摘要
用湿筛方法测定了长期田间肥料定位试验地耕层0～20cm土壤水稳性团聚体含量,研究了施肥对黑土团聚体组成、根际沉积碳在土壤团聚体中分配的影响。试验共设无肥(CK)、化肥NP(NP)、化肥NK(NK)、化肥PK(PK)、化肥NPK(NPK)和化肥NPK+有机肥(NPKM)6个处理。采用尼龙网框分隔法区分根际土和非根际土,差减法计算根际沉积碳的分配。结果表明:根际沉积碳主要增加>2mm的团聚体的形成,减少0.25～0.5mm团聚体的形成。CK、NP和NK处理的根际沉积碳增加MWD,PK处理则减少MWD。长期施用化肥使土壤各粒级团聚体有机碳含量增加,表现为NPKM>NPK>NP>PK>NK>CK的趋势。CK处理根际沉积碳分配到>2mm,2～1mm大团聚体和<0.25mm微团聚体中;缺素(NP、NK、PK)根际沉积碳分配到0.5～2mm大团聚体和<0.25mm微团聚体中;化肥配施有机肥减少1～2mm和0.25～0.5mm粒级根际沉积碳分配比例,增加0.5～1mm和<0.25mm粒级分配比例。
Aggregate fraction and the distribution of rhizodeposit - Carbon （ C ） to aggregate in wet - sieved aggregate - size classes of 0 - 20 cm layer from long - term fertilization soils were examined. There were six treatments,including inorganic fertilizer （NP, NK, PK, NPK） , inorganic and organic fertilizer （NPKM） and no -fertilizer as control （CK）. Nylon net was used to sample desired rhizosphere soil and bulk soil, and distribution of rhizodeposit - C was calculated by subtraction. Results showed that rhi- zodeposit - C induced 〉 2 mm sized aggregate formation, decreased 0.25 -0.5 mm sized aggregate formation. The MWD was increased by rhizodeposit - C of CK, NP and NK treatment, but not in PK treatment. Soil organic carbon content was increased by long - term fertilization in order of NPKM 〉 NPK 〉 NP 〉 PK 〉 NK 〉 CK. The rhizodeposit - C of CK was distributed to 〉 2 mm, 2 1 mm and 〈0.25mm sized aggregates ,while mainly to 0.5 -2mm and 〈 0.25mm sized aggregates of NP,NK and PK ,and to 0.5 - 1 mm and 〈 0.25 mm sized aggregates of NPKM treatment ,not 1 - 2mm and 0.25 - 0.5mm.
出处
《黑龙江科学》
2013年第5期24-27,共4页
Heilongjiang Science
基金
国家自然科学基金国家自然科学基金(41001138
41101219)
关键词
施肥
根际沉积碳
团聚体
黑土
Fertilization
rhizodeposit - C
aggregate
black soil
