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对中国科学院沈阳生态实验站潮棕壤在水稻田、玉米地、撂荒地和林地等经过14年不同利用方式后0-150cm各土层(2003年11月取样)N的剖面分布及N储量进行研究的结果表明不同利用方式下土壤全N、碱解N、NH4+-N和NO3--N含量发生明显的剖面差异;土壤N储量为林地>玉米地>撂荒地>水稻田,NO3--N含量为玉米地>水稻田>林地>撂荒地,说明不同利用方式下生物量差异及N的生物循环对N行为的影响。100cm深度林地土壤平均N储量为11.41t穐m-2,分别是水稻田和玉米地土壤的1.65和1.25倍,而玉米地和撂荒地的土壤N储量无显著差异。玉米地和水稻田相对较高的NO3--N含量可能由于过量施用N肥和人为干扰所致。土壤碱解N与全N含量呈线性正相关关系(R2u001f0.929,p<0.001),而自然生态系统(林地和撂荒地)中的相关性略高于农田生态系统(水稻田和玉米地)。过量施用N肥还导致耕地土壤中比撂荒地和林地积累更多的NO3--N。研究结果表明,农林复合系统对于作物生产和环境保护具有重要的潜在贡献。图2表5参23。
The profile distribution and N reserves of N in 0-150cm soil layers (sampled in November 2003) of paddy brown soil of Shenyang Ecology Experimental Station of Chinese Academy of Sciences after paddy field, corn field, wasteland and forest land have been used for 14 different years The results showed that there were obvious differences in total N, alkali N, NH4 + -N and NO3 - N contents in different utilization ways; soil N reserves were in the areas of forest land> maize land> abandoned land> paddy field, NO3 - N The content of corn was> corn field> paddy field> woodland> fallow land. The effects of different biomass utilization and nitrogen cycling on N behavior were illustrated. The average soil N N content of 100 cm depth forest soil was 11.41 t 穐 m-2, which was 1.65 and 1.25 times higher than that of paddy field and maize soil, respectively. There was no significant difference in soil N reserves between maize and abandoned land. The relatively high NO3 - N content in maize and paddy fields may be due to the excessive application of N fertilizer and human interference. There was a linear positive correlation between soil alkalinity N and total N content (R2 u001f0.929, p <0.001), while the correlation between natural ecosystems (woodland and fallow land) was slightly higher than that of farmland ecosystem (paddy field and corn Ground). Excessive application of N fertilizers also resulted in the accumulation of more NO3 - N in cultivated soils than fallow land and forestland. The results show that agroforestry system has important potential contribution to crop production and environmental protection. Figure 2 Table 5 Reference 23.