摘要
本文提出了杂草生态经济杀除阈期的概念,并在北京地区田间试验的基础上,建立了苗后放任和免除夏大豆田间杂草生长的相对时间与大豆相对产量间的函数关系,并在此基础上确立了夏大豆田间杂草群落的生态经济杀除阈期的计算模型。结果表明,夏大豆田间杂草的相对生态经济杀除阈期约处在大豆出苗至成熟期总天数的12.4％—31.0％的天数之前。在此期间进行除草.既能确保大豆不会因杂草生长而显著减产,又可节约阈期之前和之后盲目除草所消耗的费用,并在一定程度上可利用杂草的固土保肥、增加土壤有机质等作用。
A terminology of 'Eco-Economic Period Threshold For Weed Control'was proposed. On this base, field experiments were conducted during 1984, 1985 and 1991 in Beijing region to fit the functional relationships between the re- lative weedy or weedfree days of weeds and the relative yield of summer soy- beans. Calculating models of the eco-economic period threshold for the weed control were established. Results calculated by using these models showed that the eco-economic period threshold for controlling the weeds in summer soybeans ranged from 12.4% to 31.0%, namely from 11 to 27 days after emergence in Beijing re- gion. This is the critical period to remove all of the weed damage, to save weed control cost and to maximally utilize the role of the weed growth in reducing the loss of water, nutrients and soil during the growth season of summer soybeans.
基金
国家自然科学基金
关键词
杂草
防治指标
大豆
生态
杀除阈期
Soybean
Weeds
Eco-economic period threshold
Critical period
