Nitrogen Source and Rate Influence on Tall Fescue Quality and Nitrate Leaching in a Southern California Lawn

Abstract

In California, residential lawn area is second in planted acreage to production agriculture. Due to the demand for visually attractive lawns, relatively large amounts of N are often applied. The objective of this research was to investigate the effect of N source and application rate on tall fescue [Schedonorus phoenix (Scop.) Holub] visual quality and color, clipping yield, N uptake, and nitrate leaching under normal irrigation practices. Three annual N application rates (195, 293, and 390 kg ha−1) and four N sources (AN, ammonium nitrate; MUN, methylene urea; NON, natural‐organic nitrogen; and PCN, polymer‐coated nitrogen) were applied in four equal applications per year. The factorial experiment was replicated four times and conducted on a Hanford fine sandy loam at the University of California, Riverside's Turfgrass Research Facility from October 2002 to October 2004. Turfgrass visual quality and color ratings were evaluated every 2 wk. Clipping yield, clipping tissue total Kjeldahl nitrogen (TKN), and N uptake were measured or calculated in four 4‐wk growth periods per year. Suction lysimeters were used to collect soil water below the rootzone (leachate) to determine nitrate and ammonium concentrations once every two weeks. Soil nitrate and ammonium concentrations were analyzed at 12 and 24 mo. after initial fertilizer treatments. An annual N application rate of 195 kg ha−1 produced an acceptable to good quality tall fescue lawn. Higher rates were not necessary, and increased nitrate leaching. Among the N sources, slow‐release N resulted in less nitrate leaching than the fast‐release N source.

Annual Nitrogen Requirement of Bahiagrass Lawns Maintained in Subtropical Climates

“…Bahiagrass quality and color was influenced by N rate during each cycle with little or no influence from irrigation (Table 1). Increases in turf quality (Skogley and Ledeboer, 1968;Snyder and Cisar, 2000;Wu et al, 2010) and color (McGroary et al, 2009;Trenholm and Unruh, 2007) observed from increasing N rates have been noted in prior studies. The observed increase in quality is generally Turf color Growth rate , 15 Mar., 17 Apr., 18 June, and 16 Aug. 2006;and 12 Oct., 21 Dec., 20 Feb., 21 Apr., 23 June, and 3 Sept. 2007, respectively.…”

Assessing evidence on the agronomic and environmental impacts of turfgrass irrigation management

“…Variations observed in N uptake for the same species, at the same fertiliser rate and in the same study (Figure ), were related to other factors such as fertiliser source (Barton et al., ; Wu et al., ), frequency of fertiliser application (Barton et al., ; Quiroga‐Garza, Picchioni, & Remmenga, ), turfgrass age (Barton et al., ), varieties within the same species (Paré et al., ) and year of treatment (Wu et al., ). Paulino‐Paulino et al.…”

“…However, heavier soils with more organic matter and higher moisture retention will facilitate N denitrification, which may result in less leaching of (Nektarios et al., ). Sand‐based rootzones with higher organic matter content may be attained by amending the sand with compost (Espevig & Aamlid, ), by having older turf with a deeper thatch‐mat layer (Barton, Wan, Buck, & Colmer, ) or by maintaining a healthier, actively growing and denser canopy (Paré et al., ; Shaddox et al., ; Trenholm et al., ), which promotes higher N uptake (Telenko et al., ; Wu et al., ). These results are consistent with Kvalbein and Aamlid () who suggested that the risk of N leaching from dense and healthy golf greens is usually quite low, but that it may increase dramatically if the turfgrass cover becomes incomplete due to diseases, winter damage, wear or management.…”

“…Most importantly, Wu et al. () showed that the irrigation and N application rates ought to be reduced towards the end of the growing season because of the slowdown in turfgrass metabolism.…”

Subsurface‐Applied Tailored Water: Combining Nutrient Benefits with Efficient Turfgrass Irrigation

“…A number of researchers have reported results from general fertilization trials and concluded that the highest concentrations of NO 3 -N in leachate occur during the winter months when turf is either dormant or growing slowly (Geron et al, 1993;Thomas et al, 2006). In another study, nitrate concentrations leached from tall fescue plots were significantly higher from September to March than from March to August (Wu et al, 2010). In another study, nitrate concentrations leached from tall fescue plots were significantly higher from September to March than from March to August (Wu et al, 2010).…”