Effect of New Environmentally Friendly Fertilizers in a Commercial Vineyard

In this study the effectiveness of the environmentally friendly fertilizers AXION RED, BIO.L.A and QUATTRO to improve soil fertility and the nutrition status of vines was examined. Application of above three fertilizers increased significantly the level of organic matter, K, P, Mn and Fe in soil. AXION RED also improved the concentration of Ζn, Β, and Cu. Tissue analyses showed that the leaf P content was significantly increased in the vines treated with the fertilizers in comparison to control in 2012. The fertilizer QUATTRO increased the leaf concentrations of Fe and Mn contents in 2012. It was found that the fertilizer BIO.L.A significantly increased the leaf N content, while the fertilizer QUATTRO increased the leaf B content in 2013. Although there was no statistically difference, the leaf P, K and Fe contents were increased in vines treated with each one of the fertilizers tested.The results also showed that all fertilizers increased the fruit N content in comparison to control. The percentage of fruit rot was significantly higher on bunches treated with each one of the fertilizers tested than the untreated control. Finally, the results of this study showed that only the fertilizer QUATTRO significantly increased the bunch weight in 2012. Generally, the above fertilizers improved the nutrition status of vine plants and also improved the soil fertility. However, the increased fruit N content in the grapes treated with each one of the fertilizers increased the susceptibility of fruits to pathogens causing fruit rots and therefore growers should consider its use carefully.


Introduction
Vine development, yield, and grape quality depend on many environmental variables.Among them mineral elements have an important effect on canopy size and yield level, influencing berry composition and quality.The timing and amount of fertilizer application affects the amount of mineral elements leached from the root-zone (Bryla, 2011).The two above inputs are interactive and need to be managed better in order to ensure minimal impact of viticulture production on the environment and to optimize berry composition.A common cultural practice consist is to incorporate fertilizers in the soil surface at the end of winter, a period in which the vine needs in nitrogen are negligible (Lie et al., 2015).However, excessive nitrogen concentration in the soil leads to a decreased grape quality and increased sensitivity in grape pests and diseases (Vartholomaiou et al., 2008).This may damage vines and increase the cost of plant protection.
All plants receive their nutrients in chemical form.When referring to plant nutrition, the terms organic or natural generally refers to any fertilizer which is derived from plant, animal or mineral origin.It must have one or more essential nutrients for plant growth.Non-organic fertilizers (also known as synthetic) are manufactured chemically.They are made to deliver nutrients rapidly, such as those that are water-soluble, or over time as a controlled release fertilizer.Although very effective for providing rapid or prolonged periods of feeding, these have a high salt index.The potential risk to plants and the soil food web is scorching and dehydration with the leeching of unabsorbed chemicals into waterways.Organic nutrients on the other hand, must first be broken down and digested by soil microorganisms which then release these nutrients in a form available to plants.This process also produces humus, a vital ingredient to improving soil structure.As part of this structure, organically derived nutrients are very resistant to leaching and contain a very low salt index.The net result is nutrients that remain in the soil until utilized by plants and little risk of scorching or dehydration, even in periods of extreme drought or over application.

Soil Analysis
Soil analysis is presented in Table 1.Three soils samples, each 500 g (represented 10 sub-samples), were taken from 30 and 60 cm in depth in December.They were transferred in the Laboratory of Soil Science of Alexander Technological Educational Institute of Thessaloniki, where large chunks of soil were broken up and placed in a forced air oven set between 35 °C and 55 °C for 24 h.Soil was then crushed in a soil pulverizer to pass through a 2 mm mesh screen, to achieve sample homogeneity.The soil was silt-clay-loam, alkaline and calcareous.

Tissue Analysis
Tissues (leaf, grape) were first cleaned with washing powder (Tide, 2%), then washed with tap water and finally with distilled water.The samples were dried in oven at 70 °C for 48 h and ground to pass through a mesh screen to achieve sample homogeneity before analyzing for mineral concentration.
Nutrients were determined by ashing 1 g at 540 °C, treating with concentrated HCl and using the Kjeldahl method (N).Phosphorus was determined spectrometrically (the method is based upon the development of a blue complex of molybdenum with P), potassium was determined flamephotometrically and calcium and magnesium were determined volumetrically with 0.001 N EDTA (Kalra & Maynard, 1991).The concentration of trace elements Mn, Zn, Fe, and Cu were determined with atomic absorption spectrophotometry (Meyer & Keliher, 1992) and colorimetry for B (Bingham, 1982) and are reported as percentage for N, P, K, Ca, Mg, and as ppm for micronutrients

Effect of the Environmentally Friendly Fertilizers
Experiments were conducted in a commercial vineyard (wine cultivar Xinomavro Naoussa), located in Strantza Naoussa.The fertilizers ΒΙΟ.L.Α was applied at the rate of 1650 kg/hr, AXION RED at the rate of 1000 kg/hr and QUATTRO at the rate of 800 kg/hr.All applications were made in March 2012 and again in March 2013.Fertilizers were hand-applied to specific plants using the top-dressing in a ring around each plant in proportion to its size and rooting area.There were three treatments (fertilizers), each with 20 replicated plants.Plants without fertilization were used as control.The experimental design was completely randomized.
Samples of leaves for tissue analyses were collected in July of 2012 and again in July 2013.
Samples of fruit bunches were collected in September of 2012 and 2013.A scale of infection rates, with 0 = healthy and 100 = surface totally infected, was used to assess the treatment effects on fruit rot.Tissue analysis of fruits was conducted as described above.
In addition, fifteen randomly selected bunches without any symptoms of disease were collected from each treatment to record their weight.
In a second experiment, an isolate of Botrytis cinerea from infected grapes was used.This isolate was maintained on potato dextrose agar (PDA).Ten bunches for each treatment were collected from plants treated with one of the fertilizers tested.They were disinfested by dipping in 10% domestic bleach solution for 20 min.Bunches were washed with water, dried on sterilized paper and then sprayed with a spore suspension of about 4x10 -5 conidia per mL B. cinerea with 0.1% (v/v) Tween 20.Bunches sprayed with tap water were used as control.After drying at room temperature, the inoculated bunches were packed into cardboard boxes and stored at 4°C for 2 weeks.
The scale of infection rates was used to assess treatment effects.This experiment was conducted for 2 consecutive years (2012-2013).

Statistical Analysis
To analyse data for significant differences of treatment means at α = 0.05, the Generalized Linear Model (Wald's Chi-Square) was applied and for multiple comparison treatment means, the LSD0.05 was used.

Results
The effectiveness of the environmentally friendly fertilizers AXION RED, BIO.L.A and QUATTRO to improve the soil fertility and vines nutrition status were examined in this study.Application with the above fertilizers increased the content of organic matter in soil.Of all the components of soil, organic matter is probably the most important and most misunderstood.According to Craswell and Lefroy (2001), soil organic matter has many functions, the relative importance of which differs with soil type, climate, and land use.Commonly the most important function of organic matter in soil is as a reserve of the nitrogen and other nutrients required by plants, and ultimately by the human population.Other important functions include: the formation of stable aggregates and soil surface protection; maintenance of the vast array of biological functions, including the immobilization and release of nutrients; provision of ion exchange capacity; and storage of terrestrial carbon.Adding new organic matter to soil every year (by spreading a thin layer of compost on top of grass) is perhaps the most effective way to improve and build soil organic matter in established lawns (Toor & Shober, 2015).They also reported that once the soil organic matter reaches sufficient levels, it would maintain steady supply of nutrients for plant growth and promote infiltration of water.This nutrient supply from the organic matter saves growers the cost and hassle of buying and applying frequent applications of fertilizers.Lawns with good availability of nutrients will have well-established root systems, which would require less amounts of irrigation water to keep the lawns healthy.At the same time, there will be less runoff of water and nutrients from lawns and reduced potential of water quality degradation (Toor & Shober, 2015).
This study also showed that all fertilizers increased the soil K, P, Mn and Fe contents (Table 1).Note. z Values followed by the same letter are not significantly different according to Wald Test (P < 0.05).
The fertilizers AXION RED and QUATTRO also increased significantly the soil B contents, while the fertilizers BIO.L.A. and AXION RED increased significantly the soil Zn and Cu contents (Table 1).It is possible that the fertilizers enriched the soil nutrient contents directly by releasing the nutrient elements in soil and indirectly by improving the properties of soil (increased the soil organic matter).
Tissue analyses showed that the leaf P content was significant increased in the vines treated with each one of the fertilizer tested than in control in 2012 (Table 2).The fertilizer QUATTRO increased significant the leaf Fe and Mn contents in 2012.It was found that the fertilizer BIO.L.A increased significant the leaf N content, while the fertilizer QUATTRO increased the leaf B content in 2013.Although there were not statistically differences, the leaf P, K and Fe contents were increased in soils treated with one of the fertilizers tested (Table 2).These results showed a good correlation between leaf and soil mineral contents.Previous works have been proved the correlation of soil fertility with the nutrition status of plants (Lacertosa et al., 1999).Note.z Values followed by the same letter are not significantly different according to Wald Test (P < 0.05).
The results also showed that all fertilizers increased the fruit N contents in comparison to control in both years (Table 3).Note.z Values followed by the same letter are not significantly different according to Wald Test (P < 0.05).
It was also found that the percentage of fruit rot was significant higher on bunches treated with each one of the fertilizers tested than untreated control in both years (Table 4).In addition, the artificial inoculated bunches from vines treated with each one of the fertilizers showed significantly higher percentage of fruit rot caused from B. cinerea than the untreated control (Table 5).The above results showed a direct relation between the fruit N content and fruit rots.Previous works also showed that high nitrogen fertilization predisposed grapevines to infection by B. cinerea and increased disease severity (R'Houma et al., 1998).According to Mundy (2008), direct changes due to increased nitrogen nutrition include greater thickness of the wax on berry surfaces and increased concentrations of the biochemical defence compounds produced in them.Indirect changes that result from increased nitrogen include development of tighter bunches and denser canopies (Mundy & Beresford, 2007).Finally, the results of this study showed that only the fertilizer QUATTRO increased significantly the bunch weight in 2012 (Table 5).The effect of nutrition status of vineyards with the bunch size and weight has been reported in previous works with conflicting results (Abd El-Razek et al., 2011;Mohammed et al., 1993).

Conclusion
Generally, the fertilizers tested in this study and especially the fertilizer BIO.L.A. improve the nutrition status of vine plants and also improve the soil fertility.However, the increased fruit N content in the grapes treated with each one of the fertilizers increased the susceptibility of fruits to pathogens causing fruit rots and therefore growers should consider it.

Table 1 .
Soil texture class and chemical analysis of the 0-60 cm of the soil profile from the experimental orchards B (mg/kg) Fe (mg/kg) Zn (mg/kg) Mn (mg/kg) Cu (mg/kg)Treatments.K ppm Ca ppm Mg ppm P ppm B (mg/kg) Fe (mg/kg) Zn (mg/kg) Mn (mg/kg) Cu (mg/kg)

Table 3 .
Effect of QUATTRO, BIO.L.A and AXION RED fertilizers on fruit mineral contents of the vine variety Xinomavro

Table 4 .
Effect of QUATTRO, BIO.L.A and AXION RED fertilizers on susceptibility of Xinomavro fruits to fruit rot Note.z Values followed by the same letter are not significantly different according to Wald Test (P <0.05).

Table 5 .
Effect of QUATTRO, BIO.L.A and AXION RED fertilizers on fruit weight of the bunch of Xinomavro Naoussas Note.z Values followed by the same letter are not significantly different according to Wald Test (P <0.05).