Establishing three warm‐season turfgrasses with tailored water: II. Root development, nitrate accumulation in plant tissue and soil, and relationship with leaching

Abstract

Greenhouse experiments were conducted in 2015 and 2017 to assess the feasibility of establishing three warm‐season grasses—buffalograss [Buchloe dactyloides (Natt.) Eng.] ‘SWI 2000’, inland saltgrass (Distichlis spicata L.), and bermudagrass (Cynodon dactylon L.) ‘Princess77’—with tailored water (tertiary treated effluent with 15 mg L–1 of NO3–N) and to examine the impact on nitrate accumulation in soils and plant tissue and on root development. Grasses were established from seed in a loamy sand and irrigated with either tailored or potable water plus granular Ca(NO3)2 fertilizer. Leachate collected at 10‐ and 30‐cm depths was analyzed for NO3–N and electrical conductivity. Root samples were collected to measure root length density (RLD) and root surface area (RSA). Weekly clippings were collected to determine total clipping yield and measure N content. Generally, there was no difference in establishment, RLD, or RSA between the two irrigation treatments. Highest RLD values were reported for bermudagrass, followed by buffalograss and inland saltgrass. Correlation analyses suggest that nitrate levels in leachate were lower in faster‐growing grasses and in grasses with more extensive root systems, compared with slower‐growing grasses with less roots, regardless of fertilization treatment. Total N in clippings was highest in inland saltgrass and lower in buffalograss and bermudagrass, indicating that N was limiting for faster‐growing grasses. More research is needed to determine optimal N rates for establishing grasses that both optimize growth and minimize nitrate leaching.

Establishing three warm‐season turfgrasses with tailored water: I. Growth, cover, and nitrate leaching losses

“…Buffalograss has been reported to be moderately sensitive to salinity (Harivandi, 1999), exhibiting lower salinity tolerance than bermudagrass or inland saltgrass (Carrow & Duncan, 1998; Marcum et al., 2005). Our analysis of N content in clippings found no differences between bermudagrass and buffalograss (Leinauer et al, 2022), which suggests that the differences in establishment observed in 2017 between the two grasses both irrigated with tailored water may be due to varying salinity tolerances. Generally, more information is needed to understand how N and salinity interact during establishment to optimize management practices and to determine if tailored water can be used to establish turfgrasses.…”

“…No data are available on optimum N rates for inland saltgrass establishment, but Amen et al (1970) noted the beneficial effect of nitrate on breaking seed dormancy and seed germination. Although final biomasses of inland saltgrass and buffalograss were similar to those of bermudagrass (Leinauer et al, 2022), overall establishment of saltgrass was slower and coverage was less than for bermudagrass and buffalograss on three out of four year × irrigation treatment combinations (Figure 1). Such findings can be explained by the different growth habits of the three grasses.…”

How to Minimize the Nitrogen Pollution Risk of Applying Reclaimed Sewage for Urban Turfgrass Irrigation

“…On the other hand, excessive N input into the plant-soil-groundwater system poses threats to environmental safety and human health [11]. Determining the optimal concentration of N in reclaimed sewage to meet the basic requirements of plants while preventing groundwater contamination and excessive N accumulation in the soil poses a major challenge [12]. Some studies on irrigating turfgrass with reclaimed sewage have primarily focused on the effects on soil physicochemical properties (e.g., soil water, salt, and nutrient status) [13,14], turfgrass growth and quality [15,16], microbial community characteristics [17], and environmental pollution risks [18][19][20].…”