不同磷源对酸性水稻土自养异养硝化过程的影响
发布时间：2018-04-08 13:27
本文选题：水稻土 切入点：~(15)N同位素 出处：《浙江大学》2017年硕士论文
【摘要】：硝化作用是土壤氮循环过程中的关键过程,不同磷源输入将对土壤氮循环产生多方面的影响。本文以两种典型酸性稻田土壤S_1与S_2为研究对象,利用~(15)N稳定同位素示踪技术与乙炔抑制技术进行实验室培育实验,考察施加4个浓度梯度处理:不施肥处理(M0,0g/kg)、低施用量处理(Low,3.1g/kg)、中施用量处理(Medium,6.2 g/kg)、高施用量处理(High,12.4 g/kg)的常见磷源(无机磷源、有机磷源与粪源生物炭)对土壤的理化性质、N_2O释放与自养/异养硝化过程的影响。本论文的主要研究结果如下:(1)不同磷源施加后,土壤NH_4~+-N与NO_3~-N浓度发生变化。当自养硝化过程未被抑制时,土壤NH_4~+-N浓度在S_1与S_2中随无机磷源、粪源生物炭磷源施加量的增加而降低,随有机磷源施加量的增加而升高。施加无机磷源后S_1土壤NH_4~+-N平均浓度由施加量由低到高分别为13.51、12.38与11.13 mg/kg;在S_2土壤中,则分别为12.83、11.12与10.06mg/kg。施加生物炭后,其浓度在S,与S_2土壤中分别为13.51、12.38、11.13与12.83、11.12、10.06mg/kg。施加有机磷源后,土壤NH_4~+-N浓度在S_1中随施加量增加分别较空白组增加了4.25、8.45与11.32mg/kg,在S_2中则分别增加了5.51、10.00与13.39mg/kg;而土壤NO_3~--N浓度在S,与S_2中随三种磷源的施加量增加而增加。施加无机磷源后S_1土壤NO_3~--N平均浓度由施加量由低到高分别为13.40、14.64与15.44mg/kg;在S_2土壤中,则分别为15.48、16.49与19.65mg/kg。施加有机磷源后,土壤NO_3~--N浓度在S,中随施加量增加分别为16.03、17.62与19.84mg/kg;在S_2中则分别为16.78、17.99与20.09 mg/kg。施加生物炭后,其浓度在S,与S_2土壤中分别为15.01、16.03、17.29与115.87、16.91、17.81 mg/kg。当自养硝化过程被抑制时,磷源种类与施加量对土壤NH_4~+-N浓度均无显著影响;土壤NO_3~--N浓度在S,与S_2中随三种磷源的施加量增加无明显变化。土壤总氮浓度(Total-N)浓度在施加无机磷源后在两种土壤中均无变化;随有机磷源施加量的增加而增加,在S_1与S_2中分别平均增加了1.62与1.92 g/kg;与生物炭的施加仅较小程度增加,在S_1与S_2中分别平均增加了0.03与0.01 g/kg;土壤C/N比值在施加无机磷源与生物炭后呈现上升趋势施加无机磷源后其值在S,与S_2中分别平均增加了1.11与0.128;施加生物炭后其对应值则为9.04与3.61;施加有机肥后则较空白组降低,在S_1与S_2中分别降低了4.02与8.18;三种磷源施加后两种土壤Total-P与Olsen-P均增加。(2)施加无机磷源与有机磷源均促进两种土壤N_2O、CO_2排放。施加无机磷源后,在S_1与S_2中N_2O释放通量分别较空白组高出1.72与2.51mg/m~2h;在S_1与S_2中CO_2释放通量分别较空白组高出58.07与75.04 mg/m~2h。施加有机磷源后,N_2O释放通量对应增加了2.25与2.72mg/m~2h;CO_2释放通量分别较空白组增加了132.91与198.46 mg/m~2h。而粪源生物炭抑制土壤N_2O、CO_2排放,施加粪源生物炭后,在S_1与S_2中N_2O释放通量分别较空白组降低0.09与0.138 mg/m~2h;CO_2释放通量对应降低14.105与13.58 CO_2 mg/m~2h。高施加量无机磷源促进土壤NH3释放,在S_1与S_2中最高施加量的无机磷源实验组中NH3释放通量较空白组分别高出0.10与0.55 mg/m~2h;有机磷肥施加促进土壤NH3释放,在S_1与S_2中其平均值较空白组分别高出0.58与0.80 mg/m~2h;生物炭对土壤NH3释放的促进作用不如有机磷源显著,其值在S,与S_2中分别高出0.42与0.55 mg/m~2h。(3)自养硝化反应为本研究所涉及的酸性稻田土壤中NO_3~--N产生的主要途径,而异养硝化贡献率仅为2%左右。土壤S_1与S_2中总硝化率差异明显,在土壤S_1与S_2中分别为25.394与35.233 mg kg~(-1)d~(-1);三种磷源施加对土壤S_1总硝化率的影响大于S_2。三种磷源施加后土壤总硝化速率增加,而有机磷源对于土壤总硝化速率促进效果最大,在S,与S_2其平均值为49.66与59.26其;次为无机磷源与生物炭,其值对应分别为42.80、41.70与42.52、45.65 mg kg~(-1)d~(-1)。三种磷源的施加均促进土壤自养硝化过程。磷源类影响土壤异养硝化速率,生物炭提高异养硝化速率,施加生物炭后S_1与S_2异养硝化速率为0.63与0.62 mg kg~(-1)d~(-1);其次为有机磷源,其值对应为0.46与0.53 mg kg~(-1)d~(-1)。磷源种类对土壤异养硝化贡献率不同,无机磷源与有机磷源对土壤异养硝化贡献率无影响,而施加生物炭后土壤异养硝化贡献率则较空白组升高,在S_1与S_2中增量分别为0.20与0.23。
[Abstract]:Nitrification is the key process of soil nitrogen cycle in the process of different phosphorus input will have a great influence on the soil nitrogen cycle. In this paper, two kinds of typical acidic paddy soil S_1 and S_2 as the research object, using ~ (15) N stable isotope tracer technique and acetylene inhibition technique in laboratory experiment, applied study 4 concentration gradient: no fertilization (M0,0g/kg), low dosage treatment (Low, 3.1g/kg), in the fertilization treatments (Medium, 6.2 g/kg), high dosage treatment (High, 12.4 g/kg) of the common source of phosphorus (sources of inorganic phosphorus, organic phosphorus and manure derived biochar) in science chemical properties of soil, effects of N_2O and autotrophic / heterotrophic nitrification release process. The main results are as follows: (1) after applying different phosphorus sources, soil NH_4~+-N and NO_3~-N concentration changes. When autotrophic nitrification process has not been inhibited, the soil NH_4~+-N concentration in S_1 and S_2 with Inorganic phosphorus sources, increasing manure derived biochar applied phosphorus source decreases, with the increase of organic phosphorus amount increased. Applying inorganic phosphorus source after S_1 soil NH_4~+-N average concentration by applying amount from low to high were 13.51,12.38 and 11.13 mg/kg; in S_2 soil, respectively 12.83,11.12 and 10.06mg/kg. applied biochar, the concentration of S in soil and S_2, respectively 13.51,12.38,11.13 and 12.83,11.12,10.06mg/kg. applied organic phosphorus source, soil NH_4~+-N concentration in S_1 with the amount of increase were increased compared with the normal group of 4.25,8.45 and 11.32mg/kg in S_2 were increased by 5.51,10.00 and 13.39mg/kg; and the soil NO_3~--N concentration in S, increased with the increase in applied amount with three kinds of phosphorus sources in S_2. The application of inorganic phosphorus source after S_1 soil NO_3~--N average concentration by applying amount from low to high were 13.40,14.64 and 15.44mg/kg; in S_2 soil, while Don't 15.48,16.49 and 19.65mg/kg. applied organic phosphorus source, soil NO_3~--N concentration in S, with the amount of increase were 16.03,17.62 and 19.84mg/kg respectively; in S_2 16.78,17.99 and 20.09 mg/kg. biochar, the concentration of S in soil and S_2, respectively 15.01,16.03,17.29 and 115.87,16.91,17.81 mg/kg. when autotrophic nitrification process was inhibited when the source of phosphorus species and quantity had no significant effect on soil NH_4~+-N concentration; soil NO_3~--N concentration in S did not change significantly with the increase in applied amount with three kinds of phosphorus S_2. Soil total nitrogen concentration (Total-N) concentration in the application of inorganic phosphorus sources in two soils showed no changes with increasing; the amount of organic phosphorus increased in S_1 and S_2 respectively increased by 1.62 and 1.92 g/kg; with biochar only small degree increases, in S_1 and S_2 respectively increased by an average of 0.03 and 0.01 g/kg soil; The soil C/N ratio showed a rising trend in the application of inorganic phosphorus source and biochar applied inorganic phosphorus source whose value in S, and S_2 were increased by an average of 1.11 and 0.128; biochar after the corresponding values were 9.04 and 3.61; the application of organic fertilizer was lower than those in the control group, in S_1 and S_2 reduce by 4.02 and 8.18; three kinds of phosphorus sources after applying two kinds of soil Total-P and Olsen-P were increased. (2) applied inorganic phosphorus source and organic phosphorus source could promote the two kinds of soil N_2O, CO_2 emissions. The application of inorganic phosphorus source, in S_1 and S_2 in N_2O flux respectively higher than those in control group a 1.72 and 2.51mg/m~2h; S_1 and S_2 in CO_2 flux respectively compared with the blank group was 58.07 higher and 75.04 mg/m~2h. applied organic phosphorus source, N_2O flux increased by 2.25 and the corresponding 2.72mg/m~2h; CO_2 flux were increased compared with the normal group of 132.91 and 198.46 mg/m~2h. and fecal source of biochar inhibited soil N_2 O, CO_2 emission, applying manure derived biochar, in S_1 and S_2 in N_2O flux respectively lower than those in the control group 0.09 and 0.138 mg/m~2h; CO_2 flux corresponding decrease 14.105 and 13.58 CO_2 mg/m~2h. high amount of inorganic phosphorus sources to promote soil NH3 release of inorganic phosphorus sources, the experimental group was the highest in S_1 and applied in S_2 the NH3 release flux than the blank group respectively at 0.10 and 0.55 mg/m~2h; organic fertilizer applied to promote the release of NH3 in soil, S_1 and S_2 in the average 0.58 higher than the control group respectively and 0.80 mg/m~2h; biochar significantly on soil NH3 release role as organic phosphorus source, and its value in the S. S_2 were higher than 0.42 and 0.55 mg/m~2h. (3) autotrophic nitrification reaction as the main pathway of NO_3~--N involved in the research of acidic paddy soil produced by heterotrophic nitrification, the contribution rate is only about 2%. S_1 and S_2 in the soil gross nitrification rate difference is obvious, in the soil S_1涓嶴_2涓垎鍒负25.394涓，
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