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供需 1

农区草业 1

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种植业结构调整 1

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饲（草）料 1

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Influence of harvest date on seed yield and quality in forage kochia

Cody F. CREECH, Blair L. WALDRON, Corey V. RAMSOM, Dale R. ZOBELL, Joseph Earl CREECH

《农业科学与工程前沿（英文）》 2018年第5卷第1期页码 71-79 doi: 10.15302/J-FASE-2017196

摘要： Forage kochia ( ) is used for rangeland reclamation and livestock and wildlife forage, but limited research has been conducted on its seed production. Therefore, this research evaluated the effect of harvest date on seed weight, germination, and seed yield of forage kochia subspecies and . Seed was harvested from individual plants for 3 years during October, November, and December. October harvest had the lightest 100-seed weights, with the November harvest slightly heavier than December, for most accessions. Cultivar Snowstorm and breeding line Sahsel, both subsp. , had the greatest 100-seed weights in November, 155 and 143 mg, respectively, whereas, cv. Immigrant (subsp. ), the standard for forage kochia, ranked among the least for 100-seed weight. For most accessions, germination was lowest from the October harvest (11%–43%), with greater germination with November and December harvested seeds (43%–64%). Viable seed yields were greatest in November with the exception of two accessions, which peaked in October, indicating earlier maturity. Results indicate that forage kochia usually reaches optimum seed maturity by early November, after plants are exposed to freezing temperatures; however, earlier maturing accessions exist in both subspecies and .

关键词： forage rangeland seed germination seed quality

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我国饲（草）料供求及未来需求预测和对策研究

刘爱民, 贾盼娜, 王立新, 吴良杰

《中国工程科学》 2018年第20卷第5期页码 39-44 doi: 10.15302/J-SSCAE-2018.05.006

摘要：

随着我国居民生活水平的提高，人们对国内肉、禽、蛋、奶等畜禽产品消费量及生产量的持续增加，国内饲（草）料的需求也将不断增长。本文在对我国饲（草）料供求变化分析的基础上，依据未来国内畜禽产品需求量的变化，对饲（草）料需求进行了预测。研究结果表明，未来我国饲草料供需缺口仍将扩大，为保障国内饲（草）料供给的安全，应适度扩大青贮玉米的种植，发展农区草业；充分合理利用农业资源，适度增加大豆、油菜籽等作物种植，增加国内粕类的有效供给；同时充分合理利用海外农业资源，保障国内饲（草）料供给安全。

关键词：饲（草）料供需预测对策

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种植业结构调整和草牧业发展潜力分析及政策建议

李向林,沈禹颖,万里强

《中国工程科学》 2016年第18卷第1期页码 94-105 doi: 10.15302/J-SSCAE-2016.01.012

摘要：

发展农区草牧业可促进牧草与粮食作物或经济作物在时间、空间上的耦合，提高农业资源的利用效率。目前我国农区草业的资源优势尚未得到有效发挥，其发展仍然受传统农业生产模式思想的束缚，政策上对其发展的扶持力度也较小。本文分析了农区草业发展的现状与潜力，并提出了相关的政策建议。

关键词：种植业结构调整农区草业潜力政策建议

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INTENSIFICATION OF GRASSLAND-BASED DAIRY PRODUCTION AND ITS IMPACTS ON LAND, NITROGEN AND PHOSPHORUS USE EFFICIENCIES

Jouke OENEMA, Oene OENEMA

《农业科学与工程前沿（英文）》 2021年第8卷第1期页码 130-147 doi: 10.15302/J-FASE-2020376

摘要： Many grassland-based dairy farms are intensifying production, i.e., produce more milk per ha of land in response to the increasing demand for milk (by about 2% per year) in a globalized market. However, intensive dairy farming has been implicated for its resources use, ammonia and greenhouse gas emissions, and eutrophication impacts. This paper addresses the question of how the intensity of dairy production relates to N and P surpluses and use efficiencies on farms subjected to agri-environmental regulations. Detailed monitoring data were analyzed from 2858 grassland-based dairy farms in The Netherlands for the year 2015. The farms produced on average 925 Mg·yr milk. Milk production per ha ranged from<10 to>30 Mg·ha ·yr . Purchased feed and manure export strongly increased with the level of intensification. Surpluses of N and P at farm level remained constant and ammonia emissions per kg milk decreased with the level of intensification. In conclusion, N and P surpluses did not differ much among dairy farms greatly differing in intensity due to legal N and P application limits and obligatory export of manure surpluses to other farms. Further, N and P use efficiencies also did not differ among dairy farms differing in intensity provided the externalization of feed production was accounted for. This paper provides lessons for proper monitoring and control of N and P cycling in dairy farming.

关键词： ammonia externalization feed forage maize front runners manure production milk yield nitrogen surplus

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Functional characterization of caffeic acid

Fengyan WU, Zhenying WU, Aiguo YANG, Shanshan JIANG, Zeng-Yu WANG, Chunxiang FU

《农业科学与工程前沿（英文）》 2018年第5卷第1期页码 98-107 doi: 10.15302/J-FASE-2017198

摘要： Caffeic acid -methyltransferase (COMT) is a crucial enzyme that mainly methylates phenylpropanoid -hydroxyl of C in the biosynthesis of syringyl lignin in angiosperms. A putative , named as , was isolated from switchgrass ( ), a C warm-season dual-purpose forage and bioenergy crop. Our results showed that recombinant PvCOMT1 enzyme protein catalyzed the methylation of 5-OH coniferyl alcohol, 5-OH coniferaldehyde (CAld5H) and 5-OH ferulic acid. Further studies indicate that CAld5H can dominate COMT-mediated reactions by inhibiting the methylation of the other substrates. Transgenic switchgrass plants generated by an RNAi approach were further employed to study the function of in internode lignification. A dramatic decrease in syringyl lignin units coupled with an obvious incorporation in 5-OH guaiacyl lignin units were observed in the COMT-RNAi transgenic plants. However, the constitutive suppression of COMT in switchgrass plants altered neither the pattern of lignin deposition along the stem nor the anatomical structure of internodes. Consistent with the biochemical characterization of PvCOMT1, a significant decrease in sinapaldehyde was found in the COMT-RNAi transgenic switchgrass plants, suggesting that CAld5H could be the optimal intermediate in the biosynthesis syringyl lignin.

关键词： biofuel crop caffeic acid O-methyltransferase forage lignin Panicum virgatum switchgrass transgenic plant