CAJ | 학술논문

在国家紫色土肥力定位监测点,研究了长期(18年)垄作免耕和常规轮作两种耕作方式下,不同大小土壤团聚体中几种形态氮素含量及脲酶活性分布模式.结果表明,两种轮作方式下全氮、微生物生物量氮、NO3--N含量及脲酶活性在水稳性土壤团聚体中具有相似的分布模式.全氮和微生物生物最氮含量主要分布在>0.25 mm粒级的大团聚体中,其次是0.25-0.053 mm粒级的微团聚体中,粉砂与粘粒组分(<0.053 mm)中分布最少;2.0-0.25mm粒级团聚体中脲酶活性最高,0.25-0.053 mm的微团聚体中脲酶活性最低;NH4+-N和NO3--N在>2.0 mm粒级团聚体中的含量均比其他粒级高.垄作免耕下各级团聚体中全氮、微生物生物量氮、NO3--N含量及脲酶活性均高于常规轮作,其中2.0-0.25 mm粒级团聚体中的全氮含量高出23.1%;>2.0 mm粒级团聚体中NO3--N含量高出26.7%.表明垄作免耕下各团聚体中全氮、微生物生物量氮及脲酶活性显著高于常规轮作,但氮素含量及脲酶活性在不同粒径大小的土壤水稳性团聚体中的分布模式决定于土壤结构体本身,耕作方式的影响不显著.
재국가자색토비력정위감측점,연구료장기(18년)롱작면경화상규륜작량충경작방식하,불동대소토양단취체중궤충형태담소함량급뇨매활성분포모식.결과표명,량충륜작방식하전담、미생물생물량담、NO3--N함량급뇨매활성재수은성토양단취체중구유상사적분포모식.전담화미생물생물최담함량주요분포재>0.25 mm립급적대단취체중,기차시0.25-0.053 mm립급적미단취체중,분사여점립조분(<0.053 mm)중분포최소;2.0-0.25mm립급단취체중뇨매활성최고,0.25-0.053 mm적미단취체중뇨매활성최저;NH4+-N화NO3--N재>2.0 mm립급단취체중적함량균비기타립급고.롱작면경하각급단취체중전담、미생물생물량담、NO3--N함량급뇨매활성균고우상규륜작,기중2.0-0.25 mm립급단취체중적전담함량고출23.1%;>2.0 mm립급단취체중NO3--N함량고출26.7%.표명롱작면경하각단취체중전담、미생물생물량담급뇨매활성현저고우상규륜작,단담소함량급뇨매활성재불동립경대소적토양수은성단취체중적분포모식결정우토양결구체본신,경작방식적영향불현저.
Soil aggregates are the most important structures, and different sizes of aggregates have different functions in maintaining, supplying and transforming nutrients. A 18-year long-term field experiment was carried out to study distri-butions of nitrogen forms and urease activities of soil aggregates under conventional tillage (CT) and ridge tillage (RT) practices. The results show that there are similar distribution patterns of total nitrogen, microbial biomass nitrogen, NO3- -N and urease activities in soil water stable aggregates under CT and RT. Total nitrogen and microbial biomass nitro-gen are mainly distributed in soil aggregate whose size is larger than 0.25 mm, followed by those in the 0.25-0.053 mm aggregate, and those in the silt and clay component ( < 0.053 mm) are the least. Urease activities are the highest in the size of 2.0-0.25 mm aggregate, and axe the least in the size of 0.25-0.053 mm aggregate. NH4+-N and NO3--N con-eentrations are the highest in the size of larger than 2.0 mm aggregate. Total nitrogen, microbial biomass nitrogen, NO3- -N and urease activities under RT are higher than those under CT. For instanee, total nitrogen concentration within 2.0-0.25 mm aggregate under RT is 23.1% higher than that under CT, NO3--N in the size of larger than 2.0 mm aggregate is 26.7 % higher under RT than that under CT. In conclusion, total nitrogen, microbial biomass nitrogen concentrations and rease activities in different sizes of aggregates under RT are significantly higher than those under CT, the distribution patterns of nitrogen concentrations and urease activities are dependent on the structures of aggregates, while tillage meth-ods had no significant effects on them.