2018 journal article

The extent and pathways of nitrogen loss in turfgrass systems: Age impacts

SCIENCE OF THE TOTAL ENVIRONMENT, 637, 746–757.

author keywords: Reactive N; Microbial activity; N2O; Leaching; Turfgrass; Chronosequence
TL;DR: Examining both inorganic and organic N species in leachate and soil N2O emissions from intact soil cores of a bermudagrass chronosequence provides a new insight into the interactive controls of warming and substrate availability on dissolved organic N loss from turfgrass systems. (via Semantic Scholar)
UN Sustainable Development Goal Categories
2. Zero Hunger (Web of Science)
13. Climate Action (Web of Science)
15. Life on Land (Web of Science)
Source: Web Of Science
Added: October 19, 2018

Nitrogen loss from fertilized turf has been a concern for decades, with most research focused on inorganic (NO3−) leaching. The present work examined both inorganic and organic N species in leachate and soil N2O emissions from intact soil cores of a bermudagrass chronosequence (1, 15, 20, and 109 years old) collected in both winter and summer. Measurements of soil N2O emissions were made daily for 3 weeks, while leachate was sampled once a week. Four treatments were established to examine the impacts of fertilization and temperature: no N, low N at 30 kg N ha−1, and high N at 60 kg N ha−1, plus a combination of high N and temperature (13 °C in winter or 33 °C in summer compared to the standard 23 °C). Total reactive N loss generally showed a "cup" pattern of turf age, being lowest for the 20 years old. Averaged across all intact soil cores sampled in winter and summer, organic N leaching accounted for 51% of total reactive N loss, followed by inorganic N leaching at 41% and N2O-N efflux at 8%. Proportional loss among the fractions varied with grass age, season, and temperature and fertilization treatments. While high temperature enhanced total reactive N loss, it had little influence on the partitioning of loss among dissolved organic N, inorganic N and N2O-N when C availability was expected to be high in summer due to rhizodeposition and root turnover. This effect of temperature was perhaps due to higher microbial turnover in response to increased C availability in summer. However when C availability was low in winter, warming might mainly affect microbial growth efficiency and therefore partitioning of N. This work provides a new insight into the interactive controls of warming and substrate availability on dissolved organic N loss from turfgrass systems.