城市污泥生物质炭和酸雨对麻栎苗木生长的影响

Effects of Urban Sewage Sludge Biochar on Growth of Quercus acutissima Seedlings under Acid Rain Environment

2018年10月份,选用1年生麻栎(Quercus acutissima Carruth)苗木移入盆栽,进行2个月的恢复后,选择50株恢复良好、长势一致的苗木为试验苗木。设置3种强度(pH分别为4.5、3.5、2.5)的酸雨,pH为7.0的雨水为对照;按照生物质炭占苗木栽培基质体积比例设置4种添加生物质炭体积分数(0、10%、20%、30%)的苗木栽培基质;按照试验设计,对试验苗木进行酸雨和生物质炭交互作用的模拟处理试验;按照近12 a南京市月均降雨量的60%(最大酸雨频次)进行喷施,每盆每月喷施总量为1.75 L,每月喷施4次。试验处理1 a后,采集麻栎苗木叶片和根系,测定苗木生长速率、叶绿素质量分数、叶绿素荧光参数、根系活力、叶片及根系抗氧化酶活性;应用方差分析法、双因素方差分析法,分析城市污泥生物质炭、酸雨对麻栎苗木生长的影响。结果表明:在生长方面,生物质炭的添加显著提高了麻栎苗木的树高和基径增长率,且酸雨和生物质炭的交互作用对麻栎苗木树高和基径增长率的影响显著。在生理方面,酸雨和生物质炭的交互作用,对麻栎苗木叶绿素a质量分数(w_(a))、叶绿素b质量分数(w_(b))、w_(a)∶w_(b)、非光化学淬灭系数(Q_(N,P))、光化学淬灭系数(Q_(P))、实际光化学量子产量(Ф_((PSⅡ)))、叶片超氧化物歧化酶(SOD)活性、叶片过氧化物酶(POD)活性、根系超氧化物歧化酶(SOD)活性的影响显著。生物质炭的添加对麻栎苗木的生长有显著的改良作用;而对在酸雨和生物质炭交互处理时的麻栎苗木,“pH为2.5的重度酸雨+添加生物质炭体积分数为10%”的交互处理、“pH为3.5的中度酸雨+添加生物质炭体积分数为20%”的交互处理,对麻栎苗木生长起到明显的促进作用。

One-year-old Quercus acutissima seedlings were selected and transplanted into pots in October 2018.After 2-month recovery,50 seedlings with good recovery and consistent growth were selected as test seedlings,and three kinds of acid rain(pH of 4.5,3.5 and 2.5)and rain with pH of 7.0 were set as the control;four kinds of seedling cultivation substrates with biomass charcoal volume fraction(0,10%,20%and 30%)were set according to the proportion of biomass charcoal to seedling cultivation substrate volume;according to the experimental design,the test seedlings were treated with acid rain and biomass charcoal interaction simulation test;according to the spraying was carried out at 60%of the average monthly rainfall(maximum acid rain frequency)in Nanjing in the past 12 a,with a total monthly spraying volume of 1.75 L per pot and four times per month.After 1-a experimental treatment,leaves and roots of the Q.acutissima seedlings were collected to determine the growth rate,chlorophyll content,chlorophyll fluorescence parameters,root activity,leaf and root antioxidant enzyme activities;the effects of urban sludge biomass charcoal and acid rain on the growth of hemp oak seedlings were analyzed by applying ANOVA and two-factor ANOVA.The addition of biomass charcoal significantly increased the tree height and basal diameter growth rate of Q.acutissima seedlings,and the interaction between acid rain and biomass charcoal had a significant effect on the tree height and basal diameter growth rate of Q.acutissima seedlings.In terms of physiology,the interaction between acid rain and biomass charcoal significantly affected the chlorophyll a content,chlorophyll b content,chlorophyll a content/chlorophyll b content,non-photochemical extraction coefficient(N_(PQ)),photochemical extraction coefficient(q_(P)),actual photochemical quantum yield(Ф_((PSⅡ))),leaf superoxide dismutase(SOD)activity,leaf peroxidase(POD)activity and superoxide dismutase(SOD)activity on root system.The addition of biomass charcoal had a significant effect on the growth of Q.acutissima seedlings;for Q.acutissima seedlings treated with the interaction of acid rain and biomass charcoal,the interaction of“heavy acid rain at pH 2.5+addition of biomass charcoal at 10%by volume”,“moderate acid rain at pH 3.5+addition of biomass charcoal at 20%by volume”,and“moderate acid rain at pH 3.5+addition of biomass charcoal at 20%by volume”.The interaction treatment of“heavy acid rain at pH 2.5+addition of biomass charcoal volume fraction of 20%”had a significant effect on the growth of Q.acutissima seedlings.