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我国东北地区除草剂使用及问题 总被引:14,自引:2,他引:14
东北地区是我国除草剂使用历史最久、用量最大的地区,经过40余年的大面积使用,相继产生了一些比较突出的问题,如土壤处理剂过多、杂草抗药性日益发展、喷液量过大、多年生杂草危害加剧以及长残留性除草剂土壤残留对后茬作物的伤害等。今后除草剂品种更新应根据东北地区气候干旱、春季少雨、土壤有机质含量高等特点,大力发展苗后茎叶处理除草剂,适应免耕、少耕及防除多年生杂草的除草剂品种;充分发挥轮作、耕作及栽培措施的除草作用以及广泛使用增效剂是降低除草剂用量的条件。 相似文献
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影响茎叶处理除草剂效果的因素 总被引:1,自引:0,他引:1
在过去中国除草剂使用的15年时间里,土壤处理剂占居一定优势,特别是东北地区的大豆与玉米。氯嘧磺隆(豆磺隆)、乙草胺、莠去津使用面积较大,成为除草剂使用中的主流,但在大面积使用中发现:1)氯嘧磺隆对大豆安全性差,更重要的是其土壤残留严重伤害大豆后茬作物甜菜、玉米、油菜及各种蔬菜;2)莠去津土壤残留伤害后茬作物甜菜、油菜、向日葵等;3)由于土壤有机质及粘粒的强烈吸附作用,造成单位面积用药量较大;4)药效受土壤含水量的影响大,在少雨条件下,除草效果差。 相似文献
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我国除草剂造成作物的药害与预防 总被引:3,自引:1,他引:2
我国除草剂大量应用已近50年,其中一个重要问题是经常发生作物药害,从而成为制定杂草治理措施的关键所在。根据农业实践,论述了作物药害的原因及其预防措施,如正确的除草剂使用方法、限制与禁用长残留性除草剂、使用增效剂以及作物轮作、适宜的耕作与栽培措施等。 相似文献
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对改善我国除草剂品种结构状况的思考 总被引:16,自引:4,他引:16
多种因素使中国除草剂使用的效益下降,其中主要有苗前土壤处理剂比重过大使除草效果不稳定,除草剂残留造成药害时有发生,缺乏小面积作物用除草剂等。抗草甘膦转基因作物的研发推广不失为一个良好的选择。 相似文献
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长残留除草剂在土壤中的分解及其使用中带来的严重问题 总被引:6,自引:0,他引:6
1长残留除草剂在土壤中的分解途径
除草剂施用于土壤后,通过微生物或化学反应(酸水解作用)而逐步分解与消失。微生物降解是除草剂从土壤中消失的重要因素。参与降解的微生物有真菌、细菌与放线菌。土壤微生物不能降解被土壤粒子吸附的除草剂分子;酸催化的水解反应主要影响三氮苯与磺酰脲类除草剂在土壤中的消失,而土壤pH(5-8)影响除草剂在土壤中的化学反应。土壤pH〉6.8时酸水解作用接近停止。土壤pH影响长残留除草剂磺酰脲、咪唑啉酮、三氮苯与三唑嘧啶磺酰胺类除草剂在土壤中的吸附与可利用性,从而影响其滞留。 相似文献
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芸苔素内酯解除甲黄隆对水稻药害的研究 总被引:3,自引:0,他引:3
甲黄隆 (metsulfuron)为麦田优良除草剂 ,但由于其具有极高的活性和极强的选择性 ,土壤中少量的残留即可对后茬敏感作物产生药害。作为小麦下茬作物的水稻是一种对甲黄隆相当敏感的作物。有关甲黄隆对水稻生长的影响的研究有不少报道〔4〕,但使用除草剂安全剂解除其对水稻药害的研究却较少。芸苔素内酯 (Brassinolide ,简称BR)是一种新型植物生长调节剂 ,它具有极强的生物活性 ,尤其在逆境下对作物有较大的促长作用〔8〕,已广泛应用于农业生产。已有报道〔7〕其作为除草剂安全剂缓解除草剂西草净 (simetry… 相似文献
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关于除草剂田间药效试验安全性评价方法问题的探讨 总被引:7,自引:8,他引:7
在除草剂田间药效试验中,安全性评价方法十分重要。除草剂安全性评价必须全面和准确,要有倍量试验,要特别注意在不良环境条件下的试验苗前除草剂要进行不同土壤有机质、质地、pH值等试验,还要进行低温高湿、拱土期施药、混土施药等试验。苗后除草剂要进行的试验包括以下各项:高温低湿、低温高湿(最好有两天低于10℃的气温试验)、喷液量试验,作物不同生育阶段和品种试验,加不同类型的喷雾助剂及剂量试验;要特别重视长残效除草剂对后茬敏感作物安全性的评价试验。改进施药技术可避免或减轻药害。 相似文献
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磺酰脲类除草剂残留检测分析研究新进展 总被引:13,自引:0,他引:13
磺酰脲类化合物因用量低、对哺乳动物低毒及使用后易降解为无毒化合物等特点而已发展成为世界上最大的一类除草剂。在环境介质如土壤、水和动植物组织等研究分析时要求磺酰脲类除草剂残留分析的检测限达到10-9mg/kg,甚至更低。这是一个极富挑战性的工作。近些年来,国内外农药环境毒理、环境科学和生物学等领域的科研人员对环境中的磺酰脲类除草剂进行了大量的研究,提出了许多磺酰脲类除草剂残留分析方法,归结起来可分为三大类即化学分析法、生物测定法和酶联免疫测定法。笔者对磺酰脲类除草剂在环境介质中的残留性质、提取、净化、分析原理和方法等方面进行了评述,讨论了LC/MS/MS在磺酰脲类除草剂残留研究中的应用。 相似文献
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磺酰脲类除草剂残留与降解研究进展 总被引:46,自引:3,他引:46
本文概述了国内外有关磺酰脲类除草剂残留活性、降解方式及机制、影响残留和降解的环境条件及土壤因子、测定残留的方法等方面的研究进展。 相似文献
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H. Hauggaard-Nielsen M. Gooding P. Ambus G. Corre-Hellou Y. Crozat C. Dahlmann A. Dibet P. von Fragstein A. Pristeri M. Monti E. S. Jensen 《Nutrient Cycling in Agroecosystems》2009,85(2):141-155
Grain legumes are known to increase the soil mineral nitrogen (N) content, reduce the infection pressure of soil borne pathogens, and hence enhance subsequent cereals yields. Replicated field experiments were performed throughout W. Europe (Denmark, United Kingdom, France, Germany and Italy) to asses the effect of intercropping pea and barley on the N supply to subsequent wheat in organic cropping systems. Pea and barley were grown either as sole crops at the recommended plant density (P100 and B100, respectively) or in replacement (P50B50) or additive (P100B50) intercropping designs. In the replacement design the total relative plant density is kept constant, while the additive design uses the optimal sole crop density for pea supplementing with ‘extra’ barley plants. The pea and barley crops were followed by winter wheat with and without N application. Additional experiments in Denmark and the United Kingdom included subsequent spring wheat with grass-clover as catch crops. The experiment was repeated over the three cropping seasons of 2003, 2004 and 2005. Irrespective of sites and intercrop design pea–barley intercropping improved the plant resource utilization (water, light, nutrients) to grain N yield with 25–30% using the Land Equivalent ratio. In terms of absolute quantities, sole cropped pea accumulated more N in the grains as compared to the additive design followed by the replacement design and then sole cropped barley. The post harvest soil mineral N content was unaffected by the preceding crops. Under the following winter wheat, the lowest mineral N content was generally found in early spring. Variation in soil mineral N content under the winter wheat between sites and seasons indicated a greater influence of regional climatic conditions and long-term cropping history than annual preceding crop and residue quality. Just as with the soil mineral N, the subsequent crop response to preceding crop was negligible. Soil N balances showed general negative values in the 2-year period, indicating depletion of N independent of preceding crop and cropping strategy. It is recommended to develop more rotational approaches to determine subsequent crop effects in organic cropping systems, since preceding crop effects, especially when including legumes, can occur over several years of cropping. 相似文献
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The recovery of 15N-labelled fertilizer applied to a winter wheat (120 kg N ha–1) and also a perennial ryegrass (60 kg N ha–1) crop grown for seed for 1 year in the Canterbury region of New Zealand in the 1993/94 season was studied in the field. After harvests, ryegrass and wheat residues were subjected to four different residue management practices (i.e. ploughed, rotary hoed, mulched and burned) and three subsequent wheat crops were grown, the first succeeding wheat crop sown in 1994/95 to examine the effects of different crop residue management practices on the residual 15N recovery by succeeding wheat crops. Total 15N recoveries by the winter wheat and ryegrass (seed, roots and tops) were 52% and 41%, respectively. Corresponding losses of 15N from the crop-soil systems represented by un-recovered 15N in crop and soil were 12% and 35%, respectively. These losses were attributed to leaching and denitrification. The proportions of 15N retained in the soil (0-400 mm depth) at the time of harvest of winter wheat and ryegrass were 36% and 24%, respectively. Although the soil functioned as a substantial sink for fertilizer N, the recovery of this residual fertilizer by subsequent three winter wheat crops was low (1-5%) and this was not affected by different crop residue management practices. 相似文献
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土壤微生物降解磺酰脲类除草剂的研究进展 总被引:7,自引:0,他引:7
简要地综述了土壤微生物对磺酰脲类除草剂的降解、降解机理及影响微生物降解磺酰脲类除草剂的因素,并指出了利用土壤微生物修复磺酰脲类除草剂的残留药害是一个有效手段。 相似文献