生物炭与不同用量氮肥配施对小白菜生长和品质的影响

为了明确生物炭对小白菜栽培中氮肥减量施用的作用,用0、0.25 g·kg~(-1)(以N计)施氮量的土壤以及4%(w,下同)生物炭与0、0.15、0.20、0.25 g·kg~(-1)土壤施氮量配施的土壤栽培小白菜,探讨生物炭与不同用量氮肥配施对小白菜生长、品质的影响。结果表明:(1)施用生物炭可显著降低土壤容重、EC值,提高土壤孔隙度和pH(;2)在氮肥供应充足时,施用生物炭能显著增加小白菜的叶片数、总叶面积、地上部鲜质量和干质量;(3)与0.25 g·kg~(-1)的施氮量相比,生物炭与60%用量的氮肥(0.15 g·kg~(-1)土壤)配施对小白菜的产量没有显著影响,但氮肥利用效率、可溶性蛋白含量和可溶性糖含量显著提高,硝酸盐含量显著降低。研究发现,4%生物炭与60%用量的氮肥(0.15 g·kg~(-1))土壤配施可以在保证产量的前提下,提高小白菜的品质,并实现减少氮肥施用量的目的。     

Influence of plant density and time of fertilizer application on growth characteristics,nutrient uptake and yield of tomato

In a factorial experiment to investigate the combined effects of plant density and time of split application of fertilizer, 4 spacings and 3 fertilizer treatments were employed. Plant populations were varied between 24,000 and 54,000 per ha. Equal amounts of NPK were applied in different split applications and at specific physiological stages.Time to 50% flowering was delayed by fertilizer application as well as by wide within-row spacing. Total leaf N and P content declined with all treatments between flowering and mature-green stage of fruits, but increased again at table-ripe stage. Leaf K content remained constant throughout the growth period.Two-split applications of NPK, one at 2 weeks after transplanting to the field and the other at fruit set, were more beneficial than either no fertilizer or 3-split applications of equal amount of fertilizer, when the third application was at mature-green stage. This was indicated by higher fruit yields with 2-split applications.Highest fruit yields were obtained when tomatoes were planted either at 30.5 cm × 91 cm single-row spacing, or at 45.5 cm × 122.0 cm, double-row spacing, both giving 36,000 plants per hectare. Fruit yields were reduced at lower and higher population densities.     

袋控缓释肥对桃幼树生长发育的影响

袋控缓释肥根据果树树体较大的特性,结合果树养分需求特性,采用纸塑材料做成的控释袋包裹掺混肥料,袋上针刺微孔,利用微孔控制养分释放,达到供肥和养分需求相一致。大田试验结果表明,施肥后袋控缓释处理土壤Nmin比撒施稳定,土壤Nmin含量维持在60mg/kg左右,养分释放缓慢、平稳,能满足幼树生长发育需要;1次撒施处理施肥2周后土壤Nmin含量达100mg/kg,随后急剧下降,8周后降至不施肥水平;2次撒施处理每次施肥2周后土壤Nmin含量达80mg/kg,即2个高峰。袋控缓释处理桃树根系含有大量的毛细根,与其它处理差异显著,但不施肥处理根系分布范围最广。袋控缓释处理桃树地上部树势中庸,不旺长;撒施处理在第2次施肥前以1次撒施地上部长势最旺,第2次施肥后以2次撒施地上部长势最旺。袋控缓释处理2007年开花观察时,开花数和坐果量均最高;2008年休眠期观察时,单位枝条长度花芽数量最多。     

不同施肥措施对蓝莓植株生长及果实品质的影响

对伯克利蓝莓生长的3个关键期即发芽前、初夏、秋季时,施用3种肥料即硫酸铵、磷酸二铵、氮磷钾复合肥,每株按3个不同的施肥总量即25g、50g、100g进行搭配施肥试验,研究对蓝莓植株生长与果实品质的影响。结果表明,以施用NPK复合肥每株50g,分春夏秋3次分施时,蓝莓的株高、冠幅、新梢长度等生长状况,单果重、单株产量,果实的可溶性固形物含量、有机酸含量、Vc含量等品质指标均最佳。     

Root storage of nitrogen applied in autumn and its remobilization to new growth in spring of persimmon trees (Diospyros kaki cv. Fuyu)

This study was conducted to understand the effect of N supply in autumn on its uptake and distribution in tree parts and the utilization of reserve N the following year in persimmon trees (Diospyros kaki cv. Fuyu). The treated trees received 22.5-g N each for two successive years as a 3.5% urea solution from September 18 at 5-day intervals. Trees absorbed about 30% on average of the N applied in autumn. Sixty four to 83% of the N absorbed in autumn was in perennial parts, and 65–72% of that was in roots. Total N in perennial parts of the tree fertilized with N increased by over 4.28 g while leaf N changed little during senescence, indicating that the reserve N was constituted mostly by the N absorbed in autumn. Total N in the new growth was about the same as the amount of N declined in spring from perennial parts, indicating that there was little contribution by soil N to sustain new growth. Total dry weights of new growth the following year in a with-N tree were greater by over 34 g than those in a without-N tree.     

Effect of transplanting on the growth of muskmelons,and the redistribution of nitrogen absorbed in the nursery

Transplanting muskmelon seedlings from the nursery to the greenhouse did not reduce the rate of increase of total dry weight, leaf area, amount of nitrogen (N) or photosynthetic activity, but N content on a dry-weight base first decreased and then increased. Therefore, transplanting does not necessarily cause a decline of the growth rate of the seedlings. Such a decline may depend on the nitrogenous conditions at the time of transplanting.In an ¹⁵N labelling-experiment, N incorporated into the leaves was actively redistributed to the younger leaves, and N absorbed in the nursery period is thought to be important for growth immediately after transplanting.     

Isotopically-labelled nitrogen uptake and partitioning in sweet cherry as influenced by timing of fertilizer application

Sweet cherry (Prunus avium L.) is a fruit of increasing economic importance though it is less significant than other stone fruit species such as peach. Cherry has received little attention concerning nitrogen (N) uptake and dynamics in mature trees. The aim of this work was to determine N uptake and partitioning as influenced by the timing of fertilizer application in 7-year-old sweet cherry trees cultivated in a cold region (Los Antiguos, Santa Cruz, Argentina; 71°38′ W, 46°32′ S). Nitrogen (95 kg ha⁻¹) was applied as ammonium nitrate to a soil with ‘Bing’ sweet cherry trees grafted onto Prunusmahaleb rootstocks. Fertilization was split into two equal applications per treatment, involving either the commercial fertilizer ammonium nitrate or the same fertilizer labelled with ¹⁵N isotope (10% atom.). Treatments consisted of one early spring (full bloom, October 2005) or one summer (late January 2006, 15 days after harvest) application of ¹⁵N ammonium nitrate to three replicate trees. Fruit were harvested in early January and leaves were collected at both full canopy and leaf fall. All trees were excavated in winter (August, 2006). Trees were partitioned into their components: trunk, branches (current-season shoots, 1-year-old and over-1-year-old branches), buds of the same age, small roots (less than 1 mm thick), large roots, leaves (sampled in February and April), and fruit (collected at harvest). Those components were dried and analysed for total N and ¹⁵N content. Total N per tree and N content derived from the fertilizer did not differ between treatments. Summer postharvest ¹⁵N application partitioned not only to structural components (trunk and roots) but also to buds and leaves. Uptake efficiency was significantly (p = 0.0113) higher in the spring than in the summer application (65.7% vs. 37.44%). Nevertheless, 52.5% of N applied in spring was lost due to harvest and summer pruning. This emphasizes the importance of the postharvest N fertilization which increases N accumulation in both reserve organs and buds though, according to our data, it is less efficiently used. The extent of nitrogen uptake, efficiency of use and partitioning in the following growing seasons are still open questions that deserve further research.     

The effect of combined Azospirillum inoculation and nitrogen fertilizer on plant growth promotion and yield response of the blanket flower Gaillardia pulchella

The investigation was carried out to examine the performance of Azospirillum isolates on growth and N uptake of Gaillardia pulchella with two nitrogen levels. Azospirillum strain OAD-2 inoculation significantly increased plant height, number of leaves per plant, branches per plant and total dry mass accumulation in G. pulchella than other inoculations and/or uninoculated control. The application of 150 kg N ha⁻¹ further enhanced the above plant growth parameters significantly over application of 112 kg N ha⁻¹. The N uptake of G. pulchella was enhanced due to Azospirillum strain OAD-2 inoculation, which was further augmented in the presence of nitrogen. The combination of Azospirillum strain OAD-2 and 150 kg N ha⁻¹ showed the highest N uptake at 120 DAT. Plant growth and yield parameters also increased when inoculated with the non-diazotrophic, but efficient IAA producing, Azospirillum strain OAD-57. From this investigation, it can be concluded that Azospirillum strains OAD-2 and OAD-11 can play an important role in the N nutrition of G. pulchella.     

WGD-2叶面肥与植物生长调节剂对澳洲坚果的保果效应

WGD-2是南亚热带作物研究所研制的用于澳洲坚果的保果叶面肥。以澳洲坚果品种Hinde(H2)为试材,研究了6个处理对澳洲坚果在幼果期和谢花至幼果形成期的保果效果。6个处理分别为清水对照(CK)、120mg·L-1WGD-2(T1)、120mg·L-1WGD-2+1mg·L-1NAA(萘乙酸)(T2)、120mg·L-1WGD-2+10mg·L-12,4-D(2,4-二氯苯氧乙酸)(T3)、120mg·L-1WGD-2+20mg·L-1CPPU(N-(2-氯-4-吡啶基)N'-苯基脲)(T4)、120mg·L-1WGD-2+40mg·L-1GA3(赤霉酸)(T5)。结果表明各处理在幼果期(果实直径0.5cm左右)施用均有不同程度的保果效果,2次施用效果具有累加效应,即重复施用可加强保果效果,以T1、T4处理效果最好。谢花至幼果形成期施用,T1和T4处理仍然具有累加效应;T2处理没有效果;T3处理重复施用刺激幼果脱落;T5处理具有刺激幼果脱落效应。在澳洲坚果生产中推荐WGD-2单独使用或与CPPU搭配使用,并严格控制WGD-2与植物生长调节剂搭配使用的质量浓度和处理时期。     

倒春寒危害软籽石榴树的温度及受害情况研究

以突尼斯软籽石榴为试材,在倒春寒发生前2 d开始持续监测石榴树冠层温度,倒春寒结束后调查石榴树受倒春寒危害的临界低温及寒害症状。结果表明,软籽石榴树春季生长期间,岭地、沟地和台地石榴树冠层温度降至1.4℃、-0.1℃、2.3℃,气象预报低温低于6.4℃时,石榴树芽和新梢发生低温寒害,芽尖焦枯发黑,芽体展叶受阻;新梢幼叶扭曲畸形,叶缘焦枯。     

Root damage affects nitrogen uptake and growth of young Fuji/M.26 apple trees

Summary

Effects of root damage during the transplant process on growth and nitrogen (N) uptake were studied with one-year-old bench-grafted Malus domestica Borkh ‘Fuji’ on M.26 rootstock apple nursery plants. Plants were potted after grafting and grown outside for one season. At the end of the season uniform trees were selected and randomly divided into four groups. One group of plants were moved into a 2°C cold room with soil and container intact (IR Treatment). Plants in other groups were removed from pots and stored as bareroot in the same cold room for three months. In the spring, bareroot plants were either: (1) transplanted with about 10% of the root system damaged during transplant (TP Treatment and Control-CK); or (2) root pruned by 25% (by volume) prior to transplant (RP treatment). Five trees from each treatment received 1 g of ¹⁵NH₄¹⁵NO₃ at 12, 41 and 76 d after repotting. Control (CK) trees received no N. Trees were harvested 10 d after each N application, and plant growth and total N and ¹⁵N content of different tissues were determined. Root pruning reduced plant total biomass and root biomass at the first two harvests, but the plants from the RP treatment had highest total plant biomass and root biomass at the third harvest. There was no significant difference in the new stem and leaf growth among IR, RP and CK treatments at harvests but the TP treatment reduced new shoot biomass. Plants with intact roots (IR) had the higher total N content while control plants (CK) had the lowest. Root pruning reduced ¹⁵N uptake rate at the first two harvests but promoted it at the third harvest. Our results suggest that plant growth and nutrient uptake was suppressed by root pruning/damage during transplanting only in the early season, and the negative effects on growth and N uptake were offset later in the season by compensative root regeneration.     

土壤有效钾含量及钾肥用量对西瓜生长的影响

为了研究不同土壤有效钾含量下,施用钾肥对大棚西瓜品质及产量的影响,试验以‘早佳’西瓜为材料,历时2年时间,选择土壤有效钾含量不同的8个试验点,设定4~5个处理,对植株长势、果实品质及产量进行比较。结果表明,施用钾肥对西瓜有促进生长、提高含糖量、增加产量的效果。土壤有效钾质量分数低于200 mg·kg~(-1)的地区,667 m~2施K_2O 10 kg,长势好,品质优,单果质量、产量增加明显。有效钾质量分数高于200 mg·kg~(-1)的地区,667 m~2施K_2O 5~6.7 kg,有利于改善品质,对产量提高无明显作用。     

撒施复合肥柑橘园土层剖面中氮磷钾分布特征

【目的】为了探明柑橘园连续多年撒施复合肥后土层中氮、磷、钾的分布特征,【方法】2009年对重庆忠县30个紫色土柑橘园和江西省赣南地区3个县(市)24个红壤柑橘园不同土层的碱解氮、有效磷和有效钾含量进行了分析。【结果】柑橘园连续多年撒施复合肥后,不同土壤剖面中碱解氮、有效磷和有效钾含量从上往下逐渐降低。在紫色土柑橘园,碱解氮主要累积在5～25 cm土层,占累积总量的55.76%;有效磷主要累积在0～15 cm土层,占累积总量的79.41%;有效钾主要累积在5～25 cm土层,占累积总量的54.18%。在红壤柑橘园,碱解氮主要累积在10～30 cm土层,占累积总量的46.12%;有效磷主要累积在0～10 cm土层内,占累积总量的76.78%;有效钾主要累积在3～20 cm土层,占累积总量的50.56%。【结论】氮肥撒施后在土壤中移动能力较强,而磷肥在土壤中难于移动,钾肥介于氮肥和磷肥之间。     

土壤调理剂与有机肥配施对西瓜生长、产量及品质的影响

为探讨土壤调理剂与有机肥配施在盐碱地西瓜上的应用效果,设计常规施肥+土壤调理剂+有机肥(A)、常规施肥+土壤调理剂(B)、常规施肥+有机肥(C)、常规施肥(CK)4个处理。结果表明,与CK相比,单施及配施土壤调理剂和有机肥均能促进西瓜生长、提高西瓜果实产量和品质;A处理小区西瓜长势优于其他处理,对西瓜生长发育、产量和品质的影响与其他处理之间均达到显著性差异水平,主蔓长273.63 cm、667 m~2产量4 868.85 kg、中心可溶性固形物含量12.2%、边部可溶性固形物含量8.5%,较CK处理分别提高26.21%、27.24%、6.09%、4.61%;B、C处理对西瓜生长发育、产量和品质的影响与CK处理之间的差异也达到显著水平,但B、C处理之间差异不显著。综上所述,土壤调理剂和有机肥配施可有效促进西瓜生长发育,提高西瓜产量和品质,同时对西瓜田间长势和抗病性也有一定促进作用。     

不同施氮处理对设施甜瓜生长发育、产量和品质的影响

以新疆吐鲁番地方品种‘西开心’甜瓜为试材,通过5个不同施氮处理对设施甜瓜生长发育和产量品质的影响,以常规施肥(CK1)和不施肥(CK2)处理作为对照,来确定最佳施氮量和配比,为设施甜瓜种植合理开展氮肥减量增效施肥技术示范和推广提供理论依据。结果表明,(1)在试验氮素处理范围内,随着氮肥施入量的增加,对甜瓜幼苗的营养生长起到了促进作用,有利于甜瓜果实的膨大和产量品质的提高,但是超过最佳氮肥施入量后,甜瓜果实大小、平均产量和品质都开始下降;(2)根据理论计算,当纯氮量为每667 m~2施用量为16.08 kg时,每667 m~2产量达到最大值1 530.25 kg。生产实际中,我们既要考虑到甜瓜每667 m~2的产量和品质,又要兼顾投入、产出和市场等因素,所以在根据纯收入和产投比等指标综合考虑,处理3是比较适合的氮肥处理。     

Influence of rate and method of application of superphosphate on the growth and nutrient status of newly planted peach trees

A field experiment was carried out with newly planted peach trees to determine the influence of both rate and method of application of superphosphate on tree growth and nutrient status during the first growing season. Superphosphate was applied at planting at rates ranging from ¼ to 9 lb per tree, and applications were made either to the soil surface, in the planting hole, under tree roots, or in a band around the tree at a depth of 6 inches. Trees were grown under straw mulch and were irrigated as required.

Results showed that, in this soil of low initial ? content, trees receiving 9 lb superphosphate on the soil surface or in a ring band grew significantly larger than trees receiving ¼ lb superphosphate per tree (this applied for butt circumference only on surface-treated trees), but high rates of superphosphate in the planting hole or under tree roots resulted in tree death. No significant differences in growth were recorded at harvest between surface and ring-banded treatments at any phosphate rate, but leaf analysis in midsummer and tree analysis at harvest showed that the phosphate status of surface-treated trees was significantly higher than that of ring-banded trees.

At low rates of superphosphate (¼ and 1 lb per tree), surface treatment tended to give larger trees at the end of the growing season than band treatment, but differences were not significant. It is thought that this differential response occurred because the phosphate-fixing potential of the soil increased sharply with depth and hence band applications were inefficient unless very high rates of superphosphate were used.

The tree damage observed when high rates of superphosphate were applied in the planting hole or under tree roots was probably due to a combination of osmotic stress, acidity damage to the roots and possibly toxic nutrient levels in tree tissues. Hence high rates of superphosphate should not be placed close to tree roots at planting.

Leaf analysis in midsummer and tree analysis at harvest showed that the main effect of superphosphate application was on the ? status of the trees, and maximum tree growth in the surface and band treatments corresponded to a value of approximately 0.28% ? (dry weight basis) in the leaves. The efficiency of uptake of applied superphosphate was very low at all rates of application and was especially so at high rates. However, positive growth responses were recorded to 9 lb superphosphate per tree in surface and banding treatments. It is suggested that, although most of the applied superphosphate could not be utilized, tree growth rate was proportional to the concentration of ? in the soil zone which could be exploited by the roots.     

Effect of pruning and plant spacing on the growth of cherry rootstocks and their influence on stem water potential of sweet cherry trees

Summary

The aims of this work are to describe the effects of pruning and planting density on growth and water relations of ungrafted and grafted sweet cherry trees. A trial with cherry rootstocks ‘Prunus avium’, ‘CAB 11E’, ‘Maxma 14’, ‘Gisela 5’ and ‘Edabriz’ was begun in 1997. Pruning severities were applied to the rootstocks (0, 30, 60 and 90% of the vegetative growth was removed corresponding to P1, P2, P3 and P4 treatments, respectively) after planting to two plant spacings (S1 = 0.25 × 1.0 m and S2= 0.45 × 1.5 m). Canopy, root growth and leaf water potential (ψ_leaf) were quantified throughout the growing season. Pruning significantly affected root length and root weight of the rootstocks. Uncut plants (P1) showed a heavier and expanded root biomass (231 g and 108 m) than the intensively pruned plants (P4) (187 g and 75 m). The greater root biomass was obtained with the spacing/pruning combination, S1/P1 (285 g), and the smaller with S1/P4 (180 g) and S2/P4 (176 g). ψ_leaf varied significantly between the rootstocks and plant spacing but not with pruning. ‘Maxma 14’ and ‘P. avium’ attained the lowest values of midday ψ_leaf, –2.28 and –2.04 MPa, but the highest values of predawn ψ_leaf, –0.29 and –0.25 MPa, respectively. Generally, with high density (S1), the rootstocks exhibited lower predawn and midday ψ_leaf. In 1998, cultivars ‘Burlat’, ‘Summit’ and ‘Van’ were grafted onto rootstocks and a trial was installed in 1999. Predawn and midday stem water potential (ψ_stem) on cherry trees, measured in 2002, were affected significantly by the rootstock/genotype combination. Cultivars grafted on ‘P. avium’ and ‘Maxma 14’ showed the less negative midday ψ_stem, –1.36 and –1.42 MPa respectively, so these rootstock genotypes perhaps induced a higher drought resistance to the scion. Recorded data show that the scion-rootstock interaction with regard to production performance under water deficits may be an important consideration in cherry tree planting strategies.     

Improvement of compactness and floral quality in azalea by means of application of plant growth regulators

The ornamental industry's difficulties in producing compact and well branched plants have been the subject of extensive evaluation, the problems being compounded by the fact that each species, and even each cultivar, requires a specific protocol. In this work, growth regulators (daminozide, paclobutrazol and chlormequat chloride) and chemical pinching agents (fatty acids) were applied to reduce shoot extension with a view to lowering production costs whilst optimizing plant quality in the production of azalea japonica. Assessment of the effectiveness of the different treatments was achieved using image analysis as a quantitative method which we consider to be a faster and more objective technique than classic biometry. The results indicate that daminozide and paclobutrazol treatment are the best options to control vegetative development and to promote the flowering of azalea japonica in a cold and humid zone such as Asturias. However, daminozide treatment induces floral deformation in one of the tested cultivars, Blaauw's Pink.     

The effect of nitrogen,volume of media,plant density and module shape on the growth of asparagus seedlings

There were three experiments in which the seedlings were raised in media contained in plastic cells. In Experiment 1, 150 or 200 mg l^?1 N were applied in factorial combination with cell volumes of 20, 32 or 50 cm³, There were 6 successional harvests. All cells were 7.5 cm deep and cylindrical in shape. Experiment 2 compared these 3 cell volumes at densities of 983, 1532 or 2440 plants per m². Cell diameters restricted the 50-cm³ cell to the 983, and the 32-cm³ cell to the 983 and 1532 plants per m² densities. 200 mg l^?1 N increased shoot growth, but not root growth. This increase in shoot growth was not considered advantageous. Seedling growth increased with increases in cell volume, but there were no responses to changes in plant density. Experiment 3 compared a cell having an inverted pyramid shape with a cylinder. The cylinder, despite holding 20% less media, produced the larger seedlings.     

Effect of nitrogen and sulfur interaction on growth and pungency of different pseudostem types of Chinese spring onion (Allium fistulosum L.)

Effects of N and S supply on the growth and pungency (estimated as pyruvic acid levels) of Chinese spring onion (Allium fistulosum L. var. giganteum Makino) were investigated in two pot experiments using soilless growing media. In the first experiment the effects of S supply (0.01 and 4.00 mmol L⁻¹ SO₄²⁻) on the growth and pungency of Chinese spring onion were investigated among four cultivars with fleshy root type or long pseudostem type. In the second experiment the effects of different S (0.01 and 4.00 mmol L⁻¹ SO₄²⁻) and N (1.5, 3.0, 6.0, 12.0 and 24.0 mmol L⁻¹ N) supply levels on the growth and pungency of Chinese spring onion were studied. Fleshy root spring onion had stronger pungency and larger pseudostem diameter than long pseudostem spring onion, and the pungency of fleshy root spring onion was regulated to a greater extent by N and S supply compared with long pseudostem spring onion. Increasing S supply level significantly increased the biomass, N and S uptake and pungency of all cultivars tested. The biomass of Chinese spring onion of fleshy root type (cv Longyao) and long root type (cv Zhangqiu) was more influenced by N supply than it was by cultivar or S supply. Low S supply decreased the pungency of the two cultivars with increasing N supply. No significant differences in N or S uptake or pungency were observed in the two cultivars with different S supply at the N supply level of 1.5 mmol L⁻¹ N, however, cultivar differences in N and S uptake and pungency were investigated at high N supply (12.0 mmol L⁻¹ N) and S supply (4.0 mmol L⁻¹ SO₄²⁻). Excessive N supply (24.0 mmol L⁻¹) significantly inhibited plant growth, retarded S assimilation, and decreased pungency. It is therefore essential to apply the optimum recommended rate of N fertilizer in Chinese spring onion production.