Weed control by application of fresh organic materials to paddy soil in organic rice production

作者：Takuhito Nozoe, Shigenori Miura, Junko Tazawa, Akira Uchino, Weiguo Cheng · 发表于：Soil Science & Plant Nutrition · 年份：2024 · DOI：10.1080/00380768.2024.2443162 · 被引用次数：3 · 研究领域：Plant responses to water stress、Allelopathy and phytotoxic interactions、Soil Carbon and Nitrogen Dynamics

Monochoria vaginalis and Echinochloa weeds are typical weeds in organic rice production. Applying fresh organic materials to the soil is a widely accepted weed control technique. Although the application of rice (Oryza sativa L.) bran on soil surface is useful for the removal of M. vaginalis, its efficacy fluctuates according to year and field. With the incorporation of this material into soil, toxic substances (e.g. organic acids and ferrous ions (Fe2+)) increase. These harmful substances suppress the germination of this plant. In contrast, paddy soil is typically equipped with the ability to reduce oxygen (O2). This trait enhances the number of M. vaginalis, because the hypoxic condition is preferable for its germination. In other words, paddy soil with rice bran has two conflicting powers: promotion of germination by soil and the suppression by rice bran. The presence of conflicting factors may destabilize the efficacy of rice bran. Rice straw is incorporated into the topsoil after harvesting to maintain soil fertility. Seedlings of rice and Echinochloa weeds exhibit distinct tolerances to growth suppression by rice straw: rice is the most tolerant, followed by Echinochloa oryzicola, and E. crus-galli is the most susceptible. Once these weeds establish seedlings under field conditions; however, the application of organic materials does not completely remove them. Consequently, promising methods such as deep-water management are combined. It is speculated that one of the fa...