粤北林下种草对林地土壤理化性质的影响

Effects of Planting Grasses under Forests on Physical and Chemical Properties of Forest Soils in Northern Guangdong

于2017年4月在广东省天井山林场林下种植牧草,分别于2018年9月、11月、次年1月和4月共4个时间点采集无草林地(对照)、原生草林地和种草林地的土壤并测定理化性质,以期为林草复合系统在粤北地区的应用提供技术支撑。结果表明:不同处理对土壤总孔隙度有显著影响(P<0.05),对土壤田间持水量、毛管持水量和毛管孔隙度均有极显著影响(P<0.01),种草林地土壤的总孔隙度、田间持水量、毛管持水量和毛管孔隙度均较大;不同处理和取样时间对土壤容重影响不显著;随着牧草生长时间的延长,土壤物理性质得到改善;林下种草可调节土壤pH值,改善酸性土壤,增加土壤有机质、全氮、碱解氮、全磷和有效磷含量,大多数时间点各样地的有机质、全氮和碱解氮含量为种草林地>原生草林地>无草林地。

In order to provide technical support for the development of forest grass complex system in northern Guangdong,the experiment was conducted in Tianjingshan Forest Farm of Guangdong province in April 2017.Soil samples were collected from four time points in September,November,January and April of the next year from the grass-free forest land(control),native grass forest land and grass planting forest land,and their physical and chemical properties were measured.The results showed that different treatments had significant effects on the total soil porosity(P<0.05),and had extremely significant effects on soil field capacity,capillary capacity,and capillary porosity(P<0.01).The porosity,field capacity,capillary capacity and capillary porosity of grass-planted forestland were large.Different treatments and sampling times had no significant effect on soil bulk density.With the growth of grass,soil physical properties were improved.Planting grass under forest also adjusted pH value,improved acidic soil,increased soil organic matter,total nitrogen,alkali hydrolysable nitrogen,total phosphorus and available phosphorus contents.At the majority of four sampling times,the content of organic matter,total nitrogen and alkali hydrolysable nitrogen were grass-planted forestland>native grass forestland>grassfree forestland.