摘要
【目的】沼液富含氮素是其农田利用的基础,但不可忽视的是,沼液中还含有大量的HCO_(3)^(-)。探讨沼液还田过程中HCO_(3)^(-)的转化及其对水稻生长的影响,以期为沼液替代化肥,实施化肥减量及沼液资源化利用提供新的理论依据。【方法】设置沼液原液(BS)、去除HCO_(3)^(-)的沼液(BS−B)、去离子水加HCO_(3)^(-)(W+B)和去离子水(W)4个处理,采用13C标记技术,通过水稻苗期盆栽试验,观测CO_(2)释放特征,同步分析水稻光合作用速率、胞间CO_(2)浓度、干鲜重、株高,以及上覆水和土壤pH、HCO_(3)^(-)、NH 4+含量等的变化。【结果】(1)BS处理下CO_(2)释放速率为9.55-38.07 mg·kg^(-1)·h^(^(-1)),净累计释放量为4654.06 mg·kg^(-1);BS−B处理下CO_(2)释放速率为4.55-17.25 mg·kg^(-1)·h^(-1),净累计释放量为780.68 mg·kg^(-1);W+B处理下CO_(2)释放速率为3.93-26.33 mg·kg^(-1)·h^(-1),净累计释放量为1274.07 mg·kg^(-1);W处理下CO_(2)释放速率为3.22-11.90 mg·kg^(-1)·h^(-1),累计释放量为2265.20 mg·kg^(-1)。BS处理下CO_(2)平均释放速率分别是BS−B和W+B的4.18倍和2.44倍,净累计释放量分别是BS−B和W+B的5.96倍和3.65倍,均显著高于BS−B和W+B处理。同时,BS处理下的CO_(2)净累计释放量大于BS−B与W+B两个处理之和,因此HCO_(3)^(-)与沼液中其他组分在对CO_(2)释放影响方面存在协同效应。(2)培养期内BS处理下13CO_(2)的净累计释放量为32.87 mg·kg^(-1),占土壤-水稻系统CO_(2)净累计释放量的0.71%;W+B处理下13CO_(2)的净累计释放量为13.18 mg·kg^(-1)。相比较而言,BS处理下的13CO_(2)净累计释放量显著高于W+B(P<0.05),这表明沼液中的其他组分促进了HCO_(3)^(-)向CO_(2)的转化。(3)BS和BS−B处理在前12 h水稻的净光合速率显著高于W+B和W处理;添加培养液后2-7 d,BS处理下的净光合速率值显著高于BS−B,同时,整个培养期间均显著高于W+B处理(P<0.05),沼液中的HCO_(3)^(-)显著改善了水稻叶
【Objective】Biogas slurry is rich in nitrogen(N),which is the basis of its farmland utilization.However,it also contains a large amount of HCO_(3)^(-).In this study,the conversion of HCO_(3)^(-) in biogas slurry and its effect on rice growth were investigated,in order to provide a new theoretical basis for replacing chemical fertilizer with biogas slurry,reducing the amount of chemical fertilizer,and whether biogas slurry could be utilized as resources.【Method】Four treatments,including biogas slurry(BS),biogas slurry(BS-B),deionized water plus HCO_(3)^(-)(W+B)and deionized water(W),were set up in this paper.Using 13C labeling technology,the characteristics of CO_(2) release were observed through pot experiment at Rice Seedling Stage,and the photosynthetic rate,intercellular CO_(2) concentration,dry and fresh weight,plant height,overlying water and soil pH,and HCO_(3)^(-) and NH 4+contents were analyzed.【Result】(1)Under BS treatment,CO_(2)release rates ranged from 9.55 to 38.07 mg·kg^(-1)·h^(-1),with a net cumulative release of 4654.06 mg·kg^(-1).Under BS-B treatment,the CO_(2)release rates ranged from 4.55 to 17.25 mg·kg^(-1)·h^(-1),and the net cumulative release was 780.68 mg·kg^(-1).Under W+B treatment,the CO_(2) release rate was 3.93-26.33 mg·kg^(-1)·h^(-1),and the net cumulative release was 1274.07 mg·kg^(-1).Under W treatment,the CO_(2)release rate was 3.22^(-1)1.90 mg·kg^(-1)·h^(-1),and the cumulative release amount was 2265.20 mg·kg^(-1).Under BS treatment,the average CO_(2)release rate was 4.18 times and 2.44 times of BS−B and W+B,respectively,and the net cumulative CO_(2)release was 5.96 times and 3.65 times of BS-B and W+B,respectively,which were significantly higher than those under BS−B and W+B treatments.At the same time,the net cumulative release under BS treatment was greater than the sum of the two treatments(BS-B)+(W+B),and HCO_(3)^(-)had a synergistic effect with other components in biogas slurry on CO_(2)release.(2)The net cumulative release of 13CO_(2)under BS treatm
作者
万华琴
辜旭
何红梅
汤逸帆
申建华
韩建刚
朱咏莉
WAN HuaQin;GU Xu;HE HongMei;TANG YiFan;SHEN JianHua;HAN JianGang;ZHU YongLi(College of Biology and the Environment,Nanjing Forestry University,Nanjing 210037;Co-Innovation Center for Sustainable Forestry in Southern China,Nanjing Forestry University,Nanjing,210037;Huanghai Seed Stock Farm,Dongtai 224200,Jiangsu;COFCO Jiajiakang(Jiangsu)Co.,Ltd.,Dongtai 224200,Jiangsu)
出处
《中国农业科学》
CAS
CSCD
北大核心
2022年第22期4445-4457,共13页
Scientia Agricultura Sinica
基金
国家重点研发计划(2017YFC0505803)
江苏高校优势学科建设工程项目(PAPD)。
