深丘烟区烟地不同材质覆盖方式研究

研究了不同材质覆盖处理对烟田水土流失、土壤养分含量以及烤烟生长发育、产量、质量的影响。结果表明:各个覆盖处理均能减少烟田水土和养分流失,调节土壤水分含量,促进烟株生长发育,减轻病害的发生,提高烤烟的质量和产值。在5个处理中,以地膜盖垄(移栽后35 d揭膜)+稻草盖沟处理的经济效益最好,地膜盖垄处理的次之。     

生理整合对覆盖雷竹林克隆分株光合性状的影响

为揭示覆盖栽培竹林生态适应机制与策略,在新造3年雷竹林中,设置覆盖和不覆盖样方,于竹林覆盖盛笋期,进行生理整合对覆盖雷竹林克隆分株光合性状的影响研究。结果表明:相邻覆盖与未覆盖竹林净光合速率(Pn)、胞间CO2浓度(Ci)、蒸腾速率(Tr)、水分利用效率(WUE)相互间均无显著差异;覆盖竹林F3、F6样地与相邻未覆盖竹林气孔导度(Cond)差异显著;覆盖竹林Pn、Cond、Tr、WUE平均水平高于未覆盖竹林,Ci平均水平则低于未覆盖竹林;Pn与Ci呈显著负相关,与Tr呈显著正相关,与Cond呈正相关,相关系数(R值)为0.690,但相关并不显著,Ci与Cond呈显著负相关,说明Tr、Ci是Pn的重要影响因子,Cond是相对重要影响因子。结论认为:竹林覆盖出笋对竹林光合作用起到一定促进作用,但总体不显著,雷竹林冬笋产出主要还是依靠竹林种群的营养储存;覆盖竹林生理整合作用不明显,一是竹林造林时采用的是独立克隆片段和分株,随着竹林郁闭,覆盖与未覆盖竹林相接地段不一定会形成完整的、相互联络的地下茎结构;二是竹林经营过程中的施肥及翻土整地可能会造成竹鞭断脱,导致竹林地下鞭茎克隆片段化,为更好地揭示竹林种群生理整合作用及其机制,需进行种群控制性试验,以进一步得出更加科学的结论,为现代竹林可持续人工培育技术研究提供参考。     

几种覆盖方式对旱地苹果园土壤养分、酶活性及树体生长的影响

连续3a对乔化‘红富士’苹果进行园艺地布、粉碎秸秆、黑色地膜3种覆盖处理,以树盘清耕为对照,研究不同覆盖方式对树体生长量、叶片叶绿素总量、百叶质量、土壤速效磷、土壤速效钾、土壤硝态氮、铵态氮及酶活性的影响。结果表明,3种覆盖处理均能提高土壤速效养分、有机质及酶活性,尤以秸秆覆盖最显著;同时,3种覆盖方式对树体生长量、叶片叶绿素及百叶质量的提高明显高于对照,且地布覆盖秸秆覆盖地膜覆盖对照。覆盖对土壤养分及酶活性的影响主要表现在0~20cm表层土壤。并且随着土层的加深土壤养分及酶活性都降低,有机质与过氧化氢酶、脲酶、蔗糖酶极显著相关。说明:果园覆盖提高土壤速效养分质量分数、有机质质量分数和酶活性,进而改善土壤环境;并且覆盖提高树体生长量、叶片叶绿素总量及百叶质量,从而促进树体生长。可见果园覆盖是生产上有效的农艺增产措施。     

地膜覆盖对土壤微生物群落结构的影响

采用磷脂脂肪酸(PLFA)法测定了沈阳农业大学棕壤长期定位试验站地膜覆盖条件下土壤微生物磷脂脂肪酸图谱及群落结构。结果表明:在玉米苗期,长期施氮肥处理土壤覆膜后大部分脂肪酸含量都有所提高;施有机肥处理的土壤覆膜后脂肪酸的含量有降低的趋势;有机无机肥配合施用处理的土壤覆膜会增加真菌的含量,但却降低了其他脂肪酸的含量;在不施肥处理的土壤中,覆膜会使一些支链脂肪酸的含量降低。抽雄期,施有机肥的土壤覆膜后除单饱和脂肪酸含量有所下降外,其他脂肪酸都会提高;不施肥土壤覆膜处理双不饱和支链脂肪酸及放线菌标志性脂肪酸10Me18:0的含量会有所提高。成熟期,施氮肥的土壤覆膜处理大部分脂肪酸的含量降低;有机肥处理土壤中各种脂肪酸如:15∶0,a17∶0,i17∶0,i19∶0,18∶0,10Me18∶0含量覆膜高于裸地;有机无机配施处理土壤中17∶0,br17∶0,18∶0,18∶2w6,10Me18∶0含量覆膜处理高于裸地;对照土壤中i15∶0,16∶0,17∶0,a17∶0,18∶0,18∶2w6,19∶0含量覆膜高于裸地。另外,从脂肪酸的变化看出,覆膜处理土壤微生物群落整体结构发生了改变,没有表现出明显的种群优势。但是,尽管土壤的施肥处理不同,覆膜处理土壤微生物群落结构有一致化发展的趋势。     

Decomposition of Erythrina poeppigiana leaves in 3-, 9-, and 18-year-old alleycropping systems in Costa Rica

Timing the application of organic residues and therefore the release of nutrients during decomposition may be critical to the growing crop in tropical alleycropping agroforestry systems. Field experiments were carried out in Turrialba, Costa Rica, to determine differences in Erythrina poeppigiana (Walp.) O.F. Cook leaf decomposition in 3, 9 and 18-year alleycropped agroforestry systems. Treatments consisted of mulch-only, and mulch plus Arachis pintoi Krapov. and W. Gregory var. CIAT 18347 in 3 and 9-year old alleycrops under no-till cultivation. The 18-year old site consisted of treatments with mulch-only and mulch plus chicken manure under disk plow cultivation. Litterbags, filled with E. poeppigiana leaves from 3, 9 and 18-year old trees, were placed on the soil surface and collected over a period of 84 days. Results showed no significant differences in the amount of plant residues remaining after 84 days in the 3-, 9-, and 18-year-old systems, or between the manure and mulch-only treatments. Comparing mulch-only treatments, leaves in the 18-year old system decomposed most rapidly which may be due to disk-plow cultivation practices where litterbags were in direct contact with the soil as opposed to the no-till system in the younger alleycrops.     

Influence of mulching and tree shelters on 4-year survival and growth of zeen oak (Quercus canariensis) seedlings

We assessed the effect of mulching and tree shelters on the establishment and early growth of zeen oak(Quercus canariensis Willd.) during the first 4 years after planting in Northwestern Tunisia. Five mulch types(Italian Stone Pine(Pinus pinea L.), Lentisk(Pistacia lentiscus L.),and a combination of Italian Stone Pine and Lentisk(organic mulches), gravel(inorganic mulch) and control), and three tree shelter types(non-vented and vented tree shelters, and control) were tested. An increase in the number of internodes occurred under the gravel mulch, while a reduction in survival was found for the lentisk mulch. Tree shelters had no effect on survival, but increased mean height growth and reduced mean diameter growth during the 4 years(excepting a non-significant effect for vented tree shelter at year four). Comparison of the annual shoots and growth units(GU) between sheltered and unsheltered plants according to year of formation revealed two growth phases. In first phase, shoots were totally or partially inside the shelters; mean length of annual shoots and GU were greater for sheltered plants. The second phase was characterized by shoots emerging from shelters; mean length of annual shoots and GU were similar for all plants, with or without tree shelters. Results suggest that the use of tree shelters, particularly vented shelters, could contribute to the improvement of the artificial regeneration of zeen oak.The use of mulching alone or in combination with tree shelters did not improve zeen oak performance in the field.     

Tree-crop interactions in hedgerow intercropping with different tree species and tea in Sri Lanka: 1. Production and resource competition

Incorporation of tree hedges along contours has been proposed as a means of reducing soil erosion and increasing soil fertility of tea (Camellia sinensis (L.) O. Kuntz) plantations on sloping terrain in high-rainfall zones of Sri Lanka. Tea yields in these hedgerow intercrops are determined by the balance between the positive (i.e., increased soil fertility) and negative (i.e., resource competition) effects of hedgerows. Therefore, the objectives of the present study were to determine: (a) the net effect of six different hedgerow species (Calliandra calothyrsus Meissner, Senna [Cassia] spectabilis (DC.) H. Irwin and Barneby, Euphatorium innulifolium (R.M. King and H. Rob.) H.B.K., Flemingia congesta Aiton F., Gliricidia sepium (Jacq.) (Kunth.) Walp. and Tithonia diversifolia (Hemsl.) A. Gray) on long-term tea yields; (b) the effect of incorporating hedgerow prunings as mulch; and (c) the relationship between hedgerow characteristics (i.e., biomass production, canopy and root growth) and tea yield variation. Tea yields, measured over one complete pruning cycle from October 1998 to September 2001, showed reductions relative to a sole tea crop under all hedgerow species except Euphatorium. The yield reductions ranged from 22 to 40%. Tea yields under Euphatorium showed increases up to 23% relative to the sole crop control. Addition of hedgerow prunings as mulch increased tea yields in all hedgerow intercrops. The yield increases ranged from 11 to 20%, with the highest being under Euphatorium. Tea yields showed a negative relationship (R²=0.38) with the pruned biomass of hedgerows. Limitation of environmental resources (e.g., water and light) and hedgerow characters which intensified resource competition (i.e., greater canopy lateral spread and height and greater root length densities, especially in the top soil layer) were responsible for observed tea yield reductions in hedgerow intercrops.     

岷江上游干旱河谷造林技术试验研究

岷江干旱河谷是我国西部生态环境最恶劣的地区之一。为给该地区植被的恢复与重建过程中提供理论依据,本实验针对其特点,从造林树种选择及其造林方法进行了研究。本试验选择了抗旱能力相对较强的针叶树种:岷江柏、油松、辐射松、白皮松与阔叶树种:密牧豆、元宝枫、榆树、刺槐进行研究,发现岷江柏的成活率最高,达到了89.6%,其次白皮松(89.5%)>榆树(86.7%)>油松(85.8%),都达到了85%以上,再次是刺槐(78.9%);元宝枫(59.1%)、密牧豆较差(53.0%),辐射松最低(50.5%)。同时还开展了采用黑地膜、白地膜、石块覆盖以及不加覆盖物(对照)4种处理方式对林木成活与生长的研究,结果表明:从处理方式上看,表现为覆盖处理均较对照好,其中以白地膜处理下表现最好,成活率达81.8%,黑地膜表现次之,而对照最差,生长量也以白地膜处理下表现最好,对照最差。     

南疆无膜滴灌栽培对棉花出苗及生长指标的影响

为了探明无膜栽培对南疆荒漠绿洲带不同品种棉花出苗、生长指标及产量的影响。采用裂区设计,主区为栽培方式,设无膜和覆膜2个处理;副区为品种,分别为‘中619’(‘CCRI619’)、‘新陆早48号’(‘XZ48’)、‘中74’(‘CCRI74’)。通过大田试验和室内分析相结合方法对各处理棉花的出苗情况、植株性状、生长分析指标及产量等进行测定分析。结果表明：（1）无膜栽培降低了棉花的萌动速度、顶土破土能力及出苗率,出苗整齐度差;（2）无膜栽培与覆膜栽培相比,显著降低了棉花群体的经济产量,极显著降低了棉花的群体生物产量,而对棉花植株性状、干物质分配的影响较小;（3）无膜栽培棉花单株籽棉产量与覆膜栽培相比差异不显著,但无膜栽培下不同品种间单株籽棉产量和群体经济产量差异均显著,表现为‘CCRI619’的产量显著高于其余2个品种。‘CCRI619’适合南疆地区无膜栽培。     

土壤环境调控对板栗细根形态和产量的影响

Objective: To analyze the effects of interrow grass mulching combined with different fertilization treatments on soil physical and chemical properties, root system configuration, nutrient content and productivity in chestnut orchards, Qianxi, Hebei province, where drought, water shortage and problems of unscientific fertilization are serious. Methods: Eight- year- old trees of Castanea mollissima 'Yanshanzaofeng'were taken as the research object, and a split zone experiment design was adopted. The main treatment included interrow mulching with grass and clean tillage, and the secondary treatments were 4 fertilization treatments including single application of inorganic fertilizer (F), single application of organic fertilizer (M), combined application of organic fertilizer and inorganic fertilizer (F+M) and no fertilization (CK). In 2019 and 2020, we studied the effect of mulching and fertilization on water, fertilizer, gas and heat status in the soil, fine root growth, and fine root nutrient content in chestnut orchard. The most suitable soil management model was selected based on fruit productivity. Results: During the growing period (April- October), the average water contents in the soil layers of 0-20 cm and 20-40 cm were significantly higher in the mulching treatments than those in the clean tillage treatment. The average water contents in the soil layers of 0-20 cm and 20-40 cm in the mulched soils were 18.76% and 17.62% higher than those in the cleaned soils, respectively. Interrow mulching in the chestnut orchard significantly reduced the range of diurnal soil temperature change. The variation range of soil temperature in under interrow mulching in summer and autumn was 1.56℃ and 1.10℃ smaller than that in the clean tillage treatment. Mulching had obvious cooling effect in hot season and helped heat preservation in low temperature seasons. Different fertilization treatments significantly reduced the soil bulk density in 0-40 cm soil layer, increased the total porosity of soil, and reduced soil pH value. The influence of interrow mulching on the 0-20 cm soil layer was greater than on the 20-40 cm soil layer. The contents of organic matter and available nutrients in rhizosphere soil of the chestnut orchard were significantly increased by grass mulching and fertilization. Different treatments had a significant impact on the nutrient content in fine roots. The order of N, P and K contents in different treatments were F +M> F> M> CK, and that of organic carbon content was F +M> M> F> CK. The effect of mulching and fertilization on fine roots in the 20-40 cm soil layer was significant. Compared with CK, the fertilization treatments increased the root surface area, root volume, root length density, specific root length and total root length of fine roots. Besides, all the indexes in GC were higher than in CT, and the increments in GC(F+M) and CT(F+M) were the highest. Interrow grass mulching and fertilization directly affected tree roots and indirectly affected the reproductive growth, in this study, the average yield per plant of different fertilization treatments in grass mulching area was significantly higher than that in clear tillage area, and the yield per plant of organic and inorganic fertilizer combined application was the highest, and the increase range of different treatments could reach 4.95%-45.21%. Results of aggregated boosted trees analysis showed that the contribution degree of different soil physical and chemical indexes to yield per plant was Avail. N> Avail. K> Avail. P> Soil water content> Temperature> Organic matter> pH> Total porosity> Soil bulk density, among which the contribution rates of available nutrients and soil water content to yield per plant were the highest, being 52.21% and 13.91%, respectively. Conclusion: Based on the comprehensive analysis, it is concluded that the combination of organic fertilizer and inorganic fertilizer is the optimal fertilization mode for chestnut cultivation in Qianxi region, and is recommended for extensive application in production of chestnut. © 2021, Office of Journal of the Fruit Science. All right reserved.