双低菜籽粕在饲料中的应用

双低菜籽粕具有高产优质的特点,其饲用品质优于普通菜籽粕,营养价值与豆粕相当,被广泛应用于饲料。为了更有效开发其对饲料业和养殖业的应用潜力,本文就双低菜籽粕的营养价值和在动物饲用方面进行的一系列的基础性研究作一简要介绍。     

Designating a greenbelt around the city of Riga, Latvia

Latvian legislation demands that forest protection belts are established around all cities and towns. The main goal of a protection belt is to provide suitable opportunities for recreation to urban dwellers and to minimise any negative impacts caused by urban areas on the surrounding environment. Legislation states the main principles to be adopted, which include the maximum area of protection belts, their integration in territorial development plans and restrictions placed on forest management activities. The largest part of the forest area around Riga is owned by the municipality of Riga, which, as a result, has two competing interests: to satisfy the recreational needs of the inhabitants of Riga, and to maximise the income from its property. In order to compile sufficient background information to solve this problem, the Board of Forests of Riga Municipality initiated the preparation of a proposal for the designation of a new protection belt.The proposal was based on the development and application of a theoretical framework developed during the 1980s. The analysis of the recreational value of the forest (5 classes of attractiveness) was carried out based on categories of forest type, dominant tree species, dominant age, stand density, distance from urban areas and the presence of attractive objects. Information was derived from forest inventory databases, digital forest maps and topographic maps. Additional information was digitised and processed using ArcView GIS 3.2. Local foresters were asked about the recreation factors unique to different locations, such as the number of visitors and the main recreation activities. From a recreational point of view and taking into account legal restrictions and development plans for the Riga region, it was proposed to create three types of zones in the forest: a protection belt, visually sensitive areas and non-restricted areas.     

Carbon storage by urban tree cultivars, in roots and above-ground

Urban trees can favorably affect factors underlying global warming by storing carbon and by reducing energy needs for cooling and heating buildings. To estimate carbon stored in roots and above-ground portions of trees, data was collected consisting of whole tree sampling of Amelanchier, Malus, Pyrus, and Syringa cultivars. Roots were excavated using an Air-Spade^™. Regression analysis resulted in two equations for predicting total carbon storage based on height and diameter of trees up to 20 cm dbh: Y = 0.05836 (dbh²) for root carbon storage, and Y = 0.0305 (dbh² × h)^0.9499 for above-ground carbon storage, explaining 97% and 96% of the variation, respectively. Average carbon stored in roots of various cultivars ranged from 0.3 to 1.0 kg for smaller trees, those 3.8 to 6.4 cm dbh, to more than 10.4 kg for trees 14.0 cm to 19.7 cm dbh. Average total carbon stored by cultivars ranged from 1.7 to 3.6 kg for trees less than 6.4 cm dbh to 54.5 kg for trees larger than 14.0 cm. The data from these equations apply mainly to trees in nurseries and recently transplanted trees. Comparisons showed that above-ground estimates from previous studies using a sampling technique overestimated values obtained from actual above-ground weights.     

不同碳源对虎奶菇菌核蛋白质营养价值的影响

测定了四种碳源对虎奶菇菌核蛋白质营养价值的影响。结果表明，以玉米淀粉为碳源，虎奶薅菌蛋白质的化学评分，必需氨基酸指数，生物价和营养指数分别为11．63、69．80、64．40和9．98，均居四种参试碳源的第一位；氨基酸评分和氨基酸比值系数分分别为14．55和12．45，均居四种参试碳源的第二位，这些结果证实，以玉米淀粉为碳源，虎奶菇菌核蛋白质营养价值高，值得推广应用。     

有效碳数法研究及其在农药气相色谱分析中的应用

有机化合物结构与其所含有的有效碳数有一定的关系，本文给出了２０类结构化合物及其所含有有效碳数的关系，并对理论计算值和实测值进行了比较，结果十分接近，利用有效碳数法可以设计农药分析实验方案和无标样的情况下测定农药杂质含量。     

鹰嘴豆生物学特性及应用价值

鹰嘴豆是一种具有较高价值的经济植物.本文论述鹰嘴豆的生物学特性、营养成分、经济价值及开发应用前景.     

内蒙古农牧交错带饲草资源饲用价值评价

对地处内蒙古农牧交错带的林西县饲草资源进行了营养成份分析及饲用价值评价,结果表明:苜蓿粗蛋白质含量高于灌木类及青贮玉米,其营养动态变化规律是随生育期的变化粗蛋白质含量呈下降趋势,粗纤维含量呈上升趋势,各种成份在茎叶中的含量也随生育期变化而变化;灌木类饲用植物粗蛋白质含量15.69%～18.48%,青贮玉米粗蛋白质含量7.64%～11.15%。     

Prediction of chemical composition and peroxide value in unground pet foods by near‐infrared spectroscopy

The massive development of the pet food industry in recent years has lead to the formulation of hundreds of canine and feline complete extruded foods with the objective of meeting both the needs of the animals and numerous demands from pet owners. In the meantime, highly variable raw material compositions and the industry's new production techniques oblige manufacturers to monitor all phases of the extrusion process closely in order to ensure the targeted composition and quality of the products. This study aimed at evaluating the potential of infrared technology (visible and near‐infrared spectrophotometer; 570–1842 nm) in predicting the chemical composition and peroxide value (PV) of unground commercial extruded dog foods. Six hundred and forty‐nine commercial extruded dog foods were collected. For each product, an unground aliquot was analysed by infrared instrument while a second aliquot was sent to a laboratory for proximate analysis and PV quantification. The wide range of extruded dog food typologies included in the study was responsible for the wide variability observed within each nutritional trait, especially crude fibre and ash. The mean value of the 208 pet foods sampled for PV quantification was 17.49 mEq O₂/kg fat (min 2.2 and max 94.10 mEq O₂/kg fat). The coefficients of determination in cross‐validation of NIRS prediction models were 0.77, 0.97, 0.83, 0.86, 0.78 and 0.94 for moisture, crude protein, crude fat, crude fibre, ash and nitrogen‐free extract (NFE) respectively. PV prediction was less precise, as demonstrated by the coefficient of determination in cross‐validation (0.66). The results demonstrated the potential of NIRS in predicting chemical composition in unground samples, with lower accuracy for moisture and ash, while PV prediction models suggest use for screening purposes only.     

不同施肥模式对玉米各器官碳氮累积和分配的影响

以长期定位试验为依托,选取:1)不施肥(CK);2)农民习惯施肥(FP);3)推荐施肥(OP);4)有机肥氮替代100%化肥氮(OM);5)有机肥氮替代50%化肥氮(MF)5个处理,研究不同施肥模式对玉米植株及各器官碳氮含量、碳氮分配比例及C/N的影响,为西南紫色土地区合理施肥、作物增产提供科学依据。结果表明,与FP处理相比,MF处理显著增加了玉米植株生物量,达26.2%。相比OM和OP处理,MF处理显著增加玉米苞叶和根茬中碳浓度,分别增加5.4、4.2 g·kg^-1和7.4、21.3 g·kg^-1,同时增加玉米苞叶、根茬、穗轴和籽粒中的碳储量,玉米茎秆和籽粒中的氮储量也有增加。此外,相比FP处理,MF处理能显著增加玉米整株的碳储量和氮储量,达29.1%和16.9%。等氮水平下,MF、OP处理均能增加玉米苞叶和籽粒中碳同化物的分配比例,MF处理玉米籽粒中氮素的分配比例较OP和OM处理分别增加1.7%和3.6%,同时MF处理能使玉米维持较高的C/N。综上,有机肥氮替代50%化肥氮能增加玉米植株的生物量,同时提高玉米对氮素的吸收和碳素的累积,增加玉米籽粒中碳同化物和氮素的分配比例,同时,有机肥氮替代50%化肥氮能使玉米植株维持较高的C/N,有利于产量的形成,该施肥方式不仅能够促进氮素的高效利用,减少化肥的投入,还能够减少化肥损失,降低氮素损失引发的环境风险。     

不同轮作序列对旱地胡麻土壤有机碳稳定性的影响

为了探索陇中黄土高原半干旱丘陵沟壑区胡麻轮作序列对土壤碳库的影响,2012-2016年通过4年定位试验,以连作为对照,研究了不同胡麻频率下的轮作序列(F:休闲;PWFW:25%Flax、马铃薯-小麦-胡麻-小麦;WFWP:25%Flax、小麦-胡麻-小麦-马铃薯;FWPF:50%Flax、胡麻-小麦-马铃薯-胡麻;WPFF:50%Flax、小麦-马铃薯-胡麻-胡麻;FFFF:100%Flax、胡麻-胡麻-胡麻-胡麻)对土壤团聚体、总有机碳(TOC)、土壤颗粒有机碳(POC)、土壤微生物碳(MBC)和氮(MBN)的影响。结果表明,休闲、不同轮作序列和低胡麻频率显著增加了030 cm土层<0.25 mm粒级的土壤团聚体含量、TOC和POC含量,而随胡麻频率的增加三者的含量呈下降趋势。其中,25%Flax处理下土壤团聚体含量较播前和休闲处理分别显著增加了2.02%4.04%和9.56%11.73%;土壤有机碳(SOC)较连作显著增加5.95%7.48%。50%Flax处理下胡麻位置对土壤SOC影响显著,且轮作(FWPF)显著高于连作(WPFF)。060 cm土层土壤SOC含量表现为休闲>播前≈25%Flax>50%Flax>100%Flax。与连作相比,轮作显著提高了010 cm土层土壤TOC和POC含量,呈现表层富集现象。土壤POC含量表现为25%Flax≈休闲>50%Flax>100%Flax。此外,轮作换茬显著增加了土壤MBC含量,且随着胡麻频率的增加,030 cm土层土壤MBC含量逐渐降低。与播前、休闲、轮作相比,连作显著降低土壤微生物碳氮比,50%Flax(WPFF)轮作序列和土层深度对土壤有机碳和微生物量的互作效应显著。综合来看,休闲可以显著改善土壤理化性状,25%胡麻频率的轮作序列利于保持土壤团聚体稳定性,增加土壤TOC、SOC和POC含量,而50%Flax轮作序列(WPFF)能够提高土壤微生物量和微生物碳氮比。表明25%胡麻频率的轮作序列均可维持土壤有机碳的稳定性,是旱地胡麻比较理想的轮作序列。