Modelling the influence of land-use changes on biophysical and biochemical interactions at regional and global scales

Land-use changes since the start of the industrial era account for nearly one-third of the cumulative anthropogenic CO2 emissions. In addition to the greenhouse effect of CO2 emissions, changes in land use also affect climate via changes in surface physical properties such as albedo, evapotranspiration and roughness length. Recent modelling studies suggest that these biophysical components may be comparable with biochemical effects. In regard to climate change, the effects of these two distinct processes may counterbalance one another both regionally and, possibly, globally. In this article, through hypothetical large-scale deforestation simulations using a global climate model, we contrast the implications of afforestation on ameliorating or enhancing anthropogenic contributions from previously converted (agricultural) land surfaces. Based on our review of past studies on this subject, we conclude that the sum of both biophysical and biochemical effects should be assessed when large-scale afforestation is used for countering global warming, and the net effect on global mean temperature change depends on the location of deforestation/afforestation. Further, although biochemical effects trigger global climate change, biophysical effects often cause strong local and regional climate change. The implication of the biophysical effects for adaptation and mitigation of climate change in agriculture and agroforestry sectors is discussed. center dot Land-use changes affect global and regional climates through both biochemical and biophysical process. center dot Climate effect from biophysical process depends on the location of land-use change. center dot Climate mitigation strategies such as afforestation/reforestation should consider the net effect of biochemical and biophysical processes for effective mitigation. center dot Climate-smart agriculture could use bio-geoengineering techniques that consider plant biophysical characteristics such as reflectivity and water use efficiency.

El rol de los contratos en viticulturas

[ES] A pesar de que los economistas han dedicado enorme esfuerzo a examinar la racionalidad de los contratos en agricultura, pocos estudios se han llevado a cabo en viticultura. Sin embargo, se observan diferencias contractuales en la producción de uva y vino. En el presente trabajo se analizan las estructuras contractuales actualmente utilizadas en varias regiones vitivinícolas. Independientemente de las características inherentes en los contratos, se obtiene que estos mecanismos permiten a las bodegas articular sus requisitos con respecto a la calidad de las uvas producidas por los agricultores.

Transformaciones agropecuarias en Guipúzcoa durante los siglos XVI y XVII

Actas de la XII Reunión Científica de la Fundación Española de Historia Moderna, celebrada en la Universidad de León en 19-21 de junio de 2012.

Country strategy paper: Philippines

The Philippines rank 85 out of 175 countries in terms of Human Development Index. Poverty is most acute and widespread in rural areas, including many coastal municipalities, where 54% of people are living below the poverty line. Dependence on coastal and inland aquatic resources is high among rural poor people, who tend to be self-employed, primarily in agriculture, fisheries and casual labor. They are almost all landless. (PDF contains 21 pages)

Produtividade Total dos Fatores: revisão da literatura e uma aplicação exploratória para a cultura do milho usando os dados dos censos agropecuários

Este trabalho pretende contribuir para o entendimento sobre a produtividade na agricultura brasileira, bem como propõe uma reflexão sobre o debate da produtividade total dos fatores. Para isso, buscou-se, antes de tudo, debater as medidas de produtividade, sobretudo as medidas de produtividade total dos fatores e, em seguida, apresentar estimativas da produtividade total na agricultura no Brasil e no mundo. Propõem-se também uma estimativa preliminar dessa metodologia para o cálculo da produtividade total dos fatores na cultura do milho através do índice de Tornqvist. O objetivo é, então, revisar a literatura teórica e empírica sobre a produtividade total dos fatores na agricultura e calcular as produtividades parciais e totais na cultura do milho para os estados brasileiros. Apesar da maior parte dos resultados encontrados no cálculo da produtividade total para a cultura do milho no Brasil não terem sido consistentes, a conclusão geral do levantamento bibliográfico foi que tanto a agricultura brasileira quanto a agricultura mundial, independente da metodologia utilizada, apresentou uma tendência ao crescimento da produtividade total dos fatores.

Efecto del glifosato en la morfologia del tubo dogestivo y en la actividad acetilcolinesterasa de la lombriz Eisenia fetida

[EUS] Gaur egun produktu kimiko ugari erabiltzen dira nekazaritzaren produktibitatea emendatzeko eta modu honetan nekazaritza-produktuen etekin eta kalitatea hobetzeko asmoz. Hala ere, produktu kimiko hauek ekosisteman izan ditzaketen hilgarriak ez diren eraginak askotan ez dira kontuan hartzen. Azken urteotan osagai aktibo gisa glifosatoa duten herbiziden erabilera emendatu da. Lan honetan, glifosatoak ingurunean sor ditzakeen eraginak ikertu nahi izan dira, lurzoruan oso ugaria den Eisenia fetida zizarea adierazle biologiko gisa erabiliz. Esperimentuan 10 indibiduo helduz osaturiko 4 populazio erabili ziren, zeinak 14 egunez tratamendu desberdinetan ezarri ziren (kontrola, 50, 500 eta 5000 mg glifosato/Kg lur lehor). Glifosato kontzentrazio desberdinek ez zuten zizareen hilkortasunean edo pisuaren aldaketan eraginik izan. Hala ere, digestio-hodiaren epitelioaren morfologian eta azetilkolinesterasaren jardueran aldaketak behatu ziren. Glifosato kontzentrazio baxueneko ontziko zizareetan digestio-hodiko epitelioaren altueraren uniformetasun falta behatu zen, glifosato kontzentrazio ertaineko ontziko zizareetan orokorrean epitelioaren altuera txikiagoa zen, eta glifosato kontzentrazio handieneko ontziko zizareetan digestio-hodien borobiltasuna eta epitelioaren jarraitasuna galdu zen. Azetilkolinesterasaren jardueraren murrizpena behatu zen glifosatodun lurretan egondako zizareetan. Esperimentu honetan erabilitako glifosato kontzentrazioek zizareengan hilgarriak ez diren aldaketak sortzen dituzte, aztertutako biomarkatzaileak etorkizuneko ekotoxikologia testetan erabilgarriak izan daitezkeelarik.

Compostagem de Resíduos Agroextrativistas no Município de Laranjal do Jari - Amapá.

Esta dissertação tem como objetivo, a apresentação de uma proposta para os resíduos agroextrativistas a fim de encontrar um composto orgânico ideal para ser utilizado na agricultura do Município de Laranjal do Jari, no Estado do Amapá. A técnica em questão será a compostagem, gerando uma alternativa de utilização para os resíduos de natureza local, onde atualmente não vêm sendo aproveitados. Para se chegar ao composto ideal serão utilizados basicamente: caroços de açaí e cascas de castanha. Esses resíduos vêm sendo relegados através dos Serviços de Limpeza Pública, constituindo não só um problema estético ou ambiental, mas de desperdício de energia e materiais que poderiam ser utilizados na recuperação de áreas degradadas ou como composto orgânico, na fixação de nutrientes e água no solo a fim de melhorar as práticas agrícolas, reduzir custos e a importação de fertilizantes químicos. A metodologia envolve estudo bibliográfico sobre a técnica de compostagem, consistindo em desenvolver todas as etapas que se darão mais claras, no desenvolver dos trabalhos de campo, para uma futura implantação de uma Unidade de Compostagem, a ser aplicável para a agricultura do referido município.

猪粪农用的生态风险——以东北黑土为例

集约化养殖大量使用铜(Cu)作为饲料添加剂会在养殖废物的排放和利用中导致一定的环境问题。随着东北老工业基地产业结构的调整，畜牧业作为东北地区二次振兴的主要产业得到迅速发展，由此会产生大量的畜禽粪便用于农业土壤施肥。而东北地区又是我国重要的农副产品生产基地，研究畜禽粪便农用的健康及环境风险就显得殊为必要。黑土是东北地区最主要的土壤类型，本文以东北黑土为供试材料，通过在盆栽实验中添加不同Cu浓度的猪粪来模拟施肥年限不同的菜园土，研究土壤中Cu累积对小白菜(Brassica chinensis L.)地上部分生物量与Cu含量、土壤微生物生物量和土壤酶(脱氢酶、脲酶、酸性磷酸酶)活性、微生物群落功能多样性以及对土壤功能微生物——氨氧化古菌(AOA)和氨氧化细菌(AOB)等的影响，从而实现含Cu猪粪农用对食物链途径的健康风险以及土壤生态系统的生态风险的综合评价。 研究结果表明，施用猪粪显著地改善了土壤的pH，增加了小白菜地上部分生物量，对其体内Cu浓度则没有显著影响;小白菜地上部分Cu浓度与土壤全Cu和水溶态Cu浓度显著正相关(P<0.01)，而地上生物量与土壤全Cu浓度显著负相关(P<0.05)。当土壤全Cu浓度达到300 mg kg-1后，小白菜地上部分生物量受到强烈抑制。 猪粪的施用在一定时期内显著地促进了脱氢酶和脲酶的活性，但随土壤Cu浓度的增加，脱氢酶、脲酶和酸性磷酸酶的活性逐渐受到抑制。当土壤全Cu浓度达到300 mg kg-1后，微生物生物量、脱氢酶、脲酶、酸性磷酸酶等均受到强烈抑制。 施加猪粪提高了土壤微生物群落功能多样性，当土壤Cu浓度达到170 mg kg-1后，显著地抑制了微生物群落功能多样性。种植小白菜后，各处理间微生物群落功能多样性没有显著差异，意味着植物能够维持微生物群落功能多样性。主成分分析(PCA)结果显示，当土壤全Cu浓度达到300 mg kg-1后，微生物群落功能多样性与其它处理显著不同。 猪粪显著地促进了土壤的硝化潜势速率(PNR)。随着Cu浓度的增加，硝化潜势速率逐渐受到抑制，当土壤全Cu浓度达到170 mg kg-1后，即与对照无显著差异。植物在维持硝化速率方面也起到重要作用。古菌amoA基因在每克干土中的拷贝数在9.4*106~2.59*107，细菌amoA基因在每克干土中的拷贝数约为1.48*106~1.41*107。猪粪在一定时期内显著地增加了AOA和AOB的数量，当土壤Cu浓度达到300 mg kg-1后，AOA和AOB的数量显著下降，并且AOA与AOB amoA基因拷贝数的比值增加，在小白菜栽种前(B1)和小白菜收获后(B2)分别为2.33和9.26，这意味着在高Cu浓度胁迫下，AOA的耐受性更强。古菌与细菌的amoA拷贝数与PNR之间则没有显著的相关关系，意味着AOA和AOB种群结构以及其中某些种群的活性可能发生了变化。 本文通过对东北黑土菜地土壤中Cu在作物体内的迁移积累及其对土壤微生物学指标(微生物生物量、酶活性、微生物群落功能多样性及功能微生物)的影响的综合研究，揭示了含Cu猪粪农用所造成的健康和生态风险，为建立适宜的土壤环境质量标准提供了一定的科学依据。通过本研究得出，黑土蔬菜种植中Cu浓度的阈值在170-300 mg kg-1之间。

Xenobiotics removal from polluted water by a multifunctional constructed wetland

Removal efficiencies on xenobiotics from polluted water in a twin-shaped constructed wetland consisting of a vertical flow chamber with the crop plant Colocasia esculenta L. Schott and a reverse vertical flow one with Ischaemum aristatum var. glaucum Honda, were assessed by chemical analysis and bioassays. After a four-month period of application, removal efficiencies of the applied pesticides parathion and omethoate were 100%, with no detectable parathion and omethoate in the effluent. For the applied herbicides, the decontamination was less efficient with removal efficiencies of 36% and 0% for 4-chloro-2-methyl-phenoxyacetic acid and dicamba, respectively. As shown by toxicity assay with duckweed Lemna minor L., growth retardation may occur if the water treated for herbicide removal is used in irrigation of sensitive cultivars in agriculture or horticulture. In contrast to I. aristatum var. glaucum Honda, the crop C esculenta L. Schott has a high yield in biomass production as a valuable source of renewable energy. (C) 2002 Elsevier Science Ltd. All rights reserved.

Isolation and Characterization of a Methomyl-Degrading Paracoccus sp mdw-1

Methomyl, an extremely toxic pesticide, is widely used in agriculture. A strain named mdw-1 capable of degrading methomyl rapidly was successfully isolated from activated sludge in this study. It could utilize methomyl as the sole carbon or nitrogen source. The optimal temperature and medium pH for its growth and methomyl biodegradation were 30 degrees C and 7.0, respectively. It was identified as a Paracoccus sp. according to its morphological features, physiological and biochemical characteristics, and phylogenetic analysis based on the sequence of 16S rDNA. Gas chromatography-mass spectrometry (GC-MS) analysis showed that methomyl could be completely transformed to S-methyl-N-hydroxythioacetamidate in 10 h of incubation with the isolate mdw-1.

论高粱的抗旱性及在旱区农业中的地位

本文以笔者研究组多年研究结果为基础,以玉米为主要参比作物,就干旱逆境下高粱的产量表现、水分利用及抗旱特性进行了论述。认为高粱是一种综合抗旱能力很强的作物,尤其具有低耗水、高水分利用效率特性,其耐旱性显著高于玉米,也高于谷子和苜蓿,属于一种典型的模式抗旱作物,具有重要的生产和研究价值。指出高粱作为抗逆性很强的粮饲酿兼用作物,特别是作为一种能源植物,仍具良好的发展前景。建议今后在降水量低于450mm、热量可满足生长的地区扩大高粱种植面积,同时加强对其整体抗旱性机理及抗旱基因组的研究。

根系分泌物生态学研究

The study of root exudates enriches the theories and methods of rhizospheric soil ecology, and offers theory warranty that it can be used in agriculture and forest. This paper discusses the types and components of root exudates, mechanism of exudation, and the relationship between root exudates and the biotic and environmental factors. The development tendency and study aspect of root exudates in the future was evaluated as well.

农业经济用水量与我国农业战略节水潜力

在分析我国农业水资源利用现状基础上,从保障粮食安全和最大用水综合效益出发,提出了"农业经济用水量"的概念,分析了其内涵,提出了基于宏观水资源合理配置的"农业经济用水量"研究的理论基础及其相应技术基础,并从战略层面对我国未来可实现的农业经济用水量及其节水潜力进行了初步分析,为缓解我国农业用水与工业用水、生态用水之间的矛盾提供了有益的探索。

土壤中施用聚丙烯酸钠保水剂对冬小麦生长及产量影响

聚丙烯酸钠因其特殊的保水性能受到广泛重视,但是其研究仍多限于实验室模拟研究。为了促进其在农业生产中的应用与推广,该文采用大田试验,研究了聚丙烯酸钠对冬小麦生长、产量及水分利用效率(WUE)的影响。结果表明施入聚丙烯酸钠能够促进小麦生长,提高小麦叶绿素含量,提高小麦产量与WUE。采用沟施5.5 m3/hm2的1/2000聚丙烯酸钠水溶液,能够使小麦较对照增产2.9%,WUE增加3.52 kg/(hm2.mm);与肥料混合使用时,增产效果更加显著,可增产10.14%,WUE增加4.38 kg/(hm2.mm)。

延安地区农业面临的问题与增产技术研究

:1 999年 8月朱总理为了落实江总书记“再造一个山川秀美的西北地区”和“把黄河的事情办好”的重要指示 ,视察黄土高原地区农业建设 ,从根治黄土高原的大局出发 ,强调采取“退耕还林 (草 ) ,封山绿化 ,个体承包 ,以粮代赈”的措施 ,动员广大人民群众 ,大搞植树种草 ,改善生态环境 ,为根治黄河奠基。面对总理的指示精神 ,退耕还林还草之后的农业如何发展 ?在人均 0 .0 7～ 0 .1 3hm2基本农田结构如何调整 ?农林牧关系如何协调 ?带着这些问题 ,我们通过在延安 70个农户中进行调查 ,指出了农业发展中存在的主要问题和面临的挑战 ,总结出效果明显的农业技术 ,供决策部门参考