Leaching of Mineral and Organic Nitrogen from Putting Green Profiles Supporting Various Turfgrasses

Abstract

Nitrate (NO3−) leached from golf greens has the potential to impair water quality. Dissolved organic N (DON) is also increasingly recognized as a form leached from fertilized soils. A controlled experiment was conducted to determine (i) the significance of DON in total N leaching losses under simulated golf‐green profiles and (ii) the short‐term contribution of fertilizer to leaching of inorganic and organic N forms. Various turfgrasses were grown in lysimeter columns designed to simulate a golf‐green profile. Fertilizer was applied at 25 kg N ha−1 every 14 d for 55 d, and the last application was labeled with 15N. Leachates were analyzed for NO3−‐N, NH4+‐N, and DON. The 15N recovery was assessed in plant, soil, and leachates. In the presence of plants, 10 to 70% (average 40%) of total N leached was accounted for by DON. Application of 15N revealed that one‐half to two‐thirds of NO3−‐N leached in the following 14 d was derived from the fertilizer, whereas the majority of leached DON was derived from soil residual N. Nevertheless, DO15N was present in most leachate samples collected for 14 d after fertilizer application, indicating that only a few days were required to convert mineral fertilizer to leachable organic forms. We conclude that DON may be a significant component of total N leaching losses from putting greens and would account for part of the N losses traditionally attributed to volatilization and denitrification.

Nitrogen leaching and Tifway bermudagrass response to simultaneous nutrient and pre‐emergence herbicide applications

“…Cumulative N leached from treated and nontreated turfgrass did not differ between treatments and ranged from −2.22 to 5.39% of applied N. These results corroborated the findings of Paré et al. (2008), who reported that 83% of the applied N (100 kg N ha −1 over 55 d) leached through column lysimeters without turfgrass, whereas lysimeters with turfgrass resulted in N leaching losses between 1 and 20% of that applied. Paré et al.…”

Nitrogen budgets of urban lawns under three different management regimes in southern California

“…The largest uncertainty in our leaching N loss estimate is the absence of dissolved organic nitrogen (DON) measurements, which have been reported to constitute up to 10-70 % (average at 40 %) of total leaching N losses within 55 days (Pare et al 2008) and up to 50 % in 2 years (Barton et al 2009) from lawns fertilized at various rates. Pare et al (2008) showed in a 15 N-tracer experiment that most DON in leachate was from soil instead of labeled fertilizer, while Barton et al (2009) reported that the majority of DON leaching occurred during the first year of lawn establishment from sod instead of fertilizer.…”

“…Pare et al (2008) showed in a 15 N-tracer experiment that most DON in leachate was from soil instead of labeled fertilizer, while Barton et al (2009) reported that the majority of DON leaching occurred during the first year of lawn establishment from sod instead of fertilizer. Therefore, at relatively low N fertilization rates, it is possible for young lawns established from sod, or lawns with high soil organic matter (SOM) in general, to have relatively high DON leaching losses.…”

Fate of 15N‐Nitrate Applied to a Bermudagrass System: Assimilation Profiles in Different Seasons

“…The approach carries the assumption that 15 N present in fractions not recovered in the analyses would be small and not compromise conclusions. It is conceivable that some 15 N might have been present in the fl ushed solution as organic 15 N (Pare et al, 2008), which was not measured, and some 15 N may have been lost through gaseous emissions (Horgan et al, 2002) or discarded in CaSO 4 rinses of plant tissues. Nonetheless, basing interpretations on the percentage of total 15 N recovered in the columns was appropriate with our large data set because the conclusions were consistent with the absolute amounts of 15 N found in various fractions.…”