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1.
紫云英还田方式对烟田土壤微生物及酶的影响 总被引：4，自引：1，他引：3
为探明紫云英不同还田方式对土壤生物学特性的影响,选择合理的还田方式,通过定位试验进行了全层翻耕紫云英覆盖、全层翻耕紫云英深埋和全层翻耕紫云英不还田3种方法对烟草不同生育期的土壤微生物数量、微生物活度和酶活性的影响研究。结果表明:在烟草生育期内,好气性细菌数量呈现前期急速下降,中期缓慢上升,后期稍微波动的趋势,深埋处理都略高于覆盖处理;真菌数量整体呈现上升趋势,紫云英覆盖前期可显著增加真菌数量,深埋对真菌数量影响不大;放线菌数量紫云英还田处理呈现前期下降,中期急速上升,后期缓慢上升的趋势。土壤微生物活度则先下降再持续上升,至烟草成熟期,紫云英覆盖紫云英深埋不还田。土壤纤维素酶活性以旺长期为分界点,表现为前期增加、后期下降的特点,紫云英还田高于不还田;土壤脲酶活性呈现先迅速下降,再缓慢上升,再急速上升的趋势,以紫云英深埋处理的脲酶活性最高;土壤蛋白酶和过氧化氢酶的活性在烟草生育期的变化不大,都表现为早期稍微下降,以后趋于平缓,以紫云英深埋的酶活性较高。土壤生物学综合评价表明,采用全层翻耕紫云英深埋(1500kg/667m2)更利于提高土壤质量。 相似文献
2.
紫云英还田量对烟田土壤微生物及酶的影响 总被引：4，自引：0，他引：4
为在翻耕条件下合理施用紫云英,保障农业的可持续性发展,定位试验研究了15000kg·hm-2、22500kg·hm-2、30000kg·hm-2紫云英还田和22500kg·hm-2紫云英还田减施化肥(施肥时扣除紫云英中氮、磷、钾)及紫云英不还田5个处理对烟田土壤微生物数量、微生物活度、酶的影响。结果表明:烟草生育期内,不同处理好气性细菌数量呈前期均迅速上升、中期均稍有上升,但后期各有升降的趋势;烟草生长早期,紫云英还田减施化肥能增加好气性细菌数量。放线菌数量烟草生育前期略有下降,中期有所回升,后期又缓慢下降;烟草生长早期,紫云英还田能增加放线菌数量;整个烟草生育期,紫云英还田减施化肥可减少放线菌数量。真菌呈现烟草生育前中期迅速上升,后期缓慢下降的趋势;相对较少的紫云英还田量对土壤真菌数量增长的刺激作用较为明显。微生物活度呈烟草生育前期下降、中期趋于平稳、后期迅速升高达到最高点的趋势;烟草成熟期,紫云英还田的微生物活度明显高于不还田处理,增加紫云英还田量,微生物活度增加,但紫云英还田减施化肥会降低微生物活度。土壤纤维素酶活性以烟草旺长期为界点,表现出前期增加、后期下降的特点;烟草生长后期,紫云英还田土壤的纤维素酶活性高于对照土壤。土壤脲酶活性呈先快速下降,再缓慢上升,最后再快速上升趋势。土壤蛋白酶活性呈烟草生育前期下降,后期缓慢上升的特点;土壤蛋白酶活性与紫云英施用量呈正相关。过氧化氢酶活性在烟草各生育期的变化不大。土壤生物学评价发现,22500kg·hm-2紫云英翻耕还田栽培烟草较佳。 相似文献
3.
前茬冬季覆盖作物对稻田土壤的生物特征影响 总被引：13，自引：0，他引：13
通过对我国南方稻区不同冬季覆盖作物前茬对稻田主要微生物类群数量和主要土壤化学性状的变化进行研究,结果表明：冬季紫云英和黑麦草覆盖在翌年水稻田翻耕前土壤好气细菌、真菌、放线菌数量均比冬闲田高,其中好气性细菌数量差异最显著,分别是冬闲田的94.29%和25.71%;在水稻整个生长过程土壤细菌、真菌和放线菌均呈现移栽后前期迅速增加,然后随着水稻的生长发育逐渐下降,到早稻成熟期有渐渐回升,晚稻收获时又迅速下降的趋势,并且不同时期微生物数量冬季紫云英和黑麦草区均比冬闲田要高。土壤微生物活度在水稻生长过程呈增加的趋势,前茬冬季覆盖作物区明显高于冬闲田。另外土壤微生物活度与土壤有机碳含量存在显著的相关性（r^2=0.887,P〈0.05）。冬季种植覆盖作物对稻田土壤微生物有很强的改善作用,促进了土壤养分利用。 相似文献
4.
紫云英还田量对稻田土壤微生物数量及活度的影响 总被引：2，自引：0，他引：2
采用田间小区试验,进行了紫云英不同翻压量对水稻不同生育期的土壤微生物数量和微生物活度的影响研究。结果表明,紫云英还田显著提高土壤微生物数量。以紫云英22 500 kg.hm-2配施当地大田化肥用量70%处理的土壤微生物数量最多;紫云英还田使土壤好气性细菌、真菌数量增加,放线菌数量减少。在早稻分蘖盛期好气性细菌,真菌数量升到最大,放线菌数量降到最低;紫云英翻压还田能提高微生物活度。以紫云英22 500 kg.hm-2配施当地大田化肥用量70%处理的微生物活度最强。 相似文献
5.
为探明少免耕对土壤生物学特征的影响,制定合理的耕作制度培肥土壤,进行了33％稻草总重量覆盖少免耕对晚稻土生物活性影响的定位试验研究。结果表明：晚稻分蘖盛期土壤纤维素酶活性表现为免耕〉翻耕〉少耕,木聚糖酶活性、过氧化氢酶活性为少耕〉免耕〉翻耕,脲酶活性、蛋白酶活性为翻耕〉少耕〉免耕,硝化作用强度为免耕〉少耕〉翻耕,微生物活度、氨化作用强度为少耕〉翻耕〉免耕。在晚稻收获期,土壤脲酶活性、过氧化氢酶活性、木聚糖酶活性表现为少耕〉免耕〉翻耕,微生物活度、蛋白酶活性、纤维素酶活性、氨化作用强度、硝化作用强度表现为翻耕〉少耕〉免耕。少免耕能够在一定程度上改善土壤生物性状,且覆盖少量稻草时少耕能够在一定程度上促进稻草分解,有利于水稻生长。 相似文献
6.
采用室外小区试验方法,研究了抗草甘膦转基因大豆（RRS）对根际土壤细菌、真菌、放线菌、氨化细菌、硝化细菌和反硝化细菌的氨化作用强度、硝化作用强度和反硝化作用强度的影响。结果显示,RRS显著降低了根际土壤细菌和放线菌的数量,提高了根际土壤真菌的数量;RRS根际土壤氨化细菌、硝化细菌和反硝化细菌低于其亲本非转基因大豆和部分栽培大豆;RRS对根际土壤氨化作用强度和硝化作用强度有显著影响,但对反硝化作用强度的影响不显著（P〈0.05）。研究表明,RRS不同程度上降低了根际土壤微生物的数量和生化强度,并对根际土壤真菌生长有一定的促进作用。 相似文献
7.
耕作措施与秸秆还田对稻麦两熟制农田土壤养分、微生物生物量及酶活性的影响 总被引：10，自引：1，他引：9
为寻求适宜当地生产和生态环境的最适耕作措施和秸秆还田方式组合,通过开展2年(2009-2011年)田间试验,研究不同耕作措施和秸秆还田对稻麦轮作农田土壤养分、微生物量碳氮及土壤酶活性的影响.结果表明:无论是翻耕还是旋耕,秸秆还田条件下的土壤养分含量均不同程度地高于秸秆不还田,除速效钾外,差异均达显著水平;两季秸秆均还田处理土壤微生物量碳含量均显著高于两季秸秆均不还田;除旋耕秸秆两季均还田外,旋耕麦季稻秸还田处理土壤微生物量氮含量显著高于其他各处理;与翻耕秸秆不还田相比,翻耕两季秸秆均还田和旋耕两季秸秆均还田均显著提高了土壤脲酶和蔗糖酶活性,其中脲酶提高了10.96％和9.72％,蔗糖酶提高了30.36％和17.87％. 相似文献
8.
免耕和秸秆还田对潮土酶活性及微生物量碳氮的影响 总被引：9，自引：0，他引：9
利用中国科学院封丘农业生态实验站玉米-小麦轮作保护性耕作定位试验平台,研究了全翻耕（(T)、免耕（(NT)、全翻耕+秸秆还田（(TS)以及免耕+秸秆还田（(NTS)处理分别对田间0 ~ 10、10 ~ 20和20 ~ 30 cm土层酶活性及土壤微生物量碳、氮的影响。结果表明：①在0 ~ 10和10 ~ 20 cm土层内,土壤碱性磷酸酶、转化酶、脲酶、脱氢酶活性为免耕处理大于全翻耕处理,有秸秆还田处理大于无秸秆还田处理,以NTS处理最高,T处理最低;在20 ~ 30 cm土层中,土壤碱性磷酸酶、转化酶、脱氢酶活性免耕处理大于全翻耕处理,土壤碱性磷酸酶、转化酶、脲酶活性有秸秆还田处理大于无秸秆还田处理。②在0 ~10和10 ~ 20 cm土层内,土壤微生物量碳、氮均为免耕处理大于全翻耕处理,有秸秆还田处理大于无秸秆还田处理;在20 ~ 30 cm土层中,微生物量碳以NTS处理最高,微生物量氮以TS处理最高;③4种处理下的土壤酶活性和微生物量碳、氮均随着土层的加深而减少,且在各土层中差异达显著水平。 相似文献
9.
秸秆还田对土壤氮素养分及微生物量氮动态变化的影响 总被引：3，自引：0，他引：3
通过定位试验研究玉米秸秆全量粉碎还田及小麦秸秆旋耕施肥播种同步完成的前提下,秸秆还田循环利用对小麦玉米两熟制土壤氮素养分及土壤微生物量氮的动态变化。结果表明小麦、玉米秸秆还田能满足小麦旺盛生长阶段拔节期对氮素养分的需求,秸秆还田处理或施肥处理的土壤全氮量总体上在小麦拔节期处于最低值,而既无秸秆还田又没有施肥的对照处理土壤全氮含量最低值出现的时期延后,在小麦开花期出现,持续至小麦的灌浆期。对于麦玉秸秆还田但不施氮磷钾肥而言,小麦生长后期(小麦开花期以后)土壤脱氮比较严重。秸秆还田后土壤碱解氮含量在小麦整个生长发育时期呈现上升的趋势。单独施肥或秸秆还田对提高土壤微生物量氮均有一定的作用,但是仅仅施肥其后效不足。秸秆还田并且施肥显著地促进了土壤微生物的活动,能持续地增加土壤微生物量氮含量。 相似文献
10.
通过两年的田间小区定位试验,研究免耕无秸秆还田(RN)、常规翻耕无秸秆还田(RS)、垄耕无秸秆还田(RD)、免耕秸秆还田(TN)、常规翻耕秸秆还田(TS)、垄耕秸秆还田(TD)6种耕作方式对科尔沁风沙地花生耕层土壤微生物量、土壤酶活性和产量的影响,探究适合辽西风沙半干旱条件下花生高产的耕作方式。结果表明:相同耕作条件下秸秆还田处理组土壤微生物量碳、氮、磷含量和土壤酶活性均高于无秸秆还田处理组,秸秆还田能显著提高土壤微生物量碳、氮、磷含量和酶活性;在相同秸秆还田处理条件下,与常规耕作和垄耕处理相比,免耕处理能显著提高土壤微生物量碳、氮、磷含量和土壤酶活性;免耕秸秆还田处理下,花生产量高出未还田处理4.32%。综上,免耕秸秆还田处理能显著提高土壤微生物量碳、氮、磷含量和土壤酶活性,提高耕层土壤生物学肥力,促进作物增产。 相似文献
11.
Bedrock surfaces in the Ouachita Mountains, Arkansas, exposed by spillway construction and which had not previously been subjected to surface weathering environments, developed 15–20 cm thick soil covers in less than three decades. All open bedrock joints showed evidence of weathering and biological activity. Rock surfaces and fragments also showed evidence of significant weathering alteration. The results suggest a soil production function whereby weathering and increases in thickness are initially rapid. The rapid initial rate (5 to 10 mm year− 1) is facilitated by a weathering-favorable regional climate, local topography favoring moisture and sediment accumulation, and aggressive vegetation colonization. The ages of the trees on the bedrock benches suggests that a short period (< 10 years) of pedogenic site preparation is necessary before trees can become established. Initial chemical weathering within newly-exposed rock fractures in resistant sandstone strata and chemical weathering of weak shale layers, coupled with accumulation of organic and mineral debris in fractures and microtopographic depressions facilitates plant establishment, which accelerates local weathering rates. 相似文献
12.
为了给测土配方施肥提供土壤供肥能力的参考依据，1987年至2005年在土壤肥力较一致的马肝泥田上进行了土壤供肥能力的多点田间试验。结果表明，气候对土壤供肥能力影响显著。土壤供肥能力：高温少雨年份K2O〉N〉P2O5，低温多雨年份P2O5〉K2O〉N，正常年份K2O〉P2O5〉N。土壤供肥比例（N：P2O5：K2O）：高温少雨年份为1：0．23：0．58，低温多雨年份为1：0．29：0．56，正常年份为1：0．25：0．62。 相似文献
13.
Low soil populations of Rhizobium leguminosarum biovar trifolii indicate a need for inoculating clovers (Trifolium sp.) at planting. The number of rhizobia in soil varies considerably from field to field and the number needed for nodulation on the upper taproot and for vigorous seedling development is not known. Two experiments were undertaken using arrowleaf clover (T. vesiculosum Savi) and crimson clover (T. incarnatum L.) grown in pots filled with soil. Two soils were used; one contained 10 indigenous rhizobia g-1 and the other contained fewer than three. The treatments consisted of amending each soil with two strains of inoculant rhizobia to contain from 10 to approximately 1×106 rhizobia g-1 followed by planting to clover. The number of nodules near the top of the root increased as the number of rhizobia in the soil increased to the highest inoculum level. A low number (approximately 1×103 to 1×104) of rhizobia was sufficient for maximal N content of seedlings. It seems that soil containing 100 or fewer rhizobia g-1 may respond to inoculation with increased crown nodulation and seedling vigor. 相似文献
14.
Cover crops can improve soil properties, especially soil structure, through organic matter input and rooting activity. However, large variations exist among cover crops, which may lead to differences in the extent of these effects. In this study, cover crops with differing properties were compared regarding soil structure and subsequent sugar beet growth. Field experiments were conducted at two Luvisol sites in Central Germany. Four cover crops (oil radish, saia oat, spring vetch and winter rye) were compared with fallow. Cover crop effects on soil water, Nmin content, soil structure and subsequent early sugar beet growth were studied. Additionally, sugar beet received either no or optimal N fertilizer application. Rye and radish had the highest and vetch the lowest above- and belowground biomass. Soil water content was hardly affected by cover cropping, while topsoil Nmin contents in April were increased. Penetration resistance was lowered, and aggregate stability was increased by the cover crops, especially oil radish, while values after spring vetch were similar to those of fallow. Differences among the cover crops might be because of a differing root biomass. Independent of N fertilizer application, sugar beet biomass in May tended to be higher after all cover crops, in particular under oil radish. The higher aggregate stability and lower penetration resistance were found to be beneficial for early sugar beet growth. Thus, sugar beet can benefit from a 1-year cultivation of preceding cover crops. Modifications of this effect through cover crop root biomass and architecture as well as repeated cover cropping need to be investigated in further studies. 相似文献
15.
Takashi Sato Yoshihiro Kaneta Noritoshi Furuta Hitomi Kobayashi Hayato Shindo Takeshi Ota 《Soil Science and Plant Nutrition》2013,59(5):695-702
We studied the effect of the soil physical properties on soybean nodulation and N2 fixation in the heavy soil of an upland field (UF) and an upland field converted from a paddy field (UCPF) in the Hachirougata polder, Japan. Seeds of the soybean cultivar Ryuho were sown in each field with or without inoculation of Bradyrhizobium japonicum A1017. The soybean plants were sampled at 35 (V3) and 65 (Rl) d after sowing (DAS), and then nodulation and the percentage of N derived from N2 fixation in the xylem sap were determined. The soil physical properties were different between UF and UCPF, especially the air permeability and soil water regime. Nodule growth was restricted in UCPF irrespective of rhizobial inoculation, though rhizobial infection was not inhibited by the unfavorable soil physical conditions. Soybean plant growth was closely related to the nodule mass and N2 fixation activity, and the inoculation of a superior rhizobium strain was effective only at 35 DAS. These results indicate that soybean nodulation and N2 fixation was considerably affected by the physical properties of heavy soil, and that it is important to maintain the N2 fixation activity and inoculate the soybean plants with a superior rhizobium strain at a later growth stage in order to increase soybean production in heavy soil fields. 相似文献
16.
Growth and soil N supply in young Eucalyptus tereticornis stands at two sites in Kerala, India, were examined in response to cover cropping with three legume species (Pueraria phaseoloides, Stylosanthes hamata, and Mucuna bracteata). The effects of legume residues on soil N supply were investigated in a long-term (392 day) laboratory incubation using leaching micro-lysimeters. Residues from the eucalypt and legume species had different rates of net N release during the laboratory incubation. Net N release was significantly related to residue N concentration (R2 =0.94), the C:N ratio (R2 =0.91), the lignin:N ratio (R2 =0.83), and the (lignin + soluble polyphenol):N ratio (R2 =0.95). Nitrogen release rates declined in the order Mucuna > Pueraria > Eucalyptus > Stylosanthes. There was no net N release from Stylosanthes residues during the 392-day laboratory incubation, whereas Mucuna and Pueraria released N throughout the incubation period. Net N release from mixtures of legume and eucalypt residues was not additive in the early phase of the incubation, probably because eucalypt residues initially immobilized a portion of the legume-derived N in addition to the soil-derived N. Legume establishment had no significant effect on tree growth at one site (Kayampoovam), but resulted in depressed tree growth at the lower rainfall site (Punnala) at 18 months. There were no significant treatment effects on growth at Punnala after that time. Cover cropping with legumes during the early phase of forest plantation growth may be a useful mechanism to enhance soil N supply and optimize the synchrony between N supply and tree N uptake. Although these effects did not translate into improved plantation growth in the 3 years of this study, improved soil organic matter and N fertility may help ensure sustainable productivity over several rotations in the future. This study showed that the effect of legumes on N dynamics varies markedly with legume species. This, together with other factors (e.g. competition with trees, N fixation capacity), will be important in selecting suitable species for cover cropping in forest plantations. 相似文献
17.
《植物养料与土壤学杂志》2017,180(5):614-623
Coffee (Coffea arabica L.) is the major crop grown in highland and mountainous areas of Colombia, where the most common yield‐limiting factors are nitrogen (N) and soil water content. Since the eventual success of a plantation is determined by the performance of coffee plants during critical early stages, our goal was to better understand plant response to these limiting factors. Four different levels of N and soil water content were evaluated under greenhouse conditions for their effect on growth, water use efficiency, fertilizer‐N recovery efficiency (FNRE), and stem lignin and cellulose of coffee seedlings. The interaction between N and moisture did not produce a significant response in coffee growth. However, by increasing N, both water use efficiency and 13C content were enhanced, while growth, recovery of urea by plants, and stem strength were decreased. Water stress due to low soil water content increased water use efficiency, 13C content, and root to shoot ratio, but decreased shoot growth. These results demonstrate the effects of N supply and water balance and highlight the excessive amount of N typically applied to coffee seedlings as well as the importance of the acclimation process of young plants to changes in soil N and water. All of these are important considerations in improving management strategies to reduce environmental impact while sustaining optimal productivity. 相似文献
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二八灰土回填地下粮仓浮力预警试验研究 总被引：2，自引：2，他引：0
地下结构的浮力多以阿基米德定律为基础进行计算,未考虑周围回填土体。该文以某地下粮仓为研究对象,考虑周围回填二八灰土的实际工况,分别进行直径为400(模型筒A)、500(模型筒B)、600 mm(模型筒C)的室内缩尺模型试验。试验包含纯水试验和回填二八灰土试验。纯水试验结果表明,以阿基米德定律计算的实际浮力与模型筒自重(包含模型筒上部约束反力所折算自重)的理论浮力基本一致,模型筒A、B、C的实际浮力与理论浮力的误差分别为0.03%、1%、3%。在回填二八灰土试验中,通过缓慢注水,利用位移计、压力传感器监测模型筒位移及模型筒上部的约束反力,分析了模型筒整个上浮过程中位移和约束反力的变化情况。位移突变值滞后于约束反力突变值,压力传感器读数发生明显变化而位移计读数未发生明显变化所测量的水位为警戒水位,压力传感器与位移计读数均发生明显变化所测量的水位为实际起浮水位。以警戒水位和实际起浮水位作为理论计算依据,得出警戒水位和实际起浮水位时模型筒自重(包含模型筒上部约束反力所折算自重)作用下理论抵抗浮力及计算所得的实际抵抗浮力。警戒水位时模型筒A、B、C实际抵抗浮力为理论抵抗浮力的1.93、2.43、1.66倍。实际起浮水位时模型筒A、B、C实际抵抗浮力为理论抵抗浮力的2.15、3.36、2.96倍。从安全储备方面综合考虑,回填工况地下粮仓在预警水位时实际抵抗浮力为理论抵抗浮力的1.5倍,实际起浮水位时抵抗浮力为理论抵抗浮力的2倍,研究结果为今后地下粮仓及其他地下结构的抗浮设计提供参考。 相似文献
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Virginie Mirleau-Thebaud Jean Dayde Javier David Scheiner 《Journal of plant nutrition》2017,40(17):2494-2510
Sunflower rooting depth is strongly related with soil structural behavior and gravimetric water availability. A few studies have been done on sunflower, only one within a kinetic aspect, and none involving fine root study. This work's aim was to study the impact of soil compaction and its interactions with soil water content on sunflower root and shoot growth and growth rate. A destructive experiment in controlled conditions was implemented to determine the consequences of soil compaction in interaction with water management on the growth of sunflower root and shoot system. Strong modifications on root exploration, architecture and growth were reported under low and high compactions depending on their water regime, the stage sampled and the time duration. This had a negative impact on resources uptake and efficiency. Modifications on the above ground part of the plant through plant water and nutrients uptake, plant growth indicators, biomass production and leaves growth kinetics were also observed. 相似文献