Effects Of Silicon Fertilizer Application On Growth,Yield And Quality Of Table Grape (Vitis Vinifera L.) On Calcareous Soil

?Objective?Silicon?Si?is served as a beneficial element for a large number of crops,which has been proved to have significantly effects on improving growth,yield,quality and enhancing the resistance of biotic and abiotic stress.Up to now,most of these studies focused on the acidic soil gramineous crops in China southern.Information about effects of silicon on the calcareous soil horticultural crops in northern China is still rarely reported.Steel slag fertilizer and water-cooling slag fertilizer which is made of the industrial waste materials were introduced to China.However,the application of this type of silicon fertilizer was less than that of N,P,and K fertilizer.And its long-term consecutive applying may exist a risk of soil environmental safety.In this study,a continuous two-year field experiment was carried out to test the effects of silicate fertilizers applications on plant-available silicon concentration in soil,leaf silica content,table grape growth,yield and quality,investigate the mechanism of silicon added on extending the shelf-life of table grape.And the soil environmental safety was explored.The objective was to reveal the response of table grape to silicon added on the calcareous soil in Xinjiang,and provide a theoretical support for the spread and application of slag silicate fertilizer.?Method?In the present study,two-year field experiments were conducted aimed at testing the effects of different sources of silicate fertilizers applied on table grape growth,yield,fruit quality and fruit commercial characteristics during storage period in 2015 to 2016,and the method of single factor pollution index and Nemerow integrated index were used to evaluate the heavy metals pollution in soils.For this,two table grape cultivars named‘Monukka'and‘Red Globe'were tested with treatments including:???no silicate fertilizer?control?,???steel slag fertilizer and???water-cooling slag fertilizer.The application rate of silicate fertilizer was 600 kg SiO₂ ha^-1.?Result??1?Plant-available Si concentration in soil and grape leaf silicon concentration were significantly increased by silicate fertilizer?P<0.05?.Compared with the control,the average plant-available Si concentration in soil with steel slag and water-cooling slag fertilizer increased by 9.9%¹3.0%,and grape leaf silicon concentration increased by 28.4%⁴1.7%,respectively.?2?Application of silicate fertilizer significantly improved leaf dry weight,leaf thickness and yield?P<0.05?.The two-year average fruit yields for‘Monukka'grape treated with steel slag fertilizer and water-cooling slag fertilizer were 24.69 and 26.02 Mg ha^-1,respectively,being 10.4%and 16.4%higher compared with the control.The two-year average fruit yields for‘Red Globe'grape treated with steel slag fertilizer and water-cooling slag fertilizer increased by 11.8%and 14.6%relative to the control,respectively.?3?Silicon fertilization significantly improved fruit total soluble solids,the ratio of total soluble solids to titratable acidity?TSS/TA?.However,silicon fertilizer had no significant effect on fruit titratable acidity.?4?Fruit firmness was significantly improved by two types of silicon fertilizer applied.Compared with the control,the average fruit firmness for‘Monukka'grape treated with Si?water-cooling slag fertilizer and steel slag fertilizer?increased by 13.25%,and increased by 7.65%in cv.Red Globe,respectively.Applying silicate fertilizer significantly extended the fruit shelf-life by decreasing fruit respiratory intensity,decay incidence and weight loss?P<0.05?.?5?The table grape fruit POD activity with silicon fertilizer treatments was largely increased in comparison with control.Silicon fertilization significantly decreased table grape fruit MDA content.But relative to control,there was no significantly effect on the SOD activity of grape fruit with applying silicate fertilizers.?6?Silicon fertilization had no significant effect on heavy metals?i.e.Cd,Cu,Pb,Hg?in soil compared with CK,only As and Cr content has a accumulation phenomenon?P>0.05?.Nemerow integrated index was between 0.7 and 1.0 among all treatments both in 2015 and 2016,and the soil was clean.In comparison with control,silicate fertilizer application significantly decreased heavy metal?i.e.As,Cd,Pb,Cr?content in leaf,but have no significant effects on Cu,Hg content in grape leaf.?Conclusion??1?Applying of silicate fertilizer could promote table grape growth,and increase the yield and quality of grape in a calcareous soil.And the water-cooling slag fertilizer showed a stronger effect than steel slag fertilizer.?2?Silicon fertilization could decrease fruit decay incidence,weight loss and MDA content,and improve fruit firmness,POD activity,thus to prolong fruit shelf-life.?3?Long-term consecutive application of steel silicon fertilizer didn't cause the risk of soil heavy metal security.