山东半岛典型流域果园与旱地景观结构分析   总被引：1，自引：0，他引：1  

陈雅琳  常学礼  崔步礼 《中国生态农业学报》2007,15(2):173-177

以烟台市土地利用现状图和2002年9月9日的ETM影像为信息源,结合地面考察,在3S技术的支持下,选取景观百分比、斑块密度、周长-面积分维数和斑块凝聚度,对烟台市16个典型流域的果园与旱地景观结构进行了分析。结果表明,果园在各流域中的面积比重较小,旱地面积占绝对优势;但果园斑块数量多。对各种景观指数比较表明,旱地的平均景观百分比明显高于果园景观,果园景观的平均、最大及最小斑块密度均明显高于旱地景观,两种景观的周长-面积分维数相差不大但斑块凝聚度的差异显著。  相似文献   

不同园龄果园土壤硝化与反硝化活性及N₂O排放（英文）   总被引：1，自引：0，他引：1  

张玉树  丁洪  胡晓霞  张生才  秦胜金  郑祥洲 《农业科学与技术》2012,(4):843-848

[目的]评价硝化反硝化作用在果园土壤氮素损失中的贡献率以及N2O的排放量和排放特性。[方法]在室内培养条件下比较研究了3种不同园龄果园土壤及未开垦土壤之间硝化反硝化活性的差异。[结果]培养26天的未开垦土壤、5年、12年和20年园龄果园土壤的氮肥硝化率分别为6.85%、10.26%、13.29%和12.90%。4种土壤硝化活性均相对较低,但随种植年限的延长呈提高趋势,而且与土壤有机质和铵态氮含量呈显著正相关关系(P<0.05),与全氮含量呈极显著正相关关系(P<0.01),与土壤碳氮比呈显著负相关关系(P<0.05),与pH值呈极显著负相关关系(P<0.01)。3种果园土壤N2O排放量显著高于未开垦土壤(P<0.05),其中硝化作用产生的N2O排放量占施氮量的0.03%～0.08%。硝化过程产生的N2O排放量与土壤有机质、全氮、铵态氮含量呈显著正相关关系(P<0.05),而与土壤碳氮比呈显著负相关系(P<0.05),与pH值呈极显著负相关关系(P<0.01)。不同园龄果园土壤之间氮肥的反硝化活性差异显著,表现为20年>12年>5年>未开垦土壤,反硝化损失氮量占施氮量的0.01%～3.11%,与土壤有机质含量呈显著正相关关系(P<0.05)。[结论]我国南方果园土壤硝化水平相对较低,但随种植年限的延长呈提高的趋势;而土壤反硝化水平相对较高,而且随种植年限的延长显著提高。  相似文献   

用矮化中间砧苹果树建园的几点建议     

荣志祥  伊凯  刘志  杨峰  王宏  王家军  王冬梅  闫忠业 《杂粮作物》2012,(9)

利用矮化中间砧进行苹果树栽培是目前生产的方向,莲择抗逆性强的矮化砧木进行适地适栽,选用优质大苗建园,根据栽植密度、砧木类型和立地条件选择相应树形,以达到早产优质高效的栽培目标。该文针对建园中存在的主要问题,提出建议,供苹果园建园参考。  相似文献   

套种不同牧草的果园土壤对铵的吸附特性研究   总被引：1，自引：0，他引：1  

郑涛  李发林  黄炎和  郑域茹  林阳春  林晓兰  武英  谢南松 《热带作物学报》2012,33(6):1009-1013

以套种不同牧草的果园土壤为研究对象,通过室内等温吸附实验,分析比较了各个处理对氨态氮的吸附特性,并将结果用不同的数学模型拟合进行分析.结果表明:当土壤的氨浓度超过一临界值时,其对氨离子的吸附量会出现明显上升,而在此临界值以下则变化不明显；套种不同牧草可不同程度地提高土壤的铵吸附能力,具体表现为圆叶决明＞百喜草＞平托花生＞宽叶雀稗＞CK(自然生日本草)；各处理土壤铵等温吸附与多项式拟合效果最佳,与Freundlich、Temkin方程拟合达显著水平,Langmuir方程的拟合结果较差.  相似文献   

河北省中南部苹果园土壤养分的消长及分布   总被引：13，自引：0，他引：13  

刘建玲  廖文华  张志华  孙建设 《园艺学报》2006,33(4):705-708

 研究了河北省中南部苹果园1993年和2003年土壤养分的状况及分布特性。结果表明: 经过10年, 0～20 cm苹果园土壤有机质和全氮分别平均增加了2.548、0.317 g·kg^{- 1} ; 碱解氮、速效磷(Olsen-P) 、速效钾分别增加了17.1、122.3、279.5 mg·kg^{- 1} ; 有效铁、锌、锰分别增加了9.2、1.9、10.5 mg·kg^{- 1} , 差异均达极显著水平; 土壤有效铜有所增加, 差异达显著水平。苹果园土壤养分主要在0～40 cm土层积累, 40～80 cm土层也有不同程度的增加, 随着土壤深度的增加各养分积累量逐渐减少; 随着离树干距离的增加, 土壤养分积累量也逐渐减少; 各养分积累量为Olsen-P >速效钾>碱解氮>全氮和有机质。  相似文献   

A dynamic model forecasting infection of pear leaves by conidia of <Emphasis Type="Italic">Venturia nashicola</Emphasis> and its evaluation in unsprayed orchards     

B. -H. Li  J. -R. Yang  X. -L. Dong  B. -D. Li  X. -M. Xu 《European journal of plant pathology / European Foundation for Plant Pathology》2007,118(3):227-238

A dynamic model, called VenInf, was developed to forecast infection of pear leaves by conidia of Venturia nashicola. By simulating conidial infection processes following a rain event, the model estimates % conidia that successfully infected leaves at the end of an infection period. The model is mainly derived from logistic models developed from recent laboratory and glasshouse experimental results on infection of pear seedlings to estimate the rates of infection and mortality. It simulates the conidial infection process at 5 min intervals using temperature, relative humidity (RH), surface wetness and rainfall as input. The model was evaluated against pear scab in four unsprayed orchards in China over a 4-year period. In all orchards, all significant disease increases were associated with infection periods predicted by the model. In one orchard, in 2004 the incidence of leaf infection remained very low (<3%) during the entire season despite the model forecasting several severe infection periods. Results of orchard evaluation suggest that the model is able to identify all important potential infection periods. Thus, further field studies should be carried out to determine whether and how the model can be used in practice to assist farmers in making decisions on fungicide applications.  相似文献   

影响平坝华山松种子园结实量的土壤因子及对策研究   总被引：1，自引：1，他引：0  

周运超  金天喜 《种子》1999,(5):15-17

本文通过对平坝华山松种子园土壤肥力，针叶养分状况与华山松无性系开花结实相关性的研究，寻找出种子产量低的原因，结果表明低产的原因之一是营养生长差，表现在该园土壤缺Ｐ少Ｋ，缺Ｂ，针叶养分状况反映出Ｂ的缺乏，同时Ｎ，Ｐ，Ｋ也偏低，故而施肥是解决的措施之一，施Ｐ提高雄花量，是对照的１３．５倍，施Ｂ提高雌花量和座果量，为对照的１．２倍，２倍。  相似文献   

覆盖对果园土壤真菌数量年变化的影响   总被引：5，自引：0，他引：5  

高美英  冀常军  王中英  祁素萍 《山西农业科学》2000,28(1):46-48

试验结果表明，在整个果树生长期内，覆盖可明显增加各土层中真菌的数量，０ ～２０ｃｍ 土层中，年平均真菌数量增加７９ ．３９％ ，２０ ～４０ｃｍ 土层中增加２８ ．２４ ％ ，４０ ～６０ｃｍ 土层中增加８５ ．０５ ％ 。无论覆盖与对照，不同土层真菌数量年变化均呈单峰曲线变化，高峰出现在８ 月份。  相似文献   

果园开沟深施肥机机械结构设计     

程梅 《安徽农业科学》2014,(23):8086-8088

针对果园深施肥的要求,对果园开沟深施肥机的整体结构进行研究,设计了一款果园开沟深施肥机械,包括总体结构、开沟器和排肥槽。该施肥机的投入使用,将会极大地减轻果农的劳作强度,提高果园深施肥效率,从而提高产果量和果品质,将产生很好的经济效益。  相似文献   

The effect of deficit irrigation on crop yield and vegetative development of Olea europaea L. (cvs. Frantoio and Leccino)     

R. Tognetti  R. d&#x;Andria  A. Lavini  G. Morelli 《European Journal of Agronomy》2006,25(4):356-364

Water is the most important environmental constrain determining plant growth and fruit yield of olive tree plantations. Although olive trees are resilient to water-limited conditions of Mediterranean-type agroecosystems, crop yields may respond positively to any additional water up to a limit. A field experiment on olive trees was carried out with the aim to present guidelines for efficient management of irrigation scheduling, based on the relationship between plant water status and optimum fruit yield. These relationships were monitored during 2 years by analysing the influence of deficit irrigation strategies on vegetative development and yield parameters on mature modern-trained olive trees of cvs. Frantoio and Leccino. Treatments were: a non-irrigated control (rainfed) and three treatments that received seasonal water amount equivalent to 33, 66 and 100% of ET_C in the period August–September, from the beginning of pit hardening to early fruit veraison. Atmospheric evaporative demand and soil moisture conditions were regularly monitored. Seasonal dynamics of plant water relations varied among treatments, and responded to variations in tree water status, soil moisture conditions and atmospheric evaporative demand. All measurements of tree water status were highly correlated with one another. Differences in yield between treatments indicated that water availability might have affected fruit weight before flowering or during the early stages of fruit growth rather than later in summer season. Results concerning crop yield revealed that irrigation of olive trees from the beginning of pit hardening could be recommended, at least in the experimental conditions of this study and in view of differences between genotypes.  相似文献