Effects Of Biochar-based Compost Fertilizer On Characteristics And Caloric Value Of Branches And Leaves Of Morus Alba L.

Mulberry(Morus alba L.)is woody plant which has strong adaptability,high biomass and good combustion characteristics.It is an excellent energy tree species with both ecological and economic value.In this paper,the outdoor pot experiment was set up,and the karst calcareous soil was taken as the research object.The annual seedlings of M.alba.were used as the tested tree species,and the biochar-based compost fertilizer was used as the experimental material.We set eight processing levels of treatment:CK,CF,W2CF,W4CF,B2CF,B4CF,RH2CF,RH4CF(where C stands for compost,F stands for NPK chemical fertilizer,W stands for charcoal,B stands for bamboo charcoal,and RH stands for rice husk charcoal;the number in treatment represents the mass ratio of biochar in the fertilizer).The purpose of this study was to study the effects of different types and concentration gradients of biochar-based compost fertilizer of on soil nutrition,physiological ecology of M.alba.,characteristics of leaf and branch of M.alba.and its relationship with caloric value indexes.The application methods of biochar-based compost fertilizer which suitable for karst areas were selected,which provided a theoretical basis for the restoration of degraded vegetation and cultivation of local energy forests.The main results of this paper were as follows:(1)The effects of biochar-based compost fertilizer on soil organic matter,total and available NPK content in karst calcareous soil were extremely significant(except for total nitrogen)(P<0.001).There was significant difference in soil organic matter content between treatments(P<0.05).And the effect of bamboo charcoal and rice husk carbon compound fertilizer on soil nutrition was better than that of charcoal;there was a significant positive correlation between soil organic matter and caloric value indexes of leaves(P<0.001).There was a positive correlation between the soil available phosphorus,available potassium content and caloric value indexes of leaves and branches of M.alba.(P<0.05).(2)The biochar-based compost fertilizer had no significant effect on the growth index of M.alba.The biomass of leaves and branches had the highest value at B4CF,which was significantly higher than that of CK(P<0.05);The biochar-based compost fertilizer had a significant effect on the carbon and ash content of leaves and branches of M.alba.(P<0.01);Linera relations between carbon,ash content and indexes of caloric value of M.alba.had a high R~2 value and better effects.Carbon has a positive correlation with caloric value,and ash has a negative correlation with caloric value.(3)The treatment of biochar-based compost fertilizer had significant level of effects on the crude fat,lignin,cellulose,hemicellulose and crude of leaves protein,starch content of branches in quality of feed of M.alba.(P<0.01).It also had significant effects on sugar and total amino acid content(P<0.05);Linera relations and regressions between the crude fat,soluble sugar content of leaves of M.alba.had a ideal R~2 values and better effects,and they had a positively correlation with calorific value;Linera relations and regressions between the cellulose,hemicellulose content and caloric value of branches of M.alba.had a general effect,and there is a negative correlation between these indexes and calorific value.(4)The results of Multiple regressions equations between characteristics of branch and leaf and gross caloric value of was M.alba.significant(P<0.05),in which carbon and crude fat content had significant effects on gross caloric value of leaves.And the content of ash,cellulose and hemicellulose had a significant effects on gross caloric value of branches.(5)The heat of branch is greater than heat of leaf of M.alba.;The treatment of biochar-based compost fertilizer had significant effects on the characteristic indexes of caloric value of leaves and total heat of M.alba.(P<0.05),among which the bamboo charcoal fertilizer had better effect,and the total heat had the maximum under B4CF treatment.It was significantly higher than CK treatment by 26.39%(P<0.05).Therefore,the biochar-based compost fertilizer by mixing 4%bamboo charcoal with compost and chemical fertilizer can be used as a fertilization method for mulberry energy forest.