双季稻连作体系氮素管理模式下的土壤环境效应研究

发布时间：2018-04-20 20:08

本文选题：氮肥利用率 + 微生物量碳、氮　；参考：《四川农业大学》2015年硕士论文

【摘要】：选取江西红壤性双季稻水稻土为研究对象,采用大田定位试验研究了4种不同氮肥管理措施即当地农民习惯施肥(FP)、较FP减施20%化肥氮且20%有机氮替代化肥氮(T1)、在T1基础上加施Si、Zn、S三种微肥(T2)和在T2基础上采用20%缓释氮肥替代普通化肥氮(T3)对水稻农学效应、土壤肥力效应的影响,在此基础上采用15N示踪法,结合盆栽模拟试验验证,研究了双季稻轮作体系不同施肥模式下对稻田土壤主要温室气体CO2、CH4和N20排放的影响。研究得出如下主要结论：(1)三种氮肥的不同减施措施对水稻产量、氮肥农学效率及生理利用率的影响不显著；与农民习惯施肥相比,三种氮肥的不同减施措施氮肥回收率2013年分别提高了28.13%、45.66%和54.84%,其中T2、T3处理达到显著水平(p0.05)；2014年分别提高了27.41%、35.21%和37.66%,三种处理均达显著水平(p0.05)；与农民习惯施肥相比,三种氮肥的不同减施措施氮肥偏因子生产力2013年分别提高了18.18%、17.75%和15.59%,2014年分别提高了19.97%、21.09%和21.37%,三种处理两年均达显著水平(p0.05)；15N示踪试验结果显示,三种减氮施肥措施可显著增加水稻植株对氮素的吸收(p0.05),分别比FP增加18.38%、11.80%和14.82%。(2)三种氮肥的不同减施措施对土壤pH、有机质、全氮含量的影响不显著；与农民习惯施肥措施相比,三种氮肥减施措施的土壤微生物量碳含量均有不同的增长,在第四季分别增加了23.66%,25.42%和24.17%,均达到了显著水平(p0.05),其含量有早稻季高于晚稻季的规律；三种氮肥减施措施均能显著增加土壤微生物量氮的含量(p0.05),其增长率于2014年晚稻季增长最大,分别达29.91%、33.68%和28.59%：三种氮肥减施措施对土壤脲酶、蛋白酶及过氧化氢酶活性的影响不大,能显著提高土壤蔗糖酶的活性,其活性于2013年早稻季提高最大,分别提高了48.24%、50.54%和61.33%,土壤蛋白酶和蔗糖酶活性有早稻季高于晚稻季的规律；土壤微生物量碳含量分别与土壤蔗糖酶、过氧化氢酶及蛋白酶活性之间呈极显著相关(P0.01),土壤微生物量氮含量与土壤蔗糖酶间呈极显著相关(P0.01),土壤脲酶、过氧化氢酶及蛋白酶活性间显著相关(P0.05),土壤微生物量碳、氮之间显著相关(P0.05)。(3)三种减氮施肥措施对土壤CO2的排放影响不大；三种减氮施肥措施均能显著减少土壤N2O的排放,全年累计排放量以T3处理减少最多,分别比FP、 T1、T2处理减少43.06%、22.89%和20.09%,均达显著水平(P0.05),T1、T2处理与FP处理相比,分别减少26.16%和28.74%,达显著水平(P0.05)；三种减氮施肥措施均显著增加了土壤CH4的排放,分别增加了19.38%、12.67%和13.74%；与农民习惯施肥相比,对100年N20和CH4的综合温室效应的影响,T1处理显著高了9.45%(P0.05),T2、T3处理分别高3.65%和1.37%,但差异不显著(P0.05)。综上所述,20%氮肥减施的基础上有机氮肥结合缓释氮肥部分替代化肥氮并增施Si、Zn、S微肥处理在保证水稻产量及土壤养分含量持续稳定供应的同时,能显著提高氮肥回收率和生理利用率,显著提升土壤微生物量碳、氮含量,且对土壤环境效应(温室效应)的影响最小。
[Abstract]:Jiangxi red soil rice paddy soil was selected as the research object. 4 different nitrogen fertilizer management measures, namely, local farmers' FP, 20% fertilizer nitrogen and 20% organic nitrogen instead of fertilizer nitrogen (T1) were studied by the field location test. On the basis of T1, Si, Zn, S three micro fertilizer (T2) were added on the basis of T1, and 20% slow release nitrogen fertilizer was used to replace the ordinary fertilizer on the basis of T2. The effect of fertilizer nitrogen (T3) on rice agronomy effect and soil fertility effect, on this basis, the effects of 15N tracer method and pot simulation test on the emission of main greenhouse gases, CO2, CH4 and N20 in paddy soil under different fertilization models were studied. The main conclusions are as follows: (1) the difference of three nitrogen fertilizers The effects of reduction measures on rice yield, nitrogen fertilizer efficiency and physiological utilization rate were not significant. Compared with the farmers' customary fertilization, the nitrogen recovery rates of three different nitrogen fertilizer treatments increased by 28.13%, 45.66% and 54.84% respectively in 2013, of which T2 and T3 treatments reached significant levels (P0.05), and 27.41%, 35.21% and 37.66%, three in 2014, respectively. A significant level (P0.05) was reached, and the partial factor productivity of three nitrogen fertilizers increased by 18.18%, 17.75% and 15.59% in 2013, respectively, by 19.97%, 21.09% and 21.37% in 2014, and three for the two years, respectively, in 2014. The 15N tracer test showed that three nitrogen reduction results showed that there were three nitrogen reduction methods. The fertilization measures can significantly increase the uptake of nitrogen in rice plants (P0.05). The effects of 18.38%, 11.80% and 14.82%. (2) three kinds of nitrogen fertilizer on soil pH, organic matter and total nitrogen content are not significant, and the soil microbial biomass carbon content of the three fertilizer application measures is different from that of the farmers' customary fertilization measures. The increase of 23.66%, 25.42% and 24.17% respectively in the fourth quarter reached significant level (P0.05), and the content of early season rice was higher than that in late rice season. Three kinds of nitrogen reduction measures could significantly increase soil microbial biomass nitrogen (P0.05), and the growth rate increased to 29.91%, 33.68% and 28.59%: three respectively in the late rice season of 2014. The effects of nitrogen fertilizer reduction on soil urease, protease and catalase activity were not significant, and the activity of soil invertase could be improved significantly. The activity of soil invertase was increased by 48.24%, 50.54% and 61.33% in the early season of 2013, and the activity of soil protease and invertase was higher than that in late rice season. There was a significant correlation between the content of soil invertase, catalase and protease activity (P0.01). The soil microbial biomass nitrogen content was significantly correlated with soil invertase (P0.01), soil urease, catalase and protease activity were significantly correlated (P0.05), soil microbial biomass carbon and nitrogen significant correlation (P0.05). (3) three species Nitrogen reduction measures have little effect on soil CO2 emission. Three nitrogen reduction measures can significantly reduce the emission of soil N2O. The cumulative annual emissions are reduced most by T3 treatment, respectively, 43.06%, 22.89% and 20.09%, respectively, respectively, 22.89% and 20.09%, respectively, to a significant level (P0.05), T1, T2 treatment and FP treatment, respectively, by 26.16% and 28.74%, respectively. Significant level (P0.05); three nitrogen reduction measures significantly increased the soil CH4 emissions, increased by 19.38%, 12.67% and 13.74% respectively. Compared with the farmers' customary fertilization, the effects on the comprehensive greenhouse effect of 100 years N20 and CH4 were significantly higher than 9.45% (P0.05), T2, T3 treatment was 3.65% and 1.37% respectively, but the difference was not significant (P0.05). On the basis of 20% nitrogen fertilizer application, organic nitrogen fertilizer combined with slow release nitrogen fertilizer instead of fertilizer nitrogen and Si, Zn, S micro fertilizer treatment can significantly improve the nitrogen recovery and physiological utilization rate while ensuring the continuous and stable supply of rice yield and soil nutrient content, and significantly increase soil microbial biomass carbon, nitrogen content and soil environmental efficiency. The effect of the greenhouse effect is minimal.

【学位授予单位】：四川农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S511.42

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