共查询到19条相似文献,搜索用时 171 毫秒
1.
为探讨双季稻地区还田秸秆的腐解进程,用尼龙网袋法研究了不同类型水稻秸秆不同埋深(0、10 cm)对还田秸秆的腐解和氮碳释放的影响。结果表明,经过早稻90 d、晚稻120 d的腐解,早稻和晚稻的平均腐解率分别为64%和72%。秸秆在还田的前15 d腐解速度较快,在秸秆还田后的30~90(120)d秸秆腐解速度放缓。秸秆腐解率晚稻季高于早稻季,常规籼稻高于杂交籼稻,杂交籼稻高于杂交粳稻,表层秸秆腐解速率略快于下层秸秆。在当季水稻生育期结束时,还田秸秆的氮释放率为60%~70%,秸秆碳释放率达70%~80%,不同埋深对秸秆碳氮释放率影响不显著,表层碳释放略快。 相似文献
2.
不同作物秸秆在旱地和水田中的腐解特性及养分释放规律 总被引:33,自引:3,他引:30
以水稻、小麦、玉米秸秆和油菜、蚕豆青秆为研究对象,采用尼龙网袋法,研究了不同秸秆翻埋入旱地和水田后的腐解特性及养分释放规律,以期为紫色丘陵区农业秸秆循环利用和秸秆还田技术提供理论依据。结果表明:秸秆翻埋还田后,5种供试秸秆腐解速率均表现为前期(0~60 d)快、后期(60~360 d)慢。经过360 d的腐解,旱地秸秆累积腐解率为52.88%~75.80%,表现为油菜水稻玉米小麦蚕豆趋势,且蚕豆青秆累积腐解率显著低于其余秸秆;水田中秸秆累积腐解率为45.01%~62.12%,表现为水稻玉米小麦油菜蚕豆趋势。5种秸秆在旱地和水田中养分释放率均表现为钾磷氮碳,在试验终点,旱地中秸秆碳、氮、磷和钾释放率分别为65.50%~87.37%、54.64%~69.72%、89.65%~98.96%和79.92%~96.63%,且油菜秸秆养分释放率高于其他4种秸秆;水田中秸秆碳、氮、磷、钾释放率变幅分别为49.95%~69.57%、32.89%~77.11%、90.70%~96.80%、77.45%~90.47%。总体表现为秸秆在旱地土壤中的累积腐解率和养分释放率均大于水田,旱地油菜和水稻秸秆较易腐解,水田水稻和玉米秸秆较易腐解释;秸秆中钾素释放速率较高。 相似文献
3.
颗粒有机质是土壤活性有机质的重要组成部分,是评估土壤有机质变化的敏感指标。东北地区气候寒冷,稻田土壤淹水期短,非淹水期长且多处于冻结状态,水稻秸秆碳氮在黑土不同种稻年限土壤颗粒有机质中的分配如何尚不清楚。通过室内培养试验,将1%双标记(13C/15N)水稻秸秆添加到不同种稻年限(0、12、35、62和85 a)土壤,淹水培养150 d(培养温度20℃,淹水层1 cm),去除淹水层后冻结培养150 d(培养温度–15℃,饱和水分状态),研究水稻秸秆碳(氮)在不同种稻年限土壤颗粒有机碳(Particulate organic carbon,POC)和颗粒有机氮(Particulate organic nitrogen,PON)中的分配特征。结果表明,在培养过程中,未添加和添加水稻秸秆处理,各年限稻田土壤POC和PON含量均低于对照土壤(0 a),添加秸秆处理的各年限土壤POC和PON含量在淹水培养5 d时明显增加,但其后并未表现出一致的增加趋势。秸秆碳(氮)对各年限土壤POC(PON)的相对贡献率为0.2%~13.9%(0.4%~3.8%),分配... 相似文献
4.
秸秆还田和休耕对赣东北稻田土壤养分的影响 总被引:3,自引:0,他引:3
通过田间试验研究了水稻秸秆还田和休耕对稻田土壤肥力的影响.结果表明,添加秸秆的处理S1R0和S1R1土壤有机碳含量分别有高于不添加秸秆的处理S0R0和S0R1的趋势,并在2011年早稻收获时达到显著水平.添加秸秆对全量养分的影响并不显著,但显著增加了土壤碱解氮和速效钾含量.2011年早稻收获时休耕处理土壤全氮和全磷含量显著高于连续种植水稻的处理.与2009年早稻收获时相比,201 1年早稻收获时S0R0和S1R0处理土壤速效磷含量分别提高了55.5%和29.3%,说明休耕显著提高了土壤速效磷含量.休耕处理土壤中速效钾含量一直维持在较高水平,而连续种植水稻的处理速效钾含量则逐年下降. 相似文献
5.
不同还田方式对玉米秸秆腐解及土壤养分含量的影响 总被引:18,自引:1,他引:17
通过土壤耕作和秸秆还田试验,以玉米秸秆为研究对象,探讨东北棕壤土区适宜的秸秆还田方式,为秸秆资源的高效利用提供理论依据。在辽宁沈阳设置连续两年(2014-2015年)的田间定位试验,采用尼龙网袋法研究免耕覆盖(NTS)、旋耕还田(RTS)和翻耕还田(PTS)3种秸秆还田方式下秸秆腐解率和碳氮磷钾养分释放率,分析秸秆还田方式对耕层土壤养分含量的影响。结果表明,RTS和PTS秸秆腐解速率均表现为前期快、后期慢,秸秆养分释放率均表现为钾 > 磷 > 碳 > 氮。NTS、RTS和PTS处理秸秆两年平均腐解率分别为38.8%、78.0%、65.9%,两年平均碳释放率分别为56.5%、78.8%、69.4%,氮释放率为16.7%、53.5%、38.8%,磷释放率为81.3%、92.5%、89.8%,钾释放率为92.0%、99.4%、98.9%。NTS处理秸秆腐解率及碳氮释放率与还田时间符合逻辑斯蒂曲线方程,RTS和PTS处理秸秆腐解率、碳氮释放率及3种还田方式秸秆磷钾释放率随还田时间变化符合米氏方程。秸秆还田有助于提高耕层土壤有机碳和全氮含量,RTS处理土壤全磷含量显著高于PTS处理(P<0.05),与NTS处理全磷含量差异不显著,3种还田方式土壤全钾含量差异不显著。综合分析秸秆腐解和耕层土壤培肥效果,东北棕壤土区建议玉米秸秆还田方式为旋耕秸秆还田。 相似文献
6.
《南方农业》2017,(29)
为探究不同秸秆还田方法对稻田碳氮固持及土壤理化性质的影响,分析堆沤还田、粉碎还田、直接还田三种秸秆还田方法对稻田秸秆的腐解率和氮、磷钾、养分的释放特征。结果表明,经过3个月的腐解处理后,三组秸秆还田方式中,粉碎还田的腐解率最高为75.63%,而堆沤还田为71.28%,直接还田为64.55%,存在显著性差异(P0.05);堆沤还田的氮、磷、钾释放率分别为52.8%、90.1%、57.3%,粉碎还田为58.6%、95.2%、52.7%,直接还田为48.6%、87.1%、53.0%,存在显著性差异(P0.05)。不同的秸秆还田的方法均会提高稻田碳氮固持,改善土壤理化性质。其中粉碎秸秆还田可以提高腐解率,保证了氮、磷、钾以及微量元素的释放量。 相似文献
7.
不同施氮量下潮土中小麦秸秆腐解特性及其养分释放和结构变化特征 总被引:3,自引:0,他引:3
8.
由于农户施肥量差异较大,导致产生的秸秆养分含量尤其是秸秆碳氮比(C/N)不同,可能影响秸秆还田腐解。为探究不同C/N油菜秸秆腐解动态及养分释放特征,开展室内培养试验。试验选取C/N 92、C/N 116和C/N 136的油菜秸秆作为3个处理,采用尼龙网袋法淹水培养120 d。结果表明:不同C/N秸秆均表现为前期(0~10 d)迅速腐解(累积腐解率30.73%~33.59%)、中期(11~30 d)缓速腐解(累积腐解率5.10%~6.42%)、后期(31~120 d)慢速腐解(累积腐解率仅占总腐解率的4.50%)。不同C/N秸秆碳、氮、磷平均释放率分别为28.32%、46.28%、73.05%,元素释放率表现为磷>氮>碳。不同C/N秸秆养分释放差异表现在快速腐解期,其中C/N 92秸秆的氮素累积释放率相较于C/N 116和C/N 136分别高7.27%和15.16%,磷素释放率则表现为C/N 136秸秆较C/N 116和C/N 92分别高1.91%和13.53%,而不同C/N秸秆碳素在整个腐解期均无显著差异。综上所述,低C/N的油菜秸秆氮素具有更高的释放率,而高C/N秸秆磷素的释放率则高于低C/N的秸秆。 相似文献
9.
为了探讨不同水稻灌溉模式和氮肥减量对还田小麦秸秆腐解特性及土壤养分的影响,通过田间试验,设置了水稻灌溉模式(常规灌溉,W1;干湿交替灌溉,W2)和施氮水平(不施氮,N0;常量施氮,N1;减量20%施氮,N2)处理,采用尼龙网袋法研究了不同处理下小麦秸秆腐解动态、养分释放规律及土壤养分含量。结果表明,干湿交替灌溉和氮肥施用均可促进还田小麦秸秆的腐解,减量20%施氮处理小麦秸秆累积腐解率低于常量施氮处理。相同施氮水平下,干湿交替灌溉模式小麦秸秆碳与氮磷钾累积释放率高于常规灌溉模式;与常量施氮相比,减量20%施氮处理小麦秸秆碳与氮磷钾累积释放率降低。干湿交替灌溉和施氮使土壤有机质、全氮、碱解氮和有效磷含量提高,而减量20%施氮对土壤养分含量的影响较小。综上可见,干湿交替灌溉和氮肥施用促进了还田小麦秸秆腐解和养分释放,有利于土壤养分提升;而减量20%施氮对小麦秸秆腐解与养分释放以及土壤养分无明显影响。 相似文献
10.
田间条件下不同促腐菌对水稻秸秆腐解及胞外酶活性的影响 总被引:3,自引:0,他引:3
11.
稻秸还田提高我国南方典型稻田冬绿肥产量和养分积累 总被引:2,自引:0,他引:2
12.
Miyuki Nakajima Shuirong Tang Yasuaki Hori Eiko Yaginuma Satoshi Hattori 《Soil Science and Plant Nutrition》2016,62(1):90-98
Submerged rice paddies are a major source of methane (CH4) which is the second most important greenhouse gas after carbon dioxide (CO2). Accelerating rice straw decomposition during the off-rice season could help to reduce CH4 emission from rice paddies during the single rice-growth season in cold temperate regions. For understanding how both temperature and moisture can affect the rate of rice straw decomposition during the off-rice season in the cold temperate region of Tohoku district, Japan, a modeling incubation experiment was carried out in the laboratory. Bulk soil and soil mixed with 2% of δ13C-labeled rice straw with a full factorial combination of four temperature levels (?5 to 5, 5, 15, 25°C) and two moisture levels (60% and 100% WFPS) were incubated for 24 weeks. The daily change from ?5 to 5°C was used to model the freezing–thawing cycles occurring during the winter season. The rates of rice straw decomposition were calculated by (i) CO2 production; (ii) change in the soil organic carbon (SOC) content; and (iii) change in the δ13C value of SOC. The results indicated that both temperature and moisture affected the rate of rice straw decomposition during the 24-week aerobic incubation period. Rates of rice straw decomposition increased not only with high temperature, but also with high moisture conditions. The rates of rice straw decomposition were more accurately calculated by CO2 production compared to those calculated by the change in the SOC content, or in its δ13C value. Under high moisture at 100% WFPS condition, the rates of rice straw decomposition were 14.0, 22.2, 33.5 and 46.2% at ?5 to 5, 5, 15 and 25°C temperature treatments, respectively. While under low moisture at 60% WFPS condition, these rates were 12.7, 18.3, 31.2 and 38.4%, respectively. The Q10 of rice straw decomposition was higher between ?5 to 5 and 5°C than that between 5 and 15°C and that between 15 and 25°C. Daily freezing–thawing cycles (from ?5 to 5°C) did not stimulate rice straw decomposition compared with low temperature at 5°C. This study implies that to reduce CH4 emission from rice paddies during the single rice-growth season in the cold temperate regions, enhancing rice straw decomposition during the high temperature period is very important. 相似文献
13.
The influence of exogenous organic inputs on soil microbial biomass dynamics and crop root biomass was studied through two annual cycles in rice-barley rotation in a tropical dryland agroecosystem. The treatments involved addition of equivalent amount of N (80 kg N ha−1) through chemical fertilizer and three organic inputs at the beginning of each annual cycle: Sesbania shoot (high-quality resource, C:N 16, lignin:N 3.2, polyphenol+lignin:N 4.2), wheat straw (low-quality resource, C:N 82, lignin:N 34.8, polyphenol+lignin:N 36.8) and Sesbania+wheat straw (high-and low-quality resources combined), besides control. The decomposition rates of various inputs and crop roots were determined in field conditions by mass loss method. Sesbania (decay constant, k=0.028) decomposed much faster than wheat straw (k=0.0025); decomposition rate of Sesbania+wheat straw was twice as fast compared to wheat straw. On average, soil microbial biomass levels were: rice period, Sesbania?Sesbania+wheat straw>wheat straw?fertilizer; barley period, Sesbania+wheat straw>Sesbania?wheat straw?fertilizer; summer fallow, Sesbania+wheat straw>Sesbania>wheat straw?fertilizer. Soil microbial biomass increased through rice and barley crop periods to summer fallow; however, in Sesbania shoot application a strong peak was obtained during rice crop period. In both crops soil microbial biomass C and N decreased distinctly from seedling to grain-forming stages, and then increased to the maximum at crop maturity. Crop roots, however, showed reverse trend through the cropping period, suggesting strong competition between microbial biomass and crop roots for available nutrients. It is concluded that both resource quality and crop roots had distinct effect on soil microbial biomass and combined application of Sesbania shoot and wheat straw was most effective in sustained build up of microbial biomass through the annual cycle. 相似文献
14.
Martin Potthoff Jens Dyckmans Heiner Flessa Friedrich Beese 《Soil biology & biochemistry》2005,37(7):1259-1266
An incubation experiment was carried out with maize (Zea mays L.) leaf straw to analyze the effects of mixing the residues with soil and N amendment on the decomposition process. In order to distinguish between soil effects and nitrogen effects for both the phyllospheric microorganisms already present on the surface of maize straw and soil microorganisms the N amendment was applied in two different placements: directly to the straw or to the soil. The experiment was performed in dynamic, automated microcosms for 22 days at 15 °C with 7 treatments: (1) untreated soil, (2) non-amended maize leaf straw without soil, (3) N amended maize leaf straw without soil, (4) soil mixed with maize leaf straw, (5) N amended soil, (6) N amended soil mixed with maize leaf straw, and (7) soil mixed with N amended maize leaf straw. 15NH415NO3 (5 at%) was added. Gas emissions (CO2, 13CO2 and N2O) were continuously recorded throughout the experiment. Microbial biomass C, biomass N, ergosterol, δ13C of soil organic C and of microbial biomass C as well as 15N in soil total N, mineral N and microbial biomass N were determined in soil samples at the end of the incubation. The CO2 evolution rate showed a lag-phase of two days in the non-amended maize leaf straw treatment without soil, which was completely eliminated when mineral N was added. The addition of N generally increased the CO2 evolution rate during the initial stages of maize leaf straw decomposition, but not the cumulative CO2 production. The presence of soil caused roughly a 50% increase in cumulative CO2 production within 22 days in the maize straw treatments due to a slower decrease of CO2 evolution after the initial activity peak. Since there are no limitations of water or N, we suggest that soil provides a microbial community ensuring an effective succession of straw decomposing microorganisms. In the treatments where maize and soil was mixed, 75% of microbial biomass C was derived from maize. We concluded that this high contribution of maize using microbiota indicates a strong influence of organisms of phyllospheric origin to the microbial community in the soil after plant residues enter the soil. 相似文献
15.
Shigekazu Yamamuro Hideto Ueno Hiroshi Yamada Yumiko Takahashi Yoko Shiga Syuko Miyahara 《Soil Science and Plant Nutrition》2013,59(6):787-795
Nitrogen and carbon dynamics in paddy and upland soils for rice cultivation and in upland soil for corn cultivation was investigated by using 13C and 15N dual-labeled cattle manure compost (CMC). In a soil with low fertility, paddy and upland rice took up carbon and nitrogen from the CMC at rates ranging from 0.685 to 1.051% of C and 17.6–34.6% of N applied. The 13C concentration was much higher in the roots than in the plant top, whereas the 15N concentration differed slightly between them, indicating that organic carbon taken up preferentially accumulated in roots. The 13C recovery in the plant top tended to be higher in upland soil than in paddy soil, whereas 15N applied was recovered at the same level in both paddy and upland soils. In the experiment with organic farming soil, paddy rice took up C and N from the CMC along with plant growth and the final recovery rates of 13C and 15N were 2.16 and 17.2% of C and N applied. In the corn experiment, a very large amount of carbon from the CMC was absorbed, accounting for at least 7 times value for rice. The final uptake rates of 13C and 15N reached about 13 and 10% of C and N applied, respectively. Carbon emission from the CMC sharply increased by 2 weeks after transplanting and the nitrogen emission was very low. It is concluded that rice and corn can take up an appreciable level of carbon and nitrogen from the CMC through roots. 相似文献
16.
秸秆配施氮肥还田对水稻土酶活性的影响 总被引:3,自引:0,他引:3
通过田间试验研究秸秆还田时间及配施氮肥比例对水稻土酶活性的影响,以期为培育水稻土肥力和稳定稻田生态系统功能提供理论依据。试验设置2个秸秆还田时间(WS,冬季还田;SS,春季还田)和4个氮肥配施量(N0,秸秆还田,试验期内全程不添加矿质氮;NB,常规施肥,还田时不添加矿质氮;N30B,秸秆还田时添加早稻基肥用量的30%矿质氮;N60B,秸秆还田时添加早稻基肥用量的60%矿质氮)。研究结果表明:1冬季秸秆翻耕还田能增加冬闲期6种与土壤碳周转相关酶(β-葡萄糖苷酶、β-纤维二糖苷酶、β-木糖苷酶、多酚氧化酶、过氧化物酶和蔗糖酶)的活性,冬闲期冬季秸秆还田条件下土壤酶活性均高于春季还田,生育期内冬季秸秆翻耕还田措施对土壤β-葡糖苷酶和过氧化物酶有增加作用;2秸秆还田并配施氮肥措施显著地增加冬闲期和生育期β-纤维二糖苷酶的活性,但配施氮肥的3个比例间土壤酶活性并无显著差异;3除多酚氧化酶外,其他5种酶均与其有机碳投入量呈显著正相关。因此,冬季秸秆还田及配施氮肥能在一定程度上调控与碳周转相关的土壤酶活性,对推广冬闲期秸秆翻耕还田及保障作物的产量具有重要的生态学意义。 相似文献
17.
Cho Cho Tun Makoto Ikenaga Susumu Asakawa Makoto Kimura 《Soil Science and Plant Nutrition》2013,59(6):805-813
Rice straw including leaf sheaths and blades put in nylon mesh bags was placed in the plow layer of a Japanese paddy field after harvest under upland conditions and after transplanting of rice seedlings under flooded conditions. In addition, rice straw that was decomposed under the upland conditions during the off-crop season in winter was placed again in soil at the time of transplanting. The materials were collected periodically to analyze the community structure of the bacteria and fungi responsible for rice straw decomposition by PCR-RFLP analysis. The PCR products with 27f and 1492r primers designed for bacterial 16S rDNA and with EF3 and EF4 primers designed for fungal 18S rDNA were digested with four restriction endonucleases (Hinf I, Sau3A I, Hae III, EeoR I). Bacterial communities in the decomposing rice straw were different from each other between upland and flooded conditions, between leaf sheaths and blades, and between straw samples with and without decomposition under upland conditions during the off-crop season. Fungal communities in the decomposing rice straw were also different between the leaf sheaths and blades under upland soil conditions. Score plots of bacterial and fungal communities in the principal component analysis were separated from the plot of the straw materials along with the duration of the placement, indicating the succession of bacterial and fungal communities in decomposing rice straw with time. 相似文献
18.