砂栽培における培地への資材混和が培地特性とトマト果実生産に及ぼす影響(土壌管理・施肥・灌水)  [in Japanese] Effects of Substrate Materials Mixed with Sands on Substrate Properties and Tomato Fruit Production in Sandponics(Soil Management, Fertilization & Irrigation)  [in Japanese]

砂栽培システムによるトマト生産において,砂培地に混和する資材が培地特性や果実生産に及ぼす影響を調査した.ゼオライトを混和すると,培地が乾燥しやすくなり,ナトリウム含量が高まった.また培地のECおよび硝酸態窒素含量は栽培期間中低く抑えられた.ゼオライト混和培地で植物の生育や収量は低下したが,果実糖度は上昇した.活性炭を砂培地に混和すると,植物の初期生育が抑制され果実品質が低下したが,一果重は上昇した.土壌を混和した培地では,果実収量は低下せず,果実糖度が上昇した.ヤシ殻繊維を混和することで,砂培地の軽量化,保水性の向上など培地特性の改善が見られ,植物の初期生育および果実の初期収量が上昇したが,茎葉部との水分競合により可販果率は低下した.このことから砂栽培の混和資材として,ヤシ殻繊維の有用性については,今後,灌水方法を変えてさらに検討する必要があると思われた.

The effects of substrate materials mixed with sand on the physicochemical properties, fruit quality and yield of tomato plants were investigated to improve tomato production by sandponic cultivation system. Zeolite-mixed substrate lost moisture more easily and contained more Na than sand substrate. EC and NO_3-N content in this substrate remained low during the cultivation period. In the zeolite-mixed substrate, plant growth was restricted, resulting in a low yield and the production of fruits with high Brix values. Addition of activated carbon to sand restricted the early growth of plants and deteriorated fruit quality, while it increased fruit weight. The addition of soil to sand improved fruit quality without any detrimental effects on yield. The addition of coconut coir improved the physicochemical properties of substrates (e.g., gravity and water retentivity), stimulating early growth of plants and early yield. The results suggested that the potential usefulness of coconut coir as a conditioner of sand substrate should be further studied under different irrigation schedules.