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M.A. Holly P.J. Kleinman R.B. Bryant D.L. Bjorneberg C.A. Rotz J.M. Baker M.V. Boggess D.K. Brauer R. Chintala G.W. Feyereisen J.D. Gamble A.B. Leytem K.F. Reed P.A. Vadas H.M. Waldrip 《Journal of dairy science》2018,101(7):6632-6641
Nutrient management on US dairy farms must balance an array of priorities, some of which conflict. To illustrate nutrient management challenges and opportunities across the US dairy industry, the USDA Agricultural Research Service Dairy Agroecosystems Working Group (DAWG) modeled 8 confinement and 2 grazing operations in the 7 largest US dairy-producing states using the Integrated Farm System Model (IFSM). Opportunities existed across all of the dairies studied to increase on-farm feed production and lower purchased feed bills, most notably on large dairies (>1,000 cows) with the highest herd densities. Purchased feed accounted for 18 to 44% of large dairies' total operating costs compared with 7 to 14% on small dairies (<300 milk cows) due to lower stocking rates. For dairies with larger land bases, in addition to a reduction in environmental impact, financial incentives exist to promote prudent nutrient management practices by substituting manure nutrients or legume nutrients for purchased fertilizers. Environmental priorities varied regionally and were principally tied to facility management for dry-lot dairies of the semi-arid western United States (ammonia-N emissions), to manure handling and application for humid midwestern and eastern US dairies (nitrate-N leaching and P runoff), and pasture management for dairies with significant grazing components (nitrous oxide emissions). Many of the nutrient management challenges identified by DAWG are beyond slight modifications in management and require coordinated solutions to ensure an environmentally and economically sustainable US dairy industry. 相似文献
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李伟严友兵张永康袁秋红朱志伟胡隆华 《中国油脂》2020,45(4):119-122
介绍了猕猴桃籽油的护肤作用,综述了以超微细处理后的猕猴桃籽油为原料的猕猴桃祛斑油、猕猴桃嫩肤霜、猕猴桃面膜、猕猴桃沐浴露、猕猴桃洁面乳、猕猴桃抗蓝光精华液的开发利用。猕猴桃籽油富含亚油酸、α-亚麻酸、维生素E、微量元素硒等天然营养护肤成分,具有抗蓝光、祛斑、保湿、抗老化、遮盖防护等作用,可作为护肤品的主要原料,具有良好功效和广阔的市场价值。 相似文献
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黄土丘陵沟壑区小流域水土养分流失特征研究 总被引:2,自引:0,他引:2
采用人工模拟降雨和定位观测相结合的方法, 研究了典型的黄土丘陵沟壑区王家沟流域水土养分流失特征, 提出了水土流失量与降雨量、前期土壤含水率、土壤、地形、植被等有关自然因素间的定量关系. 研究结果显示坡地损失的养分总量占其养分输出总量的近 80%. 流失泥沙中的细小颗粒是养分流失的主要载体, 采用综合治理措施能有效控制小流域土水养分流失. 相似文献
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对采用液氨和湿法磷酸为原料,在大型磷酸二铵装置上转产不同养分的粒状磷酸二铵的生产技术进行研究,对生产2种总养分不同的产品过程控制、原料磷酸、料浆相对密度的不同控制点和存在问题进行分析,为磷酸二铵装置转产不同养分的磷酸二铵(DAP)产品提供借鉴。 相似文献
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The fertilizer potential of two unusual N-P compounds with cage structures was evaluated in pot experiments where plants were repetitively cut over 400 days. One of the compounds, hexamethyl-hexaaza-tetraphosphaadamantane (APA), having 41.6% P and 28.2% N, showed high fertilizer capability. After more than 400 days, dry matter yield of Rhodes grass given APA was 83–102% of that given conventional N-P sources, and yield of Townsville stylo 60–70%. Curves for N and P uptakes over time were of sigmoidal form, with the steepest parts between days 40 and 120, suggesting a slow-release feature. However growth was depressed up to day 40, presumably by some toxic factor associated with the decomposition of the APA. This toxicity was avoided if some conventional fertilizer was applied with the APA.The other compound, the tetrasulphide of APA (APAS) had only limited fertilizer potential. Plants did absorb P and S at least from this compound, but Townsville stylo yield was only 32–38% of that with conventional fertilizers, and Rhodes grass yield not much greater than from control pots. The possible slow-release feature, and the toxic effect, did not occur with APAS. 相似文献