生草果园草被残体氮磷分解规律研究

Nitrogen and Phosphorus Decomposition of Debris from Orchard Grass

采用样方收获法对人工多年生草果园草被残体的量进行测定,并进行果园草被残体原位分解试验。结果表明:4种草被(圆叶决明、百喜草、宽叶雀稗、日本草)的样方残体量分别为406.00、1 582.28、1 542.62、658.07g,分别占其样方地上部物质总量的33.8%、76.1%、59.4%、100.0%;百喜草、圆叶决明、日本草草被残体半腐解时间为5个月,而宽叶雀稗为6个月;4种草被残体年释放量为残体氮素贮量的90.86%、67.76%、88.45%、88.33%,折合果园氮素年释放81.16、119.02、219.68、58.71kg.hm-2;4种草被残体磷素年释放量分别为残体贮量的84.46%、80.32%、90.90%、87.22%,折合磷素年释放量为167.69、534.96、604.49、343.22kg.hm-2。

Grass residues and decomposition of nitrogen and phosphorus in grassing orchards were studied by using the harvest quadrat method.The residues of the 4 grasses,Chamaecrista rotundifolia,Paspalum natatum,Paspalum wetsfeteinii and Borreria latisolia,were 406.00,1 582.28,1 542.62 and 658.07 g,respectively,accounting for 33.8%,76.1%,59.4%,and 100.0% of the total,respectively.The half-decomposition time of the grass residues was 5 months for P.natatum,C.rotundifolia and B.latisolia,while 6 months for P.wetsfeteini.The nitrogen storage of the annual losses of the 4 grass residues were 90.86%,67.76%,88.45% and 88.33%,respectively,which equated the annual losses of orchard nitrogen of 81.16,119.02,219.68 and 58.71 kg·hm-2,respectively.These were far less than 864 kg·hm-2.The phosphorus storage of the annual losses of the 4 grass residues were 84.46%,80.32%,90.90% and 87.22%,respectively,which equated the annual losses of orchard phosphorus of 167.69,534.96,604.49 and 343.22 kg·hm-2,respectively.These were less than the amount of adsorbable phosphorus in the cultivated soil.