枣树经济施肥与氮素营养诊断的研究

采用3因素5水平回归最优设计方法,对枣树进行了最佳施肥量试验研究。建立了氮、磷、钾施肥量与枣树产量之间的效应模型,利用肥料效应模型,对枣树最佳施肥方案,各肥料的主效应、交叉效应和边际效应进行了探讨。与此同时,对枣树氮素营养诊断进行了研究,探讨了氮素营养状况对枣树生长、结果和果实品质的影响,确定了氮素营养诊断的临界范围。     

枣树经济施肥与氮素营养诊断的研究

采用三因素回归最优设计方法,对枣树(Zizyphus jujuba Mill)氮、磷、钾最佳施肥量进行了定量研究,建立了氮、磷、钾肥施用量与枣树产量之间的效应模型。利用肥料效应模型,对枣树最佳施肥方案,各肥料的主效应,交互效应和边际产量效应进行了探讨。同时,还对枣树氮素营养诊断进行了研究,探讨了氮素营养状况对枣树生长。结果和果实品质的影响。确定了氮素营养诊断的临界值范围。     

核桃“3414”肥料效应试验及推荐施肥量的回归分析

为了探寻最适养分施用量和最佳施肥方案,从而提高核桃产量和培肥土壤,为核桃生产中的科学施肥提供技术指导,以陕西省黄龙县栽培的‘香玲’核桃树为试验材料,采用"3414"试验设计进行了施肥效应试验,并结合试验田的基础地力水平,采用两种方法对核桃产量与肥料用量之间的关系进行了回归分析,得出了N、P2O5、K2O这3种肥料的最佳用量。结果表明:不同的施肥量对核桃产量的影响很大,缺肥或少肥都会影响核桃产量,与对照相比各施肥处理的核桃产量均有提高,其中处理6(N2P2K2)的产量最高;而且,在这3种肥料的互作效应中,N、P、K的互作效应最高,其次为N与K、N与P、P与K的互作效应。由回归方程计算得出的N、P2O5、K2O的最高施用量分别为1.009 1、0.190 4、1.227 6 kg·株-1,最佳施用量分别为0.987 5、0.1648、1.226 0 kg·株-1,最高和最佳产量分别为8.373、8.368 kg·株-1。N、P2O5、K2O含量与产量的一元二次拟合方程的拟合程度均较好(R2值均较大),但在此3种养分施用量与产量的一元二次效应方程的相关关系中,N、P2O5、K2O都没有达到显著水平。以两种拟合方程计算得到的结果相近,考虑到既要高产又能培肥土壤的目的,该研究以采用三元二次效应方程拟合的养分推荐施用量作为核桃试验地施肥的标准用量。     

配方施肥对五味子高生长的影响

通过对疏林灌丛中栽植的五味子进行配方施肥试验,结果表明,N、P、K及其组合施肥对五味子高生长产生影响,影响效应依次为N>P>K,二元肥料组合中,N、K组合>P、K组合>N、P组合,最佳三元肥料组合N、P、K分别为4.83、.47和6.59 g.株-1。     

撑绿竹纸浆原料林施肥效应研究

对撑绿竹纸浆林施肥采用"3414"三因素四水平的二次回归试验设计,建立了N、P、K施肥与撑绿竹新竹产量间的回归模型。结果表明,施用N肥是影响撑绿竹新竹产量的主导因子,N、K2O间存在一定程度的正交互作用。在设定的N、P、K肥0-3水平内符合肥料效应函数法原理的前提下,通过频率分析可得推荐施肥用量:纯N为177.744-261.096kg·hm-2,平均219.420kg·hm-2;P2O5为29.700-45.900kg·hm-2,平均37.800kg·hm-2;K2O为100.800-152.910kg·hm-2,平均126.855kg·hm-2。施肥比例:N∶P2O5∶K2O=1∶0.172∶0.578。     

绿竹笋用林施肥效应研究

以肥料种类、施肥数量与方法为因子采用正交设计绿竹笋用林施肥措施,结果表明：影响产笋量各因素的主次关系为施肥总量〉N、P、K比例〉施肥方法,各因素的最优水平组合为N：P：K为5：2：1,施肥总量1080kg/hm^2,N、P、K比例对个体重影响显著,个体重有随N肥比例的增加而增加的趋势。     

配方施肥对辣木生长效应及其初果期产量构成的影响

[目的]研究不同配方施肥对辣木生长效应及产量构件因素的影响,[方法]采用正交设计L9(34)3因素3水平进行施肥试验。[结果]施肥处理对各时期生长有显著的促进作用,且营养生长期N肥和K肥占主导作用。适合株高和地径生长的最优组合为N150P40K100,而适合冠幅和分枝数生长的最优组合为N85P85K100。生殖生长各指标较对照均有明显提高。低浓度的氮肥和高浓度的磷钾肥有助于辣木的开花和座果,同时提高果荚产量和种子产量,明显促进产量增加以及花序数、成熟果数、百粒质量和座果率的提高。[结论]合理的配比施肥显著促进辣木的生长效应以及提高产量,果荚产量和种子产量的最优组合为N_(40)P_(150)K_(100)。     

核桃配方专用肥对核桃树产量及坚果品质的影响

【目的】研究不同配比肥料对核桃树产量和坚果品质的影响情况,为陇南地区核桃生产中配方肥料的筛选提供参考依据。【方法】以栽植10年的‘清香’核桃树为研究对象,以专利配比肥料(专利号为ZL 2013 1 0478984.X,N∶P∶K=5∶3∶1)为对照组,以配方专用肥(专利配比肥料加微量元素优化肥,N∶P∶K=28∶16∶6)作为肥料甲,以生产中常用的不同配比的三元复合肥作为肥料乙(N∶P∶K=22∶14∶14)和肥料丙(N∶P∶K=25∶10∶15),每种肥料各设3个施肥水平,同一施肥水平的单位树冠投影面积的N元素用量相同,试验共设1个对照组和3个处理(即处理Ⅰ、Ⅱ、Ⅲ)组,每个处理又各设3次重复,共设10个试验组,于2017—2019年在甘肃省成县城关镇宁寨村核桃园进行了连续3年的施肥试验,并对试验树的产量与坚果品质进行了测定和分析。【结果】每平方米树冠投影面积下施入0.311 kg肥料甲(即核桃配方专用肥,其配比为N∶P∶K=28∶16∶6,N、P、K有效含量均为50%,N、P、K的施用量分别为0.087、0.050、0.019 kg·m~(-2))对核桃树的产量及坚果品质的作用效果显著(P 0.05),其次为对照组,肥料甲处理Ⅱ的核桃树每平方米树冠投影面积的干果产量平均为2.20 kg,比对照组的多0.31 kg,比肥料丙处理Ⅰ的多1.10 kg;肥料甲处理Ⅱ的平均单果质量为15.798 g,比对照组的增加0.102 g,比肥料丙处理Ⅰ的增加1.164 g;肥料甲处理Ⅱ的坚果平均出仁率为54.6%,比对照组的增加0.1%,比肥料丙处理Ⅰ的增加1.6%;肥料甲处理Ⅱ的坚果平均出油率为60.1%,比对照组的高0.9%,比肥料丙处理Ⅰ的高6.8%;肥料甲处理Ⅱ的坚果三径平均值最大。【结论】肥料甲处理Ⅱ的核桃树产量最高,其坚果品质最佳;配方专用肥甲处理Ⅱ的肥料配比(N∶P∶K=28∶16∶6)和肥料用量(每平方米树冠投影面积的施肥量为0.311 kg)是目前促使陇南地区核桃树丰产、提高其坚果品质的最佳配比和最适用量。     

不同氮、磷、钾施肥水平对盐碱地水稻旱育秧苗的影响

采用最佳回归设计，通过对水稻旱育秧不同N、P、K施肥水平对秧苗素质的影响进行研究。从而为科学确定肥料的施用范围，培育壮秧，提高水稻产量提供理论依据。     

绿竹笋营养成分及笋期叶养分的施肥效应

研究施有机肥、复合肥、无机肥对绿竹笋营养成分及笋期叶片N、P、K含量的影响。结果表明 :3种肥料处理对绿竹笋N、P、K含量、粗蛋白质、粗纤维、蛋白质水解氨基酸含量有明显的促进作用 ,竹笋N和蛋白质含量以无机肥处理最高 ,P含量、氨基酸总量、必需氨基酸总量以复合肥处理最高 ,K含量、粗纤维、半需氨基酸总量以有机肥处理最高 ,但还原糖、总可溶性糖、蔗糖、淀粉含量不施肥处理明显高于施肥处理。 3种肥料处理对绿竹叶片N、P、K含量的影响在不同发笋时期表现出一定的差异性 ,发笋初期N、P、K含量施肥处理明显高于不施肥处理 ,以无机肥处理最高 ;盛期叶片N、P含量以有机肥处理最高 ,K含量以无机肥处理最高 ;末期N含量以有机肥处理最高 ,P含量以不施肥处理最高 ,K含量以无机肥处理最高 ,表现出不同肥料施肥效应的差异性。     

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.