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31.
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S. Delin 《Soil Use and Management》2011,27(4):415-426
The nitrogen (N) fertilizer effect of layer hen and broiler manure applied at different times on spring barley yield was studied in seven Swedish field experiments during 2005–2008. Two experiments had parallel field incubations to study N release after fertilizer application. The effect of total N in manure on N offtake was 30–40% that of mineral N, except in a dry year, when the effect was very low. Although the relative proportions of ammonium N, uric acid N and other N differed between the hen and broiler manure, the effect of total N was similar for both. In field incubations, mineral N decreased from 75 to 60% of total N applied in hen manure, whereas it increased from 20 to 50% in broiler manure, because of net immobilization and release, respectively. The limited fertilizer nitrogen replacement value, corresponding to only 30–40% of total N, could be as a result of ammonia volatilization after rather shallow incorporation with harrow. Net N release from broiler manure lasted for 6–8 weeks after application, after which it generally ceased. In some cases, manure application in early spring gave better yield effects than application at sowing, probably because of better synchronization of the N release with crop N requirements. The residual N effect on the N offtake in crop in the year after manure application was on average 3% of the total N applied, equivalent to a fertilizer replacement value of about 6%. 相似文献
33.
《The Journal of Applied Poultry Research》2016,25(3):443-454
Organic agriculture has increased greatly over the past several years as consumer demand for these products has risen. Organic meat production, including poultry, has grown especially quickly, resulting in increasingly stringent guidelines being put in place to ensure safe, uniform, and ideal products for these consumers. Feed formulation and manufacturing for organic poultry in the United States are strictly regulated by the United States Department of Agriculture National Organic Program. Currently, no synthetic amino acids are allowed to be used in organic poultry diets in the United States except for limited quantities of synthetic methionine since it is typically considered the first or second limiting amino acid in corn and soybean meal based poultry diets and it is a critical nutrient for maintaining bird growth and productive performance, especially regarding egg size in laying hens. The aim of the review herein is to discuss the impacts that current organic regulations on synthetic methionine have on diet formulation when using readily available ingredients. High levels of crude protein must be used to meet bird methionine requirements with this restriction in place, which both increases feed costs and can have negative impacts on bird health and on air quality and the surrounding environment due to increased ammonia emissions. Atypical feed formulation strategies have been explored to address this issue, including such methods as feeding alternative ingredients and providing forage materials. Another possibility would be to use an average lifetime maximum inclusion rate for synthetic methionine, which may allow for better flexibility to provide sufficient methionine throughout various phases of growth and production since the requirements of the bird change with age. 相似文献
34.
Aiming at the oneness of acid to deliquesce stratum-jam applied in scene at the present time,which is incapable of deliquescing complex dirty simultaneously,this article confects a new multifunctional O/W acid.This acid is an emulsified mixture containing 15% hydrochloric acid as its extro-posture,high dissolved oil as its internal state under the function of some proper exterior active reagent.It is composed of 0.5%OP-10,0.5%Span80,0.2%Tween80,0.06%imidazole and 0.01%twelve-alcohol,and the content of oil is equal to the acid content.It can be indicated that this acid has good ability of resolving mineral(CaCO_3,MgCO_3) and organic compound(mainly colloidal bitumen) when it was poured into the stratum,so that it can deliquesce oleic stratum-jam,resume and improve the penetrability of stratum,boost the ability of liquid flowing up. 相似文献
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以宁夏荒漠草原不同土地利用方式(耕地、弃耕地、草地和柠条地)的土壤为研究对象,测定了不同土层土壤有机碳和活性有机碳含量,分析了土壤活性有机碳占有机碳的比例,以期探寻不同土地利用方式对土壤活性有机碳的影响。结果表明:不同土地利用方式土壤总有机碳含量范围在1.78~6.17 g·kg^-1,具体表现为弃耕地>柠条地>草地>耕地。表层(0~5 cm)土壤有机碳含量显著高于深层(10~60 cm),说明荒漠草原土壤有机碳主要富集在表层;4种土地利用方式土壤易氧化有机碳含量为0.57~1.38 mg·g^-1,变化趋势具体表现为柠条地>草地>耕地>弃耕地,且柠条地在每个土层都高于其它3种土地利用方式;土壤可溶性有机碳含量范围为6.8~11.1 mg·kg^-1,变化趋势表现为草地>耕地>柠条地>弃耕地。土壤易氧化有机碳含量占有机碳的比例范围为13.7%~43.1%,大小排序为柠条地>耕地>草地>弃耕地;土壤可溶性有机碳含量占有机碳的比例范围为0.11%~0.48%,比例大小为耕地>草地>柠条地>弃耕地,耕地和草地中土壤可溶性有机碳含量占有机碳比例随着土壤深度的增加而减小,这与有机碳在耕地和草地中变化趋势一致。土地利用变化可以显著影响土壤活性有机碳的含量与分布,能够敏感的反映土壤碳库的变化,可以作为评价宁夏荒漠草原土壤质量和肥力的指标之一。 相似文献
37.
为探究‘辽宁1号’核桃较适宜的有机肥种类及施肥方式,以‘辽宁1号’核桃树为试验材料,利用半焦肥、鸡粪及生物菌肥三种有机肥进行施肥处理,检测不同有机肥对土壤及核桃产量品质的影响。结果表明,生物菌肥施肥能显著提高果仁黄酮含量;鸡粪能显著提高果仁Fe、Zn含量以及土壤速效磷、速效钾含量;5.0 kg半焦肥能显著提高果仁多酚、土壤有机质含量;10.0 kg半焦肥施肥能显著提高核桃单果重、横径、脂肪含量,矿质元素中K、Ca、Mg、Cu的含量以及土壤全磷含量。综合比较,10.0 kg/株半焦肥施肥对核桃相关果实品质的影响较大;根据隶属函数分析得出10.0 kg/株半焦肥施肥是较优施肥方式。 相似文献
38.
为揭示典型潮土微生物群落及其生态网络对秸秆还田的响应机制,选择长期小麦-玉米轮作下不同秸秆还田处理的试验地为对象,应用高通量测序和生态网络等方法,阐明秸秆掩埋配施不同氮肥后土壤细菌群落组成、细菌网络共存关系以及与土壤养分的关联。结果表明:(1)与秸秆移除且不施氮肥处理相比,秸秆还田配合常规施肥处理显著降低土壤pH,提高了土壤全氮、有机碳、有效磷、速效钾和硝态氮含量(P < 0.05)。秸秆掩埋配施氮肥有利于增加土壤养分含量。(2)不同秸秆还田方式和氮肥施用量处理的细菌Alpha多样性无显著差异,而细菌群落结构差异显著。pH、SOC和TN等因子驱动了细菌群落结构变异。酸杆菌门、变形菌门、拟杆菌门和绿弯菌门是潮土细菌群落的主要优势菌门。(3)共现网络分析得到4个主要的生态集群,均与土壤养分有显著相关性。模块1中物种丰度与SOC、TN、TP、NO3- -N、AP和AK呈极显著负相关(P < 0.001),与pH呈极显著正相关(P < 0.001);模块2和模块3中物种丰度与大部分养分含量呈正相关,与pH呈负相关。因此秸秆还田配施氮肥可以通过调节细菌互作关系,从而调控土壤肥力。研究结果可为秸秆的资源化利用和土壤施肥管理提供科学依据。 相似文献
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40.
I. Holoubek 《Land Degradation \u0026amp; Development》1993,4(4):333-337
Polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and dibenzofurans, HCBs and p, p'-DDE were determined in soil and sediment samples from selected sites in Czecho-Slovakia. for the first three groups of chemicals soil pollution in Czecho-Slovakia is very high. in general, The pollution is higher in the Elbe than in the Danube catchment sediments. 相似文献