不同施肥下典型农田氮素残留特征及可利用性

发布时间：2018-05-26 03:45

本文选题：长期施肥 + ~(15)N　；参考：《贵州大学》2015年硕士论文

【摘要】：我国氮肥传统利用率仅为30%左右,远低于西方国家的50-60%。实际上,传统氮肥利用率的计算方法仅考虑了当季作物对养分的吸收利用,而没有反映肥料氮在土壤中的残留及可利用性。本研究通过对我国6个不同气候区的长期试验农田土壤历史数据分析,结合模拟残留氮肥进入土壤被再利用过程的外源~(15)N室内培养试验,阐明了施用化肥、化肥和有机肥配施及秸秆还田条件下我国典型农田土壤氮素残留特征,揭示了土壤不同氮组分的有效性及作物利用率。取得的主要研究结果和结论如下:长期试验历史数据分析结果表明:长期试验期间,我国典型农田的年平均氮肥残留率(Nitrogen residual efficiency,NRE)为16.9%。水田、水旱轮作和旱作三种土地利用方式下的NRE依次为13.2%、23.9%和13.6%。单施化肥处理中,氮钾化肥(NK)处理的NRE最高为16.2%,其次为氮磷化肥(NP)处理(15.8%)、氮磷钾化肥(NPK)处理(16.0%)。水旱轮作与旱作下单施氮肥(N)和氮磷钾配施有机肥(NPKM)处理的NRE分别为21.7%、19.0%。水田和旱地下的氮磷钾与秸秆还田(NPKS)处理的NRE平均为10.4%。外源~(15)N室内培养试验结果显示,化肥氮素固持率在不施肥(CK)处理下最高为22.2%;NPKM处理最低为13.7%;NPK和NPKS处理,分别为16.8%和18.1%。细自由颗粒有机氮(ffPON)组分氮素固持率最低,其次是物理保护有机氮(iPON)组分;在粗自由颗粒有机氮(cfPON)组分中,NPK和NPKM处理分别比CK处理低1.80%、1.69%;在微团聚体内部矿物结合有机氮(μ-mSON)组分和微团聚体外部矿物结合有机氮(d-mSON)组分上,CK较其他处理高1.29%-3.70%、2.18%-3.19%。cfPON组分固持氮素有效率在NPKM处理下最高为19.0%,其次是NPK处理为16.8%,CK处理与NPKS处理相同为13.9%。iPON组分下,CK、NPK、NPKS、NPKM处理的有效率分别为12.1%、10.9%、6.27%、5.66%。μ-mSON组分的有效率最低为2.99%-4.85%,CK处理与其他处理相比低1.37%-1.86%。d-mSON组分的有效率为12.4%-23.1%,其中NPK处理与其他处理相比高9.22%-10.8%。
[Abstract]:The traditional utilization rate of nitrogen fertilizer in China is only about 30%, which is far lower than that of 50-60 in western countries. In fact, the traditional calculation method of nitrogen fertilizer use efficiency only considered the nutrient absorption and utilization of the current crop, but did not reflect the residue and availability of fertilizer nitrogen in the soil. Based on the analysis of the soil historical data of 6 different climatic regions in China, the application of chemical fertilizer was elucidated by combining with the experiment of simulating the residual nitrogen fertilizer entering into the soil to be reused. The characteristics of nitrogen residue in Chinese typical farmland soil under the condition of fertilizer and organic fertilizer combined application and straw return revealed the availability and crop utilization efficiency of different nitrogen components in the soil. The main results and conclusions are as follows: during the long term experiment, the results of historical data analysis show that the average annual nitrogen residue rate (NREs) of typical farmland in China is 16. 9%. The NRE of paddy field, crop rotation and dry cropping were 13.2g% and 13.6%, respectively. In the treatment of single fertilizer application, the highest amount of NRE was 16.2in nitrogen and potassium fertilizer treatment, followed by 15.8m in nitrogen and phosphorus fertilizer treatment, and 16.0 in nitrogen, phosphorus and potassium fertilizer treatment. The NRE of N (N) and NPK (N) and K (N) and N (K) combined with organic fertilizer (NPKM) were 21.790 and 19.0, respectively. The average NRE of N, P and K treatments in paddy field and dry land was 10.4 kum. The results showed that the highest nitrogen fixation rate of fertilizer treatment was 22.2g / kg and the lowest was 13.7g / NPKS (16.8% and 18.1%, respectively). The organic nitrogen sequestration rate of fine free particles was the lowest, followed by the physical-protected organic nitrogen iPON. NPK and NPKM treatments were 1.80- 1.69 lower than CK treatments in coarse free particle organic nitrogen (NPKM) fractions, and CK was 1.29-3.70% higher than that of other treatments in microaggregates (渭 -mSON) and micro-aggregates (渭 -mSON) and organic nitrogen (d-mSON) components outside microaggregates, which were 1.29-3.70g 2.18-3.19.cfPON group. The highest effective rate of nitrogen retention under NPKM treatment was 19.0. The second was that the highest effective rate of nitrogen retention was 16.8in NPK treatment and the same as that in NPKS treatment. The effective rate of 13.9%.iPON treatment was 12.1g 10.9 and 6.276.66.The lowest effective rate of 渭 -mson component was 2.99-4.85ck treatment was lower than that of other treatments. The effective rate of the components was 12.4- 23.1.The NPK treatment was 9.22% -10.8% higher than other treatments.
【学位授予单位】：贵州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S143.1

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