Publications by authors named "Warwick Dougherty"

In dairy grazing systems, livestock urine patches are hotspots that contribute to global warming, both directly through nitrous oxide (NO) emissions, and indirectly, through nitrate leaching. However, under warm-dry temperate environments, NO emission factors (EFs) have not been thoroughly evaluated, accounting for the influence of urinary nitrogen (N) concentration and urine volume, and emissions measurement approach through different urine application methods. Here we quantified and compared NO emissions and EFs on a moderately well-drained sandy loam soil from urine patches established in naturally expanding effective area (NEEA), representing urine volumes of 2, 3 and 4 L m (equivalent to urine -N loadings of 141, 211 and 282 kg N ha), and using the uniformly wetted area (UWA) with urine applied at 10 L m (709 kg N ha), under two different soil moistures (below field capacity, BFC; field capacity, FC).

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Unnecessary accumulation of phosphorus (P) in agricultural soils continues to degrade water quality and linked ecosystem services. Managing both soil loss and soil P fertility status is therefore crucial for eutrophication control, but the relative environmental benefits of these two mitigation measures, and the timescales over which they occur, remain unclear. To support policies toward reduced P loadings from agricultural soils, we examined the impact of soil conservation and lowering of soil test P (STP) in different regions with intensive farming (Europe, the United States, and Australia).

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The potential loss of P in runoff is a function of the combined effects of fertilizer-soil interactions and climatic characteristics. In this study, we applied a Bayesian approach to experimental data to model the annualized long-term risk of P runoff following single and split P fertilizer applications using two example catchments with contrasting rainfall/runoff patterns. Split P fertilizer strategies are commonly used in intensive pasture production in Australia and our results showed that three applications of 13.

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Fertilizer phosphorus (P) and grazing-related factors can influence runoff P concentrations from grazed pastures. To investigate these effects, we monitored the concentrations of P in surface runoff from grazed dairy pasture plots (50 x 25 m) treated with four fertilizer P rates (0, 20, 40, and 80 kg ha(-1) yr(-1)) for 3.5 yr at Camden, New South Wales.

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Phosphorus transfer in runoff from intensive pasture systems has been extensively researched at a range of scales. However, integration of data from the range of scales has been limited. This paper presents a conceptual model of P transfer that incorporates landscape effects and reviews the research relating to P transfer at a range of scales in light of this model.

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