本文關鍵詞： DSSAT-CENTURY模型 土壤有機碳 土壤無機氮 氮淋失　出處：《吉林農業(yè)大學》2015年碩士論文　論文類型：學位論文

【摘要】：東北黑土地區(qū)是我國重要的糧食產業(yè)基地,近年來隨著不合理的施肥耕作導致黑土日益退化,這樣不僅對我國的糧食產量造成了嚴重的影響,而且對生態(tài)環(huán)境也產生了巨大的威脅。因此運用DSSAT-CENTURY土壤模型,研究不同長期施肥措施對土壤碳氮循環(huán)的變化規(guī)律,以及不同長期農業(yè)耕作措施對土壤碳庫以及氮淋失的影響,不僅有助于利用模型系統(tǒng)對土壤時效性進行評價和預測,為模型的區(qū)域發(fā)展提供理論支持,而且有助于實現農業(yè)的可持續(xù)發(fā)展。本研究以吉林省公主嶺市長期定位試驗基地為研究對象,通過四個施肥處理(1)CK:不施肥(2)NPK:施氮磷鉀肥(3)MNPK:施有機肥和氮磷鉀化肥(4)1.5MNPK:1.5倍有機肥和氮磷鉀化肥,運用DSSAT-CENTURY土壤模型探討長期施用有機肥條件下對玉米產量、土壤有機碳、全氮含量、土壤C/N的動態(tài)變化規(guī)律,并且通過模擬不同碳庫的含量比例變化,無機氮平衡以及不同耕層土壤硝態(tài)氮和銨態(tài)氮含量的分布,得出以下結論:NPK相比,長期施用有機肥能夠顯著提高作物產量,受降水量較少的干旱年份影響顯著。有機肥對土壤有機碳和全氮含量的影響較大,土壤SOC含量由高到低依次為1.5MNPKMNPKNPK,土壤全氮含量與有機碳變化趨勢基本一致。有機肥與無機肥配施能夠顯著減少土壤無機氮含量和降低氮淋失的風險。通過模型模擬得出的C/N比值也可說明:施用有機肥的C/N升高表明土壤有機碳的增加速度高于有機氮,且土壤慢性庫SOM2的變化決定土壤有機碳含量的變化�？傆袡C碳庫受慢性碳庫的影響較為顯著,而惰性碳庫的變化最不顯著,而在CK處理下的惰性碳庫比例顯著上升說明土壤在逐漸老化。降水量較多的年份土壤氮淋失量表現出顯著增加的趨勢,說明降水造成土壤硝態(tài)氮向土壤深層次淋溶,通過施用有機肥使得土壤礦化氮(無機氮)總量顯著增加,說明土壤礦化作用處于較高水平。不同耕層中的硝態(tài)氮含量不同,而不同施肥措施造成硝態(tài)氮的淋溶峰值不同,施用有機肥后峰值顯著向根區(qū)移動,淋失風險降低。各個土壤耕層的銨態(tài)氮含量變化基本一致,深層次土壤變化不如硝態(tài)氮變化明顯。因此在氮肥投入的同時,應當重視有機肥碳素的歸還水平,因此大力推廣使用農家肥來提高土壤養(yǎng)分含量,實現農業(yè)生態(tài)環(huán)境的綜合可持續(xù)發(fā)展。
[Abstract]:The Northeast Black soil region is an important food industry base in China. In recent years, with unreasonable fertilization and tillage, black soil is increasingly degraded, which not only has a serious impact on China's grain production. Therefore, DSSAT-CENTURY soil model was used to study the changes of soil carbon and nitrogen cycle with different long-term fertilization measures. The effects of different long-term agricultural practices on soil carbon pool and nitrogen leaching are not only helpful to evaluate and predict the soil timeliness by using the model system, but also provide theoretical support for the regional development of the model. And it is helpful to realize the sustainable development of agriculture. This study takes the long-term positioning test base of Gongzhuling City of Jilin Province as the research object. Through four fertilization treatments, CK: no fertilization, 2n, NPK, N, P, K, N, P, K, N, P, K, N, P, K, N, P, K, N, P, K, N, P, K, and N, P, K, 1.5 MNPK: 1.5 times organic fertilizer and nitrogen, phosphorus and potassium fertilizer. DSSAT-CENTURY soil model was used to study the dynamic changes of maize yield, soil organic carbon, total nitrogen content and soil C / N under long-term application of organic fertilizer. And through the simulation of different carbon pool content ratio, inorganic nitrogen balance and the distribution of nitrate and ammonium nitrogen in different topsoil, the following conclusions are drawn: 1. Long-term application of organic fertilizer could significantly increase crop yield, especially in dry years with less precipitation. Organic fertilizer had a great effect on soil organic carbon and total nitrogen content. The content of SOC in soil was 1.5MNPKMNPKNPK from high to low. The total nitrogen content of soil is basically consistent with the change trend of organic carbon. The combination of organic fertilizer and inorganic fertilizer can significantly reduce the content of inorganic nitrogen in soil and reduce the risk of nitrogen leaching. The C / N ratio obtained by model simulation can also be explained. The increase of C / N in organic fertilizer indicated that the increasing rate of soil organic carbon was higher than that of organic nitrogen. The total organic carbon pool was significantly affected by the chronic carbon pool, but the inert carbon pool was the least significant. But the proportion of inert carbon pool increased significantly under CK treatment, which indicated that the soil was aging gradually. The nitrogen leaching loss of soil showed a significant increase trend in the years with more precipitation. The results showed that precipitation resulted in soil nitrate leaching, and the total amount of soil mineralized nitrogen (inorganic nitrogen) increased significantly by applying organic fertilizer. The results showed that the mineralization of soil was at a high level. The nitrate content in different tillage layer was different, but the leaching peak value of nitrate nitrogen was different with different fertilization measures, and the peak value moved to root area significantly after application of organic fertilizer. The risk of leaching is reduced. The change of ammonium nitrogen content in each soil tillage layer is basically the same, and the change of nitrate nitrogen is less obvious in the deep layer soil than in the deep soil layer. Therefore, the carbon return level of organic fertilizer should be paid more attention to while the nitrogen fertilizer input. Therefore, the use of farm manure to improve soil nutrient content and realize the comprehensive sustainable development of agricultural ecological environment.
【學位授予單位】：吉林農業(yè)大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：S158.5

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本文編號：1470202