阴山北麓农牧交错区农田土壤风蚀影响因子及防治对策

土壤风蚀是阴山北麓农牧交错区土地退化的主要原因之一.从风蚀气候因子、地表粗糙度、植被覆盖度、土壤性质和人为影响因素等方面对农田土壤风蚀的主要影响因子进行了分析,探讨了这一地区农田土壤风蚀的防治对策,提出了以实施保护性耕作为主,辅之以间作、轮作的防治风蚀措施.这种措施既能发挥保护性耕作带残茬降风速、保水土、抗风蚀的作用,并对翻耕带形成保护;又可满足地区种植结构,解决保护性耕作带来的杂草防治和农家肥施用难题,对实现地区可持续农业发展具有重要意义.     

晋西果农间作光竞争及产量研究

以晋西黄土高原现有主要果农复合模式即富士苹果--大豆(PD)、富士苹果--花生(PH)、富士苹果--玉米(PY)3种配置结构为研究对象,通过定位对比测定分析3种复合模式中富士苹果与作物光合有效辐射(PAR)、净光合速率(Pn)与产量的关系。结果表明:3种间作模式中随着作物植株由低到高(花生<大豆<玉米),作物接收的光合有效辐射逐渐增高,而果树的光合有效辐射则随着间作作物植株高度增加而逐渐减少;果树的净光合速率变化和光合有效辐射变化一致,在PY、PH、PD模式中间作作物净光合速率逐渐减小;作物距果树树干由近及远,作物的光合有效辐射和净光合速率也逐渐增高。说明在果树栽植密度确定条件下,不同作物高度、种植密度决定不同复合模式光竞争状况;PD、PH、PY3种复合模式产投比分别为4.042:1、4.036:1和3.404:1,PD、PH2种间作模式效益要高于单作苹果的效益,可在晋西地区推广。     

枣粮间作的生态影响及效益分析

本文研究了枣粮间作对区域生态环境的有效影响和作用,从而对枣树在山、沙、碱、旱地区生态环境建设中的作用和地位加以肯定.     

水稻田条带间作大豆、玉米对稻飞虱和缨小蜂种群数量的影响

选择在闽北地区广泛种植的经济作物玉米和大豆与水稻条带间作,利用吸虫器进行取样调查,探讨多样化种植对稻飞虱及其卵期寄生蜂缨小蜂种群动态和雌性比例的影响.结果表明:条带间作大豆或玉米既不能显著减少稻飞虱的个体数量,也不能显著增加缨小蜂的种群数量;间作系统中白背飞虱、褐飞虱、灰飞虱及缨小蜂的雌性比例与水稻单作无显著性差异.因此,本研究所采用的多样化种植模式不能有效抑制稻飞虱的种群数量.     

Integrated management of Striga hermonthica, stemborers,and declining soil fertility in western Kenya

Striga hermonthica (Delile) Benth., stemborers, and declining soil fertility are serious threats to sustainable food production in the Lake Victoria zone of Kenya. To address these constraints, promising integrated crop management technologies were evaluated, using a multi-locational design in four sub-locations in Siaya and Vihiga district (western Kenya) for six cropping seasons. Technologies evaluated consisted of the traditional maize (Zea mays L.) – bean (Phaseolus vulgaris L.) intercrop, maize – Desmodium (Desmodium uncinatum (Jacq.) DC.) push–pull intercrop, Crotalaria (Crotalaria ochroleuca G. Don) – maize rotation, and soybean (Glycine max (L.) Merr) – maize rotation. Within each of these systems, imazapyr-coated herbicide-resistant maize (IR-maize) and fertilizer were super-imposed as sub-plot factors. The push–pull system was observed to significantly reduce Striga emergence and stemborer damage from the second season onwards. IR-maize reduced and delayed Striga emergence from the first cropping season. Differences in Striga emergence and stemborer damage between the other systems were not significantly different. After five cropping seasons, the Striga seedbank was significantly higher in the maize-bean intercrop system than in the push–pull system under both maize varieties while the rotational systems had intermediate values not different from the day zero values. Under IR-maize, the Striga seedbank was significantly lower than under local maize for all cropping systems. Maize yields varied between seasons, districts, and cropping systems. Yields in the push–pull system were higher than in the maize-bean intercrop after two seasons and in the absence of mid-season drought stress. Both maize and soybean responded significantly to fertilizer application for both districts and for most seasons. The various interventions did not substantially affect various soil fertility-related parameters after five seasons. In the short term, IR-maize integrated in a push–pull system is the most promising option to reduce Striga while the rotational systems may need a longer timeframe to reduce the Striga seedbank. Finally, farmer-led evaluation of the various technologies will determine which of those is really most acceptable under the prevailing farming conditions.     

TIBA对不同耐荫性大豆套作苗期生长和倒伏率的影响

三碘苯甲酸(TIBA)是一种生长素运输抑制剂,具有抑制顶端生长的作用。为分析套作模式中,喷施TIBA对不同耐荫性大豆品种幼苗期生长和倒伏的调控效应,本研究设置50,100,150,200和250 mg·kg^-1的TIBA浓度处理,以清水和无遮荫为对照处理,调查大豆形态、干物质和倒伏性状。结果表明:与无荫蔽对照相比,荫蔽下大豆株高增加,茎粗、节数、分枝数、SPAD、干物质则显著降低,倒伏率显著增加。喷施TIBA后,大豆株高显著降低,茎粗、节数无改变,分枝数增加,叶面积下降,叶片SPAD无变化,干物质下降,大豆倒伏率显著降低。套作模式下大豆幼苗期TIBA喷施的适宜浓度为50~100 mg·kg^-1,且适宜浓度与品种自身耐荫能力有关,强耐荫品种南豆12适宜浓度为50 mg·kg^-1,而荫蔽敏感型大豆XBM为100 mg·kg^-1。浓度高于150 mg·kg^-1处理虽然更有利于降低株高、减少倒伏,但大豆干物质积累量偏低,不利于培育壮苗。     

桃树林间作鸡腿菇技术探讨

采用不同的培养料配方,对桃树林和大棚(CK)内栽培的鸡腿菇进行了研究。结果表明,各配方处理桃树林内枝培的鸭腿菇均能正常生长．且优于对照,但存在差异,配方B效果最佳,表现为菌丝生长快、洁白、健壮、出菇早、子实体性状优良、产量高。     

Effect of Planting Geometry on the Growth and Yield Performance of Maize Intercropped with Rice

A field experiment with maize and rice planted under four planting configurations in an intercropping system was conducted to evaluate the plant competition effects on the performance of component crops. Intercropping substantially reduced grain yields of both rice and maize. Rice yield was generally low giving monocrop yield of 1,084 kg/ha. Intercropped rice ranged between 179 kg/ha and 615 kg/ha depending on maize planting arrangement. Monocrop maize yielded highest in square planting (3,617 kg/ha) and lowest in skip-row (2,600 kg/ha) planting, but planting geometry did not influence intercropped maize yield. Monocrop maize outyielded the combined yield of component crops suggesting no yield advantage through rice-maize intercropping.     

泰国—缅甸边境地区珠芽魔芋资源分布及利用现状

泰国达府、北碧府及缅甸孟邦、克伦邦及德林达依省2国狭窄边境地带是全球16个混杂珠芽魔芋核心分布区。泰国占总量的10%~15%,缅甸占85%~90%。其中,4个具特异性、一致性及稳定性栽培种,葡甘聚糖含量高、生物产量高、粘度大,适宜东南亚低海拔高温高湿环境规模种植。该区域大面积橡胶林、柚木林为珠芽魔芋提供了天然遮荫蔽护,林下高矮套种模式能为2国魔芋增产带来巨大空间。     

春玉米生姜间作不同配置方式作物生理效应及综合效益研究

春玉米与生姜间作是根据二者空间生态位、时间生态位与营养生态位相协调而设计的。本试验以行比为处理，研究了间作后春玉米与生姜的生理特性变化及互补与竞争关系。结果表明：间作的春玉米叶绿素含量、根系活力、光合速率较单作都有提高；而生姜的生理特性则随配置方式及生育期的不同而不同。运用灰色关联分析法对不同配置方式的综合效益进行评价，得出1：2式为春玉米与生姜间作的最优模式。