Imazaquin mobility and persistence in a Sharkey clay soil as influenced by tillage systems
Imazaquin mobility and persistence in a Sharkey clay soil as influenced by tillage systems
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DOI：
10.1614/0043-1745(2001)049
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发表时间：
2001-07-01
期刊：
影响因子：
2.5
通讯作者：
Wesley, RA
中科院分区：
文献类型：
--
作者：
Seifert, S;Shaw, DR;Wesley, RA
1996年、1997年和1998年，在密西西比州斯通维尔的三角洲研究和推广中心进行了实地研究，以评估耕作制度(传统耕作和深松耕作)对沙基粘性土壤中伊马喹环境命运的影响。施药剂量为140g ai ha(-1)。深松在秋季并不影响咪唑喹的消散、径流总量、土壤中的咪唑喹浓度。径流，或土壤中的咪唑喹浓度，由化学萃取法测定。玉米根部生物测定表明，耕作制度对土壤中植物有效咪唑喹的影响没有差异。用化学萃取法或生物测定法测得的伊马扎喹浓度随着时间的推移而减少，半衰期从8天到25天不等。1997年和1998年利用棉花和玉米进行了田间生物测定，使用的是前一年使用过伊马扎喹的地块。1997年，种植2周后，棉花和玉米的受害程度在3%到15%之间，而在1998年没有观察到伤害。随着时间的推移，伤害症状逐渐减少，无论哪一年，种植后5周都没有受伤。尽管1997年早季棉花发育迟缓和玉米轻微变色，但咪草喹残留物并不影响随后棉花或玉米的营养生长和生殖生长模式。1998年，与常规耕作相比，深松地块的玉米和棉花高度显著增加。
Field studies were conducted at Delta Research and Extension Center, Stoneville, MS, in 1996, 1997, and 1998 to assess the effect of tillage systems (conventional tillage and subsoiling) on the environmental fate of imazaquin in a Sharkey clay soil. Imazaquin was applied preemergence at 140 g ai ha(-1). Subsoiling in the fall did not affect imazaquin dissipation, total volume of runoff, imazaquin concentration in. runoff, or imazaquin concentration in soil, as determined by chemical extraction. A corn root bioassay revealed no differences due to tillage systems in plant-available imazaquin in soil. Imazaquin concentration measured by chemical extraction or bioassay diminished over time, with a half-life ranging from 8 to 25 d. A field bioassay utilizing cotton and corn was conducted in 1997 and 1998 using plots that had received imazaquin the previous year. In 1997, 2 wk after planting, cotton and corn injury ranged from 3 to 15%, whereas no injury was observed in 1998. Injury symptoms declined over time, with no injury 5 wk after planting in either year. Although early-season cotton stunting and slight discoloration of corn was apparent in 1997, imazaquin residues did not affect subsequent vegetative and reproductive growing patterns of cotton or corn. In 1998, corn and cotton height were significantly greater in subsoiled plots compared to conventional tillage.