from plane to ridge. Overall, long-term LM treatment is a valid strategy for increasing SOC storage and improving soil quality in a purple paddy soil in Southwest China.

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Application of digital image processing in slope surface runoff velocity analysis under simulated rainfall conditions

Hydrology Research ◽

10.2166/nh.2017.040 ◽

2017 ◽

Vol 49 (4) ◽

pp. 1304-1312

Author(s):

Tiexiong Gong ◽

Yuanjun Zhu

Keyword(s):

Image Processing ◽

Surface Runoff ◽

Lateral Diffusion ◽

Ease Of Use ◽

Velocity Analysis ◽

Slope Gradient ◽

Tracer Method ◽

Dye Tracer ◽

The Mean ◽

High Runoff

Abstract To have accurate runoff velocity, there is need to improve dye tracer method for estimating surface runoff velocity. This can enhance the calculations of relevant hydrologic parameters that will lead to a better understanding of hydrological processes and soil erosion. In this study, an integrated dye tracer and image processing method (IPV) and dye tracer method (AOV), respectively, were used to estimate runoff velocity under three slope gradients (5°, 10°, and 15°) and three slope positions (up-slope, mid-slope, and down-slope). The results showed more variation in runoff velocity under IPV than AOV. Both IPV and AOV were positively correlated with slope gradient. IPV values were close to AOV ones for slope gradients ≤5°, but were significantly different for slope gradients ≥10°. The mean AOV value was 10.6% higher than that of IPV. Regression analysis showed that compared with AOV, IPV overestimated and underestimated runoff under low and high runoff velocity conditions, respectively. The use of image processing in IPV was advantageous because of its ease of use with fewer artificial errors and its suitability for lateral diffusion of runoff. Irrespectively, additional studies are needed to verify and/or improve further the use of this method in runoff velocity analysis.

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An efficient semi-distributed hillslope erosion model for the subhumid Ethiopian Highlands

Hydrology and Earth System Sciences ◽

10.5194/hess-17-1051-2013 ◽

2013 ◽

Vol 17 (3) ◽

pp. 1051-1063 ◽

Cited By ~ 58

Author(s):

S. A. Tilahun ◽

C. D. Guzman ◽

A. D. Zegeye ◽

T. A. Engda ◽

A. S. Collick ◽

...

Keyword(s):

Surface Runoff ◽

Source Area ◽

Sediment Concentration ◽

Erosion Model ◽

Ethiopian Highlands ◽

Source Areas ◽

Blue Nile Basin ◽

Field Evidence ◽

Sediment Loss ◽

Main Variable

Abstract. Erosion modeling has been generally scaling up from plot scale but not based on landscape topographic position, which is a main variable in saturation excess runoff. In addition, predicting sediment loss in Africa has been hampered by using models developed in western countries and do not perform as well in the monsoon climate prevailing in most of the continent. The objective of this paper is to develop a simple erosion model that can be used in the Ethiopian Highlands in Africa. We base our sediment prediction on a simple distributed saturated excess hydrology model that predicts surface runoff from severely degraded lands and from bottom lands that become saturated during the rainy season and estimates interflow and baseflow from the remaining portions of the landscape. By developing an equation that relates surface runoff to sediment concentration generated from runoff source areas, assuming that baseflow and interflow are sediment-free, we were able to predict daily sediment concentrations from the Anjeni watershed with a Nash–Sutcliffe efficiency ranging from 0.64 to 0.78 using only two calibrated sediment parameters. Anjeni is a 113 ha watershed in the 17.4 million ha Blue Nile Basin in the Ethiopian Highlands. The discharge of the two watersheds was predicted with Nash–Sutcliffe efficiency values ranging from 0.80 to 0.93. The calibrated values in Anjeni for degraded (14%) and saturated (2%) runoff source area were in agreement with field evidence. The analysis suggests that identifying the runoff source areas and predicting the surface runoff correctly is an important step in predicting the sediment concentration.

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