Phosphorus transport in subsurface flow from a stony soil under irrigated and non-irrigated lucerne

Gray, C. W.; McDowell, R. W.; Graham, Scott L.; Hunt, John E.; Laubach, Johannes; Rogers, G. M.; Carrick, Sam; Whitehead, David

doi:10.1080/00288233.2020.1792514

Cited by 3 publications

(2 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Papers within the first category cover underpinning data on the transport of P in subsurface flowrevealing new knowledge about a transport system for P that is often neglected in favour of studying surface runoff losses (Gray et al 2021), the refinement of the Catchment Land Use and Environmental Sustainability model used to estimate concentrations and loads of contaminants in surface waters (Semadeni-Davies et al 2021), and the development of a new framework to link the land, surface and groundwater systems together at a national scale (Srinivasan et al 2021).…”

Section: Land Use and Water Qualitymentioning

confidence: 99%

Land use and water quality

McDowell

2021

New Zealand Journal of Agricultural Research

Self Cite

View full text Add to dashboard Cite

Section: Land Use and Water Qualitymentioning

confidence: 99%

Land use and water quality

McDowell

2021

New Zealand Journal of Agricultural Research

Self Cite

View full text Add to dashboard Cite

“…A range of methods have been used to evaluate drainage and nutrient losses under irrigation, including lysimeters (Gray et al 2021;Graham et al 2022), modelling (Vogeler et al 2019), and drainage flux meters (DFMs) (Loo et al 2019;Norris et al 2023). DFMs have a buried, cylindrical collector outfitted with a wick to provide tension for draining the column of soil above.…”

Section: Introductionmentioning

confidence: 99%

Nitrogen and phosphorus leaching losses under cropping and zone-specific variable-rate irrigation

Drewry,

Hedley,

McNeill

et al. 2023

Soil Res.

View full text Add to dashboard Cite

Context Agricultural land use is intensifying globally. Irrigation and other farm practices associated with intensification, such as cultivation, grazing, and fertiliser application, can increase nutrient losses. Variable rate irrigation (VRI) systems manage irrigation to spatially variable soils and different crops (zones). We lack knowledge on nutrient losses under zone-specific irrigation for mixed-cropping systems (combined crop and livestock grazing). Aims This study evaluated drainage, nitrogen, and phosphorus leaching losses under zone-specific irrigation for a temperate mixed-cropping system. Methods The study site had sheep grazing and crops including peas, beans, wheat, turnips, plantain, and ryegrass-white clover pasture. It had a variable-rate centre-pivot irrigator for two soil zones (free draining Zone 1; poorly drained Zone 2). Drainage flux meters (DFMs) collected drainage leachate, and samples for measurement of nitrogen (N) and phosphorus (P) concentrations. Soil water balance data and statistical modelling evaluated nutrient leaching losses over 5 years. Key results The mean leaching load of NOx-N (nitrate + nitrite) across 5 years was 133 (s.d. 77) and 121 (s.d. 97) kg N/ha/year for Zone 1 and Zone 2, respectively. Similarly, the mean leaching load of reactive P across all years was 0.17 (s.d. 0.30) and 0.14 (s.d. 0.14) kg P/ha/year for Zone 1 and Zone 2, respectively. The nitrogen concentrations and loads generally had greater uncertainty in Zone 2. Conclusions The DFMs worked well for the free draining sandy soil. However, fewer samples were collected in the silt soil, requiring the statistical modelling developed in this study. This study gave a reasonable estimate of annual leaching load means, but the indicators of their within-year variation were not reliable, partly due to differences in sampling frequency. With some exceptions, there was generally more NOx-N leaching from the free draining Zone 1. VRI provided a system to control irrigation-related drainage and leaching in these soil zones. Implications Drainage flux meters are more reliable in well-drained than in poorly drained soil. Given the lack of published studies, this study has improved knowledge of nutrient losses under zone-specific irrigated mixed-cropping systems in a temperate climate.

show abstract

Determining Chemical Factors Controlling Abiotic Codenitrification

Wilson

Song

Phillips

2021

ACS Earth Space Chem.

View full text Add to dashboard Cite

Codenitrification is a reactive nitrogen (N) removal pathway producing hybrid dinitrogen (N2) by combining nitrite (NO2 –) and a partner-N substrate. Abiotic codenitrification also produces hybrid N2 through nitrosation of organic N by NO2 –, but it is poorly constrained in soil N cycles. We determined the importance of abiotic codenitrification in soils and examined factors controlling abiotic codenitrification using live soils, sterile soils, and sterile solutions. Abiotic codenitrification in sterile soils ranged from 0.12 ± 0.001 to 0.60 ± 0.08 nmoles 29N2-N g–1 day–1, which accounts for 2.3 to 8.2% of total N2 production measured in live soils. Increased abiotic N2 production was observed in soils with the addition of an organic N partner (glutamine). Consistent with previous work, higher rates were observed in lower-pH soils, but the highest rate was found in the soil with the highest carbon:nitrogen (C:N) ratio. We further investigated a range of organic N partners and the influence of concentration and pH on abiotic codenitrification in solution. Similar to sterile soil incubations, abiotic 29N2 production was negatively correlated with increasing pH in solution. Greater rates of abiotic 29N2 production were measured as the substrate concentration increased and pH decreased. Solution experiments also showed that addition of organic N partners increased abiotic codenitrification rates, which are positively correlated with the C:N ratios of organic N partners. This is the first study demonstrating the importance of N removal through abiotic codenitrification in acidic soils and the C:N ratio of organic N partners as a controlling factor in abiotic codenitrification.

show abstract

Phosphorus transport in subsurface flow from a stony soil under irrigated and non-irrigated lucerne

Cited by 3 publications

References 44 publications

Land use and water quality

Land use and water quality

Nitrogen and phosphorus leaching losses under cropping and zone-specific variable-rate irrigation

Determining Chemical Factors Controlling Abiotic Codenitrification

Contact Info

Product

Resources

About