不同水旱田農耕生態系統對田間雜草相變動之影響

Different Agro-Ecosystems Affect Population and Density of Weeds in Paddy-Paddy and Paddy-Upland Rotation Systems

蕭巧玲(Chiao-Ling Hsiao) ； 楊純明(Chewn-Ming Yang) ； 何佳勳(Chia-Hsun Ho)

《台灣農業研究》 62卷2期 (2013/06) Pp. 106-125

https://doi.org/10.6156/JTAR.2013.06202.02

摘要

在不同耕作制度（系統）下，農地雜草相必將發生短期的變異與長期的變遷。為期瞭解雙期作水田農耕生態系（paddy-paddy agro-ecosystem; PP）及一期作水稻、二期作落花生之水旱田輪作農耕生態系（paddy-upland rotation agro-ecosystem; PU）下雜草相之變異與變遷，本研究乃於行政院農業委員會農業試驗所溪口農場之長期農業生態系研究（long-term agricultural ecological research; LTER）試驗場址進行雜草相調查。本報告為2010年至2011年之兩年試驗，調查與分析不同農耕生態系之雜草相變動情形。兩種農耕法分別包括慣行農耕（conventional cropping system; CC）及低投施農耕 （low-input cropping system; LC），合計四種農耕生態系組合，即PP-CC、PP-LC、PU-CC及PU-LC。根據調查結果，雜草密度在一期作LC處理區多於CC處理區，且2011年多於2010年，惟LC處理區雜草生質量在2010年小於CC區，而2011年卻大於CC區，推測農耕處理尚未使雜草相穩定故兩年間表現未趨一致。二期作的雜草相分布，PP生態系大於PU生態系，以年際變化而言2011年少於2010年，顯示試區水田雜草相較旱田豐富且受到氣候影響。在四種農耕生態系中，一期作所發生的雜草科別數及種別數均少於二期作，惟年際間表現不一，可知影響雜草相之因子多而複雜。發生密度最多的雜草科別，雙期作皆為水田的PP生態系，一期作在2010年以千屈菜科最多、2011年則為玄參科，二期作在兩年皆以玄參科密度最高。在水旱田輪作的PU生態系，一期作在2010年的PU-CC及PU-LC以菊科與千屈菜科分布較高，2011年則為莎草科與菊科；二期作在2010年皆以菊科佔多數，而2011年之PU-CC與PU-LC則分別以菊科及茄科發生最多。進一步分析分布最多的雜草物種，PP生態系（PP-CC及PPLC）一期作在2010年以水莧菜、2011年以母草最多，二期作兩年皆以母草最多。PU生態系（PU-CC及PULC）於一期作在2010年由霍香薊、香附子分占一、二位，在2011年則為水莧菜及鱧腸，於二期作在2010年分別為霍香薊、鱧腸，2011年則分別為香附子、燈籠草。顯然雜草的科別數及物種數將因為生態、農耕及氣象等條件的不同，呈現期作與年份上的變動，各生態系雜草相是否可以逐漸達到穩定狀態，則可能需要更多時間予以觀察、釐清。

關鍵字

長期農業生態系 ； 雙期作水田生態系 ； 水旱田輪作生態系 ； 慣行農耕 ； 低投施農耕

並列摘要

Changes in population and density of weeds occur in different cropping systems with time. To delineate variation and progress of weeds under paddy-paddy agro-ecosystem (PP) and paddyupland rotation agro-ecosystem (PU) of a two-crop system, studies were conducted at long-term agricultural ecological research (LTER) station located in Sikou Experimental Farm of Taiwan Agricultural Research Institute. Within each agro-ecosystem, there were two types of practice, conventional cropping system (CC) and low-input cropping system (LC), making up four agroecosystems in total, namely, PP-CC, PP-LC, PU-CC and PU-LC. This paper summarized the results from investigations and analyses of data acquired in 2010 and 2011. As the results shown, weed density was higher in LC than in CC and in 2011 than in 2010 in first crops, suggesting that cropping treatments were not yet stabilized so that LC treatment was not have less weeds as expected. Because of such a situation, weed biomass of CC was higher than LC in 2010, but not in 2011. In second crops, PP had a larger weed population and density than that of PU, particularly in 2010, indicating richer weeds in paddy fields than in uplands. Among these four agro-ecosystems, generally larger numbers of weed family and species were found in second crops, yet vary yearly, reflecting a complicated factors intervention in weed infestations. The most populated weed family of PP was Lythraceae in 2010 and was Scrophulariaceae in 2011 for first crop, and was Scrophulariaceae for second crop in both years. Of the PU, family of Compositae and Lythraceae were the most populated weeds for PU-CC and PU-LC, respectively, in first crop of 2010, and it was family of Cyperaceae and Compositae, respectively, in 2011. Weeds of family Compositae were predominant in both agro-ecosystems in second crop of 2010 and weeds of family Compositae and Solanaceae were the predominated ones in 2011 for PU-CC and PU-LC, respectively. As for weed species, plants of Ammannia baccifera occupied the most in PP in first crop of 2010, while Lindernia procumbens took the lead in 2011 as well as in second crop of both years. In PU, population of Agcratum conyzoides was the highest, followed by Cyperus rotundus in first crop of 2010. The top two populations in 2011 were Ammannia baccifera and Eclipta prostrate. In second crop, Agcratum conyzoides and Eclipta prostrata were listed in the first two rankings in 2010, but were Cyperus rotundus and Physalis angulata in 2011. Apparently, changes in weed family and species will be affected by multifactors such as ecology, cropping system and climate and hence, will fluctuate in seasons and years. It requires more investigations to clarify how long weed populations will reach a dynamic balance among each other.

並列關鍵字

Long-term agricultural ecosystem ； Paddy-paddy agro-ecosystem ； Paddy-upland rotation agro-ecosystem ； Conventional cropping system ； Low-input cropping seasons