土壤质地对柱花草生长发育、生物量及土壤肥力变化的影响

采用大田试验的方法,在云南省元谋县小雷宰流域内壤土、砂壤土和重壤土3种质地土壤上,以热研5号柱花草为材料,研究土壤质地对柱花草生长发育、生物量及土壤有机质、有机碳、全氮和全磷的影响。试验结果表明:3种土壤质地上种植柱花草,柱花草地上部和地下部生长量和生物量表现幼苗期增加缓慢,而分枝期后增加快的趋势。壤土耕性好,兼有砂土和重壤土的优点,有利柱花草地上部分的生长发育,柱花草地上部生长量、生物量及改善土壤肥力方面显著高于重壤土。砂壤土有利于柱花草根系向深层土壤生长,柱花草地下部生长量、生物量及根瘤显著高于种植在重壤土。在3种土壤质地种植柱花草后,土壤有机质、有机碳、全氮和全磷均有上升趋势。综合而言,通气性和保肥保水能力居中的壤土更适合柱花草的生长发育及干物质的积累。

Effects of Soil Textures on Growth, Biomass of Stylosanthes Guianensis and Fertility of Soils

Field experiment was conducted in Xiaoleizai Watershed to study the effects of three different soil textures (loam, sandy loam and heavy loam) on the growth and biomass of S. guianensis. Reyan 5 and the fertility of soils (organic matter, organic carbon, total nitrogen and phosphorus). The results showed that the growth and biomass of aboveground and underground of S. guianensis changed slowly at seedling stage but fast at branch stage in all three soils. Loam soil performed best, the growth and biomass of aboveground part of S. guianensis and improvement of loam soil fertility were higher significantly than those of heavy loam soil. The roots of S. guianensis grew deeper in sandy soil, the growth, biomass and nodule amount of underground part of S. guianensis were higher significantly than those of clay soil. Except at seedling stage, aboveground growth and biomass of S. guianensis were higher in loam soil than sandy loam and heavy loam soils, underground growth and biomass of S. guianensis in sandy loam soil were higher than loam and heavy loam soils. Organic matter, organic carbon and total nitrogen changed greatest in loam soil, followed by heavy loam and sandy loam soils, while total phosphorus changed greatest in sandy loam and heavy loam soils, followed by loam soil. The above results suggested that loam soil, with medium levels of aeration and water and fertilizer conservation compared with sandy loam soil and heavy loam soil, is most suitable for the growth and dry matter accumulation ofS. guianensis.