This review discusses the impacts of nitrogen addition in the vineyard and winery, and establishes the effects that nitrogen has on grape berry and wine composition and the sensory attributes of wine. Nitrogen is the most abundant soil-derived macronutrient in a grapevine, and plays a major role in many of the biological functions and processes of both grapevine and fermentative microorganisms. Manipulation of grapevine nitrogen nutrition has the potential to influence quality components in the grape and, ultimately, the wine. In addition, fermentation kinetics and formation of flavour-active metabolites are also affected by the nitrogen status of the must, which can be further manipulated by addition of nitrogen in the winery. The only consistent effect of nitrogen application in the vineyard on grape berry quality components is an increase in the concentration of the major nitrogenous compounds, such as total nitrogen, total amino acids, arginine, proline and ammonium, and consequently yeast-assimilable nitrogen (YAN). Both the form and amount of YAN have significant implications for wine quality. Low must YAN leads to low yeast populations and poor fermentation vigour, increased risk of sluggish/stuck/slow fermentations, increased production of undesirable thiols (e.g. hydrogen sulfide) and higher alcohols, and low production of esters and long chain volatile fatty acids. High must YAN leads to increased biomass and higher maximum heat output due to greater fermentation vigour, and increased formation of ethyl acetate, acetic acid and volatile acidity. Increased concentrations of haze-causing proteins, urea and ethyl carbamate and biogenic amines are also associated with high YAN musts. The risk of microbial instability, potential taint from Botrytis-infected fruit and possibly atypical ageing character is also increased. Intermediate must YAN favours the best balance between desirable and undesirable chemical and sensory wine attributes. ‘Macro tuning’, of berry nitrogen status can be achieved in the vineyard, given genetic constraints, but the final ‘micro tuning’ can be more readily achieved in the winery by the use of nitrogen supplements, such as diammonium phosphate (DAP) and the choice of fermentation conditions. This point highlights the need to monitor nitrogen not only in the vineyard but also in the must immediately before fermentation, so that appropriate additions can be made when required. Overall, optimisation of vineyard and fermentation nitrogen can contribute to quality factors in wine and hence affect its value. However, a better understanding of the effect of nitrogen on grape secondary metabolites and different types of nitrogen sources on yeast flavour metabolism and wine sensory properties is still required.

Implications of nitrogen nutrition for grapes, fermentation and wine

In nature, trace element toxicities occur in all living organisms. The consequences of these toxicities have been described in crops, livestock and humans. In some instances, the toxicities are a direct consequence of the organism's position in the food chain and their environment, while in others, they are based upon genetic abnormalities resulting in physiological impairment.Nutrient toxicities in crops are more frequent for manganese (Mn) and boron (B) than for other nutrients. Manganese toxicity is found on acid soils in many parts of the world. Boron toxicities occur in irrigated regions where the well or irrigation waters are exceptionally high in B. Most other nutrient toxicities occur when large amounts of nutrients in question have been added in waste, e.g., sewage sludge. Crops grown near mines and smelters are prone to nutrient toxicities. Generally, the symptoms of toxicity in crops occur as burning, chlorosis and yellowing of leaves. Toxicities can result in decreased yield and/or im...

Trace element toxicity relationships to crop production and livestock and human health: implications for management

Publisher Summary The chapter provides a state-of-the-art review of advances in fertigation. Topics that are covered include an overview of past trends in fertigation, principles of fertigation, managing crop fertigation, modeling fertigation, monitoring and safety, and future trends and areas needing more research. Monitoring should be advanced on two fronts: (i) development of rapid and reliable methods to determine crop dry-matter weight and nutrient contents, for comparison with the corresponding objective curves; and (ii) improving the methodology of determining nutrient concentrations in the soil solution, by allowing farmers to do it alone in the field, so that correction measures based on soil tests will be timely and effective. A further research objective is to transform reliable soil-crop-atmosphere models into real-time fertigation management models, by introducing input-optimization algorithms based on economic and environmental considerations. Achievement of this objective will depend on prior significant developments in fruit-quality simulation in crop models, without which, crop yield value cannot be evaluated.

Advances in Fertigation

Growth, gas exchange, water relations, and ion composition of Phaseolus species grown under saline conditions

With pressure increasing on potable water supplies worldwide, interest in using alternative water supplies including recycled wastewater for irrigation purposes is growing. Wastewater is derived from a number of sources including domestic sewage effluent or municipal wastewater, agricultural (farm effluents) and industrial effluents, and stormwater. Although wastewater irrigation has many positive effects like reliable water supply to farmers, better crop yield, pollution reduction of rivers, and other surface water resources, there are problems associated with it such as health risks to irrigators, build-up of chemical pollutants (e.g., heavy metal(loid)s and pesticides) in soils and contamination of groundwater. Since the environment comprises soil, plants, and soil organisms, wastewater use is directly associated with environmental quality due to its immediate contact with the soil–plant system and consequently can impact on it. For example, the presence of organic matter in wastewater-irrigated sites significantly affects the mobility and bioavailability of heavy metal(loid)s in the soil. Wastewater irrigation can also act as a source of heavy metal(loid) input to soils. In this chapter, first, the various sources of wastewater irrigation and heavy metal(loid) input to soil are identified; second, the effect of wastewater irrigation on soil properties affecting heavy metal(loid) interactions is described; and third and finally, the role of wastewater irrigation on heavy metal(loid) dynamics including adsorption and complexation, redox reactions, transport, and bioavailability is described in relation to strategies designed to mitigate wastewater-induced environmental impacts.

The Influence of Wastewater Irrigation on the Transformation and Bioavailability of Heavy Metal(Loid)s in Soil

Okanagan Riesling (Vitis sp.) vines, planted on a sandy soil in 1983, were trickle irrigated with municipal wastewater or well water and with each source of water there were 3 rates of N fertilization (0, 17 and 34 g N as NH4NO3 vine−1 y−1), 1984–1987. The zero-N treatment was increased to 8.5 g N vine−1 in 1986–1987. Wastewater-irrigated vines had increased petiole P, K and Ca but decreased Mg and in 2 of 3 yr decreased N in August. Increased rate of N fertilization increased petiole N at bloomtime but not in August, had minor effects on petiole P, K, Ca and Mg, and increased petiole Mn at highest N rates, especially (2 of 4 yr) in association with wastewater irrigation. Yield increased both for vines irrigated with wastewater and linearly with rate of applied N in 2 of the 3 fruiting years. Increased yield was not associated with increased petiole N concentration in August. Minor increases in soluble solids and juice pH of grapes at harvest were measured for wastewater-irrigated grapes in 2 yr. No horti...

The effect of municipal wastewater irrigation and rate of n fertilization on petiole composition, yield and quality of okanagan riesling grapes

Tomato (Lycopersicon esculentum L.), sweet pepper (Capsicum annuum L.), onion (Allium cepa L.), cucumber (Cucumis sativus L.), bush bean (Phaseolus vulgaris L.), and melon (Cucumis melo L.) were grown from 1983 through 1986 with trickle irrigation using either well water or secondary effluent. Yields with effluent irrigation were greater than or similar to yields obtained with well water (...)

Yield and plant nutrient content of vegetables trickle-irrigated with municipal wastewater

Lambert sweet cherry (Prunus avium L.) established on Osoyoos loamy sand in 1983 was subjected to treatments involving all combinations of two types of irrigation (wellwater or municipal wastewater) and three rates of N fertilization (0, 68 and 136 g of N as NH4NO3 tree−1 yr−1), 1984–1987. The zero-N treatment was increased to 34 g N tree−1 in 1986–1987. Wastewater irrigation increased leaf N, P, K, B and Mn concentration, decreased leaf Mg and Ca and had few consistent effects on leaf Fe and Cu. Tree growth was increased after 2 yr but not after 5 yr by wastewater irrigation. Inadequate N and Zn nutrition appeared to limit long-term tree growth. After 5 yr, wastewater-irrigated soils had higher extractable P, K, and B and lower Ca and Mg than well-water-irrigated soils which had higher Ca and Mg to 0.9-m depth. Wastewater irrigation also increased extractable Na throughout the soil but insufficiently to adversely affect tree growth. Soil pH and electrical conductivity also increased during the experiment...

D. S. Stevenson

Papers

The effect of municipal wastewater irrigation and rate of n fertilization on petiole composition, yield and quality of okanagan riesling grapes

Yield and plant nutrient content of vegetables trickle-irrigated with municipal wastewater

Soil and sweet cherry responses to irrigation with wastewater.