Leaf litter and crop residue decomposition in ginkgo agroforestry systems in eastern China: Soil fauna diversity and abundance,microbial biomass and nutrient release

The response of soil fauna to the litter decomposition process has received considerable attention,but this effect has not been fully examined in agroforestry systems.A 1-year in situ decomposition experiment was carried out in a pure ginkgo plantation and two ginkgo agroforestry systems using a litterbag method(11 different treatments were tested in three systems).We found that the application of different organic materials(crop residues)produced positive effects on the number of soil fauna in the ginkgo planting systems;the mixture of ginkgo leaves and corn leaves was the best performing treatment.Collembola and Acarina were the predominant groups in the litter bags and were mainly responsible for the differences among the treatments.Litter mixing promoted the abundance,richness,and diversity of soil fauna,and significant differences regarding the Shannon–Wiener index of the soil fauna were observed among the 11 treatments in July.Significantly higher soil MBC(microbial biomass carbon)and MBN(microbial biomass nitrogen)were observed in agroforestry systems than in pure ginkgo plantations.These results suggest that the practice of intercrop residue application plays an important role in enhancing soil ecosystem function in ginkgo agroforestry systems and may ultimately contribute to sustainable intercrop production,soil fertility,and local economic diversity.     

黄土区果农复合系统种间水分关系研究

选择黄土区7种典型果农复合类型,进行野外实验布设。利用土钻取样和烘干称重法进行土壤含水量的测定,研究了不同果农复合类型土壤水分含量的水平方向变化与垂直剖面变化规律,分析了黄土区果农复合类型种间水分竞争关系。研究表明,在水平方向上,果农复合类型土壤水分含量的变化与林带的方位、距离有关,果农复合对水分竞争并不显著,树木对光遮蔽作用的强弱,才是影响土壤水分水平变化的主要因素。在垂直方向上,根系对土壤水分的竞争区域主要在0-60cm土层范围内。同单作作物土壤水分的比较得出,苹果和其它农作物的复合有助于土壤水分的保持;核桃、桃与其它农作物的复合,则表现为不同的影响,即对玉米的协助大于竞争,对花生的竞争大于协助。     

薄壳山核桃-小麦套作系统土壤微生物群落研究

为研究薄壳山核桃-小麦套作系统产量效益及土壤微生物群落情况,以薄壳山核桃单作(P)和薄壳山核桃-小麦套作(PW)为研究对象,分析比较2种模式下的产量效益,利用Illumina Miseq高通量测序技术对土壤细菌及真菌多样性、群落结构、标志物种和共现网络进行研究,并探究土壤化学性质与微生物的关系。结果表明：1)套作后坚果产量显著低于单作,总产值显著高于单作;2)套作导致土壤细菌多样性和真菌丰富度显著降低;3)细菌和真菌群落结构因套作显著改变,放线菌门(Actinobacteria)与担子菌门(Basidiomycota)丰度显著提高,酸杆菌门(Acidobacteria)丰度显著降低,微球菌科(Micrococcaceae)、黄色杆菌科(Xanthobacteraceae)、小单孢菌科(Micromonosporaceae)、鞘脂单胞菌属(Sphingomonas)、热酸菌属(Acidothermus)、芽单胞菌属(Gemmatimonas)、假节杆菌属(Pseudarthrobacter)和外瓶霉属(Exophiala)等标志物种于套作土壤中富集;4)套作使细菌网络复杂性增强,真菌网络...     

How do hedgerows influence soil organic carbon stock in livestock‐grazed pasture?

Hedgerows have the potential to influence ecosystem function in livestock‐grazed pasture. Despite this, they are often ignored when quantifying farmland ecosystem service delivery. In this study, we assess the contribution of hedgerows to the ecosystem function of carbon (C) storage, with a particular emphasis on soil organic carbon (SOC). We measured SOC stock (kg C m^?2), on an equivalent soil mass basis, at 0–0.15 m depth in pasture adjacent to 38 hedgerows (biotic) and 16 stone walls or fences (abiotic controls) across ten farms in the county of Conwy, Wales, UK. Pasture SOC stock (~7 kg C m^?2) was similar adjacent to biotic and abiotic field boundaries, positively associated with soil moisture and negatively with soil bulk density (BD). For biotic boundaries, two further variables were significantly associated with SOC stock, distance from hedgerow (decrease in SOC stock) and slope orientation (upslope SOC stock greater than downslope). For pasture adjacent to hedgerows, a model combining the aforementioned variables (BD, soil moisture, distance from hedgerow, slope orientation) explained 78% of variation in SOC stock. This study demonstrates that whilst hedgerows do have subtle positive effects on SOC stock in adjacent pasture, SOC storage adjacent to field boundaries is influenced more by soil moisture content and BD than field boundary type.     

基于Probit-ISM模型的农户林农复合经营行为影响因素分析

基于苏北27个村302户林农的调研数据,利用Probit模型和ISM模型,分别探究农户林农复合经营行为的影响因素及各因素间的关联性及层级结构。研究结果表明:户主的年龄、性别、家庭人口规模和对农林业相关政策的了解程度在5%水平上显著;户主的学历水平、家庭年收入、林地面积、是否加入合作社、是否有农技推广站和贷款意愿在1%水平上显著。其中,家庭年收入、是否有农技站和贷款经营意愿是表层直接因素,林地面积和对相关政策的了解程度是中层间接因素,家庭人口规模、户主的学历水平和是否加入合作社是深层根源因素。     

青稞替代玉米对育肥牦牛生产性能和肉品质的影响

本试验旨在研究青稞替代玉米对育肥牦牛生产性能、屠宰性能、养分表观消化率及肉品质的影响。采用2×3交叉设计,以日粮类型(玉米、60%青稞+40%玉米)和不同精粗比(30∶70、40∶60和50∶50)为两因素,选取36头年龄4周岁左右、体重为(144±21.0)kg的麦洼公牦牛,随机分为6组,每组6个重复,每个重复1头牛。预饲期15d,正试期180d。结果表明:1)日粮类型及精粗比对牦牛生产性能无显著影响(P>0.05)。2)青稞-玉米组的净肉率显著高于玉米组(P<0.05),但屠宰率和眼肌面积无显著差异(P>0.05);精粗比对屠宰性能无显著影响(P>0.05);日粮类型和精粗比二因素对眼肌面积的互作影响显著(P<0.05),以青稞-玉米(40∶60)组效果最优。3)日粮类型对养分表观消化率无显著影响(P>0.05);与30∶70相比,40∶60和50∶50极显著提高了有机物(OM)和总能(GE)的表观消化率(P<0.01)、显著提高了粗蛋白(CP)的表观消化率(P<0.05);日粮类型和精粗比二因素对GE、OM和粗脂肪(EE)的表观消化率有显著的互作影响(P<0.05),以玉米(40∶60)组效果最佳。4)青稞-玉米组和玉米组背最长肌亮度值(L*)、红度值(a*)、pH值均无显著差异(P>0.05),但青稞-玉米组的黄度值(b*)和滴水损失显著低于玉米组(P<0.05)、蒸煮损失极显著低于玉米组(P<0.01);随着精粗比的升高,蒸煮损失有逐渐降低的趋势(P=0.075)。5)日粮类型对背最长肌的嫩度无显著影响(P>0.05);随着精粗比的升高,剪切力逐渐减小(P>0.05),肌纤维直径有减小的趋势(P=0.059),肌纤维密度显著增加(P<0.05),肌纤维面积显著减小(P<0.05)。综上所述,以青稞替代日粮中60%的玉米能够提高育肥牦牛的屠宰性能,改善牦牛肉的品质;日粮精粗比为40∶60时饲喂效果最佳。     

三峡库区农林复合经营模式及其可持续发展研究

】针对三峡库区农林复合经营的主要模式、经营特点、效益及存在的问题,提出了农林复合经营的可持续发展对策和农林复合经营技术是实现库区持续发展的有效途径。     

生态农业的一种模式——农林复合

生态农业是当今世界上生态脆弱区农业发展的方向,也是持续农业在该区的体现。我国黄土高原水土流失严重、生态环境恶化,发展生态农业十分必要。本文以淳化县泥河沟流域综合治理为背景,提出了农林复合生态农业模式,较系统的阐述了建立的思路、结构,主要工作和技术,并分析了该系统的功能,给出评价,最后提出不足作为今后努力的方向。     

江汉湿地平原林农复合系统中种间关系的初步研究

研究了用下间作黄麻和苏丹草在不同树龄阶段的林木生长情况和作物产量,结果发现５－６ａ树龄时的林农复合系统具有树木的偏利作用,而６ａ树龄后的树木对农作物有偏害作用。     

毛竹食用菌复合经营模式研究

利用毛竹林生态环境条件,以竹笋加工废料笋壳为培养基质,进行食用菌生产试验。结果表明,以笋壳作为培养料的平菇、榆黄蘑产量分别为592.59 kg/100 m²、187.50 kg/100 m²,分别占同样条件下以木屑作为培养料所获产量的44.06%和20.15%;以笋壳作为培养料的食用菌生产经历了2潮明显的出菇高峰,时间周期短而集中;而木屑培养料的食用菌则经历了3潮明显的出菇过程,时间周期较长。在产量方面,虽然平菇比榆黄蘑产量高,但榆黄蘑的市场价格较高,因此也值得推广。与木屑相比,笋壳具有生产成本低、生态环保、市场潜力大等优势,具有很高的潜在利用价值。