模拟酸雨对福州平原水稻田土壤碳、氮、磷含量及其生态化学计量学特征影响

为阐明酸雨对水稻田土壤碳(TC)、氮(TN)、磷(TP)含量及其生态化学计量学特征影响,以福州平原水稻田为研究对象,在早稻和晚稻生长期中,设置对照(CK)、模拟酸雨(pH为2.5,3.5,4.5)处理,对酸雨影响下福州平原水稻田土壤TC、TN和TP含量进行了测定与分析。结果表明:综合早稻和晚稻生长期来看,酸雨处理下土壤TC、TN和TP含量均值均大于CK组(P<0.05),水稻成熟期各处理土壤TC含量均值均小于返青期和拔节期(P<0.01),水稻拔节期各处理土壤TN含量均值均小于返青期和成熟期(P<0.01),水稻成熟期各处理土壤TP含量均值均小于返青期和拔节期(P<0.01);整个生长期内,酸雨处理下土壤C/N、C/P和N/P的变化范围分别在7.87~10.86,8.38~9.91,0.82~1.26,早稻各生长期酸雨处理下土壤C/N、C/P和N/P均小于CK组(P<0.05);与早稻相比,晚稻N/P有显著下降,且C/N、C/P和N/P在返青期均大于CK组(P<0.05);早、晚稻拔节期各处理土壤C/N均大于返青期和成熟期(P<0.01);早、晚稻各生长期内C/P差异不显著;早、晚稻拔节期各处理土壤N/P均小于返青期和成熟期(P<0.01)。总体来看,酸雨处理提高了稻田土壤各生长期土壤碳、氮、磷含量,且稻田土壤碳、氮、磷生态化学计量学特征受酸雨影响显著,并具有较为明显的生长期变化。

Effects of Simulated Acid Rain on Soil Carbon, Nitrogen, and Phosphorus Contents and Ecological Stoichiometry Characteristics of Paddy Field in Fuzhou Plain

In order to clarify the effect of acid rain on soil carbon (TC), nitrogen (TN), phosphorus (TP) content, and ecological stoichiometry characteristics, taking the paddy field in Fuzhou Plain as the research object, setting the control (CK), simulated acid rain(pH 2.5, 3.5, 4.5) treatment in the early rice and late rice growth period, the TC, TN and TP contents in paddy soil of Fuzhou Plain were measured and analyzed under the influence of acid rain. The results showed that the TC, TN, and TP contents in the soil under the acid rain treatments were higher than those in the CK (P<0.05). The average TC content in the soil at the maturity stage was lower than that at the greening stage and the jointing stage (P<0.01). The average TN content of each treatment in soil at the jointing stage of rice was less than that at the regreening stage and maturity stage (P<0.01). The average soil TP content at maturity stage was less than that at regreening stage and jointing stage (P<0.01). During the whole growth period, the C/N, C/P, and N/P ratios in the soil under acid rain treatment ranged from 7.87~10.86, 8.38~9.91 and 0.82~1.26, respectively. The C/N, C/P, and N/P ratios were smaller than that of the CK (P<0.05). Compared with early rice, the N/P ratio of late paddy decreased significantly, and the C/N, C/P, and N/P ratios were higher at the regreening stage than in the CK (P<0.05). The C/N ratio at jointing stage was higher than that at regreening and maturity stages (P<0.01). The difference of C/P ratio was not significant during the growth periods of early and late rice. The N/P ratio of each treatment at jointing stage of early and late rice was lower than that at regreening and maturity stages (P<0.01). In general, acid rain treatment increased soil carbon, nitrogen, and phosphorus contents in paddy soils, and the ecological stoichiometry characteristics in paddy soils was also significantly affected by acid rain, moreover, appeared obviously growth period variation.