Pig manure vermicompost as a component of a horticultural bedding plant medium: effects on physicochemical properties and plant growth

This experiment was designed to characterize the physical, chemical and microbial properties of a standard commercial horticultural, greenhouse container, bedding plant medium (Metro-Mix 360), that had been substituted with a range of increasing concentrations (0%, 5%, 10%, 25%, 50% and 100% by volume) of pig manure vermicompost and to relate these properties to plant growth responses. The growth trials used tomatoes (Lycopersicon esculentum Mill.), grown in the substituted media for 31 days under glasshouse conditions, with seedling growth recorded in 20 pots for each treatment. Half of the tomato seedlings (10 pots per treatment) were watered daily with liquid inorganic fertilizer while the other half received water only. The percentage total porosity, percentage air space, pH and ammonium concentrations of the container medium all decreased significantly, after substitution of Metro-Mix 360 with equivalent amounts of pig manure vermicompost; whereas bulk density, container capacity, electrical conductivity, overall microbial activity and nitrate concentrations, all increased with increasing substitutions of vermicompost. The growth of tomato seedlings in the potting mixtures containing 100% pig manure vermicompost was reduced, possibly as a result of high soluble salt concentrations in the vermicompost and poorer porosity and aeration. The growth of tomato seedlings was greatest after substitution of Metro-Mix 360 with between 25% and 50% pig manure vermicompost, with more growth occurring in combinations of pig manure vermicompost treated regularly with a liquid fertilizer solution than in those with no fertilizer applied. Some of the growth enhancement in these mixtures seemed to be related to the combined effects of improved porosity, aeration and water retention in the medium and the high nitrate content of the substrate, which produced an increased uptake of nitrogen by the plant tissues, resulting in increased plant growth. When the tomato seedlings were watered daily with liquid inorganic fertilizer, substitution of Metro-Mix 360 with a very small amount (5%) of pig manure vermicompost resulted in a significant increase in the growth of tomato seedlings. Such effects could not be attributed solely to the nutritional or physical properties of the pig manure vermicompost. Therefore, it seems likely that the pig manure vermicompost provided other biological inputs, such as plant growth regulators into the container medium, that still need to be identified fully.     

蚓粪和益生菌互作对土壤性状及番茄产量和品质的影响

本试验研究了两株益生细菌(巨大芽孢杆菌BM和解淀粉芽孢杆菌BA)与化肥和蚓粪配施对土壤性状、番茄产量和品质的影响．结果表明:与化肥相比,在等养分条件下蚓粪能够提高番茄产量、果实可溶性糖和蛋白质含量,并提高土壤pH和速效磷含量．与单施蚓粪相比,益生菌与蚓粪配施不仅能提高番茄产量、果实可溶性糖、蛋白质、维生素C含量和糖酸比,降低有机酸和硝态氮含量,而且增加了土壤pH和硝态氮含量,降低了土壤电导率;益生菌与化肥配施的效果不如益生菌与蚓粪配施．BA和BM与化肥或蚓粪配施时,番茄品质无显著差异,但BA配施蚓粪处理的番茄产量显著高于BM配施蚓粪处理;BM与化肥配施处理显著提高了土壤速效磷含量,而BA与蚓粪配施处理则显著提高了土壤速效钾含量．本研究表明,益生菌和蚓粪可替代化肥用于番茄生产和土壤肥力改良.     

施蚯蚓粪对日光温室土壤及番茄产量与品质的影响

设施蔬菜化肥过量施用造成土壤劣化、土传病虫害发生严重,从而导致蔬菜产量和品质下降。蚯蚓粪在改善土壤环境和促进蔬菜生长、提高产量和品质方面具有良好的效果。本试验在日光温室采用等量撒施和沟施两种方式研究了增施蚯蚓粪对土壤养分、酶活性、微生物数量及番茄生长、产量和品质的影响。结果表明: 与不施蚯蚓粪的对照相比,撒施蚯蚓粪和沟施蚯蚓粪处理均改善了土壤环境,显著增加了土壤有机质和氮、磷、钾等养分含量;显著提高了蔗糖酶和过氧化氢酶活性,增加了土壤中细菌、放线菌数量,降低了真菌数量。沟施蚯蚓粪处理明显促进了植株地上部的生长,撒施效果不显著。蚯蚓粪处理明显增强了植株根系活力,提高了叶片的光合作用和叶绿素含量,促进了植株氮和钾含量的积累。撒施和沟施蚯蚓粪处理的番茄产量比对照分别提高了22.7%和32.6%。沟施处理果实中可溶性蛋白、可溶性糖、维生素C和可滴定酸含量分别提高了66.1%、11.0%、122.6%和29.9%,硝酸盐含量降低了65.7%,而撒施处理对番茄果实品质提升效果不明显。     

Suppression of insect pest populations and damage to plants by vermicomposts

The effects of commercial vermicomposts, produced from food waste, on infestations and damage by aphids, mealy bugs and cabbage white caterpillars were studied in the greenhouse. Vermicomposts were used at substitution rates into a soil-less plant growth medium, MetroMix 360 (MM360), at rates of 100% MM360 and 0% vermicompost, 80% MM360 and 20% vermicompost, and 60% MM360 and 40% vermicompost to grow peppers (Capsicum annuum L.), tomatoes (Lycopersicon esculentum Mill.) and cabbages (Brassica oleracea L.), in pots. Groups of 10 pots containing young plants were distributed randomly in nylon mesh cages (40 cm x 40 cm x 40 cm). Groups of 10 pepper seedlings in a single cage were infested with either 100 aphids (Myzus persicae Sulz.) or 50 mealy bugs (Pseudococcus spp.) per cage. Similar groups of tomato seedlings were infested with 50 mealy bugs per cage. Groups of four cabbage seedlings in pots in cages were infested with 16 cabbage white caterpillars (Pieris brassicae L.). Populations of aphids and mealy bugs were counted after 20 days and the shoot dry weights of peppers, tomatoes and cabbages were measured at harvest. Numbers of cabbage white caterpillars and loss in shoot weights were measured after 15 days. The substitution rates of 20% and 40% vermicomposts suppressed populations of both aphids and mealy bugs on peppers, and mealy bugs on tomatoes, significantly. Substitutions with vermicomposts into MM360 decreased losses of dry weights of peppers, in response to both aphid and mealy bug infestations, decreased losses in shoot dry weights of tomatoes after mealy bug infestations significantly. There were significantly decreased losses in leaf areas of cabbage seedlings in response to the cabbage white caterpillar infestations.     

Growth of bedding plants in commercial potting substrate amended with vermicompost

Vermicompost has been promoted as a viable alternative container media component for the horticulture industry. The purpose of this research was to investigate the use of vermicompost at different points in the production cycle of tomato, marigold, pepper, and cornflower. The incorporation of vermicompost of pig manure origin into germination media up to 20% v/v enhanced shoot and root weight, leaf area, and shoot:root ratios of both tomato and French marigold seedlings; however amendment with vermicompost had little influence on pepper and cornflower seedling growth. Moreover there was no effect on the germination of seed of any species. When seedlings of tomato, French marigold, and cornflower were transplanted into 6-cell packs there was greater plant growth in media amended with vermicompost compared to the control media, and the greatest growth when vermicompost was amended into both the germination and transplant media. This effect was increased when seedlings in the transplant media were irrigated with water containing fertilizer.     

Biocontrol of Fusarium and Verticillium Wilt of Tomato by Penicillium oxalicum under Greenhouse and Field Conditions

Treatments with conidia of Penicillium oxalicum produced in a solid‐state fermentation system were applied at similar densities (6 × 10⁶ spores/g seedbed substrate) to tomato seedbeds in water suspensions (T1: 5 days before sowing, or T2: 7 days before transplanting; 15 days after sowing), or in mixture with the production substrate (T3: 7 days before transplanting; 15 days after sowing). Treatments T2 and T3 significantly (P = 0.05) reduced fusarium wilt of tomato in both greenhouse (artificial inoculation) (33 and 28%, respectively) and field conditions (naturally infested soils) (51 and 72%, respectively), while treatment T1 was efficient only in greenhouse (52%). Verticillium wilt disease reduction was obtained with T3 in two field experiments (56 and 46%, respectively), while T1 and T2 reduced disease only in one field experiment (52% for both T1 and T2). Treatment with conidia of P. oxalicum plus fermentation substrate (T3) resulted in better establishment of a stable and effective population of P. oxalicum in seedbed soil and rhizosphere providing populations of approx. 10⁷ CFU/g soil before transplanting. Results indicate that it will be necessary to apply P. oxalicum at a rate of approx. 10⁶–10⁷ CFU/g in seedbed substrate and rhizosphere before transplanting for effective control of fusarium and verticillium wilt of tomato, and that formulation of P. oxalicum has a substantial influence on its efficacy.     

Garden-waste-vermicompost leachate alleviates salinity stress in tomato seedlings by mobilizing salt tolerance mechanisms

The incidence of salinity-induced plant stress as a result of natural and anthropogenic factors in arid and semi-arid agricultural lands is great. In South Africa alone, 9 % of irrigated agricultural land is salt-affected. Commercial fertilizers used for improving soil nutrient levels are costly and affect the quality, lifespan and sustainability of soil and water resources. Organic farming practices are based on cost-effective and environmentally-aware management systems. Vermicompost leachate (VCL) is a vermicompost-derived liquid product that has become recognised as a suitable soil amendment product. Commercial tomato (Lycopersicon esculentum Mill var. Heinz-1370) seedlings were subjected to sodium chloride (NaCl) concentrations of 0, 25, 50 and 100 mM and were treated with 1:10 (v/v) WizzardWorms VCL prepared in Hoagland’s nutrient solution under greenhouse conditions. Morphological characters of VCL-treated tomato seedlings showed improved root growth and stimulated overall aboveground growth with significantly higher numbers of leaves, greater stem thickness and increased leaf area, even at a high NaCl-tested concentration (100 mM). The accumulation of compatible solutes such as proline and total soluble sugars indicate an induced salt tolerance or adaptive mechanism in VCL-treated tomato seedlings. The current investigation demonstrates the potential of an organic liquid to maximise tomato productivity by improving seedling growth performance under salt stress conditions.     

岩棉育苗对番茄幼苗生长发育的影响

采用岩棉和营养土方作育苗基质,观测了基质对番茄幼苗各时期生长的影响。其试验结果是：以岩棉作基质培育功苗能增加番茄幼苗全株的干重,其中幼苗根系的干重增加较为显著。在播种２４ｄ内,岩棉育苗的幼苗高度、茎干重、叶面积和干重的增长略低于营养土方育苗,２４ｄ以后,岩棉育苗则增长迅速,说明岩棉育苗具有增加幼苗干物质累积、培育壮苗的特点,证实岩棉是一种良好的育苗基质。     

Observations on the suppression of root-knot nematode (Meloidogyne arenaria) on tomato by incorporation of cyanobacterial powder (Oscillatoria chlorina) into potting field soil

Experiments were carried out to investigate the nematicidal potential of a cyanobacterium, Oscillatoria chlorina, against the root-knot nematode, Meloidogyne arenaria on tomato plants grown in pots filled with 500 cm3 of field soil infested with 12-s stage juveniles (J2)/cm3 soil. Incorporation of freeze-dried cyanobacterial powder into potted field soil at the rate of 0.2%, 0.4%, 0.6%, 0.8% and 1.0% (w/w) 5 days prior to tomato planting, reduced root galling, final population of M. arenaria and increased vegetative growth of tomato plants and root-mass production, compared with untreated control (P > or = 0.05). The beneficial effect of adding cyanobacterial powder into infested potted field soil increased exponentially with concentration up to 0.8%. Root galling and nematode population decreased by 68.9% and 97.6%, respectively at the highest dose (1%) of cyanobacterial powder compared with the untreated control. Addition of cyanobacterial powder into infested potted field soil at 5 days before planting was the most effective followed by 2 days before and at the time of tomato planting. We conclude that application rate and timing are important factors in the control of root-knot nematodes with O. chlorina.     

Integration of soil solarization with chemical, biological and cultural control for the management of soilborne diseases of vegetables

The long-term effectiveness of soil solarization integrated with (integration of pest management [IPM]) a biological control agent (Trichoderma virens), chemical fungicide (pentachloronitrobenzene [PCNB]), organic amendment (chicken litter) or physical method (black agriplastic mulch) to reduce southern blight (Sclerotium rolfsii) and southern root-knot diseases (Meloidogyne incognita) were evaluated on vegetable production. Results showed that the long-term effectiveness of IPM plus soil solarization reduced soilborne diseases of vegetables more than two years following the termination of solarization. These disease management strategies in 1991 and 1992, following soil solarization in 1990, reduced the numbers of sclerotia in the soil, and the number of plants killed by southern blight and root-knot of tomatoes, compared to nonsolarized bare soil treatment. The integration of a reduced dosage level of PCNB or T. virens in field plots, reduced southern blight of tomatoes by 100% and 71%, respectively, in solarized soil, compared to nonsolarized bare soil two years following soil solarization. PCNB effectively controlled southern blight in nonsolarized bare soil both years. All solarized treatments, except PCNB plus solarized soil increased tomato yields compared to nonsolarized bare soil plots. In the second study (1992) following soil solarization in 1991, the effectiveness of solarized bare soil, and nonsolarized bare soil mulched with black agriplastic film, with or without Reemay spunbounded polyester row cover, were effective in reducing root-knot of tomatoes as indicated by the root-knot gall index. Following a one year fallow period in 1994 three years following soil solarization, the root-knot gall index for severity of tomato roots grown in solarized bare soil, nonsolarized bare soil, black agriplastic mulched bare nonsolarized soil and black agriplastic mulched solarized bare soil, were 1.0, 3.0, 3.0 and 2.0, respectively, on a 0–5 scale, where 0=0% and 5=100% root-knot galled. In the third study 1992 and 1993, different dosage levels of chicken litter were used to amend soil artificially infested with sclerotia of S. rolfsii at different depths following solarization, decreased the number of viable sclerotia by 85–100%. All solarized treatments and nonsolarized bare soil amended with 18.8 MT/ha of chicken litter, were effective in controlling southern root-knot damage, and postharvest storage root rots of sweetpotato storage roots (Fusarium root rot [Fusarium solani] and Java black rot [Diplodia tubericola]). Our study showed that all soil solarization treatments, and soils amended with chicken litter, stimulated a shift in the soil microbial population dynamics. Rhizobacteria of Bacillus spp. and fluorescent pseudomonads increased significantly in the rhizosphere, rhizoplane, and interior root tissues of tomatoes and sweetpoatoes, grown in solarized soil compared to nonsolarized soil. These microorganisms may have contributed to the increased growth response of vegetables and some were probably suppressive to soilborne diseases     

Iron-phosphorus relationship in the nutrition of tomato seedlings grown on alluvial and calcareous soils

Summary In typical alluvial and calcareous soils of Egypt 5 levels of each of P and Fe were added to study their effect on the dry matter and on their uptake by tomato seedlings in greenhouse. Application of phosphorus significantly increased the dry matter yields and both P and Fe uptake by tomatoes grown on both soils. However, application of Fe had no significant effect on the dry matter and P-uptake by tomatoes grown on alluvial soil while they were significantly increased on the calcareous one.     

Effects of vermicomposts produced from food waste on the growth and yields of greenhouse peppers

Vermicomposts, produced commercially from food wastes, were substituted at a range of different concentrations into a soil-less commercial bedding plant container medium, Metro-Mix 360 (MM360), to evaluate their effects on the growth and yields of peppers in the greenhouse. Six-week-old peppers (Capsicum annum L. var. California) were transplanted into 100%, 80%, 60%, 40%, 20% or 10% MM360 substituted with 0%, 10%, 20%, 40%, 60%, 80% and 100% vermicompost. All plants were watered three times weekly with 200 ppm Peter's Nutrient Solution from the time of transplanting up to 107 days. Peppers grown in potting mixtures containing 40% food waste vermicomposts and 60% MM360 yielded 45% more fruit weights and had 17% greater mean number of fruits than those grown in MM360 only. The mean heights, numbers of buds and numbers of flowers of peppers grown in potting mixtures containing 10-80% vermicompost although greater did not differ significantly from those of peppers grown in MM360. There were no positive correlations between the increases in pepper yields, and the amounts of mineral-N and microbial biomass-N in the potting mixtures, or the concentrations of nitrogen in the shoot tissues of peppers. Factors such as: an improvement of the physical structure of the potting medium, increases in populations of beneficial microorganisms and the potential availability of plant growth-influencing-substances produced by microorganisms in vermicomposts, could have contributed to the increased pepper yields obtained.     

Effects of Arugula Vermicompost on the Root-Knot Nematode (Meloidogyne javanica) and the Promotion of Resistance Genes in Tomato Plants

Root-knot nematodes are the most important plant-parasitic nematodes worldwide. Many efforts have been made to find non-chemical, risk-free, and environmentally friendly methods for nematode control. In this study, the effects of compost and vermicompost of arugula (Eruca sativa) on Meloidogyne javanica were investigated in three glasshouse experiments. In addition, the expression of the defense-related genes nonexpressor of pathogenesis-related 1 (NPR1) and lipoxygenase 1 (LOX1) was detected in tomato plants treated with vermicompost of arugula at 0, 2, 7, and 14 days after nematode inoculation. The result showed that the vermicompost of arugula significantly reduced the reproduction factor of the nematode by 54.4% to 70.5% in the three experiments and increased the dry weight of shoots of infected tomato plants. Gene expression analysis showed that LOX1 expression increased on the second and seventh day after nematode inoculation, while NPR1 expression decreased. The vermicompost of arugula showed stronger nematode inhibitory potential than the vermicompost of animal manure. The vermicompost of arugula is superior to arugula compost in suppressing the activity of M. javaniva and reducing its impact. It manipulates the expression of resistance genes and could induce systemic resistance against root-knot nematodes.     

中药渣蚓粪对玉米生长及土壤肥力特性的影响

采用盆栽试验,研究了中药渣蚓粪对玉米生长及土壤肥力的影响.结果表明: 随着蚓粪施用量的增加,玉米的株高、茎粗、叶面积、叶绿素含量均显著增加;生长60 d收获时,多数蚓粪处理的土壤容重显著降低;蚓粪处理的土壤pH显著高于对照和相应的化肥处理.蚓粪处理的土壤全氮、有机质含量也明显高于化肥处理,且随蚓粪施用量的增加,效果越趋显著.中药渣蚓粪可作为一种高效有机肥,其合理施用有助于改善土壤物理结构,缓解土壤的酸化进程,提高土壤有机质和氮素含量,有效促进作物生长.     

不同水肥条件下番茄土壤微生物群落多样性及其与产量品质的关系

采用内含子切接点引物 (Intron-splice junction primer) 和长随机引物的PCR (Polymerase chain reaction, 聚合酶链) 标记技术, 就黄土高原不同水肥处理对日光温室番茄土壤微生物群落多样性进行了研究, 并对产量、品质的影响进行了分析。结果表明, 所用的6个引物共能扩增出182条稳定清晰的条带, 其中142条为多态性条带, 多态性条带为78.02%。聚类分析与主坐标分析表明, 水肥对土壤微生物群落多样性的变化有不同的影响。土壤微生物群落多样性指数与番茄产量、果实的Vc、可溶性蛋白质含量成正相关, 尤其与Vc的相关系数达0.9211, 而与可溶性固形物含量成负相关关系。6个水肥组合中WmFh (中水高肥) 土壤微生物群落多样性指数最高, 且番茄果实的Vc、可溶性蛋白质含量及产量显著高于其他处理, 可溶性固形物含量较低。该组合有利于土壤微生物群落的多样性和稳定性的提高, 利于土壤生态环境的改善和番茄优良品质的形成。     

Growth,mineral nutrition and mycorrhizal colonization of red clover and cucumber plants grown in a soil amended with composted urban wastes

The utility of an urban solid waste, either freshly composted or vermicomposted, for improvement of plant growth in a soil B horizon was investigated. Growth, mineral nutrition and arbuscular mycorrhizal (AM) colonization of cucumber and red clover plants were studied in an experiment carried out under controlled growing conditions, using different mixtures of soil and composts as plant substrates. Soil inoculation with the AM fungus Acaulospora sp. did not benefit growth of plants when soil was used as the only substrate, possibly due to its poor fertility. Results showed that neither mycorrhizal plant species grew when soil was mixed with composted urban waste or when compost was used as the only substrate. However, amendment of soil with 10 or 50% vermicompost significantly increased dry matter yields of red clover and cucumber plants, compared to treatments where soil was the only substrate. Addition of vermicompost also increased Olsen-P and other mineral elements in soil and shoot P, Ca, Mg, Cu, Mn and Zn concentrations, but caused a significant reduction on root length colonized by AM fungi in red clover plants. It is concluded that application of high amounts of vermicompost from composted urban wastes to soils might cause a significant reduction of activity of AM fungi, which must be taken into account when using these organic amendments in agricultural systems.     

成串采收对番茄果实采后乙烯合成及贮藏品质的影响

为研究成串采收对番茄果实采后乙烯合成及贮藏品质的影响,对广西田阳县两个栽培区两种嫁接砧木的串收番茄的采后生理指标进行测定,探讨了该采收方式对番茄果实采后保鲜的作用机制。结果表明:整个贮藏期,不同栽培区不同嫁接砧木的番茄成串采收的果实,乙烯生成量明显低于对照的常规单果采收。其中,砧木1号Ⅰ区的串收番茄的乙烯生成量,采后5 d即下降至最低点(0.35 nL·g~(-1)·h~(-1)),显著低于其对照(1.36 nL·g~(-1)·h~(-1)),其他栽培区和砧木组合的串收番茄,在采后15 d乙烯生成量达到最低值。串收番茄的类胡萝卜素、番茄红素和抗坏血酸等果实内天然抗氧化物质的含量,在贮藏前期快速升高,且峰值显著高于对照。此外,成串采收处理还一定程度抑制了果实后熟阶段可溶性糖的积累和可滴定酸的分解。因此,番茄成串采收处理,可能通过抑制果实采后乙烯的合成,同时提高类胡萝卜素、番茄红素和抗坏血酸的水平,并且推迟糖和酸等营养物质的后熟变化进程,实现其延长果实货架期,提高商品品质的作用。     

Vermicompost derived from mushroom residues improves soil C/P cycling,bacterial community, and fungal abundance

The utilization of agricultural waste organic materials through composting technology has gained significant traction in agricultural production as an effective means of crop nutrient management. However, the differences in the impact of organic amendments prepared by traditional composting and vermicomposting on soil properties still deserve further research. Based on field experiments conducted in greenhouse, compared to chemical fertilizer treatments as control, we utilized traditional compost (OF) and vermicompost (VcF) derived from agricultural organic waste edible mushroom bran and cow manure (2:8). Variations in soil physiochemical properties, activities of soil enzymes related C and P cycling, abundances and diversities of bacterial 16S rRNA and fungal ITS gene at total DNA level were analyzed. Both compost treatments enhanced soil organic carbon, soil total phosphorus, and soil available P content significantly and also increased the activities of soil α-glucosidase, β-glucosidase, acid phosphomonoesterase, and alkaline phosphomonoesterase significantly. The above results suggested that soil C and P transformations were stimulated effectively by both organic amendments. OF and VcF increased the fungal ITS absolute abundances significantly while diversity indices of soil bacterial community increased significantly under both treatments. Correlation analysis indicated that bacterial community composition was strongly correlated with several soil property indexes while fungal community composition was only significantly correlated with soil total phosphorous content. In conclusion, similar to traditional compost, vermicompost significantly improved soil nutrient cycling (especially C and P aspects). In terms of soil microbes, bacteria and fungi showed different responding mechanism to vermicompost: bacteria adjust microbial structure, while fungi tend to proliferated. In consideration of the advantages of vermicompost in technology and economic cost, it could be applied in the subsequent agricultural production more frequently.     

Evaluation of a vermicompost and leachates on <i>Solidago x hybrida</i> and organic carbon mineralization under aerobic incubations

In the floriculture region of Tenancingo in the State of Mexico, the application of stabilized organic matter, such as vermicompost and leachates, contributes to improve the quality of the soil and plant nutrition. However, it is important to know the chemical composition of a vermicompost and the mineralization process. This is because the amount and speed of nutrient release which will be available to the crop will depend on that knowledge. The objective of the study was to evaluate the effect of the application of a vermicompost and leachates on various quantitative variables of Solidago x hybrid, and the mineralization of organic carbon under aerobic incubations. Vermicompost (74 and 36 g/kg soil), leachates (5 and 10 L/kg soil), 0.33 g/kg soil of chemical fertilizer Ca (NO₃)₂, and not treated soil (control) were applied under greenhouse conditions to evaluate their effects on plant growth variables. Mixtures of 100 g of soil with vermicompost and leachates were made in the laboratory which were incubated during 9 weeks to obtain the potentially mineralizable organic carbon (Corg PM) and the rate of mineralization (k) after adjusting an exponential model. In the greenhouse experiment there were no statistical differences after applying vermicompost and leachates on the quantitative variables (number of stems per plant, diameter of the panicle, fresh weight, plant length and stem diameter) with respect to the control (p>0.05). The effect among the applied doses was evident only for variables such as fresh weight, panicle length and stem diameter with respect to the control. In incubated soils, k values ranged between 0.209-0.325 C mg/kg soil/week. Only with the application of leachates in high doses two pools of organic matter were shown: one soluble labile (102.9 mg/kg soil) and the other hydrolysable (819 mg/kg soil). The soluble, labile fraction favored nutrient availability immediately after its application to the soil. However, a single pool of hydrolysable organic C (987-1074 mg/kg soil) was found when vermicompost was applied. It was associated with a release of organic matter during crop development, and to a possible stimulation of microbial activity. High values of electrical conductivity in vermicompost and leachates (8.2-11.7 mS/m) suggest a moderate application of both products.     

嫁接对辣椒根际土壤环境的影响及其与抗病性和产量的关系

以‘卫士’(WS)和‘部野丁’(BYD)辣椒为砧木,‘新丰2号’(XF)辣椒为接穗嫁接,以‘新丰2号’自根嫁接辣椒(XF/XF)为对照(CK),研究嫁接对辣椒根际土壤微生物量、物理性质、养分含量及土传病害和产量的影响.结果表明: 嫁接辣椒新丰/卫士(XF/WS)与新丰/部野丁(XF/BYD)根际土壤的真菌和放线菌数量较多,放线菌比例较大;定植60 d时,嫁接辣椒根际土壤过氧化氢酶(CAT)和过氧化物酶(POD)活性显著高于CK;定植90 d时,XF/WS根际土壤磷酸酶、蔗糖酶、脲酶、硝酸还原酶(NR)活性显著高于CK;此外,嫁接辣椒根际土壤浸提液中的烃类化合物增多,XF/WS和XF/BYD根际土壤N、P、K含量显著低于CK,根际土壤电导率(EC)略高,XF/WS的pH显著高于CK,而XF/BYD与CK差异不显著.说明嫁接可优化辣椒根际土壤环境,增强其对土传病害的抗性,XF/WS和XF/BYD的产量分别比CK增加40.8%和28.7%.