【目的】为探究3种糯高粱生长及其对镉污染农田土壤中的镉吸收移除效果。【方法】选用“川糯粱1号”、“兴湘粱2号”和“晋糯梁5号”为实验材料,以休耕为对照,采用“一种两收”种植方式,研究3种糯高粱的生长和镉吸收差异及其对土壤养分...【目的】为探究3种糯高粱生长及其对镉污染农田土壤中的镉吸收移除效果。【方法】选用“川糯粱1号”、“兴湘粱2号”和“晋糯梁5号”为实验材料,以休耕为对照,采用“一种两收”种植方式,研究3种糯高粱的生长和镉吸收差异及其对土壤养分和镉含量的影响。【结果】兴湘梁2号的两季秸秆生物量最高(19461.0 kg hm^(−2)),其次为晋糯梁5号(19143.5 kg hm^(−2)),川糯梁1号最低(18982.5 kg hm^(−2))。兴湘梁2号的两季籽粒产量最高(11887.0 kg hm^(−2)),其次为川糯粱1号(11527.5 kg hm^(−2)),晋糯梁5号最少(10929.5 kg hm^(−2))。兴湘梁2号秸秆和籽粒镉吸收量分别为15342.0 mg hm^(−2)和186.0 mg hm^(−2),其秸秆两季镉吸收量显著高于川糯粱1号和晋糯梁5号。3种糯高粱品种头季和再生季植株镉含量、土壤pH值和有效镉含量均无显著差异。【结论】在镉轻度污染农田中,“一种两收”的糯高粱种植方式是可复制可推广的模式,可为区域重金属污染土壤治理提供技术支撑;另外,兴湘梁2号是本地区更适宜推广的糯高粱品种。展开更多
为揭示微生物群落结构特征和多样性对不同施肥的响应机制及与土壤环境因子的关系,以黄泥田水稻土为研究对象,设置不施肥(CK)、单施化肥(NPK)、化肥配施秸秆(NPKS)3个处理,采用Illumina Miseq高通量测序平台对土壤细菌16S r RNA基因和真...为揭示微生物群落结构特征和多样性对不同施肥的响应机制及与土壤环境因子的关系,以黄泥田水稻土为研究对象,设置不施肥(CK)、单施化肥(NPK)、化肥配施秸秆(NPKS)3个处理,采用Illumina Miseq高通量测序平台对土壤细菌16S r RNA基因和真菌ITS基因进行测序,分析不同施肥对细菌、真菌群落结构和多样性的影响。结果表明,黄泥田土壤细菌的主要类群为Acidobacteria、Proteobacteria、Chloroflexi、Actinobacteria和Firmicutes,而真菌主要由Ascomycota、Basidiomycota和Zygomycota构成。长期施肥导致土壤细菌和真菌群落结构及相对丰度产生显著差异。与CK相比,NPK和NPKS处理黄泥田土壤的Proteobacteria、Actinobacteria和Zygomycota相对丰度分别增加26.58%和45.84%、30.36%和55.45%、86.17%和68.08%。细菌的α多样性方面,不同处理的Shannon和Simpson指数无显著性差异,但NPK处理的Chao1和ACE指数均显著低于CK和NPKS处理。真菌α多样性指数均表现为NPK处理显著低于CK和NPKS处理。RDA分析结果表明,细菌群落结构主要受盐度、孔隙度、总氮、微生物生物量氮、有机质、微生物生物量碳和含水量的影响,而真菌群落结构的关键影响因素是含水量、孔隙度和盐度,其次为总氮、微生物生物量氮、有机质和微生物生物量碳。土壤p H对细菌和真菌的群落结构影响较小。因此,不同施肥影响细菌和真菌的群落结构组成和多样性。有机无机肥配施提高细菌和真菌的多样性,改变细菌和真菌的群落结构组成,为改良土壤质量和维持农田生态系统功能提供理论依据。展开更多
Rapid nitrogen(N) transformations and losses occur in the rice rhizosphere through root uptake and microbial activities. However,the relationships between rice roots and rhizosphere microbes for N utilization are stil...Rapid nitrogen(N) transformations and losses occur in the rice rhizosphere through root uptake and microbial activities. However,the relationships between rice roots and rhizosphere microbes for N utilization are still unclear. We analyzed different N forms(NH+4,NO-3, and dissolved organic N), microbial biomass N and C, dissolved organic C, CH4 and N2O emissions, and abundance of microbial functional genes in both rhizosphere and bulk soils after 37-d rice growth in a greenhouse pot experiment. Results showed that the dissolved organic C was significantly higher in the rhizosphere soil than in the non-rhizosphere bulk soil, but microbial biomass C showed no significant difference. The concentrations of NH+4, dissolved organic N, and microbial biomass N in the rhizosphere soil were significantly lower than those of the bulk soil, whereas NO-3in the rhizosphere soil was comparable to that in the bulk soil. The CH4 and N2O fluxes from the rhizosphere soil were much higher than those from the bulk soil. Real-time polymerase chain reaction analysis showed that the abundance of seven selected genes, bacterial and archaeal 16 S rRNA genes, amoA genes of ammonia-oxidizing archaea and ammonia-oxidizing bacteria, nosZ gene, mcrA gene, and pmoA gene, was lower in the rhizosphere soil than in the bulk soil, which is contrary to the results of previous studies. The lower concentration of N in the rhizosphere soil indicated that the competition for N in the rhizosphere soil was very strong, thus having a negative effect on the numbers of microbes. We concluded that when N was limiting, the growth of rhizosphere microorganisms depended on their competitive abilities with rice roots for N.展开更多
文摘【目的】为探究3种糯高粱生长及其对镉污染农田土壤中的镉吸收移除效果。【方法】选用“川糯粱1号”、“兴湘粱2号”和“晋糯梁5号”为实验材料,以休耕为对照,采用“一种两收”种植方式,研究3种糯高粱的生长和镉吸收差异及其对土壤养分和镉含量的影响。【结果】兴湘梁2号的两季秸秆生物量最高(19461.0 kg hm^(−2)),其次为晋糯梁5号(19143.5 kg hm^(−2)),川糯梁1号最低(18982.5 kg hm^(−2))。兴湘梁2号的两季籽粒产量最高(11887.0 kg hm^(−2)),其次为川糯粱1号(11527.5 kg hm^(−2)),晋糯梁5号最少(10929.5 kg hm^(−2))。兴湘梁2号秸秆和籽粒镉吸收量分别为15342.0 mg hm^(−2)和186.0 mg hm^(−2),其秸秆两季镉吸收量显著高于川糯粱1号和晋糯梁5号。3种糯高粱品种头季和再生季植株镉含量、土壤pH值和有效镉含量均无显著差异。【结论】在镉轻度污染农田中,“一种两收”的糯高粱种植方式是可复制可推广的模式,可为区域重金属污染土壤治理提供技术支撑;另外,兴湘梁2号是本地区更适宜推广的糯高粱品种。
文摘茶园土壤是重要的N_(2)O排放源,了解茶园土壤N_(2)O排放因素,为减排措施提供一定的理论依据。基于全球田间原位监测和室内培养试验的茶园土壤文献数据进行荟萃分析(Meta analysis),量化茶园土壤N_(2)O年排放量,分析主要影响因素。全球茶园土壤田间原位监测结果表明平均N_(2)O-N年排放量为16.82 kg hm^(-2)(95%置信区间(CI):12.99~21.27 kg hm^(-2)),而室内培养试验结果表明N_(2)O-N排放速度为0.04 mg kg^(-1)d^(-1)(CI:0.02~0.07 mg kg^(-1)d^(-1))。茶园土壤N_(2)O平均直接排放系数(EFd)为2.25%,高于IPCC的建议值(1%)。方差分解分析(VPA)发现施氮量对茶园土壤N_(2)O排放的总解释量最大,贡献值为49.71%。施缓控释肥、生物炭和石灰材料分别可以减少茶园土壤35%、52%和55%的N_(2)O排放。上述结果表明,茶园土壤N_(2)O排放量大,施肥量是主控因子,通过改良施肥措施可有效减少N_(2)O排放。
文摘为揭示微生物群落结构特征和多样性对不同施肥的响应机制及与土壤环境因子的关系,以黄泥田水稻土为研究对象,设置不施肥(CK)、单施化肥(NPK)、化肥配施秸秆(NPKS)3个处理,采用Illumina Miseq高通量测序平台对土壤细菌16S r RNA基因和真菌ITS基因进行测序,分析不同施肥对细菌、真菌群落结构和多样性的影响。结果表明,黄泥田土壤细菌的主要类群为Acidobacteria、Proteobacteria、Chloroflexi、Actinobacteria和Firmicutes,而真菌主要由Ascomycota、Basidiomycota和Zygomycota构成。长期施肥导致土壤细菌和真菌群落结构及相对丰度产生显著差异。与CK相比,NPK和NPKS处理黄泥田土壤的Proteobacteria、Actinobacteria和Zygomycota相对丰度分别增加26.58%和45.84%、30.36%和55.45%、86.17%和68.08%。细菌的α多样性方面,不同处理的Shannon和Simpson指数无显著性差异,但NPK处理的Chao1和ACE指数均显著低于CK和NPKS处理。真菌α多样性指数均表现为NPK处理显著低于CK和NPKS处理。RDA分析结果表明,细菌群落结构主要受盐度、孔隙度、总氮、微生物生物量氮、有机质、微生物生物量碳和含水量的影响,而真菌群落结构的关键影响因素是含水量、孔隙度和盐度,其次为总氮、微生物生物量氮、有机质和微生物生物量碳。土壤p H对细菌和真菌的群落结构影响较小。因此,不同施肥影响细菌和真菌的群落结构组成和多样性。有机无机肥配施提高细菌和真菌的多样性,改变细菌和真菌的群落结构组成,为改良土壤质量和维持农田生态系统功能提供理论依据。
基金Supported by the National Natural Science Foundation of China(No.41090280)
文摘Rapid nitrogen(N) transformations and losses occur in the rice rhizosphere through root uptake and microbial activities. However,the relationships between rice roots and rhizosphere microbes for N utilization are still unclear. We analyzed different N forms(NH+4,NO-3, and dissolved organic N), microbial biomass N and C, dissolved organic C, CH4 and N2O emissions, and abundance of microbial functional genes in both rhizosphere and bulk soils after 37-d rice growth in a greenhouse pot experiment. Results showed that the dissolved organic C was significantly higher in the rhizosphere soil than in the non-rhizosphere bulk soil, but microbial biomass C showed no significant difference. The concentrations of NH+4, dissolved organic N, and microbial biomass N in the rhizosphere soil were significantly lower than those of the bulk soil, whereas NO-3in the rhizosphere soil was comparable to that in the bulk soil. The CH4 and N2O fluxes from the rhizosphere soil were much higher than those from the bulk soil. Real-time polymerase chain reaction analysis showed that the abundance of seven selected genes, bacterial and archaeal 16 S rRNA genes, amoA genes of ammonia-oxidizing archaea and ammonia-oxidizing bacteria, nosZ gene, mcrA gene, and pmoA gene, was lower in the rhizosphere soil than in the bulk soil, which is contrary to the results of previous studies. The lower concentration of N in the rhizosphere soil indicated that the competition for N in the rhizosphere soil was very strong, thus having a negative effect on the numbers of microbes. We concluded that when N was limiting, the growth of rhizosphere microorganisms depended on their competitive abilities with rice roots for N.
