In 16 Mediterranean vineyards representing both a pedoclimate and a soil management gradient, we measured the mass loss of green above-ground biomass of 50 weed communities during decomposition in standard conditions and key leaf traits of dominant species [e.g. leaf dry matter content (LDMC) and leaf lignin to nitrogen ratio (lignin:N)]. Both the mean [i.e. community-weighted mean (CWM)] and diversity (i.e. Rao index) were computed at the community level. Path analysis was used to quantify the effects of agro-environmental filters on the mass loss of weed communities through their functional properties.
Tillage and mowing filtered more decomposable communities than chemical weeding (16 and 8 % of higher mass loss after 2 months of decomposition). Path analysis selected weed management practice type as the main factor determining mass loss through its effect on functional properties, while soil and climate had minor and no effects, respectively. Chemical weeding favoured communities with higher investment in resistant leaves (e.g. 38 % higher lignin:N, 22 % lower leaf nitrogen content) which resulted in lower mass loss compared with tilled and mowed communities. Mowing favoured communities with 47 % higher biomass and with 46 % higher nitrogen content.
Weed management significantly influenced weed mass loss, while the pedoclimate had little effect. Our results suggest that mowing is a promising alternative to herbicide use, favouring higher biomass, nitrogen content and decomposability potential of weeds.
在16个地中海葡萄园中,既代表了pedoclimate,又代表了土壤管理梯度,我们测量了在标准条件下分解过程中50个杂草群落的绿色地上生物量的质量损失以及优势种的关键叶片性状[例如叶片干物质含量(LDMC)和叶片木质素与氮的比率(木质素:N)]。平均值[即社区加权平均值(CWM)]和多样性(即Rao指数)均在社区水平上计算。路径分析用于量化农业环境过滤器通过其功能特性对杂草群落质量损失的影响。
耕作和割草比化学除草过滤了更多的可分解群落(分解2个月后较高的质量损失的16%和8%)。路径分析选择杂草管理实践类型作为确定质量损失的主要因素,通过其对功能特性的影响,虽然土壤和气候影响很小,但没有影响,分别。化学除草有利于对抗性叶子投资较高的社区(例如,木质素:N高38%,叶片氮含量降低22%),与耕作和割草群落相比,质量损失较低。割草有利于生物量高47%,氮含量高46%的社区。
杂草管理显著影响杂草质量损失,而pedoclimate几乎没有效果。我们的结果表明,割草是除草剂使用的一种有希望的替代方法,有利于更高的生物量,杂草的氮含量和可分解潜力。