草业科学
草業科學
초업과학
Pratacultural Science
2015年
10期
12-21
,共10页
刘晓东%尹国丽%武均%陈建纲%马隆喜%师尚礼
劉曉東%尹國麗%武均%陳建綱%馬隆喜%師尚禮
류효동%윤국려%무균%진건강%마륭희%사상례
高寒草甸%氮元素添加%土壤物理性状%土壤团聚体%土壤团聚体稳定性
高寒草甸%氮元素添加%土壤物理性狀%土壤糰聚體%土壤糰聚體穩定性
고한초전%담원소첨가%토양물이성상%토양단취체%토양단취체은정성
alpine meadow%nitrogen addition%soil physical properties%soil aggregates%soil aggregate stability
依托设置于青藏高原东部夏河县桑科草原的天然草地刈割型草场培育定位试验,探讨不同氮元素添加量对高寒草甸草地土壤物理性状的影响。本试验共设4个处理,分别为对照(CK,0 kg N/hm2)、低氮(LN,50 kg N/hm2)、中氮(MN,100 kg N/hm2)、高氮(HN,150 kg N/hm2)。通过对高寒草甸草地土壤容重、孔隙度、紧实度、土壤团聚体等物理性状进行测定与分析,结果表明,MN 与 HN 处理可显著降低0~10 cm 土壤容重与土壤紧实度、增加土壤总孔隙度、非毛管孔隙度与最大持水量。20~30 cm 土层中 LN、MN、HN 处理均可显著增加土壤容重、土壤紧实度,降低土壤总孔隙度、最大持水量。对土壤团聚体的影响,与 CK 处理相比 MN、HN 处理可显著提高各土层≥0.25 mm 机械稳定性土壤团聚体含量、提升土壤团聚体平均重量直径(MWD);较之 CK 处理,LN、MN处理可显著提升各土层≥0.25 mm 水稳性团聚体含量,同时不同氮元素添加处理均可显著提升水稳性团聚体和MWD,表明氮元素添加对该区土壤侵蚀性有较好的抑制作用,进而减少水土和养分的流失。对地上和地下生物量的影响,MN、HN 处理能显著提升草地地上生物量;MN 处理显著增加了地下生物量、HN 处理显著降低了地下生物量;LN 处理对地上与地下生物量的影响不显著。通过试验得出结论 MN 处理对土壤物理性状的改善效果较好,该处理改善了土壤容重、孔隙度及土壤紧实度,提高了土壤干筛≥0.25 mm 机械稳定性团聚体与湿筛≥0.25 mm水稳性团聚体含量及其稳定性(MWD),增加了草地地上生物量和地下生物量。
依託設置于青藏高原東部夏河縣桑科草原的天然草地刈割型草場培育定位試驗,探討不同氮元素添加量對高寒草甸草地土壤物理性狀的影響。本試驗共設4箇處理,分彆為對照(CK,0 kg N/hm2)、低氮(LN,50 kg N/hm2)、中氮(MN,100 kg N/hm2)、高氮(HN,150 kg N/hm2)。通過對高寒草甸草地土壤容重、孔隙度、緊實度、土壤糰聚體等物理性狀進行測定與分析,結果錶明,MN 與 HN 處理可顯著降低0~10 cm 土壤容重與土壤緊實度、增加土壤總孔隙度、非毛管孔隙度與最大持水量。20~30 cm 土層中 LN、MN、HN 處理均可顯著增加土壤容重、土壤緊實度,降低土壤總孔隙度、最大持水量。對土壤糰聚體的影響,與 CK 處理相比 MN、HN 處理可顯著提高各土層≥0.25 mm 機械穩定性土壤糰聚體含量、提升土壤糰聚體平均重量直徑(MWD);較之 CK 處理,LN、MN處理可顯著提升各土層≥0.25 mm 水穩性糰聚體含量,同時不同氮元素添加處理均可顯著提升水穩性糰聚體和MWD,錶明氮元素添加對該區土壤侵蝕性有較好的抑製作用,進而減少水土和養分的流失。對地上和地下生物量的影響,MN、HN 處理能顯著提升草地地上生物量;MN 處理顯著增加瞭地下生物量、HN 處理顯著降低瞭地下生物量;LN 處理對地上與地下生物量的影響不顯著。通過試驗得齣結論 MN 處理對土壤物理性狀的改善效果較好,該處理改善瞭土壤容重、孔隙度及土壤緊實度,提高瞭土壤榦篩≥0.25 mm 機械穩定性糰聚體與濕篩≥0.25 mm水穩性糰聚體含量及其穩定性(MWD),增加瞭草地地上生物量和地下生物量。
의탁설치우청장고원동부하하현상과초원적천연초지예할형초장배육정위시험,탐토불동담원소첨가량대고한초전초지토양물이성상적영향。본시험공설4개처리,분별위대조(CK,0 kg N/hm2)、저담(LN,50 kg N/hm2)、중담(MN,100 kg N/hm2)、고담(HN,150 kg N/hm2)。통과대고한초전초지토양용중、공극도、긴실도、토양단취체등물이성상진행측정여분석,결과표명,MN 여 HN 처리가현저강저0~10 cm 토양용중여토양긴실도、증가토양총공극도、비모관공극도여최대지수량。20~30 cm 토층중 LN、MN、HN 처리균가현저증가토양용중、토양긴실도,강저토양총공극도、최대지수량。대토양단취체적영향,여 CK 처리상비 MN、HN 처리가현저제고각토층≥0.25 mm 궤계은정성토양단취체함량、제승토양단취체평균중량직경(MWD);교지 CK 처리,LN、MN처리가현저제승각토층≥0.25 mm 수은성단취체함량,동시불동담원소첨가처리균가현저제승수은성단취체화MWD,표명담원소첨가대해구토양침식성유교호적억제작용,진이감소수토화양분적류실。대지상화지하생물량적영향,MN、HN 처리능현저제승초지지상생물량;MN 처리현저증가료지하생물량、HN 처리현저강저료지하생물량;LN 처리대지상여지하생물량적영향불현저。통과시험득출결론 MN 처리대토양물이성상적개선효과교호,해처리개선료토양용중、공극도급토양긴실도,제고료토양간사≥0.25 mm 궤계은정성단취체여습사≥0.25 mm수은성단취체함량급기은정성(MWD),증가료초지지상생물량화지하생물량。
A 3-year study was conducted from 2012 to 2014 to determine the effects of nitrogen (N)addition on the physical properties of soil in an alpine meadow in Xiahe County on the eastern Qinghai-Tibetan Plateau.The four treatments were as follows:CK (control,no N addition),LN (low N,50 kg N/ha),MN (medium N,100 kg N/ha),and HN (high N,150 kg N/ha).Each N-addition treatment had three replicates of 54 m2 (6 m×9 m),with a 1.5 m isolation band between adjacent plots.Analyses of soil bulk density,soil porosity,soil compaction,and soil aggregates showed that MN and HN treatments reduced soil bulk density and soil compac-tion,increased soil porosity and non-capillary porosity,and maximized water-holding capacity in the 0-10 cm soil layer.In the 20-30 cm soil layer,compared with CK,all N-addition treatments showed higher soil bulk density and soil compaction,reduced soil porosity,and maximized water-holding capacity.In terms of the effect of N addition on the stability of soil aggregates in the 0-30 cm soil layer,the LN,MN,and HN treat-ments dramatically increased the macro-aggregate content (≥0.25 mm)and MWD (mean weight diameter), with the MN treatment having the strongest effect.Compared with CK,LN and MN dramatically improved the water-stable aggregate content.All of the N-addition treatments significantly promoted soil aggregation and in-creased the MWD of aggregates.The results indicated that N addition could effectively prevent soil erosion, and hence,control the loss of water and soil nutrients.The MN and HN treatments significantly increased the aboveground biomass in the grassland,while underground biomass was increased in the MN treatment and de-creased in the HN treatment.The results of this study showed that the MN treatment was the most beneficial treatment in terms of improving soil properties.This treatment increased soil bulk density,reduced soil porosi-ty,and increased soil compaction,increased the content of ≥0.25 mm soil aggregates and improved aggregate stability,and increased both the aboveground and underground biomass of plants in the grassland.