| Object:Our sugar industry can produce up to 4 million tons of sugar wastewater every year,how to effectively use the sugar wastewater produced in large quantities every year is a huge challenge,sugar wastewater contains rich organic matter and nutrients to make it have great potential in the improvement of soil,therefore,this study took different types of beets as objects,Molasses water-soluble fertilizer was prepared from sugar wastewater,to explore the effects of molasses water-soluble fertilizer on the growth,production quality and soil characteristics of beets,This thesis provides theoretical reference for the rational cultivation of beet and utilization of molasses as byproduct of sugar mill in north China.Methods:Through field control experiments,different types of sugar beets（high sugar type,high yield type）were used as research objects,and different types of fertilizers（Commercially available conventional fertilizer,Kashi sugar plant to provide molasses water soluble fertilizer）were applied.A total of 6treatments were set up:No fertilizer（CKZ,CKE）was applied at all,commercial conventional fertilizer（ZP,EP）was applied,molasses water-soluble fertilizer（ZH,EH）was applied,nitrogen fertilizer was N 235kg/hm2,phosphate fertilizer was P2O5 145 kg/hm2 and potassium fertilizer was K2O 200 kg/hm2 during the whole growth period.The effects of molasses water-soluble fertilizer on the growth,yield,nutrient absorption and soil physicochemical properties of beet under drip irrigation were analyzed.Results:（1）Field control experiments showed that water soluble molasses fertilizer treatment significantly improved the growth,yield quality and nutrient absorption of beet root tuber under drip irrigation.With the advance of the growth period of beet,the length,root width and root volume of different types of beet showed an increasing trend,and reached the peak value in the sugar accumulation period of beet.The yield of different treatments showed EH>EP>ZH>ZP>CKE>CKZ.Sugar yield of high sugar type and high yield type beet treated with molasses water soluble fertilizer reached 121.33 t/hm2 and 132.02 t/hm2,respectively,which significantly increased by 79.35%and 74.33%compared with no fertilizer treatment.Sugar yield was shown as ZH>EH>EP>ZP>CKZ>CKE.Sugar yield of high sugar type and high yield type beet treated with molasses water-soluble fertilizer reached 19.22 t/hm2 and 17.51 t/hm2,respectively,which significantly increased by 130.18%and 124.77%compared with no fertilizer treatment..（2）The effects of molasses water-soluble fertilizer on leaf growth and photosynthetic physiological characteristics of different types of beet were different.The number of leaves,leaf area index,net photosynthetic rate,stomatal conductivities,actual photochemical efficiency of PSⅡand photochemical quenching coefficient of high-sugar beet treated with molasses water-soluble fertilizer were significantly higher than those treated without fertilization.The net photosynthetic rate,stomatal conductance,transpiration rate and photochemical quenching coefficient of high-yield beet treated with molasses water-soluble fertilizer were significantly higher than those treated without fertilization,but the leaf number and leaf area index were significantly lower than those treated with conventional fertilization since seedling stage.（3）The effects of molasses water-soluble fertilizer on soil p H,EC,organic matter,alkali-hydrolyzed nitrogen,available phosphorus,available potassium and soil enzyme activities under drip irrigation were analyzed.The application of molasses water-soluble fertilizer could control the increase of soil p H and EC,and increase the contents of soil organic matter,alkali-hydrolyzed nitrogen,available phosphorus and available potassium in 0-20cm soil layer.In addition,the application of molasses water-soluble fertilizer had a positive effect on soil enzyme activities,and soil urease activities,sucrase activities,alkaline phosphatase activities and catalase activities were significantly higher than those without fertilization.Conclusion:After applying molasses water-soluble fertilizer,soil physical and chemical properties and soil enzyme activity were improved,which promoted the absorption of nutrients in beet,and then promoted the growth of beet leaves and root tuber and leaf photosynthesis,and finally increased the yield and sugar yield of beet root tuber.The effect of promoting the yield of high-yield beet varieties was better,and the effect of increasing the sugar yield of high-sugar beet varieties was better. |
