Abstract Nitrification inhibitors are intended to improve the productivity of agricultural crops; however, there are limited data available on the efficacy of this approach in potato crop production. A field experiment was carried out in temperate Australia to compare the effect of standard commercial fertilizer nitrogen (N) management with fertilizer treated with two nitrification inhibitors, 3,4‐dimethylpyrazole phosphate ( DMPP ) and 1H‐1,2,4‐triazole and 3‐methylpyrazole (3 MP + TZ ) on potato productivity and soil N dynamics for three irrigation regimes. Despite evidence of increased soil ammonium ( ) concentrations in the DMPP and 3 MP + TZ treatments, crop yield and quality parameters (tuber number, average tuber size, potato‐specific gravity, three tuber size classes and grade yields) were similar across treatments. Further, DMPP and 3 MP + TZ treatments did not reduce either the concentration or the flux of nitrate leached. These findings suggest that further research into the agronomic benefits of nitrification inhibitors for potatoes grown in cool temperate regions is needed.

Ammonium nitrate

10.1111/sum.12459

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Citations (3)

Influence of antecedent soil moisture on hydraulic conductivity in a series of texture‐contrast soils

Hydrological Processes (2011)

Marcus Hardie RB Doyle WE Cotching Kathrin Mattern S Lisson

Abstract Antecedent soil moisture significantly influenced the hydraulic conductivity of the A1, A2e and B21 horizons in a series of strong texture‐contrast soils. Tension infiltration at six supply potentials demonstrated that in the A1 horizon, hydraulic conductivity was significantly lower in the ‘wet’ treatment than in the ‘dry’ treatment. However in the A2e horizon, micropore and mesopore hydraulic conductivity was lower in the ‘dry’ treatment than the ‘wet’ treatment, which was attributed to the precipitation of soluble amorphous silica. In the B21 horizon, desiccation of vertic clays resulted in the formation of shrinkage cracks which significantly increased near‐saturated hydraulic conductivity and prevented the development of subsurface lateral flow in the ‘dry’ treatment. In the ‘wet’ treatment, the difference between the hydraulic conductivity of the A1 and B21 horizons was reduced; however, lateral flow still occurred in the A1 horizon due to difficulty displacing existing soil water further down the soil profile. Results demonstrate the need to account for temporal variation in soil porosity and hydraulic conductivity in soil‐water model conceptualisation and parameterisation. Copyright © 2011 John Wiley & Sons, Ltd.

Infiltration (HVAC)

Soil texture

10.1002/hyp.8325

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Citations (25)

Root architecture of barley in duplex soils under irrigation

Rhizosphere (2011)

Matuszek Tina Acuña David Cecil Parsons Marcus Hardie

Subsoil

Soil horizon

Soil texture

Source

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Citations (0)

Effect of sprinkler droplet size on the development of a surface crust and infiltration of a highly cultivated agricultural soil

FA Chamley Marcus Hardie S. M. Lambert RB Doyle

Infiltration (HVAC)

Source

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Citations (0)

Development of Unstable Flow and Reduced Hydraulic Conductivity due to Water Repellence and Restricted Drainage

Vadose Zone Journal (2012)

Marcus Hardie Markus Deurer RB Doyle S Lisson WE Cotching

The effect of water repellence and antecedent soil moisture on wetting front stability and infiltration rate are reported for a seasonally water repellent topsoil. The effect of water repellence on infiltration was determined by comparing the in situ infiltration of water to that of a 7M ethanol solution. Wetting front stability was measured during infiltration of water into repacked, wettable and water repellent soils, within a Hele‐Shaw chamber. Water repellence restricted in situ movement of water through large macropores (>500 μm), which decreased intrinsic permeability by 1 to 2 orders of magnitude. In repacked soils, water repellence caused the development of unstable wetting fronts and reduced infiltration from 240 mm h − 1 to 101.7 mm h − 1 . Infiltration into wettable soils at moisture contents near field capacity was expected to result in rapid infiltration and stable wetting fronts. However in repacked soils, wetting front instability developed, and infiltration rates were 190% lower when air and/or water movement through the base of the chamber was restricted. Infiltration into in situ soil was also slower at high antecedent soil moisture. The hydraulic conductivity of the 7M ethanol solution decreased significantly from 112.3 mm h − 1 in dry water repellent conditions, to 35.6 mm h − 1 in wettable soils at high antecedent moisture contents. Consequently the previously reported development of wetting front instability and reduced infiltration into in situ wettable soils at high moisture contents were confirmed and attributed to difficulty displacing existing soil water during infiltration of new water.

Infiltration (HVAC)

Water repellent

Macropore

10.2136/vzj2011.0099

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Citations (23)

Evaluation of electrical resistivity imaging (ERI) for in situ mapping of drip irrigation and fertigation wetting patterns

J Ridgers Marcus Hardie N Swarts Dugald C. Close

Drip fertigation is regarded as a precise and efficient method of supplying water and nutrients to tree crops. Despite its widespread use in a range of agricultural industries, there is limited research into the distribution of water and solutes after fertigation and irrigation events. Here, we compare Electrical Resistivity Imaging (ERI) with dye tracer patterns and soil nitrate distribution in a commercial apple orchard in southern Tasmania. Fertigated calcium nitrate was applied with dye tracer through pressure compensated drippers along the treeline of the orchard row. This was followed by a single irrigation event the next day via in-line drippers, split into high and low treatments over the fertigated area. Two dimensional ERI was conducted over a 16 meter length of crop row, immediately before and at four occasions post fertigation. ERI was shown to be a potentially useful tool for mapping infiltration of irrigation and nitrate, as changes in resistivity appeared to be correlated with infiltration, although the contribution to the change in resistivity from irrigation as opposed to the solute content of the fertigation could not be determined. Dye analysis indicated infiltration of water resulted from preferential flow processes whereas infiltration of the nitrate indicated it was absorbed by organic matter within the A1 horizon.

Fertigation

Infiltration (HVAC)

Orchard

Electrical Resistivity Tomography

Source

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Effect of antecedent soil moisture on preferential flow in a texture-contrast soil

Journal of Hydrology (2010)

Marcus Hardie WE Cotching RB Doyle Greg Holz S Lisson

Soil texture

Antecedent moisture