福岡県農業総合試験場研究報告

イグサにおける連作障害の軽減技術の確立
第２報イグサ－水稲体系における深耕と堆肥施用効果

藤冨慎一・内村要介^１）・北原郁文・住吉　強
（筑後分場）

［摘要］イグサ－水稲連作体系における深耕と堆肥施用によって土壌理化学性を改善し、連作に伴うイグサの減収および品質低下を軽減する技術を検討した。深耕処理１年目では、堆肥無施用の場合、深耕に伴う低肥沃度の下層土混入により地力が低下し、生育不良となり、減収および部分変色茎の増加が認められた。また、深耕時におがくず入り牛ふん堆肥を２ｔ／10ａ施用すると、部分変色茎の軽減効果が認められた。深耕処理２年目では地力が改善されるとともに、下層根が多くなったため生育良好となり、１年目に比べて増収した。特に、堆肥を２ｔ／10ａ施用した場合、適度な初期生育と旺盛な後期生育を示し、部分変色茎が軽減した。

［キーワード：イグサ、連作障害、深耕、牛ふん堆肥、部分変色茎］

　Establishment of Techniques for Decreasing Injury to Mat Rush Due to Continuous Cropping. 2.Effects of Deep Plowing and Barnyard Manure Application on Mat Rush and Rice Cropping System. FUJITOMI Shinichi, Yosuke UCHIMURA, Ikufumi KITAHARA and Tsuyoshi SUMIYOSHI (Fukuoka Agric. Res. Cent., Chikushino, Fukuoka 818-8549, Japan) Bull Fukuoka Agric. Res. Cent., 36 - 39(1999)

　In the mat rush and rice continuous cropping system, we investigated the effects of deep plowing and barnyard manure application on the yield and the quality of mat rush. In the first year of the deep plowing treatment, soil fertility deteriorated from the subsoil being mixed with the top soil in this treatment, and resulted in poor growth and yield decrease of mat rush. When 2 tons per 10a of barnyard manure were applied, the number of partially discolored stems of mat rush decreased. In the second year of the deep plowing　treatment, when the manure was applied again, soil fertility recovered. Particularly, when 2 tons per 10a of manure were applied, the yield increased, and the number of partially discolored stems could be reduced by the appropriate early growth and the promoted latter growth of mat rush.