Legume recovery in pastures following broadleaf weed control

入侵物种是牧草生产中普遍存在的问题。虽然除草剂对杂草仍然有效，但除草剂也会去除有益的豆类，以最小的成本增加产量。虽然豆科植物的迅速回归是一个重要的目标，但豆科植物在杂草控制后在牧场重新建立的能力取决于几个因素。它们包括喷洒除草剂后的降解率，土壤中存活的豆科种子的存在，以及在田间条件下有利于豆科幼苗出苗和生长所需的特定生长条件。我们采用田间试验（短期和长期）和补充温室试验相结合的方法，1)量化两种新型除草剂（氨基环丙草胺和氨基吡啶）的“残留”特性的降解，2)评估它们对两种常见豆科植物（苜蓿和白三叶草）的出苗和存活的影响，3)评估环境（光和水分）对豆科植物幼苗出苗、生长和存活的影响。4)记录喷施后牧场植物种类组成的长期变化；5)描述北温带牧场土壤种子库，包括豆科植物的丰富度。信息将用于帮助种植者有效地重建豆科植物，保持生产力和牧场生物多样性。

Invasive species are a widespread problem in pastures limiting forage production. While herbicides remain effective against weeds, herbicides also remove beneficial legumes known to increase production at minimal cost. Although prompt return of legumes is an important goal, the ability of legumes to re-establish in pastures following weed control depends on several factors. They include the rate of herbicide degradation following spraying, the presence of viable legume seeds in the soil, and the specific growing conditions needed to favor legume seedling emergence and growth under field conditions. We use a combination of field experiments (short and long-term) and complementary greenhouse trials to 1) quantify the degradation of two new herbicides (aminocyclopyrachlor and aminopyralid) with 'residual' properties, 2) assess their effect on the emergence and survival of two common legumes (alfalfa and white clover) following application, 3) evaluate the effect of environment (light and moisture) on legume seedling emergence, growth and survival, 4) document long-term changes in plant species composition of pasture following spraying, and 5) describe the soil seed bank in northern temperate pastures, including the abundance of legumes. Information will be used to assist growers to effectively re-establish legume and maintain productivity and pasture biodiversity.