Nutrients and Pesticides in Stormwater Runoff and Soil Water in Production Nurseries and Citrus and Avocado Groves in California

Abstract

<jats:p>Potential water quality impacts of agricultural production include runoff and leaching losses of nutrients, pesticides, and sediment. Stormwater runoff and soil water samples were collected from citrus (<jats:italic>Citrus</jats:italic> spp.), avocado (<jats:italic>Persea americana</jats:italic>), and ornamental nursery sites in Ventura County, CA, across 19 months. Nitrate–nitrite–nitrogen concentrations in runoff ranged from 0.07 to 31.1 mg·L<jats:sup>−1</jats:sup>, with medians for groves and nurseries of 4.2 and 5.7 mg·L<jats:sup>−1</jats:sup>, respectively. Constituents in runoff exceeding benchmarks for surface waters included turbidity, chlorpyrifos, and some organochlorine pesticides. When detected, chlorpyrifos concentration was linearly related to sample turbidity (<jats:italic>P</jats:italic> = 0.0025, <jats:italic>r<jats:sup>2</jats:sup></jats:italic> = 0.49). This suggests that the retention of waterborne sediments on-site may be an effective method for mitigating runoff of this pesticide. Bifenthrin, permethrin, and diazinon were also detected in runoff, but concentrations did not exceed water quality benchmarks. Nutrient concentrations in soil water were generally similar to nutrient concentrations in stormwater runoff, suggesting that potential groundwater contamination from leaching at citrus, avocado, and nursery sites may be as much of a concern as stormwater from these operations, particularly on sites with sandy or structured soil texture or flat topography. Nitrate–nitrite–nitrogen and orthophosphate concentrations in soil water were linearly related to nitrogen and phosphorus fertilizer application rates across sites, respectively (<jats:italic>P</jats:italic> &lt; 0.0001, <jats:italic>r<jats:sup>2</jats:sup></jats:italic> = 0.49 and 0.50, respectively), suggesting that proper nutrient management is important in reducing potential groundwater contamination at these operations.</jats:p>

Seasonal changes in nutrient content and concentrations in a mature deciduous tree species: Studies in almond (Prunus dulcis (Mill.) D. A. Webb)

“…leaching of nitrogen to ground water (Weinbaum et al, 1992) with nitrate levels in ground water now exceeding the maximum contamination level of 45 ppm in many parts of the world (Nightingale, 1972;Burow et al, 1998;Esser et al, 2002;Neilsen and Neilsen, 2002;Burow et al, 2008;Mangiafico et al, 2009;Clarisse et al, 2010;Viers et al, 2012). In annual crops understanding of crop nutrient demand and the application of fertilizers at rates and times consistent with crop demand has been central to the improvement of nitrogen use efficiency and the reduction in leaching potential (Di and Cameron, 2002;Meisinger and Delgado, 2002;Li et al, 2007;Gheysari et al, 2009;Fessehazion et al, 2011).…”

Monthly Levels and Criteria Considerations of Nutrient, pH, Alkalinity, and Ionic Variables in Runoff Containment Basins in Ornamental Plant Nurseries

“…Systematic evaluations are needed to better understand what detrimentally influences water quality from a plant production consideration, which potentially could include excessive nutrient levels and pesticide residuals (Mangiafico et al, 2009). Several studies indicate nutrient, pH, alkalinity, and ionic properties of water quality of many operations are not hurting plant growth (Chen Fig.…”

Novel flow-through bioremediation system for removing nitrate from nursery discharge water

“…Median nitrate-N concentrations in irrigation drainage water ranged from 57 to 210 mg L À1 . Within the larger drainage infrastructure within nurseries, nitrate-nitrogen concentrations ranging from 0.1 to 135 mg L À1 have been reported (Alexander, 1993;Mangiafico et al, 2009;Yeager et al, 1993). Yeager et al (1993) reported concentrations as high as 23 mg L À1 in nursery retention ponds.…”