Atrazine and nitrate leaching through soil columns as affected by conservation tillage

A leaching experiment was designed to study the effects of a commercial nitrification inhibitor containing nitrapyrin on nitrification, microbial nitrogen (N) immobilization, and nitrate leaching. Soil columns were treated with 100 mg N kg−1 from pig slurry, cattle slurry, and anaerobic digestate in a mixture with or without the nitrification inhibitor. Destructive sampling was carried out after 0, 7, and 28 days of incubation in the dark at 18 °C. At each sampling date, artificial rain (200 mm of 0.01 M calcium chloride over 4 h) was added to the soil columns. The leachate was collected, and the soil was removed from the columns and sectioned into 5 cm segments. Results indicated that after 28 days of incubation, nitrapyrin enhanced ammoniacal N accumulation in the top layers of the soil columns and reduced the nitrate concentration in the leachates with pig slurry and anaerobic digestate. Furthermore, in the soil columns treated with anaerobic digestate, nitrapyrin promoted microbial N immobilization. These findings suggest that the use of nitrapyrin in a mixture with animal slurry and anaerobic digestate has the potential to reduce nitrate leaching and increase N retention in the topsoil, affording both environmental and economic advantages.

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Applicability of Darcy’s law for predicting irrigation head: what are the limits?

Soil Research ◽

10.1071/sr12257 ◽

2013 ◽

Vol 51 (1) ◽

pp. 10

Author(s):

V. K. Phogat ◽

R. Horn

Keyword(s):

Water Movement ◽

Darcy’S Law ◽

Conservation Tillage ◽

Hydraulic Head ◽

Darcy's Law ◽

Soil Cores ◽

Soil Columns ◽

Undisturbed Soil ◽

Positive Correlation Coefficient ◽

Undisturbed Soil Cores

Modelling soil water movement has increased the demand for accurate measurements of soil physical and hydraulic properties. Data on saturated hydraulic conductivity (K), which was measured by using different hydraulic heads, are presented for artificially packed soil columns and for different soil layers of undisturbed soil cores taken from a long-term experiment on conservation tillage. In the majority of the samples in both artificially packed soil columns and undisturbed soil cores, increasing hydraulic head caused significant deviation (i.e. significant positive correlation coefficient between hydraulic head and the measured values of K) from the conventional criterion for Darcy’s law that flux remains linear with hydraulic gradient. The study, therefore, emphasis the need to define the hydraulic head for measuring K values to be used for studying water movement in soils, to facilitate efficient utilisation of water resources for irrigating field crops in different soils and under different planting systems and irrigation methods.

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Evaluation of Nitrate Leaching in Lateritic Soil under Saturated or Unsaturated Conditions in Soil Columns

Communications in Soil Science and Plant Analysis ◽

10.1080/00103624.2020.1718686 ◽

2020 ◽

Vol 51 (4) ◽

pp. 541-553 ◽

Cited By ~ 1

Author(s):

Rajiv Kumar Srivastava ◽

Rabindra Kumar Panda ◽

Arun Chakraborty ◽

Debjani Halder

Keyword(s):

Nitrate Leaching ◽

Lateritic Soil ◽

Soil Columns

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Use of Paper-mill Wastes on Agricultural Soils: Is This a Way to Reduce Nitrate Leaching?

Acta Agriculturae Scandinavica Section B - Soil & Plant Science ◽

10.1080/09064710310003925 ◽

2003 ◽

Vol 53 (2) ◽

pp. 56-63 ◽

Cited By ~ 3

Author(s):

Holger Kirchmann ◽

Lars Bergström

Keyword(s):

Nitrate Leaching ◽

Agricultural Soils ◽

Paper Mill

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An evaluation of a strategic de-stocking regime for dairying to improve nitrogen efficiency and reduce nitrate leaching from dairy farms in nitrate-sensitive areas

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.2000.62.2401 ◽

2000 ◽

pp. 105-110

Author(s):

Cecile De Klein ◽

Jim Paton ◽

Stewart Ledgard

Keyword(s):

New Zealand ◽

Nitrate Leaching ◽

Management Practice ◽

Field Measurements ◽

Dairy Farms ◽

Nitrogen Efficiency ◽

Management Tool ◽

Pasture Production ◽

Leaching Losses ◽

Sensitive Areas

Strategic de-stocking in winter is a common management practice on dairy farms in Southland, New Zealand, to protect the soil against pugging damage. This paper examines whether this practice can also be used to reduce nitrate leaching losses. Model analyses and field measurements were used to estimate nitrate leaching losses and pasture production under two strategic de-stocking regimes: 3 months off-farm or 5 months on a feed pad with effluent collected and applied back to the land. The model analyses, based on the results of a long-term farmlet study under conventional grazing and on information for an average New Zealand farm, suggested that the 3- or 5-month de-stocking could reduce nitrate leaching losses by about 20% or 35-50%, respectively compared to a conventional grazing system. Field measurements on the Taieri Plain in Otago support these findings, although the results to date are confounded by drought conditions during the 1998 and 1999 seasons. The average nitrate concentration of the drainage water of a 5-month strategic de-stocking treatment was about 60% lower than under conventional grazing. Pasture production of the 5-month strategic de-stocking regime with effluent return was estimated based on data for apparent N efficiency of excreta patches versus uniformlyspread farm dairy effluent N. The results suggested that a strategic de-stocking regime could increase pasture production by about 2 to 8%. A cost/ benefit analysis of the 5-month de-stocking system using a feed pad, comparing additional capital and operational costs with additional income from a 5% increase in DM production, show a positive return on capital for an average New Zealand dairy farm. This suggests that a strategic destocking system has good potential as a management tool to reduce nitrate leaching losses in nitrate sensitive areas whilst being economically viable, particularly on farms where an effluent application system or a feed pad are already in place. Keywords: dairying, feed pads, nitrate leaching, nitrogen efficiency, productivity, strategic de-stocking

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