Effects of Different Intercropping Patterns on Population Yield and Benefit of Fresh Maize and Mung Bean

In order to find the best intercropping pattern of fresh maize and mung bean, five planting patterns, namely fresh maize monocropping, mung bean monocropping, fresh maize and mung bean intercropping at row ratios of 2∶4, 3∶3 and 4∶2 were set up, and the yields and economic benefits of these planting patterns were analyzed. The results showed that the LERs of the three intercropping patterns were all above 1, and the economic benefits of 2∶4, 3∶3 and 4∶2 fresh maize and mung bean intercropping patterns were seen an increase of 2.85%, 17.64% and 14.26% respectively compared with fresh maize monocropping and an increase of 52.06%, 73.92% and 68.93% respectively compared with mung bean monocropping.Among the three intercropping patterns, the intercropping pattern with row ratio 3∶3showed the best effect, which also derived the highest LER with greatest economic benefit.

Effects of Intercropping Systems of Castor Bean, Maize and Common Bean on Their Growth and Seed Yield in the Soudano Guinea Zone of Cameroon

Field trial was carried out in the Soudano-Guinean zone of Cameroon to investigate the effect of intercropping systems of castor bean with common bean and maize on their growth and yield. Randomized complete block design with three replications was used and five treatments： castor bean in monoculture or in association with common beans or maize, common bean in monoculture and in association with castor bean, maize in monoculture and in association with castor bean. The growth parameters and seed yield were evaluated. Castor beans associated with either maize or common bean grew faster compared to the monoculture system. In addition common bean exhibited fast growth and high seed yield when associated to castor bean, while, no significant difference was observed for maize. In conclusion, the culture of castor bean in association with common bean or maize is advantageous for the peasants in the Adamawa Cameroon region.

High-efficiency Planting Techniques of Five Crops a Year for Fresh Edible "Faba Bean/Spring Mazie+Soybean-Autumn Maize/Autumn Soybean"

The high-efficiency planting mode for five crops a year of fresh edible ＂faba bean/spring maize＋soybean-autumn maize/autumn soybean＂ was introduced, and its yield and economic benefits were compared with the planting mode of three crops a year of ＂faba bean-spring maize/red bean＂. The results showed that the planting method for fresh edible ＂faba bean/spring maize＋soybean-autumn maize/autumn soybean＂ was much easier to operate with the input-output ratio of about185.6%, and its yield and economic benefits were 2.09 and 1.83 times of that of the planting mode for three crops a year, significantly improving the agricultural yield and income of farmers. In addition, the cropping index of the planting mode for fresh edible fresh edible ＂faba bean/spring maize ＋soybean-autumn maize/autumn soybean＂ reached up to 350%, and planting faba bean once a year and soybean twice a year could make the biological fixation amount of nitrogen increase 350-450kg/m^2, which equaled to up to 700 kg/m^2 of urea, showing significant ecological and social benefits. Based on the comparison results, the high-yield culture techniques of the planting mode of fresh edible ＂faba bean/spring maize＋soybean-autumn maize/autumn soybean＂ were summarized.

Yield performance and optimal nitrogen and phosphorus application rates in wheat and faba bean intercropping

Yield performance in cereal and legume intercropping is related to nutrient management,however,the yield response of companion crops to nitrogen(N)input is inconclusive and only limited efforts have focused on rationed phosphorous(P)fertilization.In this study,two multi-year field experiments were implemented from 2014-2019 under identical conditions.Two factors in a randomized complete block design were adopted in both experiments.In field experiment 1,the two factors included three planting patterns(mono-cropped wheat(MW),mono-cropped faba bean(MF),and wheat and faba bean intercropping(W//F))and four N application rates(N0,0 kg N ha^(-1);N1,90 and 45 kg N ha^(-1) for wheat and faba beans,respectively;N2,180 and 90 kg N ha^(-1) for wheat and faba beans,respectively;and N3,270 and 135 kg N ha^(-1) for wheat and faba beans,respectively).In field experiment 2,the two factors included three P application rates(P0,0 kg P_(2)O_(5) ha^(-1);P1,45 kg P_(2)O_(5) ha^(-1);and P2,90 kg P_(2)O_(5) ha^(-1))and the same three planting patterns(MW,MF,and W//F).The yield performances of inter-and mono-cropped wheat and faba beans under different N and P application rates were analyzed and the optimal N and P rates for intercropped wheat(IW)and MW were estimated.The results revealed that intercropping favored wheat yield and was adverse to faba bean yield.Wheat yield increased by 18-26%,but faba bean yield decreased by 5-21% in W//F compared to MW and MF,respectively.The stimulated IW yield drove the yield advantage in W//F with an average land equivalent ratio(LER)of 1.12.N and P fertilization benefited IW yield,but reduced intercropped faba bean(IF)yield.Nevertheless,the partial LER of wheat(pLER_(wheat))decreased with increasing N application rates,and the partial LER of faba bean(pLER_(faba bean))decreased with increasing P application rates.Thus,LER decreased as N input increased and tended to decline as P rates increased.IW maintained a similar yield as MW,even under reduced 40-50% N fertilizer and 30-40% P fertilizer conditions.The estimated optimum N application rates for IW and MW were 150 and 168 kg ha^(-1),respectively,and 63 and 62 kg ha^(-1) for P_(2)O_(5),respectively.In conclusion,W//F exhibited yield advantages due to stimulated IW yield,but the intercropping yield benefit decreased as N and P inputs increased.Thus,it was concluded that modulated N and P rates could maximize the economic and ecological functions of intercropping.Based on the results,rates of 150 kg N ha^(-1) and 60 kg P_(2)O_(5) ha^(-1) are recommended for IW production in southwestern China and places with similar conditions.

Competitive Relationships and Yield Advantage of Intercropping Faba Bean with Sugar Beet under Bio-Organic Additives and Mineral Nitrogen Fertilizer Rates

A field experiment was conducted at El-Serw Agricultural Research Station, Damietta Governorate, Egypt during 2016/2017 and 2017/2018 seasons to reduce mineral N inputs of sugar beet with increased land use efficiency and profitability under intercropping conditions. Seven treatments included five treatments (90 kg nitrogen “N” + 30 m3 farm yard manure “FYM”/fad, 80 kg N +30 m3 FYM/fad, 70 kg N +30 m3 FYM/fad and 400 g of Cerealine + 30 m3 FYM/fad for intercropping faba bean cultivar Spanish with sugar beet cultivar Gloria) and two treatments (90 and 20 kg N/fad for solid culture of sugar beet and faba bean, respectively, as recommended mineral N fertilizer rate) were compared in a randomized complete block design with three replications. Solid culture of sugar beet with the application of recommended rate (90 kg N/fad) gave the highest top, root and sugar yields/fad, as well as the percentage of purity compared with the other treatments in both seasons. Intercropping faba bean with sugar beet plants with application of 90 kg N + 30 m3 FYM/fad gave the highest number of leaves/plant, leaf area/plant, root length, root diameter and root weight/plant followed by intercropped sugar beet plants that fertilized with 80 kg N + 30 m3 FYM/fad compared with the other treatments in both seasons. On the other hand, intercropped sugar beet that received 400 g of Cerealine + 30 m3 FYM/fad had the highest percentages of T.S.S. and sucrose followed by 70 kg N + 30 m3 FYM/fad compared with the other treatments in both seasons. Solid culture of faba bean with the application of 20 kg N/fad gave the highest plant height, number of seeds/pod and seed yield/fad, meanwhile the highest number of branches/plant and pod length were achieved by intercropping faba bean with sugar beet with application of 90 kg N + 30 m3 FYM/fad followed by intercropped faba bean plants that fertilized with 80 kg N + 30 m3 FYM/fad compared with the other treatments in both seasons. However, intercropped faba bean plants that fertilized with 70 kg N + 30 m3 FYM/fad gave the highest number of pods per plant, number of seeds per pod, seed index and seed yield per plant compared with the other treatments in both seasons. Land equivalent ratio (LER), land equivalent coefficient (LEC) and relative crowding coefficient (RCC) were high by intercropping faba bean with sugar beet with the application of 80 kg N + 30 m3 FYM/fad indicating yield advantage was achieved. The value of aggressivity (Agg) of sugar beet was negative for all combinations indicating that sugar beet is dominated component in the present study. Intercropping faba bean with sugar beet with the application of 80 kg N + 30 m3 FYM/fad achieved higher total income and monetary advantage index (MAI) than the other treatments. Growing sugar beet plants in both sides of beds (1.2 m width) with one faba bean row in middle of sugar beet beds with the application of 80 kg N + 30 m3 FYM/fad decreased mineral N fertilizer rate by 10.00% of the recommended sugar beet mineral N fertilizer rate, as well as increased land usage and profitability for Egyptian farmers compared with sugar beet solid culture.

The role of maize root size in phosphorus uptake and productivity of maize/faba bean and maize/wheat intercropping systems

Interspecific root/rhizosphere interactions affect phosphorus (P) uptake and the productivity of maize/faba bean and maize/wheat intercropping systems. The aim of these experiments was to determine whether manipulation of maize root growth could improve the productivity of the two intercropping systems. Two near isogenic maize hybrids (the larger-rooted T149 and smaller-rooted T222) were intercropped with faba bean and wheat, under conditions of high- and low-P availability. The larger-rooted T149 showed greater competitive ability than the smaller-rooted T222 in both maize/faba bean and maize/wheat intercropping systems. The higher competitive ability of T149 improved the productivity of the maize/faba bean intercropping system in P-sufficient conditions. In maize/wheat intercropping systems, root growth, shoot biomass, and P uptake of maize were inhibited by wheat, regardless of the P-supply. Compared with T222, the larger-rooted T149 suffered less in the intercropping systems. The total biomass of the maize/wheat intercropping system was higher for wheat/T149 than for wheat/T222 under low-P conditions. These data suggested that genetic improvement of maize root size could enhance maize growth and its ability to compete for P resources in maize/faba bean and maize/wheat intercropping systems. In addition, depending on the P availability, larger maize roots could increase the productivity of intercropping systems.

套作蚕豆对梨园土壤肥力和微生物群落结构的影响

为探讨套作蚕豆对梨园土壤肥力及微生物的影响,本研究于蚕豆的苗期、开花期和成熟期,分别采集不套作(对照,CK)、套作苏蚕3号(CT1)、套作苏蚕4号(CT2)和套作慈蚕1号(CT3,本地品种)处理土壤,对土壤理化性质和微生物活性及群落结构变化进行研究。结果表明:套作蚕豆后苗期土壤硝态氮(NO_(3)^(-)-N)和有效磷(OlsenP)含量有所增加,开花期土壤电导率、可溶性有机碳(DOC)、可溶性有机氮(DON)和NO_(3)^(-)-N含量显著增加,pH和OlsenP含量显著降低;套作蚕豆增加了土壤微生物量碳(MBC),成熟期CT1和CT2土壤MBC含量分别较CK显著增加36%和51%(P<0.05);套作蚕豆还降低了与碳氮磷降解相关的水解酶活性。此外,套作蚕豆增加了细菌微生物丰富度指数和香农指数,其中增加了浮霉菌门(1.5~1.7个百分点)、厚壁菌门(0.9~3.4个百分点)、芽单胞菌门(0.7~1.1个百分点)和疣微菌门(0.3~0.5个百分点)细菌相对丰度,降低了变形菌门(1.3~2.7个百分点)、放线菌门(1.9~2.8个百分点)和酸杆菌门(0.1~1.1个百分点)细菌相对丰度。Mantel和CCA分析结果显示,pH和NO_(3)^(-)-N是微生物活性的重要驱动因子,MBC是影响细菌群落结构的重要因子。研究表明,套作蚕豆有助于提高土壤微生物量及其群落结构多样性,对维持土壤微生态多样性具有重要的保育作用。

小麦蚕豆间作提高氮素吸收量的优势及其相关环境因子的贡献分析

在明确间作作物提高氮素吸收利用的基础上,探讨间作体系氮素的种间关系以及相关环境因子的贡献,为阐明间作养分高效利用优势提供一定数据支撑。通过两年(2021—2023年)的田间定位试验,在不施氮(N0)、低氮(N1,N 90 kg/hm^(2))、常规施氮(N2,N 180 kg/hm^(2))和高氮(N3,N 270 kg/hm^(2))4个施氮水平下,研究了小麦蚕豆间作对氮素收获指数、系统氮素生产力及其氮素种间关系的影响,并基于ABT(aggregated boosted tree)和network分析,结合相关环境因子综合探讨其对间作促进氮素吸收利用的作用贡献。结果表明,与单作处理相比,两年的间作小麦氮素收获指数平均增幅5.30%,间作蚕豆显著性增加15.55%,间作体系的氮素系统生产力均值达到66.47 kg/hm^(2)。不同处理下小麦和蚕豆均表现出不同程度的氮素种间竞争,其相对种间竞争强度分别为-0.83和-0.73,其氮素种间相对关系指数范围分别为0.087~0.11(小麦)和0.047~0.12(蚕豆),体现出了不同程度的间作互利效应,较蚕豆而言,间作小麦氮素相对种间竞争力平均达到了0.43,表现出明显的种间竞争优势。对于土壤环境因子和氮素种间关系指标对氮素收获指数的贡献率,单作小麦和蚕豆的第一贡献因子均为速效钾和氮素相对种间竞争强度,间作小麦的第一贡献因子为碱解氮和氮素种间相对关系指数,间作蚕豆为碱解氮和氮素相对种间竞争强度。小麦蚕豆间作提高了氮素收获指数,在氮素种间竞争的同时保持了体系的氮素互补作用以及小麦的氮素竞争优势地位,并通过改善土壤碱解氮以及氮素种间相对关系指数等因子的相对贡献,稳定了间作体系的氮素系统生产力和氮素吸收利用的优势。

大城县大豆玉米带状复合种植技术

推广大豆玉米带状复合种植,力争玉米单产与清种基本相当,尽可能增加大豆产量,集成创新适合大城县的大豆玉米带状复合种植技术模式,实现作物带间轮作,改良土壤结构,减少病虫发生,降低化肥农药使用量。

施氮对蚕豆/玉米间作系统蚕豆农艺性状及结瘤特性的影响

【目的】旨在探明施氮对蚕豆/玉米间作体系蚕豆农艺性状和结瘤特性的影响,为河西走廊灌区豆科/禾本科间作体系氮素管理和高产高效提供科学依据。【方法】于2006-2007年在甘肃省农科院白云试验站分别采用裂区设计和原位根系行分隔法设计了蚕豆/玉米间作体系的氮梯度试验和根系分隔微区试验,研究不同氮水平下蚕豆/玉米种间互作对蚕豆农艺性状和结瘤特性的影响。【结果】施氮对蚕豆地上部生长和产量性状均无显著影响,但显著地抑制了蚕豆结瘤,产生了"氮阻遏"效应,且随着施氮量增加和蚕豆生长,"氮阻遏"效应愈加明显。随着蚕豆与玉米两种作物生长发育,作物根系相互促进作用逐渐增强,显著地促进了根瘤发育,且产生了"减缓效应",平均为14.4%;根系互作相对于无根系互作处理蚕豆结瘤平均增加10.2%。【结论】蚕豆/玉米种间根系相互作用促进了蚕豆结瘤,减缓了"氮阻遏"效应,显著提高了蚕豆产量性状而实现了蚕豆增产。

间作缓解蚕豆连作障碍的根际微生态效应

通过田间小区试验,研究了3个品种蚕豆(92-24、云豆324、凤豆6号)与小麦间作对蚕豆产量、枯萎病病情指数、根际镰刀菌数量、根际真菌代谢功能多样性和土壤酶活性的影响。结果表明:与单作蚕豆相比,云豆324与小麦间作(YD324/W)和凤豆6号与小麦间作(FD6/W)处理均显著提高了蚕豆地上部干重、籽粒产量和百粒重。YD324/W和FD6/W处理使蚕豆枯萎病发病初期病情指数分别降低57.14%和41.67%,镰刀菌数量分别降低32.06%和29.88%,而92-24与小麦间作(92-24/W)处理蚕豆产量、枯萎病病情指数和镰刀菌数量与单作蚕豆均无显著差异。YD324/W和FD6/W处理显著提高了蚕豆根际真菌的多样性指数和丰富度指数,并使蚕豆根际真菌的AWCD值分别比单作蚕豆提高了61.75%和46.49%;YD324/W和FD6/W处理明显改变了蚕豆根际真菌的群落结构。而92-24/W处理对蚕豆根际真菌的多样性指数、丰富度指数和AWCD值均无显著影响,也未明显改变真菌的群落结构。不同发病时期,YD324/W和FD6/W处理均显著提高了蚕豆根际土壤的蔗糖酶、脲酶和过氧化氢酶活性;而92-24/W处理蚕豆根际蔗糖酶、脲酶和过氧化氢酶活性与单作蚕豆均无显著差异。总之,小麦与不同品种蚕豆间作改变了蚕豆根际的真菌群落结构,提高了蚕豆根际真菌的活性、多样性和丰富度,提高土壤酶活性并改善蚕豆生长,增加了蚕豆产量。表明小麦与蚕豆间作改善了根际土壤的微生态环境,降低了镰刀菌的数量,缓解了蚕豆连作障碍,但蚕豆品种的差异影响间作控病效果。

种间互作和施氮对蚕豆/玉米间作生态系统地上部和地下部生长的影响

为河西走廊绿洲灌区豆科/禾本科间作体系的养分管理提供科学依据,于2007年在武威绿洲农业试验站应用田间原位根系行分隔技术研究了蚕豆/玉米种间互作和施氮对玉米抽雄期的根系空间分布、根系形态和作物地上部生长的影响。研究结果表明:种间互作和施氮均增加了玉米和蚕豆在纵向和横向两个尺度上的根重密度、根长密度、根表面积、根系体积。根长密度和根表面积与两种作物产量和氮素吸收均呈正相关,而与蚕豆的根瘤重呈负相关;抽雄期的土壤含水量与玉米产量和养分吸收呈显著的负相关。玉米根系可以占据蚕豆地下部空间,但蚕豆的根却较少到间作玉米的地下部空间,也就是间作后增加了玉米根系水平尺度的生态位。蚕豆和玉米根系主要分布分别在0—40 cm浅土层和0—60 cm土层,且间作玉米根系在60—120 cm比单作和分隔的多。因此,种间互作和施氮扩大了两作物根系纵向和横向的空间生态位,改变了作物根系形态,即扩展了两者水分和养分吸收的生态位,增加了作物吸收养分的有效空间,从而提高了间作生态系统的生产力。

不同竞争强度间作体系氮素利用和土壤剖面无机氮分布差异

田间小区试验,研究大麦/玉米间作、小麦/玉米间作和蚕豆/玉米间作及其对应单作体系,在不施氮和施氮225 kg/hm2情况下,对氮素吸收利用效率和土壤剖面无机氮变化的影响。结果表明,作物对养分的竞争能力与其根区土壤无机氮浓度和累积量密切相关。两作物共生期不施氮肥时,0—100 cm土层,土壤剖面无机氮残留量是间作大麦和间作小麦根区分别比间作蚕豆根区减少2032~82和10717~1 kg/hm2;与大麦和小麦间作的玉米根区分别比与蚕豆间作的玉米根区减少931~20和5687~kg/hm2。土壤无机氮累积量受作物类型、种间相互作用强度及实时土壤环境条件影响。种间相互作用提高了间作大麦和小麦的氮素当季回收率,但使与其间作的玉米氮素当季回收率降低。大麦/玉米和小麦/玉米竞争体系在不施氮肥时氮素利用效率最高。施用氮肥使大麦、小麦氮素收获指数降低,玉米氮素收获指数升高,对蚕豆无影响。在选择配对作物时,为获得间作优势要充分考虑作物竞争能力、土壤基础肥力条件、施肥水平及配套栽培措施等。低肥力土壤宜选择豆科/禾本科互惠体系,高肥力土壤宜选择禾本科/禾本科竞争体系。

小麦蚕豆间作对蚕豆根际微生物群落功能多样性的影响及其与蚕豆枯萎病发生的关系

通过田间小区试验,研究了小麦与蚕豆间作对蚕豆枯萎病发生和根际微生物代谢功能多样性的影响。结果表明,小麦与蚕豆间作使蚕豆枯萎病的发病率和病情指数分别比单作显著降低20%和30.4%。与单作相比,间作处理显著增加了蚕豆和小麦根际微生物对31种碳源的平均利用率(AWCD),其中间作蚕豆的AWCD值最高,比单作增加82.7%,单作蚕豆最低。间作蚕豆和间作小麦根际微生物的Shannon多样性指数与丰富度指数均显著高于单作,间作使蚕豆和小麦的丰富度指数分别增加29.2%和30.3%。根际微生物对6类碳源的利用强度百分比以糖类、羧酸类和氨基酸最高,分别为41.96%,19.80%和18.13%。主成分分析表明,小麦与蚕豆间作改变了根际微生物的群落组成;相关分析表明,糖类、羧酸类和氨基酸类碳源是区分单间作处理差异的主要碳源,其中氨基酸类碳源是最敏感的碳源。小麦与蚕豆间作增加了根际微生物活性,提高了Shannon多样性指数和丰富度指数,改变了微生物群落功能多样性,是抑制蚕豆枯萎病的有效措施为阐明根际微生物功能多样性变化在间作体系病害控制中的作用与机制奠定了理论基础。

供肥对小麦间作蚕豆群体产量及根系的调控

利用田间、池栽、盆栽等方法 ,对不同N、P水平下小麦间作蚕豆群体根系的时空分布及产量效应进行了研究 .结果表明 ,供P对小麦 蚕豆间作系统有明显的增产作用 .与不供P相比 ,田间试验中供P处理间作小麦和蚕豆分别提高了 4 8.39%和 16 .6 9% ,池栽试验中群体产量增产幅度为 2 0 .0 7%～ 4 3.14 % ,间作蚕豆经济产量增幅为 5 8.4 6 %～ 78.78% .小麦间作蚕豆多作系统 2种作物根密度生长高峰期交错出现 ,小麦的峰值出现早于蚕豆 .其中 ,小麦和蚕豆根干重最大值分别出现在抽穗期和成熟期 ,而根长的最大值分别出现在拔节期和成熟期 .这在一定程度上减轻了共生期 2种作物对水肥的竞争 ,也是此群体增产增效的原因之一 .施P处理间作小麦的根重、根长和根表面积分别比不施P处理提高 5 4 .33%、4 8.88%和4 7.0 0 % ;施N处理间作小麦的根重、根长和根表面积分别比不施N的增加 15 .2 5 %、11.6 1%和 11.4 6 % .间作小麦根重的 5 7.6 1%和蚕豆的 6 9.2 0 %分布在 0～ 30cm土层 ,随施P水平的提高 ,总根干重及根密度都趋于增加 。

大麦/蚕豆间作条件下供氮水平对作物产量和大麦氮吸收累积的影响

为给云南地区非豆科/豆科作物合理间作种植提供理论依据,通过田间小区试验,研究了N0、N112.5、N225和N337.54个施氮水平（0、112.5、225和337.5 kg N.hm-2）下大麦/蚕豆间作作物产量及氮素养分吸收累积的特点及差异。结果表明,大麦/蚕豆间作具有间作产量优势,4个施氮水平中N225的土地当量比最高,达到1.13。不同施氮水平下间作大麦产量表现出第一行〉第二行〉第三行的趋势。与单作相比,间作大麦地上部和地下部氮含量平均提高5.8%~35.8%,地上部氮素累积吸收量及吸收速率提高7%~32.1%。在N0、N112.5、N225水平下,氮含量、氮素累积吸收量及吸收速率均呈间作第一行〉间作第三行〉单作的趋势。单作大麦氮素累积吸收量和吸收速率以N337.5水平最高,分别为95.46 kg.hm-2和1.736 kg.hm-2.d-1,而间作大麦则以N225水平最高,分别为105.03 kg.hm-2和1.910 kg.hm-2.d-1。

小麦-蚕豆间作条件下氮肥施用量对根际微生物区系的影响

通过田间小区试验,研究了小麦/蚕豆间作条件下4种施氮水平(0、90、180和270kg·hm-2)对根际微生物区系和多样性的影响.结果表明:在整个生育期,微生物数量有一定的波动,但均以开花期数量最高.与单作相比,间作显著增加了小麦和蚕豆根际的细菌、真菌、放线菌数量和微生物总量,而显著降低了开花期和成熟期蚕豆根际的微生物多样性.在不施氮(N0)和低氮(N90)水平下,间作与单作在微生物数量上的差异较大.间作对土壤微生物数量的促进效应在分蘖期和开花期最大,成熟期显著降低.小麦根际的微生物数量随施氮量的增加先增加后降低,以常规施氮处理(N180)的微生物数量最多,氮肥用量对单作小麦的影响大于间作小麦.施氮量对蚕豆根际细菌、真菌、放线菌数量和微生物多样性无显著影响,但降低了间作蚕豆根际微生物总量.适量施用氮肥能有效调节根际微生物区系,间作系统地上部植物多样性与地下部微生物区系间存在紧密联系.

小麦//蚕豆间作中的种间氮营养差异比较研究

通过根系分隔和15N标记土壤的盆栽试验,研究间作蚕豆和小麦对不同氮素来源利用的差异。结果表明,根系不分隔的处理小麦生长改善,其生物量、吸氮量都高于其它2种分隔方式;蚕豆的生长则表现被抑制,其生物量在根系不分隔时生物量和吸氮量皆最低。在尼龙网分隔的处理中,小麦植株体内15N%丰度高于其它2种分隔方式,而蚕豆则表现为根系未分隔的处理15N%丰度最低。表明小麦竞争肥料氮的能力强于蚕豆,小麦的竞争促进了蚕豆固定更多的空气氮。

蚕豆/玉米间作系统经济生态施氮量及对氮素环境承受力

通过河西走廊灌区田间试验,对不同施氮水平下蚕豆/玉米间作系统的生产力、氮素吸收利用率及土壤无机氮累积量进行了研究,并利用线性加平台模型探讨了间作系统的经济生态施氮量。结果表明间作系统的生产力与施氮量的线性加平台模型的相关性达到极显著水平(P<0.001),0～160 cm土壤无机氮累积量与施氮量间以二次曲线模型相关性最高;种间互作显著提高系统生产力和氮素吸收,增幅分别为23%和33%;间作系统生产力、养分吸收量及土壤无机氮量随着施氮量的增加而增加;高氮肥量和种间互作使作物发生氮素"奢侈吸收"。如果充分考虑到生产、生态和经济效益,则间作系统适宜施氮量为186 kg/hm2,对应生产力为10.6×103 kg/hm2,增产14%,节约38%氮,减少75%土壤无机氮残留。

蚕豆/玉米间作接种AM真菌与根瘤菌对其吸磷量的影响

盆栽试验研究不同根系分隔方式蚕豆/玉米间作接种AM真菌和根瘤菌对其吸收有机磷影响结果表明,接种AM真菌均显著促进玉米和蚕豆吸收有机磷,与对照相比吸P量分别增加138.1%和82.3%;接种AM真菌和根瘤菌对蚕豆吸收有机磷有协同促进作用,蚕豆根瘤数、根瘤重和菌根侵染率显著增加,并改善与其间作玉米的营养状况,明显促进玉米生长。