福州不同农田土地利用类型土壤碳氮磷生态化学计量学特征

为阐明不同土地利用类型土壤碳(C)、氮(N)、磷(P)生态化学计量学特征,对福州农田不同土地利用类型(水稻田、菜地和茉莉园)下的土壤全碳(TC)、全氮(TN)、全磷(TP)含量及其生态化学计量学特征进行测定和分析。结果表明:土壤TC含量均值基本表现为水稻田菜地茉莉园(P0.05);在春、秋季节土壤TN含量均值表现为水稻田菜地茉莉园(P0.05),在夏、冬节季表现为菜地水稻田茉莉园(P0.05);在各个季节菜地土壤TP含量均值均为最大(P0.05),在冬季土壤TP含量均值达到最大(P0.05)。土壤C/N、C/P和N/P在各个土地类型下均值分别为10.17～12.89,0.46～0.86,4.76～9.61,C/N季节差异不显著,唯有夏季略高于其他季节,菜地土壤C/N在各个季节均低于水稻田和茉莉园(P0.05);C/P和N/P在全年内季节差异不显著,均表现为水稻田菜地茉莉园(P0.05)。菜地土壤C和N储量在各个季节均高于水稻田与茉莉园土壤(P0.05),各个季节里水稻田和茉莉园土壤C和N储量无明显差异,秋季各个土壤类型C和N储量基本低于其他季节(P0.05)。在各个季节P储量均值表现为菜地茉莉园水稻田(P0.05)。总体来看,与其他土壤相比,茉莉园土壤C、N、P含量最低,菜地土壤N和P含量以及储量较高,且土壤碳氮磷生态化学计量学特征在不同土地利用类型下差异显著,其生态化学计量学特征对土壤碳氮磷固持及限制性养分具有一定的指示作用。

Ecological Stoichiometric Characteristics of Soil Carbon, Nitrogen and Phosphorus Under Different Agricultural Land-Use Types in Fuzhou

In order to clarify the ecological stoichiometric characteristics of soil carbon (C), nitrogen (N) and phosphorus (P) in different land-use types (paddy field, vegetable field and jasmine garden) of Fuzhou farmland, the contents of total carbon (TC), total nitrogen (TN) and total phosphorus (TP) and their ecological stoichiometric characteristics were measured and analyzed. The results showed that the averaged TC content in soil was:paddy field > vegetable field > jasmine garden (P<0.05). In spring and autumn, the averaged TN content in soil was:paddy field > vegetable field > jasmine garden (P<0.05). However, in summer and winter, the averaged TN content in soil was:vegetable field > paddy field > jasmine garden (P<0.05). In each season, the averaged content of TP in vegetable soils was the largest (P<0.05), and in winter, the averaged content of TP in vegetable soils appeared the maximum (P<0.05). The C/N value, C/P value and N/P value of soil were between (10.17~12.89), (0.46~0.86) and (4.76~9.61) respectively in different land types. The seasonal difference of C/N value was not significant, except in summer, which was slightly higher than that of other seasons. It is worth mentioning that the C/N value of vegetable soil was lower than that of paddy field and jasmine garden in each season (P<0.05). C/P value and N/P value had no significant seasonal difference in the whole year, which showed:paddy field > vegetable field > jasmine garden (P<0.05). The C and N storage of vegetable soil were higher than those of paddy soil and jasmine garden soil in each season (P<0.05). There was no significant difference in C and N storage between paddy soil and jasmine garden soil in each season, but the C and N storage of different soil types in autumn were lower than those of other seasons (P<0.05). Overall, compared with other soils, the content of C, N and P in jasmine garden soil were the lowest, while the content and storage of N and P in vegetable soil were higher. What''s more, the ecological stoichiometric characteristics of soil carbon, nitrogen and phosphorus were obviously different in those three land-use types, and it can be used to indicate the fixation of carbon, nitrogen and phosphorus in soil and the limited nutrient of soil.