{"title":"Sustainable weed management in a lettuce growing conservationist system","authors":"A. C. S. Hirata, P. A. Monquero, Edson Hirata","doi":"10.21475/ajcs.21.15.10.p3379","DOIUrl":null,"url":null,"abstract":"Soil disturbance, irrigation, and nitrogen fertilization excesses in lettuce crops have reduced the sustainability of the sector and favoured competition against weeds. This study aimed to evaluate the effect of cover crops and nitrogen fertilization management on weed control, weed-species dynamics, and soil seed bank in successive lettuce cultivation under no-tillage. The experiment was carried out in a tropical region during summer and arranged in a (3×4) +1 factorial scheme. Treatments consisted of three soil cover managements (Crotalaria juncea, Urochloa ruziziensis, and fallow) and four nitrogen (N) topdressing rates (0, 60, 120, and 180 kg ha−1) in a lettuce crop under fertigation. A conventional tillage system under more intense soil disturbance was also evaluated at the highest N rate. The results showed that lettuce cultivation on U. ruziziensis stood out regarding weed control. Higher soil disturbance in the conventional tillage increased weed emergence (288.9 and 245.8 plants m−2) compared to the fallow area (13.9 and 38.9 plants m−2), U. ruziziensis (4.2 and 9.7 plants m−2), and C. juncea (56.9 and 20.8 plants m−2) in successive cultivations, respectively. Soil cover management changed the dynamics of weed species emergence, especially in the first cultivation. Nitrogen topdressings did not affect weed dry matter and density at the time of weeding. The average number of non-dormant weed seeds within the 0.0-0.10 m soil seed bank layer reached 7,077 seeds m−2, with no difference among treatments. Therefore, sustainable management of lettuce cultivation using cover crops in rotation, associated with no-tillage, effectively controls weed communities, with emphasis on U. ruziziensis, regardless of the nitrogen fertilization management","PeriodicalId":10904,"journal":{"name":"Day 2 Tue, October 19, 2021","volume":"94 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2021-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Day 2 Tue, October 19, 2021","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.21475/ajcs.21.15.10.p3379","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Soil disturbance, irrigation, and nitrogen fertilization excesses in lettuce crops have reduced the sustainability of the sector and favoured competition against weeds. This study aimed to evaluate the effect of cover crops and nitrogen fertilization management on weed control, weed-species dynamics, and soil seed bank in successive lettuce cultivation under no-tillage. The experiment was carried out in a tropical region during summer and arranged in a (3×4) +1 factorial scheme. Treatments consisted of three soil cover managements (Crotalaria juncea, Urochloa ruziziensis, and fallow) and four nitrogen (N) topdressing rates (0, 60, 120, and 180 kg ha−1) in a lettuce crop under fertigation. A conventional tillage system under more intense soil disturbance was also evaluated at the highest N rate. The results showed that lettuce cultivation on U. ruziziensis stood out regarding weed control. Higher soil disturbance in the conventional tillage increased weed emergence (288.9 and 245.8 plants m−2) compared to the fallow area (13.9 and 38.9 plants m−2), U. ruziziensis (4.2 and 9.7 plants m−2), and C. juncea (56.9 and 20.8 plants m−2) in successive cultivations, respectively. Soil cover management changed the dynamics of weed species emergence, especially in the first cultivation. Nitrogen topdressings did not affect weed dry matter and density at the time of weeding. The average number of non-dormant weed seeds within the 0.0-0.10 m soil seed bank layer reached 7,077 seeds m−2, with no difference among treatments. Therefore, sustainable management of lettuce cultivation using cover crops in rotation, associated with no-tillage, effectively controls weed communities, with emphasis on U. ruziziensis, regardless of the nitrogen fertilization management
土壤扰动、灌溉和过量氮肥对生菜作物的影响降低了该部门的可持续性,有利于与杂草的竞争。本研究旨在评价覆盖作物和氮肥管理对免耕莴苣连作杂草控制、杂草物种动态和土壤种子库的影响。试验于夏季在热带地区进行,采用(3×4) +1因子方案。处理包括3种土壤覆盖管理(芥菜、褐藻和休耕)和4种氮肥追肥率(0、60、120和180 kg ha - 1)。在土壤扰动较强的常规耕作方式下,施氮量最高。结果表明,生菜栽培对杂草的控制效果较好。与休耕区(13.9株m−2和38.9株m−2)相比,常规耕作条件下土壤扰动较大的杂草出苗率分别为288.9株和245.8株m−2,而连作条件下,ruziziensis(4.2株m−2和9.7株m−2)和juncea(56.9株和20.8株m−2)分别增加。土壤覆盖管理改变了杂草物种的出现动态,特别是在第一次耕作中。施氮对除草时的干物质和密度没有影响。0.010 m ~ 0.10 m土壤种子库层非休眠杂草种子平均数量为7077粒m−2,处理间无显著差异。因此,在不考虑氮肥管理的情况下,利用覆盖作物轮作生菜种植的可持续管理与免耕相结合,可以有效地控制杂草群落,重点是U. ruziziensis