@article{oai:soar-ir.repo.nii.ac.jp:00011009,
 author = {荒瀬,  輝夫 and 内川,  義行},
 journal = {信州大学農学部AFC報告},
 month = {Mar},
 note = {棚田の保全と雑草管理についての基礎的知見を得るため，姨捨棚田地域（長野県千曲市）において，雑草 および水稲の生長と収量を調査した。実験計画は，栽植密度（疎植区，密植区）と除草方法（６パターン） を要因とする２反復の２元配置とした。栽培管理および調査は，2009年５月～９月に実施した。水田内で19 種の植物が確認され，主要雑草はコナギとホタルイであった。植生調査データに基づくＶ値による分析では， 疎植区で除草の作業労力と主要雑草量との相関が有意であったが，密植区では除草効果が不明瞭で，作業効 率も悪かった。籾収量は平均408～637㎏/10aで，栽植密度によって除草効果の現れかたが異なっていた。６ 月，７月，８月の雑草量を説明変数とした収量の予測では，係数の値の異なる有意な重回帰式が得られ，６ 月と８月の除草がより効果的であった。また，雑草量をあるレベル以下に抑えれば，水稲収量の減収は僅少 であることが確認された。 In order to obtain the basic information for conservation and weed control in a terraced paddy field, we examined the growth of weeds and rice (Oryza sativa)and estimated rice yields in Obaste in Chikuma, Nagano Prefecture, Japan.The experiment had a two-way layout with two replicates, and employed rice planting density(sparse and dense)and method of weed control(6 patterns)as factors.Rice cultivation and the investigation were conducted from May to September 2009. Nineteen weed species were identified, with two species considered dominant (Monochoria vaginalis and Scirpus juncoides). Analysis of the V -values, based on the vegetation data, showed that weeding effort was correlated with dominant weed quantities in sparsely planted plots.However, in densely-planted plots, weeding was difficult and the effect was not apparent. The average yield of unhulled rice was 408 to 637 kg/10 a, and the effect of weeding differed according to planting density. Using weed quantity in June, July and August as explanatory variables for predicting rice yields, the magnitude of the regression coefficients for each month differed from one another, i.e. weeding in June and in August were more effective for increasing rice yields. In addition, weed quantity under a certain level appeared to decrease rice yields only slightly., Article, 信州大学農学部AFC報告 9: 83-91(2011)},
 pages = {83--91},
 title = {棚田における栽植密度と除草管理法の違いが水稲収量に及ぼす影響},
 volume = {9},
 year = {2011}
}