不同施氮水平下杨树-苋菜间作系统对土壤氮素流失的影响  

Effects of poplar-amaranth intercropping system on the soil nitrogen loss under different nitrogen applying levels

作　　者：褚军[1] 薛建辉[1] 吴殿鸣[2] 金梅娟[1] 吴永波[1] 

机构地区：[1]南京林业大学生物与环境学院江苏省林业生态工程重点实验室,南京210037 [2]苏州科技学院,江苏苏州215009

出　　处：《应用生态学报》2014年第9期2591-2597,共7页Chinese Journal of Applied Ecology

基　　金：江苏省高校自然科学研究重大项目(12KJA180003);江苏省普通高校研究生科研创新计划项目(CXZZ13_0513);江苏高校生物学优势学科建设工程项目(2014-PAPD)资助

摘　　要：采用田间试验方法,研究了杨树-苋菜间作系统,即株行距2 m×5 m(L1)和2 m×15 m(L2)在0(N0)、91(N1)、137(N2)和183(N3)kg·hm-2施氮水平下的土壤氮素流失特征.结果表明:不同施氮水平对地表径流量、淋溶量和土壤侵蚀量的控制效果均为L1>L2>L3(单作苋菜);L1、L2地表径流量分别比L3降低65.1%、55.9%;L1、L2距林带0.5 m处淋溶量比L3降低30.0%、28.9%,距林带1.5 m处淋溶量比L3降低25.6%、21.9%;L1、L2土壤侵蚀量分别比L3降低65.0%、55.1%.对地表径流和淋溶损失中TN、NO3--N、NH4+-N流失量的控制效果均为L1>L2>L3;常规施氮(91 kg·hm-2)水平下,L1地表径流中TN、NO3--N、NH4+-N流失量较L3分别降低62.9%、45.1%、69.2%,L2较L3分别降低23.4%、6.9%、46.2%;杨树间作密度越大、距离林带越近,对土壤NO3--N、NH4+-N的淋溶损失削减作用越强.同一间作密度下,随着施氮量的增加,地表径流中NO3--N流失比例减少,NH4+-N流失比例增加;淋溶流失中NO3--N、NH4+-N浓度变化趋势一致,均为N3>N2>N1>N0.Characteristics of soil nitrogen loss were investigated based on field experiments in two types of poplaramaranth intercropping systems （spacing： L1 2 m×5 m, L2 2 m×15 m） with four N application rates, i.e., 0 （N1）, 91 （N2）, 137 （N3） and 183 （N4） kg·hm-2. The regulation effects on the soil surface runoff, leaching loss and soil erosion were different among the different types of intercropping systems： L1〉L2〉L3 （amaranth monocropping）. Compared with the amaranth monocropping, the soil surface runoff rates of L1 and L2 decreased by 65.1% and 55.9%, the soil leaching rates of L1 and L2 with a distance of 0.5 m from the poplar tree row decreased by 30.0% and 28.9%, the rates with a distance of 1.5 m decreased by 25.6% and 21.9%, and the soil erosion rates decreased by 65.0% and 55.1%, respectively. The control effects of two intercropping systems on TN, NO3--N and NH4＋-N in soil runoff and leaching loss were in the order of L1〉L2〉L3. Compared with the amaranth monocropping, TN, NO3--N and NH4＋-N loss rates in soil runoff of L1 decreased by 62.9%, 45.1% and 69.2%, while the loss rates of L2 decreased by 23.4%, 6.9% and 46.2% under N1 （91 kg·hm-2）, respectively. Higher treeplanting density and closer positions to the polar tree row were more effective on controlling the loss rates of NO3--N and NH4＋-N caused by soil leaching. The loss proportion of NO3--N in soil runoff decreased with the increasing nitrogen rate under the same treeplanting density, while that of NH4＋-N increased. Leaching loss of NO3--N had a similar trend with that of NH4＋-N, i.e., N3〉N2〉N1〉N0.

关 键 词：杨树-苋菜间作系统 地表径流量 淋溶损失量 氮素流失 

分 类 号：S158[农业科学—土壤学]