Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Turfgrass establishment and fertilization under subsurface drip and saline irrigation

Auteur : Matteo Serena

Université de soutenance : New Mexico State University

Grade : Doctor of Philosophy (Ph.D) 2014

Résumé
In the arid southwestern part of the United States turfgrass areas are considered high water-use ground cover and water conservation strategies are being implemented. One of the most widely used strategy is replacing potable with saline water. A study was conducted to evaluate emergence and establishment of several cool- and warm-season turfgrasses from coated seed (ZEBA®) in combination with saline irrigation. Generally, seed coating did not affect seeding emergence negatively when irrigated with saline water. During fall, perennial ryegrass (Lolium perenne L.) exhibited fastest emergence under both saline and potable irrigation and bermudagrass [Cynodon dactylon (L.) Pers.] was the only grass to show greater emergence when irrigated with saline water. Seed coating delayed early establishment (<50% coverage) but did not affect days to reach 95% coverage (DAS95). All grasses established faster when seeded in spring compared to fall. Saline water had no effect on establishment when grasses were sown in fall. Surprisingly, grasses established in spring and irrigated with saline water reached 95% coverage 26 days faster than plots irrigated with potable water. A second study was conducted to investigate the establishment of ’Princess 77’ bermudagrass from seed and sod, irrigated from either a sprinkler or a subsurface drip system, with potable (EC=0.6 dS m⁻¹) or saline (EC=2.2 dS m⁻¹) water and propagated either dormant (March)or late (June). When coverage data were averaged over water qualities, plots propagated by sod and irrigated from a sprinkler system established fastest, followed by drip-irrigated plots sodded early and sprinkler-irrigated plots seeded early. Root length density was higher in sprinkler-irrigated plots compared to SDI plots at all depths. A third study investigated the effect of different fertilizers and nitrogen rates applied to warm-season grasses irrigated with either potable (EC=0.6 dS m⁻¹) or saline (EC=3.1 dS m⁻¹), using either a sprinkler or subsurface drip system. Generally, seashore paspalum (Paspalum vaginatum O. Swartz) took longer to green up than bermudagrass and the combination of sprinkler irrigation and granular fertilizers (either quick or slow release) applied at the high rate provided the quickest spring green-up. Overall, bermudagrass exhibited higher turf quality than seashore paspalum. Subsurface drip-irrigated plots also exhibited higher quality in spring and had higher fall color retention. Fertilizer type did not appear to affect carbohydrate content. Result indicates that sampling year and varying climate conditions affected spring green up of warm-season grasses to a much greater extent than fertilizer type or rates.

Mots clés : Turfgrasses — Irrigation — Methodology. Turfgrasses — Fertilization. Microirrigation.

Présentation

ProQuest