MODELING SOIL ORGANIC-MATTER IN ORGANIC-AMENDED AND NITROGEN-FERTILIZED LONG-TERM PLOTS
MODELING SOIL ORGANIC-MATTER IN ORGANIC-AMENDED AND NITROGEN-FERTILIZED LONG-TERM PLOTS
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DOI：
10.2136/sssaj1992.03615995005600020023x
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发表时间：
1992-03-01
影响因子：
2.9
通讯作者：
PERSSON, J
中科院分区：
文献类型：
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作者：
PAUSTIAN, K;PARTON, WJ;PERSSON, J
为了研究有机质和肥料添加对土壤有机质（SOM）动态的影响，我们使用CENTURY模型分析了瑞典30年的田间试验结果。砂质粘土壤土的田间处理包括每年添加（最多4000千克碳/公顷）秸秆、锯末和无有机添加，添加和不添加氮肥（80千克氮/公顷），以及绿肥、农家肥和裸休耕。模拟了土壤C和N、作物生产（小粒和块根作物）、氮吸收、氮的矿化和固定化，并与田间测量结果进行了比较。土壤C和N在30年后的变化可达30%，模型总体上较好地反映了土壤C和N的变化。土壤有机质的处理差异主要由有机质输入速率、木质素含量、碳氮比以及氮肥对地下碳输入的影响来解释。然而，氮供应似乎对SOM积累有额外的积极影响，但模型并未完全解释这一点。有机改良剂的质量通过控制氮矿化和固定化，强烈影响氮素吸收和作物生产力。平均年氮素吸收量从木屑改良土壤的3.1 g m-2到施肥、秸秆改良土壤的9.2 g m-2不等。模拟氮损失占总氮输入的7% ~ 20%。该模型估算的氮平衡与4个处理的观测数据一致，但低氮可利用性处理似乎有额外的、无法解释的氮输入。
To study the effects of organic matter and fertilizer additions on soil organic-matter (SOM) dynamics, we analyzed results from a 30-yr-old Swedish field experiment, using the CENTURY model. Field treatments on a sandy clay loam included bannual addition (up to 4000 kg C ha-1) of straw, sawdust, and no organic additions, with and without N fertilizer (80 kg N ha-1), and green manure, farmyard manure, and bare fallow. Soil C and N, crop production (small-grain and root crops), N uptake, and mineralization and immobilization of N were modeled and compared with field measurements. Changes in soil C and N, as much as 30% after 30 yr, were generally well represented by the model. Most of the treatment differences in SOM could be explained by the rate of organic-matter input, its lignin content, and C/N ratio, plus the effect of N fertilizer on belowground C inputs. However, there appeared to be additional positive effects of N supply on SOM accumulation that were not fully explained by the model. The quality of organic amendments strongly influenced N uptake and crop productivity, through controls on N mineralization and immobilization. Mean annual N uptake ranged from a low of 3.1 g m-2 in sawdust-amended soil to a high of 9.2 g m-2 in fertilized, straw-amended soil. Simulated N losses accounted for 7 to 20% of total N inputs. Nitrogen-balance estimates by the model were consistent with the observed data for four of the treatments, but treatments with low N availability appeared to have additional, unexplained N inputs.