The study of root exudates enriches the theories and methods of rhizospheric soil ecology, and offers theory warranty that it can be used in agriculture and forest. This paper discusses the types and components of roo...The study of root exudates enriches the theories and methods of rhizospheric soil ecology, and offers theory warranty that it can be used in agriculture and forest. This paper discusses the types and components of root exudates, mechanism of exudation, and the relationship between root exudates and the biotic and environmental factors. The development tendency and study aspect of root exudates in the future was evaluated as well.展开更多
以单施秸秆为对照,研究秸秆还田配施不同比例化肥对土壤温度、土壤根际微生物和酶活性的影响。结果表明:(1)在水稻不同生育期,与对照相比秸秆还田配施化肥各处理在8:00和20:00均提高了土壤温度,而在14:00降低了土壤温度。从地温日较差...以单施秸秆为对照,研究秸秆还田配施不同比例化肥对土壤温度、土壤根际微生物和酶活性的影响。结果表明:(1)在水稻不同生育期,与对照相比秸秆还田配施化肥各处理在8:00和20:00均提高了土壤温度,而在14:00降低了土壤温度。从地温日较差分析可知,秸秆还田配施化肥处理的整日地温变化幅度低于对照,且差异显著。此外随着土层深度的增加,秸秆还田配施化肥处理与对照间的差距逐渐减少,调温作用逐渐减弱。(2)秸秆还田配施化肥各处理能够增加根际土壤总细菌、放线菌、真菌、氨氧化细菌、好气性自生固氮菌、亚硝酸细菌、磷细菌和好气性纤维素分解菌的数量,但普遍区组间差异不显著。除了秸秆还田配施低量NP处理(SNP1,秸秆3 000 kg hm-2+N 150 kg hm-2+P2O575 kg hm-2)以外,秸秆还田配施化肥各处理的过氧化氢酶、脲酶、转化酶活性均高于对照,但区组间均未达到显著差异。因此,秸秆还田配施化肥能合理调节土壤温度,显著提高土壤微生物的数量与活性,有利于土壤生态环境的改善,其中秸秆还田配施NPK处理(SNPK1,秸秆3 000 kg hm-2+N 150 kg hm-2+P2O575 kg hm-2+K2O 37.5 kg hm-2;SNPK2,秸秆3 000 kg hm-2+N 225 kg hm-2+P2O5112.5 kg hm-2+K2O 56.3 kg hm-2)效果最为显著。展开更多
Rhizosphere and nonrhizosphere soils were sampled from corn field at harvest time.Total number and genus of the bacteria mineralizing lecithin or dissolving phosphate were measured.It was found that the number of eith...Rhizosphere and nonrhizosphere soils were sampled from corn field at harvest time.Total number and genus of the bacteria mineralizing lecithin or dissolving phosphate were measured.It was found that the number of either organic or inorganic phosphobacteria in the rhizosphere soil was 10 to 20 times higher than those in the nonrhizosphere soil.The community structure was much more complicated in the rhizosphere than in the nonrhizosphere.Pseudomonas and Flavobacteria were advantageous orgainc phosphobacteria in the rhizosphere, but Erwinia for inorganinc phosphobacteria.In nonrhizosphere, most of organic phosphobacteria were Bacillus. However, no advantageous genus of inorganic phosphobacteria were found in the nonrhizosphere soil.展开更多
文摘The study of root exudates enriches the theories and methods of rhizospheric soil ecology, and offers theory warranty that it can be used in agriculture and forest. This paper discusses the types and components of root exudates, mechanism of exudation, and the relationship between root exudates and the biotic and environmental factors. The development tendency and study aspect of root exudates in the future was evaluated as well.
文摘以单施秸秆为对照,研究秸秆还田配施不同比例化肥对土壤温度、土壤根际微生物和酶活性的影响。结果表明:(1)在水稻不同生育期,与对照相比秸秆还田配施化肥各处理在8:00和20:00均提高了土壤温度,而在14:00降低了土壤温度。从地温日较差分析可知,秸秆还田配施化肥处理的整日地温变化幅度低于对照,且差异显著。此外随着土层深度的增加,秸秆还田配施化肥处理与对照间的差距逐渐减少,调温作用逐渐减弱。(2)秸秆还田配施化肥各处理能够增加根际土壤总细菌、放线菌、真菌、氨氧化细菌、好气性自生固氮菌、亚硝酸细菌、磷细菌和好气性纤维素分解菌的数量,但普遍区组间差异不显著。除了秸秆还田配施低量NP处理(SNP1,秸秆3 000 kg hm-2+N 150 kg hm-2+P2O575 kg hm-2)以外,秸秆还田配施化肥各处理的过氧化氢酶、脲酶、转化酶活性均高于对照,但区组间均未达到显著差异。因此,秸秆还田配施化肥能合理调节土壤温度,显著提高土壤微生物的数量与活性,有利于土壤生态环境的改善,其中秸秆还田配施NPK处理(SNPK1,秸秆3 000 kg hm-2+N 150 kg hm-2+P2O575 kg hm-2+K2O 37.5 kg hm-2;SNPK2,秸秆3 000 kg hm-2+N 225 kg hm-2+P2O5112.5 kg hm-2+K2O 56.3 kg hm-2)效果最为显著。
文摘Rhizosphere and nonrhizosphere soils were sampled from corn field at harvest time.Total number and genus of the bacteria mineralizing lecithin or dissolving phosphate were measured.It was found that the number of either organic or inorganic phosphobacteria in the rhizosphere soil was 10 to 20 times higher than those in the nonrhizosphere soil.The community structure was much more complicated in the rhizosphere than in the nonrhizosphere.Pseudomonas and Flavobacteria were advantageous orgainc phosphobacteria in the rhizosphere, but Erwinia for inorganinc phosphobacteria.In nonrhizosphere, most of organic phosphobacteria were Bacillus. However, no advantageous genus of inorganic phosphobacteria were found in the nonrhizosphere soil.
