Impact of genetically modified crops and their management on soil microbially mediated plant nutrient transformations
Impact of genetically modified crops and their management on soil microbially mediated plant nutrient transformations
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DOI：
10.2134/jeq2004.0816
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发表时间：
2004-05-01
影响因子：
2.4
通讯作者：
Means, NE
中科院分区：
文献类型：
--
作者：
Motavalli, PP;Kremer, RJ;Means, NE
近年来全球转基因作物种植面积迅速增加，其潜在的环境影响之一是土壤微生物介导的过程和功能发生变化。土壤生物区系的许多基本功能包括土壤有机质分解、养分矿化和固定、氧化还原反应、生物固氮和增溶。然而，相对较少的研究已经审查了转基因作物及其管理对微生物介导的土壤养分转化的直接和间接影响。本文的目的是审查现有的文献转基因作物的环境影响和管理土壤微生物介导的养分转化，并考虑土壤性质和气候因素，可能会影响转基因作物对这些过程的影响。改善植物营养的目标遗传性状包括植物对碱性土壤中低铁有效性的更大耐受性，增强土壤无机和有机P的获得，以及增加土壤N的同化。转基因作物及其管理的潜在直接影响包括由于根分泌物的量和组成的差异而引起的土壤微生物活性的变化、由转基因作物的基因转移引起的微生物功能的变化以及由于转基因作物的管理实践（例如施用农药、耕作、以及无机和有机肥料源的施用。转基因作物可能产生的间接影响，包括转基因作物残留物命运的改变以及土地利用和土壤侵蚀率的改变，值得进一步研究。尽管公众普遍关注，但目前还没有确凿的证据表明，目前发布的转基因作物，包括抗除草剂和抗虫害作物，对刺激或抑制田间环境中的土壤养分转化产生重大的直接影响。在评估转基因作物对土壤养分转化的影响时，需要进一步考虑土壤性质的广泛影响，包括粘土量及其矿物学、pH值、土壤结构和土壤有机质，以及转基因作物可能生长的气候条件的变化。未来对正在开发的各种转基因作物的影响进行环境评估，可能会加深对土壤生物功能和过程的理解。
One of the potential environmental effects of the recent rapid increase in the global agricultural area cultivated with transgenic crops is a change in soil microbially mediated processes and functions. Among the many essential functions of soil biota are soil organic matter decomposition, nutrient mineralization and immobilization, oxidation-reduction reactions, biological N fixation, and solubilization. However, relatively little research has examined the direct and indirect effects of transgenic crops and their management on microbially mediated nutrient transformations in soils. The objectives of this paper are to review the available literature related to the environmental effects of transgenic crops and their management on soil microbially mediated nutrient transformations, and to consider soil properties and climatic factors that may affect the impact of transgenic crops on these processes. Targeted genetic traits for improved plant nutrition include greater plant tolerance to low Fe availability in alkaline soils, enhanced acquisition of soil inorganic and organic P, and increased assimilation of soil N. Among the potential direct effects of transgenic crops and their management are changes in soil microbial activity due to differences in the amount and composition of root exudates, changes in microbial functions resulting from gene transfer from the transgenic crop, and alteration in microbial populations because of the effects of management practices for transgenic crops, such as pesticide applications, tillage, and application of inorganic and organic fertilizer sources. Possible indirect effects of transgenic crops, including changes in the fate of transgenic crop residues and alterations in land use and rates of soil erosion, deserve further study. Despite widespread public concern, no conclusive evidence has yet been presented that currently released transgenic crops, including both herbicide and pest resistant crops, are causing significant direct effects on stimulating or suppressing soil nutrient transformations in field environments. Further consideration of the effects of a wide range of soil properties, including the amount of clay and its mineralogy, pH, soil structure, and soil organic matter, and variations in climatic conditions, under which transgenic crops may be grown, is needed in evaluating the impact of transgenic crops on soil nutrient transformations. Future environmental evaluation of the impact of the diverse transgenic crops under development could lead to an improved understanding of soil biological functions and processes.