生物质炭对黄棕壤理化性质及龙脑樟幼苗生长的影响

Effects of Biochar on Physicochemical Properties of Yellow-brown Soil and Growth of Cinnamomum camphora Seedlings

以南京林业大学下蜀林场黄棕壤为试验对象,采用室外盆栽试验,研究生物质炭不同施用量(炭土质量比0、1%、2%、4%)对黄棕壤理化性质及龙脑樟幼苗生长的影响。结果表明:生物质炭可有效改良黄棕壤物理性质,4%施用量改良效果最好,与仅施化肥处理相比,土壤总孔隙度、饱和持水量、毛管持水量和田间持水量显著提高,土壤容重显著降低(P<0.05);施用生物质炭可显著提高土壤pH(P<0.05),改善土壤酸碱性;生物质炭施用对土壤氮磷有效性影响显著(P<0.05),低施用量下土壤碱解氮含量最高,高施用量下土壤有效磷含量最高。生物质炭1%施用量下,龙脑樟叶片产量最高(41.54 g),分别比对照和仅施化肥处理提高141.53%和11.16%;而苗高相对生长速率较仅施化肥处理显著降低6.79%,有利于矮化苗木。可见生物质炭改良土壤理化性质和促进苗木生长的最佳施用量并不相同。考虑到经济效益,1%的生物质炭施用量对龙脑樟叶片产量的提高较为适宜。

An outdoor pot experiment was conducted to study the effects of different dosages of biochar （0, 1%, 2%, 4%） on yellow brown soil physicochemical properties and the growth of Cinnamomum camphora seedings. Results showed that： 4% of biochar dosage amended yellow-brown soil most effectively, compared with chemical fertilizer treatment （CoF）, soil total porosity, saturation moisture capacity, capillary moisture capacity and field moisture capacity were significantly increased, while soil bulk density was significantly reduced （P〈0.05）. Biochar increased soil pH significantly （P〈0.05）. Biochar improved nitrogen and phosphorus availabilities, which was the highest in N availability with low biochar dosage and the highest in P availability with high biochar dosage. With the dosage 1%, Cinnamomum camphora＇s leaves biomass reached the maximum （41.54 g）, 141.53% and 11.16% higher than those of the control （CK） and CoF, respectively; The relative growth rate in height was decreased by 6.79% compared with that of CoF, which is helpful for dwarf trees. So, the appropriate dosages of biochar were different for soil physico-chemical properties and for the growth of Cinnamomum camphora seedings. Considering the economic benefits, 1% of biochar dosage is appropriate to leaf biomass of Cinnamomum camphora.