施肥对生长期毛竹林土壤呼吸的影响

采用Li-6400便携式光合作用测量系统配备的Li-09土壤呼吸室,对浙江富阳地区典型北亚热带林区施肥的毛竹(Phyllostachys heterocycla cv.pubescens)林地生长期土壤呼吸进行研究。结果表明,不同施肥处理造成土壤有机碳含量差异极显著(P<0.01)。施肥能有效提高土壤有机碳含量,其中施用有机肥的处理土壤有机碳含量最高;施肥能显著提高毛竹林生长期的土壤呼吸速率,不同施肥处理造成土壤呼吸差异极显著(P<0.01);施用有机肥的土壤呼吸比施无机肥的要高;不同施肥处理对Q10的影响差异不显著。     

不同施肥对雷州半岛桉树林地土壤培肥效应研究

本文研究了雷州半岛两种主要类型砖红壤有机肥与无机肥配施对桉树土壤养分特征和土壤培肥效应。结果表明:在雷州半岛低地力的土壤中种植桉树时,浅海沉积物发育的砖红壤有机质有所提高,而玄武岩砖红壤有机质下降;土壤有机质含量与林木生长量相关性为极显著水平,与施肥量的相关性较低,未达到显著水平。随施有机肥数量的增加,有机质呈上升趋势。施用滤泥1.5～2.5 kg.株-1时,土壤有机质比单施无机肥提高0.02%～0.21%,比不施肥提高0.07%～0.26%。经施肥后5a测定,施有机肥处理容重比施无机肥的降低0.01%～0.22%,总孔隙度比施无机肥的提高0.1%～7.1%,说明施用有机肥改良砖红壤物理特性。因此,两种类型砖红壤中有机肥施用对桉树土壤肥力具有极显著培肥效应。     

怎样提高棚栽果树座果率

1　合理施肥施肥分有机肥、无机肥。增施有机肥应在扣棚前 (落叶后 )结合土壤深翻施入 ,一般每 667ｍ2 施 5 0 0 0ｋｇ左右 ,施肥后充分浇水。同时可适量掺施锌肥、硼肥等微肥。棚内栽培果树 ,由于自然降雨的淋溶作用减少 ,无机肥的利用率提高 ,各种化肥的施用量为自然条件下的     

不同施肥处理对黄瓜土壤速效养分变化的影响研究

对黄瓜菜地进行了不同施肥处理,通过测定土壤养分,研究了化肥减量及增施有机肥对土壤养分的影响。结果表明:按当地化肥施用量的处理在成熟期土壤速效磷、铵态氮、速效钾含量均比其他处理高,但养分利用率较低;化肥施用量减少20%的处理次之;化肥施用量减少40%+20%有机肥的处理养分全量较高,并且速效养分不高,其养分流失量少,肥料利用率高;而化肥用量减60%+40%有机肥的处理养分全量及速效养分含量都较低,其肥料利用率比化肥施用量减少40%+20%有机肥的处理差。化肥施用量减少40%+20%有机肥能很好地提高土壤各种养分含量,且供肥平稳,能满足黄瓜生长需要,为最合理施肥处理。     

生物有机肥施用量对木瓜杏果实品质及其栽培土壤肥力的影响

【目的】了解生物有机肥施用量对杏园土壤理化性质和杏树生长的影响情况，确定生物有机肥的适宜施用量，为杏园的科学施肥提供理论依据和技术指导。【方法】以河北省张家口市蔚县细弦子村15年生的木瓜杏为试材，于2020—2021年，设置生物有机肥施用量分别为0、1、2、3 kg/株的4个施肥处理（其编号依次为Ⅰ、Ⅱ、Ⅲ、Ⅳ）对杏树进行施肥试验，测定不同施肥处理的不同土层的土壤养分含量、叶片营养元素、叶绿素含量及果实品质等指标，并对其相关性进行分析。【结果】与处理Ⅰ的相比，处理Ⅱ、Ⅲ、Ⅳ的土壤养分含量和果实品质指标值均有不同程度的增加，且其土壤pH值均得以改善。不同施用量的生物有机肥其作用效果也不同，随着生物有机肥施用量的增加，土壤养分含量总体呈现出先升高后降低的变化趋势。施用生物有机肥能更加明显地提高果实品质中可溶性固形物和可滴定酸的含量，且能显著提高其固酸比，还能增加果实中各种矿质元素的含量。土壤pH值与叶片全氮、全磷、全钾含量、叶绿素含量、单果鲜质量、固酸比及果实钾、钙含量之间均呈显著负相关，而与果实硬度呈显著正相关；土壤全氮含量与叶片全钾含量和类胡萝卜素含量之间均呈极显著正相关，而与叶绿素a...     

施肥对苹果园土壤养分及土壤酶活性的影响

以辽西地区苹果园土壤为研究对象,研究不同施肥方式对苹果园土壤养分及酶活性的影响。结果表明:土壤施肥处理对果园土壤养分和土壤酶活性都有显著影响,有效养分含量及酶活性大小顺序都是有机肥+无机肥有机肥无机肥CK,养分含量和活性都是以有机肥+无机肥处理最高,所以这种施肥方式对土壤质量的改善有很好的促进作用。     

生物有机肥对苦瓜品质及土壤氮、磷、有机质含量的影响

研究生物有机肥对有效改善土壤环境质量,探求提高北方寒地保护地栽培蔬菜品质有机肥的施用技术。选用低肥力土壤施用不同量生物有机肥,测定土壤中N、P和有机质含量及苦瓜中叶绿素、有机酸和可溶性糖含量。当生物有机肥施用为0.8kg/m2时,促进土壤中养分的转化,土壤中N、P和有机质含量有效提高,苦瓜中叶绿素、有机酸等含量显著增加;当生物有机肥施用量大于0.8kg/m2时,土壤中N、P、有机质含量增加幅度减小,苦瓜中叶绿素、有机酸等含量降低。生物有机肥施用量为0.8kg/m2时,可增强土壤肥力,改善土壤环境,促进苦瓜生长,提高苦瓜品质。     

太子峪大枣生态园土壤养分分析

本文通过对北京丰台太子峪大枣生态园土壤养分、PH值的测定和分析,探讨了枣园土壤改良和优化施肥方案。结果表明,太子峪生态园中土壤有机质与速效磷含量较低、PH值远高于果园PH适宜范围。建议遵循以有机肥为主、有机肥与无机肥相配合、氮磷钾按比例施用、微量元素适当补充的施肥原则,进行合理的土壤改良提高有效磷含量、调节PH值,以达到增收降耗的目的。     

甘肃中部引黄灌区枸杞施肥管理与土壤养分状况调查分析

通过对景泰县草窝滩镇枸杞幼龄园(1～4年生)和盛果期成龄园(5～8年生)施肥管理现状调查,并结合其20～40 cm土壤养分测试,分析目前该区构杞养分管理中存在的问题及不同龄期枸杞园土壤养分特征.结果表明,该区枸杞养分管理中注重有机肥投入,但施用量不足;化肥施用中重氮素、磷素,轻钾素现象较为普遍.全量养分中有机质和全氮含...     

果树管理中的误区

<正>1施肥误区1.1重化肥,轻有机肥有机肥是改造土壤提高土壤肥力,营造根系良好生长环境的基础肥料,足量的施用有机肥既可确保树体健壮,增强树体抗病虫能力,又可确保连年优质丰产。目前,普遍认可的有机肥指标为,每年产1kg果施入有机肥1.5～2kg。每年每公顷应施入15～60m3优质有机肥,如鸡粪、牲口粪、圈肥、适量的饼肥等腐熟的有机肥。而事实上大多数果园有机肥施入量明显不足,甚至有的果农从来就没施过有机肥。相反,却非常重视化肥的施用,认为化肥施足了就可连年丰产了,殊不知,连年施入大量的化肥,会导致土壤板结,破坏土壤环境及土壤微生物群落。同时在施用化肥时,由于没有通过土壤化验进行配方施肥(平衡施肥)而是凭经验并沿用传统的施用方法,也会导致某种营养元素的过量而产生拮抗作用,或者出现缺素症等一些生理病害。使果树不能正常的生长发育,并使果品产量、质量及效益降低。     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha⁻¹ target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha⁻¹. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹); (2) Lolium perenne L. var. Tove (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m², with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.