Irrigation practices, nutrient applications, and mulches affect soil nutrient dynamics in a young Merlot (Vitis viniferaL.) vineyard

Abstract

There is growing interest among commercial wine grape (Vitis vinifera L.) growers in reducing water and fertilizer consumption, but little information exists on how best to combine conservative irrigation and soil management practices in the vineyard. In a 3-year-old Merlot vineyard in the semi-arid Okanagan Valley, British Columbia, the interactive effects of resource-conserving micro-irrigation (drippers or microsprinkers), nutrient applications (fertigation or compost), and surface mulching (wood and bark chips) on nitrogen (N) and phosphorus (P) dynamics in the wetted zone of surface soils were examined throughout the growing season using ion-exchange resins. Treatment differences in soil carbon and major nutrient pools, temperature, and moisture were also measured. Higher NO 3 -N was adsorbed by resins buried under drippers than under microsprinklers except in mulched plots, where NO 3 -N was uniformly low. By enhancing soil carbon availability and moderating soil microclimate, surface mulches may have promoted microbial immobilisation of N. Compost applications increased soil ortho-P levels, especially on mulched plots, suggesting that both P inputs (from compost) and enhanced microbial biomass (from mulch) promoted soil P cycling. Future work will examine the interactive effects of these resource-efficient practices on leaching losses, greenhouse gas emissions, crop productivity, and fruit quality.Key words: micro-irrigation, nitrogen, phosphorus, compost, mulch, wine grapes.Résumé : Les viticulteurs songent de plus en plus à réduire la quantité d'eau et d'engrais consommée par le raisin de cuve (Vitis vinifera L.), mais on sait peu de choses sur la meilleure façon de combiner l'irrigation de conservation et la gestion du sol dans les vignobles. Les auteurs ont examiné les effets des interactions des pratiques de conservation que sont la micro-irrigation (goutteurs ou microasperseurs), l'application d'éléments nutritifs (fertigation ou compost) et le paillage (copeaux de bois et d'écorce) sur la dynamique du N et du P dans la partie humide du sol de surface. L'étude s'est déroulée dans un vignoble de type Merlot de trois ans, dans la vallée semi-aride de l'Okanagan, en Colombie-Britannique, pendant la période végétative. Les chercheurs ont recouru pour cela à des résines échangeuses d'ions et en ont profité pour mesurer les écarts au niveau de la concentration de carbone et des principaux éléments nutritifs dans le sol, de la température et de la teneur en eau résultant du traitement. Les résines enfouies sous les goutteurs absorbent plus de N-NO 3 que celles enterrées sous les microasperseurs, sauf sur les parcelles paillées, où la concentration de N-NO 3 est uniformément faible. Parce qu'ils améliorent la disponibilité du carbone dans le sol et atténuent le microclimat au niveau du sol, les paillis pourraient contribuer à l'immobilisation du N par la microflore. L'application de compost améliore la concentration d'ortho-P dans le sol, surtout celui des parcelles paillées, ce qui laisse suppose...

Yield and must composition of 'Cabernet Sauvignon' grapevines subjected to nitrogen application in soil with high organic matter content

“…This is expected and consistent, since there was an increase in cluster weight (Table 1) (Cheng et al, 2014). This normally promotes the dilution of sugars due to the effect of accumulated rainfall and, consequently, of TSS values (Hannam et al, 2016).…”

“…Part of the soil organic matter and plant residues deposited on the soil may be mineralized by the microbial population, increasing the concentration of N forms in soil solution, which can be absorbed by the grapevines (Barlow et al, 2009;Burns et al, 2016), reducing the use of N derived from the fertilizer (Agnelli et al, 2014;Brunetto et al, 2016). However, part of the N derived from higher N doses may be lost in vineyards by surface runoff (Sorrenti & Toselli, 2016) leaching (Lorensini et al, 2012) and volatilization as ammonia and nitrous oxide (Lorensini et al, 2012;Hannam et al, 2016), reducing the amount of N derived from the fertilizer used by the plants (Brunetto et al, 2016).…”

Recent Achievements and New Research Opportunities for Optimizing Macronutrient Availability, Acquisition, and Distribution for Perennial Fruit Crops

“…Elevated levels of SOC have been reported to improve orchard replant success [25], particularly in cases where nutritional deficiencies exist [26]. Management practices that enhance organic matter content in orchard soils may reduce N-fertilizer losses via leaching or volatilization, and promote nutrient cycling [27][28][29]. Enhancing SOC stocks in agricultural soils as a means of mitigating atmospheric greenhouse gas emissions has also received considerable attention, although most of this work focused on field crops [30][31][32].…”

“…For example, in table grape, the use of Trifolium repens L. as an inter-row cover crop increased P concentrations in leaves and fruit clusters [43]. Additionally, the use of surface mulches and composts in fertigated orchards and vineyards also promotes soil P cycling and improve P availability and is thought to be a consequence of increased soil phosphatase enzyme activity [44] and higher concentrations of ion-exchange resin P [28]. However, increased leaching of P below the root zone following compost application in an apple orchard suggests that compost applications may, in some cases, increase the risk of P-contamination of nearby water sources [45].…”

“…In contrast, large single doses of P in conjunction with micro-irrigation can increase P in the soil solution over a longer period compared with the application of multiple doses, likely by saturating soil P adsorption sites. [28] used ion-exchange resins to measure NO 3 -N in the soil and reported that concentrations were higher under drip irrigation than under micro-sprinkler irrigation. Surface mulches work to limit water losses through evaporation but also affect nutrient cycling and movement in the soil.…”