地膜覆盖和有机肥施用对农田土壤和作物C、N、P化学计量学的影响

Effects of plastic film mulching and organic manure application on C,N,P stoichiometry of soil and crop

为了解长期地膜覆盖和施用有机肥对农田土壤和作物C、N、P化学计量学的影响,于2015年采集沈阳农业大学长期地膜覆盖和施肥定位试验(建于1987年)土壤和玉米植株不同组织(根、秸秆、叶片、籽粒),测定了土壤和作物C、N、P含量。结果表明:长期地膜覆盖和施用有机肥均对土壤pH产生显著影响(P<0.01),且两者存在显著的交互作用(P=0.001);地膜覆盖对土壤全碳、全氮、全磷、碱解氮、有效磷,以及土壤C∶N∶P化学计量学均没有显著影响(P>0.05),而施用有机肥会显著增加土壤全碳、全氮、全磷含量以及碱解氮和有效磷含量(P<0.01),降低土壤C/P和N/P(P<0.01);除了叶片N含量和籽粒P含量及C/P以外,地膜覆盖对玉米各组织中C、N、P含量及C∶N∶P化学计量均没有显著影响(P>0.05);而有机肥施用显著增加了玉米各组织中N含量(P<0.05),从而降低C/N(P<0.05),但只增加了根和籽实中P含量(P<0.05),降低了玉米籽实的C/P(P<0.001)。综上所述,土壤和作物的C、N、P化学计量学随长期施用有机肥而变化,但受地膜覆盖的影响较小。

To examine the effects of plastic film mulching and organic manure application on C,N,and P stoichiometry of soil and crop,we collected soil and corn tissues(root,stem,leaf,and seed)in 2015 from a long-term experiment at Shenyang Agricultural University,which was initiated in 1987.We measured C,N and P concentrations in soil and crop tissues.Results showed that the main and interactive effects of long-term film mulching and manure application on soil pH were statistically significant.Film mulching did not affect soil C,N,P,available N and P concentrations,and soil C∶N∶P ratios(P>0.05).Manure application significantly increased soil total C,N,P,available N,and available P concentrations(P<0.01),and significantly decreased soil C/P and N/P ratios(P<0.01).Film mulching did not affect the stoichiometry of C,N,and P in all plant tissues except for leaf N and seed P concentration and C/P ratio.Organic fertilizer application significantly increased N concentration and decreased C/N ratios in all tissues(P<0.05).Manure application increased root and seed P concentrations(P<0.05)and decreased seed C/P ratio(P<0.001).In conclusion,soil and crop C,N,and P stoichiometry could be affected by long-term organic fertilizer application but not by plastic film mulching.