施肥和水位对土壤-水稻生态化学计量特征的影响

Effects of fertilization and water level on ecological stoichiometry of soil and rice straw

基于36年长期定位施肥和2个田间水位控制试验,研究了长期施肥和水位控制及其交互作用对水稻秸秆和土壤全碳(C)、全氮(N)、全磷(P)和全硫(S)生态化学计量特征的影响。结果表明:与施化肥相比,常量有机肥处理的土壤C、N和S元素含量分别提高了35%、15%和56%,高量有机肥处理的土壤全C、N和S元素含量分别提高了67%、42%和43%;而高量有机肥和常量有机肥土壤P含量分别降低了38%和21%;其中土壤C、N元素含量最高均为高量有机肥处理;与此相反,长期施用化肥的秸秆C、N和P含量最高;后续施肥改变后,土壤和秸秆元素含量变化更依赖于后续施肥情况;总体上,土壤元素含量比秸秆对施肥响应更敏感;不同水位处理试验结果表明,除高量有机肥处理土壤P含量低水位大于高水位外,其他处理试验土壤C、N、S和P含量均为高水位显著大于低水位;另外,双因素方差分析表明,施肥和水位对土壤和植物生态化学计量的影响存在交互作用。

The effects of long-term fertilization and field water level variation on the contents and stoichiometric ratios of total carbon(C),nitrogen(N),phosphorus(P),and sulfur(S)in rice straw and soil were examined based on a 36-year fertilization experiment in combination with a two-water-level controlling field experiment.The results showed that,compared with chemical fertilizer application,the contents of C,N,and S increased by 35%,15%,and 56%in soil treated with normal-level organic fertilizer,increased by 67%,42%and 43%in the soil treated with high-level organic fertilizer,respectively.Soil P contents under treatments of high-level organic fertilizer and normal-level organic fertilizer were decreased by 38%and 21%,respectively.The highest soil C and N contents were found under the treatment with high-level organic fertilizer.In contrast,plants with long-term chemical fertilizer application had the highest levels of C,N and P.Changes in element contents of soil and plant were more dependent on subsequent fertilization scheme.In general,soil element content was more sensitive to fertilization than that in plants.The results of different water level treatments showed that soil C,N,S and P contents at high water level were significantly higher than those at low water level,except that higher P content in soil was observed at low water level treated with high-level organic fertilizer.In addition,there was an interactive effect between fertilization and water level on soil and plant ecological stoichiometry.