首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 15 毫秒
1.
秸秆生物反应堆与菌肥对温室番茄土壤微环境的影响   总被引：7，自引：3，他引：7  
为研究秸秆生物反应堆、微生物菌肥及两者配套措施对土壤理化性质和微生物功能多样性,以及作物生长的长期影响,试验以传统种植方式为对照(CK,常规栽培),研究了菌肥(T1,微生物菌肥4 kg/667 m2)、内置式秸秆生物反应堆(T2,秸秆(4 t/667 m2)+发酵沟菌剂(8 kg/667 m2)+腐熟猪粪(600 kg/667 m2))及2种措施配套处理(T3,秸秆(4 t/667 m2)+发酵沟菌剂(8 kg/667 m2)+微生物菌肥(4 kg/667 m2)+腐熟猪粪(600 kg/667 m2))对土壤理化性质和微生物功能多样性的影响。结果表明:1)与CK相比,秸秆生物反应堆能够在一定时期内提高土壤含水率;而菌肥能够在一定时期内降低土壤含水率,秸秆生物反应堆能够显著降低土壤酸性和电导率(EC,electrical conductivity)值,缓冲土壤酸化和次生盐渍化;而单施菌肥对土壤酸碱性和EC值没有显著影响。2)秸秆生物反应堆(T2)增加了土壤中有机质的含量和土壤微生物量,降低土壤中速效磷、钾的含量;微生物菌肥(T1)降低了土壤中有机质含量和微生物量,而显著提升了土壤的速效磷、速效钾含量,两种措施配套处理效果则更明显。3)菌肥能够改善土壤微生物对多聚物、碳水化合物和氨基酸的利用效率,而秸秆生物反应堆能够促进土壤微生物对于一部分氨基酸、羧酸类、酚酸类和胺类物质的利用。而2种措施同时使用时,其促进和改善微生物碳代谢能力的作用则更加显著。4)各处理均能够在一定程度上增加各年度番茄产量。综合考虑,认为内置式秸秆生物反应堆和菌肥配套处理(T3)能够更好的改善和修复日光温室连作土壤,增加作物产量,是一种较为有效的农艺措施。  相似文献   

2.
为评价栽培年限对新建日光温室土壤供氮能力的影响,采用盆栽生物耗竭试验和间歇淋洗好气培养法相结合的方法研究了陕西杨凌不同年限新建日光温室(温室建造前的大田及温室建造后第2年和第3年取样)耕层(0~20 cm)土壤供氮能力的变化。结果表明:随着温室栽培年限的增加,番茄生物量和吸氮量与温室栽培前相比均显著增加,其中栽培年限为第2年和第3年的番茄株高、茎粗、地上及根系生物量、叶片SPAD值均显著高于温室建造前,而第2年和第3年间各指标无显著差异;第2年和第3年温室的番茄吸氮量分别是建造前大田的2.53倍和3.01倍;与种植前土壤相比,第3年温室土壤有机质、全氮和速效养分含量均显著增加,第2年及第3年温室土壤可矿化氮量分别是建造前大田的2.84倍和2.96倍,说明随栽培年限的增加,温室土壤供氮能力显著增强。相关分析表明,土壤有机质、全氮、初始矿质氮及累积矿化氮量与番茄吸氮量间呈极显著正相关关系,其中以土壤累积矿化氮量与番茄吸氮量间的相关系数最大,说明这些指标均可用于评价土壤供氮能力。随栽培年限的增加,日光温室土壤供氮能力显著提高,生产中应随温室栽培年限增加适当降低氮肥用量。  相似文献   

3.
矿化作用和硝化作用是土壤氮素转化的主要途径,通过室内培养试验,对设施和露天栽培方式下有机菜地土壤氮素的矿化与硝化作用进行了比较研究。结果表明,除培养第1d外,设施有机菜地土壤氮素矿化量、矿化率在整个培养期间都显著高于露天有机菜地土壤;设施有机菜地土壤硝化量、硝化率在培养前两周内高于露天有机菜地土壤;设施有机菜地土壤矿化与硝化作用总体比露天有机菜地土壤强烈。矿化作用可能与全氮、C/N、微生物活性关系密切,而硝化作用强弱可能与微生物活性有关。无论施肥与否,设施有机菜地土壤N2O排放速率在培养期间总体高于露天有机菜地土壤,前者N2O累积排放量显著高于后者,这可能与土壤C/N有关。  相似文献   

4.
The productivity of agricultural areas in semi‐arid regions can be improved through the use of irrigation. However, the intensive cropping of such soils can have detrimental effects, especially with regard to soil organic matter (SOM) pools. The goal of this work was to evaluate soil organic carbon and nitrogen stocks of different irrigated agricultural systems and compare these to preserved natural ecosystems adjacent to each of the cropping systems. We selected four cropping systems: banana, a maize/bean succession (MB), pasture (P) and guava (G), as well as areas covered by native vegetation. Stocks of total soil organic carbon (TOC), amounts of unprotected and protected soil organic carbon, carbon and nitrogen in microbial biomass and microbial respiration were quantified. Surface soil TOC stocks under banana, G and P grass were significantly greater than under native vegetation and MB system. The most intensive management system was the MB, and the least intensive systems were P and G. The least intensive cropping systems were grouped on the basis of similarities in TOC, POC, total soil nitrogen and N in microbial biomass stocks. These results show that the degree of soil degradation resulting from changes in land use systems increases with the intensity of the land use systems themselves. This confirms the established hypothesis that the extent of degradation of soil properties and changes in some SOM fractions depend on the intensity of soil use. Furthermore, the adoption of conservation practices may remediate soil degradation and increase SOM stocks, mainly at the soil's surface. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

5.
In this study, leguminous crops like Atylosia scarabaeoides, Centrosema pubescens, Calopogonium mucunoides, and Pueraria phaseoloides. grown as soil cover individually in the interspaces of a 19‐yr‐old coconut plantation in S. Andaman (India) were assessed for their influence on various microbial indices (microbial biomass C, biomass N, basal respiration, ergosterol, levels of ATP, AMP, ADP) in soils (0–50 cm) collected from these plots after 10 years. The effects of these cover crops on . CO2 (metabolic quotient), adenylate energy charge (AEC), and the ratios of various soil microbial properties viz., biomass C : soil organic C, biomass C : N, biomass N : total N, ergosterol : biomass C, and ATP : biomass C were also examined. Cover cropping markedly enhanced the levels of organic matter and microbial activity in soils after the 10‐yr‐period. Microbial biomass C and N, basal respiration, . CO2, ergosterol and levels of ATP, AMP, ADP in the cover‐cropped plots significantly exceeded the corresponding values in the control plot. While the biomass C : N ratio tended to decrease, the ratios of biomass N : total N, ergosterol : biomass C, and ATP : biomass C increased significantly due to cover cropping. Greater ergosterol : biomass C ratio in the cover‐cropped plots indicated a decomposition pathway dominated by fungi, and high . CO2 levels in these plots indicated a decrease in substrate use efficiency probably due to the dominance of fungi. The AEC levels ranged from 0.80 to 0.83 in the cover‐cropped plots, thereby reflecting greater microbial proliferation and activity. The ratios of various microbial and chemical properties could be assigned to three different factors by principal components analysis. The first factor (PC1) with strong loadings of ATP : biomass C ratio, AEC, and . CO2 reflected the specific metabolic activity of soil microbes. The ratios of ergosterol : biomass C, soil organic C : total N, and biomass N : total N formed the second factor (PC2) indicating a decomposition pathway dominated by fungi. The biomass C : N and biomass C : soil organic C ratios formed the third principal component (PC3), reflecting soil organic matter availability in relation to nutrient availability. Overall, the study suggested that Pueraria phaseoloides. or Atylosia scarabaeoides were better suited as cover crops for the humid tropics due to their positive contribution to soil organic C, N, and microbial activity.  相似文献   

6.
加工番茄连作对土壤理化性状及微生物量的影响   总被引：7，自引：0，他引：7  
通过在石河子大学农学院试验站开展加工番茄连作定点微区试验,研究了不同连作处理(种植1 a、连作3 a、5 a和7 a)对新疆加工番茄土壤理化性状、微生物生物量和酶活性的影响。结果表明,随着连作年限的延长,土壤p H升高,全磷、速效磷及全钾含量呈先升后降的趋势,土壤容重无明显变化。连作7 a时土壤有机质、全氮及速效钾含量较对照分别下降了8%、21%和29%(p0.05)。土壤微生物量碳(SMBC)、微生物量氮(SMBN)和微生物商(q MB)呈显著下降趋势,与对照相比分别降低了52.3%、78.8%和48.2%(p0.01);微生物量磷(SMBP)呈先升后降趋势,连作3a时,SMBP含量达到最大值,是对照的1.65倍(p0.01)。土壤过氧化氢酶活性呈显著升高趋势,而脲酶、蔗糖酶、多酚氧化酶及磷酸酶活性的变化则相反。连作导致加工番茄产量显著下降,连作7 a时产量下降达34%(p0.01)。相关分析表明,p H、微生物量、q MB、酶活性及养分之间相关性极为密切,说明土壤微生物量和酶活性相结合,可以反映土壤质量的变化。加工番茄连作导致土壤p H和电导率升高,显著抑制了土壤微生物活性,降低了土壤肥力,最终造成产量下降,连作障碍明显。  相似文献   

7.
 Soil organic matter level, mineralizable C and N, microbial biomass C and dehydrogenase, urease and alkaline phosphatase activities were studied in soils from a field experiment under a pearl millet-wheat cropping sequence receiving inorganic fertilizers and a combination of inorganic fertilizers and organic amendments for the last 11 years. The amounts of soil organic matter and mineralizable C and N increased with the application of inorganic fertilizers. However, there were greater increases of these parameters when farmyard manure, wheat straw or Sesbania bispinosa green manure was applied along with inorganic fertilizers. Microbial biomass C increased from 147 mg kg–1 soil in unfertilized soil to 423 mg kg–1 soil in soil amended with wheat straw and inorganic fertilizers. The urease and alkaline phosphatase activities of soils increased significantly with a combination of inorganic fertilizers and organic amendments. The results indicate that soil organic matter level and soil microbial activities, vital for the nutrient turnover and long-term productivity of the soil, are enhanced by use of organic amendments along with inorganic fertilizers. Received: 6 May 1998  相似文献   

8.
Soil organic matter contents, soil microbial biomass, potentially mineralizable nitrogen (N) and soil pH values were investigated in the Ap horizons of 14 field plots at 3 sites which had been under organic farming over various periods. The objective was to test how these soil properties change with the duration of organic farming. Site effects were significant for pH values, microbial biomass C and N, and for potentially mineralizable N at 0—10 cm depth. The contents of total organic C, total soil N, and potentially mineralizable N tended to be higher in soils after 41 versus 3 years of organic farming, but the differences were not significant. Microbial biomass C and N contents were higher after 41 years than after 3 years of organic farming at 0—10 cm depth, and the pH values were increased at 10—27 cm depth. Nine years of organic farming were insufficient to affect soil microbial biomass significantly. Increased biomass N contents help improve N storage by soil micro‐organisms in soils under long‐term organic farming.  相似文献   

9.
Quantifying how tillage systems affect soil microbial biomass and nutrient cycling by manipulating crop residue placement is important for understanding how production systems can be managed to sustain long-term soil productivity. Our objective was to characterize soil microbial biomass, potential N mineralization and nutrient distribution in soils (Vertisols, Andisols, and Alfisols) under rain-fed corn (Zea mays L.) production from four mid-term (6 years) tillage experiments located in central-western, Mexico. Treatments were three tillage systems: conventional tillage (CT), minimum tillage (MT) and no tillage (NT). Soil was collected at four locations (Casas Blancas, Morelia, Apatzingán and Tepatitlán) before corn planting, at depths of 0–50, 50–100 and 100–150 mm. Conservation tillage treatments (MT and NT) significantly increased crop residue accumulation on the soil surface. Soil organic C, microbial biomass C and N, potential N mineralization, total N, and extractable P were highest in the surface layer of NT and decreased with depth. Soil organic C, microbial biomass C and N, total N and extractable P of plowed soil were generally more evenly distributed throughout the 0–150 mm depth. Potential N mineralization was closely associated with organic C and microbial biomass. Higher levels of soil organic C, microbial biomass C and N, potential N mineralization, total N, and extractable P were directly related to surface accumulation of crop residues promoted by conservation tillage management. Quality and productivity of soils could be maintained or improved with the use of conservation tillage.  相似文献   

10.
To assess cultivation-induced changes followed during the Green Revolution on continuous rice–rice and rice–wheat cropping, fence-line comparisons between cultivated and adjacent noncultivated soils were made to (a) quantify changes in selected soil chemical and biological properties at two moisture conditions, (b) determine the N, P, and K uptake of rice and wheat as affected by changes in soil properties, and (c) determine the relationship between N, P, and K uptake and soil properties. Two parallel experiments were conducted: laboratory incubation and a greenhouse experiment with soils collected from seven rice–wheat and two rice–rice soils. As an average, NH4OAc-extractable K, water soluble organic carbon, and hot water soluble organic carbon were all lower by 48%, total carbon by 35%, total nitrogen by 33%, and microbial biomass carbon by 38% in the cultivated soils, whereas no significant change was observed in the enzyme activities. Changes were mostly associated with the existing fertilizer practices and moisture status of the soil during cultivation. In general, fertilizers were not sufficient to replenish crop removal. Soil type also influenced cultivation changes especially soil carbon parameters. Lighter soil texture had higher decomposable organic C and total C declined than heavy soils. Soils with higher declined in both decomposable organic C and total C had higher reduction in functional diversity of culturable microorganisms. The declining C pools caused lower N uptake and there was a clear association between organic matter parameters and N uptake. Olsen P was correlated with P uptake and extractable K with K uptake. As expected, crop biomass correlated with N, P, and K uptake of plants. Comparison of cultivated and its corresponding uncultivated soil provides possibility to determine management effect on soil status.  相似文献   

11.
通过在石河子大学农学院试验站开展加工番茄连作定点微区试验,采用氯仿熏蒸和磷脂脂肪酸(PLFA)法相结合,研究了不同连作处理(种植1 a、连作3 a、5 a和7 a)对新疆加工番茄花果期和成熟期根际土壤微生物群落结构及土壤微生物量的影响。结果表明,连作导致土壤微生物量碳(SMBC)、微生物量氮(SMBN)和微生物熵(q MB)下降,SMBC/SMBN升高,而微生物量磷(SMBP)随连作年限和生育期的变化而不同。连作显著增加了真菌PLFAs含量,降低了细菌PLFAs含量、土壤PLFAs总量及细菌/真菌PLFAs的比值,而放线菌PLFAs含量变化无规律。连作7 a时,成熟期的细菌PLFAs含量、土壤PLFAs总量较对照分别减少62.9%、50.3%(P0.05),而真菌PLFAs含量较对照升高60.2%(P0.05)。从多样性指数分析看,Shannon-Wiener指数、Simpson指数、Brillouin指数和Pielou指数均随连作年限的延长呈先升后降的变化,其中连作3 a时各项指数最大,连作7 a时最小,表明在本试验年限范围内,连作使得微生物群落多样性与均匀程度皆出现了一定程度的降低。相关性分析表明,土壤微生物各类群PLFAs量、微生物量及土壤肥力之间存在相关性,说明土壤微生物量与土壤肥沃程度相关,可作为评价土壤肥力的生物学指标。可见,加工番茄连作改变了土壤微生物群落结构,降低了土壤微生物量,最终在根际土壤微生态系统和环境因子等因素的综合作用下产生连作障碍。  相似文献   

12.
淮南大通矿区复垦土壤微生物量碳氮的分布特征   总被引：2，自引：1，他引：1  
通过野外调查和室内分析,研究了淮南大通煤矿复垦区表层(0—10cm)土壤理化性质及微生物量碳(SMBC)、微生物量氮(SMBN)的分布特征。结果表明,耕地(油菜地、小麦地、蔬菜大棚)土壤有机碳、氮、磷等含量均高于林地,而土壤pH值则相反。土壤SMBC含量依次为:蔬菜大棚油菜地小麦地林地对照样,蔬菜大棚显著高于其他农业用地方式。土壤SMBN则为:蔬菜大棚小麦地油菜地林地,林地土壤微生物量氮显著低于其他农业用地方式。林地土壤微生物商最高,表明在有机质积累的同时林地更有利于土壤微生物活动。土壤微生物量碳氮之间显著相关,进一步证实土壤微生物量碳、氮可以作为表征土壤肥力的敏感因子。  相似文献   

13.
Intensive vegetable cultivation has developed very rapidly in China, and investigation of current soil nutrient problems in vegetable fields and their potential environmental risk is important for local soil nutrient management strategies. Three hundred and sixty‐six soil samples were collected from greenhouse vegetable fields, open vegetable fields and rice/wheat rotation fields in southern Jiangsu Province, the most intensive vegetable‐producing areas in Yangtze River Delta, China, for the analysis of their soil fertility status. Soil acidification and P enrichment were the main problems identified in this area of vegetable production, with about 20 and 17% of the open and greenhouse vegetable field soils, respectively, being extremely acid with soil pH values below 5.0. In contrast, no soils under rice/wheat rotation fields were as acidic. Percentages of sites with Olsen‐P concentrations < 90 mg/kg were 61, 85 and 0% for soils growing greenhouse vegetable, field vegetable and rice/wheat, respectively. The nitrogen (N) surplus for vegetable fields exceeded 170 kg/ha/crop, and the phosphorus (P) surplus exceeded 40 kg/ha/crop. Thus, current vegetable production leads to potential environmental risks of N and P pollution of nearby aquatic bodies. Insufficient supplementation with potassium fertilizers was found in some vegetable fields. Several ameliorative measures are proposed.  相似文献   

14.
上海市郊旱作农田土壤养分资源状况   总被引：8，自引：1，他引：8  
研究了上海市郊旱作农田土壤养分特征,结果表明：自80年代以来经过近20年的土壤耕作演替,上海市郊蔬菜、瓜果旱作土壤总体养分状况表现为有机质、氮素、磷素和钾素含量均很丰富。土壤氮、磷养分积累明显,较80年代第二次土壤普查有大幅度增加,一方面施用过多肥料造成浪费,另一方面带来潜在的非点源污染,对周围的环境造成威胁。各区域由于受土壤质地、土壤类型、气候条件、作物种类、耕作方式等不同土壤养分有所差异。不同耕作方式对农田土壤养分的含量影响较大,其水平高低依次为：大棚土壤、露天菜地土壤、传统自留地土壤。大棚瓜、菜地土壤有酸化趋势,菜园土壤有效磷含量远高于稻麦田土壤,这主要和施肥水平有关。  相似文献   

15.
寿光大棚菜地土壤呼吸强度、酶活性、pH与EC的变化研究   总被引：4，自引：1，他引：3  
为防治土壤退化、促进农业可持续发展提供科学依据,以寿光地区露地土壤作对照,研究了连作1、5、8和12年大棚蔬菜(番茄)土壤有关生物学指标的变化。结果表明,土壤呼吸强度和脱氢酶活性棚内高于棚外,并随连作年限延长开始增强而后减弱,由于管理差异,12年棚龄土壤又回升。随着连作年限延长,土壤脲酶活性逐渐减弱,而过氧化氢酶活性逐渐增强;土壤呼吸强度和酶活性都由表层向底层逐渐减弱。土壤pH随连作年限增加逐渐下降,而EC逐渐增加,至12年棚龄时,与对照比0—20 cm土层pH下降了1.06单位,其他层次变化不显著。试验还表明,该地区表层土壤pH变化于6.45~7.51,EC 0.5 mS/cm,能较好地满足作物生长需要,同时,EC是影响土壤pH及酶活性变化的重要因素。土壤EC及过氧化氢酶活性可作为反映大棚菜地土壤质量变化的参考指标。  相似文献   

16.
Soil drying and wetting impose significant influences on soil nitrogen (N) dynamics and microbial communities. However, effects of drying-wetting cycles, while common in vegetable soils, especially under greenhouse conditions, have not been well studied. In this study, two greenhouse vegetable soils, which were collected from Xinji (XJ) and Hangzhou (HZ), China, were maintained at 30% and 75% water-holding capacity (WHC), or five cycles of 75% WHC followed by a 7-day dry-down to 30% WHC (DW). Soil inorganic N content increased during incubation. Net N mineralization (Nmin), microbial activity, and microbial biomass were significantly higher in the DW treatment than in the 30% and 75% WHC treatments. The higher water content (75% WHC) treatment had higher Nmin, microbial activity, and microbial biomass than the lower water content treatment (30% WHC). Multivariate analyses of community-level physiological profile (CLPP) and phospholipid fatty acid (PLFA) data indicated that soil moisture regime had a significant effect on soil microbial community substrate utilization pattern and microbial community composition. The significant positive correlation between Nmin and microbial substrate utilization or PLFAs suggested that soil N mineralization had a close relationship with microbial community.  相似文献   

17.
 The effects of growing trees in combination with field crops on soil organic matter, microbial biomass C, basal respiration and dehydrogenase and alkaline phosphatase activities were studied in soils under a 12-year-old Dalbergia sissoo (a N2-fixing tree) plantation intercropped with a wheat (Triticum aestivum) – cowpea (Vigna sinensis) cropping sequence. The inputs of organic matter through D. sissoo leaf litter increased and crop roots decreased with the increase in tree density. Higher organic C and total N, microbial biomass C, basal soil respiration and activities of dehydrogenase and alkaline phosphatase were observed in treatments with tree-crop combination than in the treatment without trees. Soil organic matter, microbial biomass C and soil enzyme activities increased with the decrease in the spacing of the D. sissoo plantation. The results indicate that adoption of the agroforestry practices led to an improved organic matter status of the soil, which is also reflected in the increased nutrient pool and microbial activities necessary for long-term productivity of the soil. However, tree spacing should be properly maintained to minimize the effects of shading on the intercrops. Received: 21 February 1997  相似文献   

18.
To reveal the regulatory mechanisms underlying the productivity of long-term continuous cropping of processing tomato, a multi-year study was carried out to understand the effects of long-term continuous cropping on the community structures of the root zone microbes. Soil samples collected from continuous cropping of processing tomato after 3, 5 and 7 years were used for this study. Results showed that soil microbial biomass C (SMBC), N (SMBN) and microbial quotient (qMB) significantly decreased with longer cropping. After seven years of continuous cropping, the SMBC and SMBN contents, and qMB respectively significantly decreased by 52.3%, 78.8% and 48.2% (p?相似文献   

19.
于西藏中部生态条件下,就麦类作物轮作、麦油轮作对土壤化学和生物性质的影响以及农田养分平衡等进行了初步研究。结果表明,不同轮作方式对土壤化学和生物学过程具有显著不同的影响。轮作周期内春青稞→春油菜、春小麦→春油菜轮作对以细菌为主导的土壤微生物的生长与繁殖具有显著的促进作用,耕层土壤有机质、全氮、全磷的绝对增长量分别达3.05~3.06g/kg,0.06~0.07g/kg,0.01~0.26g/kg。麦类作物间,春小麦→春青稞轮作对土壤肥力亦具明显的恢复作用;春小麦→春小麦连作、春青稞→冬小麦轮作土壤微生物区系构成不甚协调,土壤细菌数量明显较低,0~30,31~60cm土层有机质、全氮、全磷总体呈不同程度的退化趋势。在较高外源钾投入条件下,不同轮作方式的土壤钾素均呈不同程度的亏缺状态。  相似文献   

20.
Abstract

Soil nitrogen (N) supply plays a dominant role in the N nutrition of wetland rice. Organic matter has been proposed as an index of soil N availability to wetland rice. This is based on the finding that mineralizable N produced under waterlogged conditions is related to soil organic carbon (C) and total N. The relationship between organic matter and mineralizable N is a prerequisite for determining the N requirement of wetland rice. However, no critical analysis of recent literature on organic matter–mineralizable N relationships has been made. This article evaluates current literature on the relationships of mineralizable N or ammonium N production with soil organic C in wetland rice soils. A number of studies with diverse wetland rice soils demonstrate a close relationship of N mineralized (ammonium‐N) under anaerobic conditions with organic C or total N. However, a few recent studies made on sites under long‐term intensive wetland rice cropping showed that strong positive relationships of mineralizable N with organic C or total N do not hold. Clearly, both quantity and quality of organic matter affect N mineralization in wetland rice soils. Future research is needed to clarify the role of quality of organic matter, especially its chemistry, as modified by the chemical environment of submerged soils, on the mineralization of organic N in wetland rice soils.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号