| Watermelon is one of the main summer fruits in China.It is widely planted in China.Since the reform and opening up,the watermelon industry has developed rapidly.By 2018,the total cultivated area of melon class in China reached 2,177,200 hm2,among which,the cultivated area of watermelon was 1,517,900 hm2,accounting for 69.72%of the total cultivated area.The scale of watermelon industry is gradually expanding,and the quality and yield of watermelon are constantly improving.However,at present,excessive application of chemical fertilizer and blind application of organic fertilizer exist in watermelon production,and farmers lack knowledge of the law of watermelon fertilizer requirements and lack scientific reasonable guidance.Therefore,the increase of yield and income mainly depends on excessive application of fertilizer.This not only leads to serious waste of resources,but also causes a series of problems such as reduced yield and quality of watermelon,soil degradation,environmental pollution and so on,which seriously restricts the development of watermelon industry.In this experiment,watermelon variety"Tian Wang"was used as scion and white seed pumpkin as rootstock.Field experiments were carried out by facility cultivation,the amount of chemical fertilizer was reduced on the basis of conventional fertilization,and different gradations of vermicompost fertilizer or bacterial fertilizer were set,and no fertilization and conventional fertilization were taken as the control.To study the effects of different fertilization treatments on the growth characteristics,yield and quality of grafted watermelon,in order to determine the appropriate organic fertilizer or bacterial fertilizer gradient on the basis of reduced chemical fertilizers,and to screen out suitable treatments to replace conventional fertilization,to provide theoretical basis for scientific fertilizer application of watermelon in Shaanxi facilities.The following conclusions are obtained through the research:1.Reduce fertilizer increasing different gradient vermicompost fertilizer processing of plant length,fruit stage and swollen stage of chlorophyll content,net photosynthetic rate,transpiration rate,intercellular CO2 concentration had no significant effect,stem diameter increased with the increase of vermicompost fertilizer gradient showed a trend of reducing the rise,then Q500 processing effect is best.The growth indexes of Q500 treatment,such as stem diameter,chlorophyll content,net photosynthetic rate and fruit diameter had no significant difference with CF.2.Reduce the application of chemical fertilizers and increase the application of different gradients of vermicompost organic fertilizer treatments have no significant effect on the single melon quality,yield and quality of watermelon fruits,such as central soluble solids,organic acid content,soluble protein and other quality indicators.The ratio of sugar to acid,Vc,reducing sugar,and total soluble sugar increased first and then decreased with the increase of the vermicompost fertilizer gradient,and the Q500 treatment reached the highest value.Partial fertilizer productivity and fertilizer agronomic utilization rate gradually decrease with the increase of the earthworm manure organic fertilizer gradient,and the Q400 treatment reaches the maximum.3.Compared with CF,Q500 treatment（N 5.76 Kg/667 m2,P2O5 4 Kg/667 m2,K2O5.28 Kg/667 m2,vermicompost 500 Kg/667 m2）has no significant reduction in single melon,quality and yield,but the partial productivity of fertilizers and the utilization rate of fertilizer agronomy are significantly improved.The quality of the fruit treated with Q500was significantly improved.Compared with CF,the central soluble solid content was 8.5%,the sugar-acid ratio was 46.90%,the Vc content was 16.8%,the soluble protein content was20.12%,and the reducing sugar content was 3.5%.Compared with the CF treatment,the Q500 treatment reduces the fertilizer consumption by N 46%,P2O5 72%,and K2O 57%.The fertilizer agronomic utilization rate is greatly improved,and the economic input of fertilizer is reduced by 26.55%.4.Treatments with reduced chemical fertilizers and increase different gradients of bacterial fertilizers had no significant effects on plant vine length,stem thickness,net photosynthesis rate,transpiration rate,etc.The chlorophyll content increased first and then stabilized with the increase of bacterial fertilizer gradient.Growth indicators such as stem thickness,chlorophyll content,net photosynthetic rate,and fruit length and breadth diameter of J300 treatment were no significant difference compared with CF.5.Treatments with reduced chemical fertilizers and different gradient bacterial fertilizers had no significant effect on the single melon quality,yield and quality of watermelon fruits,such as,central soluble solids,soluble protein,reducing sugar,total soluble sugar and other quality indicators.The ratio of sugar to acid and Vc first increased and then decreased with the increase of bacterial fertilizer gradient.Fertilizer partial productivity and fertilizer agronomic utilization rate first increase and then decrease with the increase of bacterial fertilizer gradient,and the J300 treatment reaches the maximum.6.Compared with CF,J250 treatment（N 5.76 Kg/667 m2,P2O5 4 Kg/667 m2,K2O5.28 Kg/667 m2,bacterial fertilizers 250 Kg/667 m2）did not significantly decrease the quality,yield and single melon.Partial fertilizer productivity and fertilizer agronomic utilization rate have been significantly improved.J250 treatment has the best quality,and significantly improves the central soluble solids by 10.38%,sugar-to-acid ratio 37.55%,Vc content 7.47%,and soluble protein content 16.09%compared with CF.Compared with CF,J250 treatment reduces the amount of fertilizer N 46%,P2O5 72%,and K2O 57%.The agronomic utilization rate of fertilizer is greatly improved,and the economic input of fertilizer is reduced by 32.35%. |
