Pokharel Sabin Saurav, Yu Han, Fang Wanping, Parajulee Megha N, Chen Fajun
Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
Department of Forest Genetics and Breeding, College of Forestry, Nanjing Forestry University, Nanjing 210037, China.
Plants (Basel). 2023 Jun 18;12(12):2361. doi: 10.3390/plants12122361.
The intercropping of cover crops has been adopted in several agroecosystems, including tea agroecosystems, which promotes ecological intensification. Prior studies have shown that growing cover crops in tea plantations provided different ecological services, including the biocontrol of pests. Cover crops enrich soil nutrients, reduce soil erosion, suppress weeds and insect pests, and increase the abundance of natural enemies (predators and parasitoids). We have reviewed the potential cover crops that can be incorporated into the tea agroecosystem, particularly emphasizing the ecological services of cover crops in pest control. Cover crops were categorized into cereals (buckwheat, sorghum), legumes (guar, cowpea, tephrosia, hairy indigo, and sunn hemp), aromatic plants (lavender, marigold, basil, and semen cassiae), and others (maize, mountain pepper, white clover, round-leaf cassia, and creeping indigo). Legumes and aromatic plants are the most potent cover crop species that can be intercropped in monoculture tea plantations due to their exceptional benefits. These cover crop species improve crop diversity and help with atmospheric nitrogen fixation, including with the emission of functional plant volatiles, which enhances the diversity and abundance of natural enemies, thereby assisting in the biocontrol of tea insect pests. The vital ecological services rendered by cover crops to monoculture tea plantations, including regarding the prevalent natural enemies and their pivotal role in the biocontrol of insect pests in the tea plantation, have also been reviewed. Climate-resilient crops (sorghum, cowpea) and volatile blends emitting aromatic plants (semen cassiae, marigold, flemingia) are recommended as cover crops that can be intercropped in tea plantations. These recommended cover crop species attract diverse natural enemies and suppress major tea pests (tea green leaf hopper, white flies, tea aphids, and mirid bugs). It is presumed that the incorporation of cover crops within the rows of tea plantations will be a promising strategy for mitigating pest attacks via the conservation biological control, thereby increasing tea yield and conserving agrobiodiversity. Furthermore, a cropping system with intercropped cover crop species would be environmentally benign and offer the opportunity to increase natural enemy abundance, delaying pest colonization and/or preventing pest outbreaks for pest management sustainability.
包括茶园生态系统在内的多种农业生态系统都采用了覆盖作物间作的方式，这促进了生态集约化。先前的研究表明，在茶园种植覆盖作物能提供不同的生态服务，包括害虫生物防治。覆盖作物能丰富土壤养分、减少土壤侵蚀、抑制杂草和害虫，并增加天敌（捕食者和寄生蜂）的数量。我们综述了可纳入茶园生态系统的潜在覆盖作物，特别强调了覆盖作物在害虫防治方面的生态服务。覆盖作物分为谷类（荞麦、高粱）、豆类（瓜尔豆、豇豆、鱼藤、毛木蓝和印度麻）、芳香植物（薰衣草、万寿菊、罗勒和决明子）以及其他（玉米、山胡椒、白三叶草、圆叶决明和匍匐木蓝）。豆类和芳香植物是最有效的覆盖作物物种，因其具有特殊益处，可在单一栽培的茶园间作。这些覆盖作物物种能提高作物多样性，并有助于大气固氮，包括通过释放功能性植物挥发物，这能增加天敌的多样性和数量，从而协助对茶害虫进行生物防治。还综述了覆盖作物为单一栽培茶园提供的重要生态服务，包括常见天敌及其在茶园害虫生物防治中的关键作用。推荐抗气候作物（高粱、豇豆）和释放挥发性混合物的芳香植物（决明子、万寿菊、千斤拔）作为可在茶园间作的覆盖作物。这些推荐的覆盖作物物种能吸引多种天敌，并抑制主要的茶害虫（茶绿叶蝉、粉虱、茶蚜和盲蝽）。据推测，在茶树行间种植覆盖作物将是一种有前景的策略，可通过保护生物防治减轻害虫侵袭，从而提高茶叶产量并保护农业生物多样性。此外，间作覆盖作物物种的种植系统对环境有益，并提供了增加天敌数量的机会，可延缓害虫定殖和/或防止害虫爆发，以实现害虫管理的可持续性。
