扁穗牛鞭草的水肥耦台效应研究

在牛鞭草人工栽培过程中,水肥管理是重要的农艺措施。试验设置不同的水分(正常供水、轻度干旱、中度干旱)和施肥(无肥、低肥、中肥、高肥)组合,盆栽研究了水肥耦合对牛鞭草生长、产量、品质及有关生理指标等的影响。结果表明,供水减少,牛鞭草叶片脯氨酸含量倍增,施肥对叶片脯氨酸含量无显著影响。在中旱无肥处理中,脯氨酸含量最高,牛鞭草生长最差,说明干旱危害严重,不支持“脯氨酸积累有益于提高植物抗旱性”的观点。施肥提高叶片相对含水量,增强硝酸还原酶活性和根系活力,增加植株氮、磷、钾含量和吸收量以及在土壤中的生物有效性,有益于减轻干旱危害,提高产量品质。在轻度干旱条件下,牛鞭草根冠比增加,氮、钾含量提高,叶绿素、硝酸还原酶活性、植株含磷量和土壤有效氮、磷、钾无显著降低。因此,在轻旱高肥组合的处理中,牛鞭草生长最好,产量最高,品质最佳;在不同水分与无(低)肥组合的处理中,牛鞭草生长不佳,产量低,品质差。在三峡库区牛鞭草的人工栽培过程中,频繁的短时干旱可能对产量品质无显著影响,施足肥料有益于高产优质。

Water and fertilizer interaction in Hemarthria compressa cultivation

Water and fertilization management are the main agronomic decisions during artificial cultivation of Hemarthria compressa.Water treatments,including normal water supply,and light and moderate drought,and fertilization treatments,including no fertilizer,low,moderate and high fertilizer rates,were included in a pot experiment to study the effects of water and fertilizer and their interaction on the growth,yield,quality and some physiological indexes of H.compressa.The proline content of leaves was increased by reduced water supply,but was unaffected by fertilizer treatment.Under moderate drought without fertilizer,the proline content was the highest and the growth of H.compressa was the lowest,showing that the drought effect was serious,which indicates that proline accumulation is not always sufficient to overcome drought exposure effects in plants.Fertilizer resulted in increased relative water content of leaves,nitrate reductase activity,root vitality,uptake of nitrogen,phosphorus and potassium,and soil nutrient availability,which mitigated drought damage,and improved yield and quality.The light drought increased root ∶ shoot ratio,the content of nitrogen and potassium,while there was no significant decrease in chlorophyll content,nitrate reductase activity,the phosphorus content of the plant and soil available nitrogen,phosphorus and potassium.Thus,the light drought with high fertilizer provided the best growth,yield and quality;whereas all these parameters were adversely affected in the various water treatments with no fertilizer or low fertilizer.To conclude,frequent short-term drought had no significant effect on the yield and quality,providing adequate fertilizer was applied.These findings may be relevant to achieving high yield and quality in artificial cultivation of H.compressa in the Three Gorges Reservoir area.