不同播种期对圆叶决明和百喜草生长及产量的影响

Effects of Sowing Time on Growth and Yield of Chamaecrista rotundifolia and Paspalum notatum

为确定长汀及周边地区春季牧草最佳播种期,研究气候变化对圆叶决明和百喜草产量及水土保持特性的影响,开展不同播种时间(3月5日、4月12日、5月5日、6月11)对圆叶决明和百喜草出苗期、出苗率、覆盖度、株高及产草量的影响研究。结果表明:随着播种期的推迟,圆叶决明和百喜草的出苗期缩短,出苗率升高;不同播种时间处理,两草种均能正常越夏,覆盖度在生长前期略低,生长中后期覆盖度有所提升并保持稳定。圆叶决明和百喜草株高在不同播种期试验中变化趋势是一致的,均在5月播种株高达最大值,与其余处理组相比差异不显著;圆叶决明5月播种鲜草产量显著高于3、4月播种产量,百喜草5月鲜草产量则显著高于其他处理组。综合分析得出,5月份播种,圆叶决明和百喜草生长状况均表现较好,出苗率高,苗期生长整齐,后期覆盖度更加稳定,株高及产量也均达到最大值。

This study aimed to determine the optimal time to seed forage grass in Changting and nearby areas,as well as the effects of climatic changes on yield of Chamaecrista rotundifolia and Paspalum notatum,as well as on soil/water conservation.Seeding on March 5,April 12,May 5,and June 11 in 2014 were carried out for the experimentation.Seedling time,emerging rate,coverage area（from August to November）,plant height,and yield of the grasses were monitored.The results showed that,as the seeding was delayed,the seedling time of C.rotundifolia and P.notatum shortened,and the emerging rate increased.Nonetheless,both grasses adequately grew through the summer.The grasscoverage was slightly slow initially,but increased and maintained a stable expansion later on.The changes on the plant heights of the two grasses were similar,reaching a maximum when sowed in May,with no significant difference among the treatment groups.The fresh grass yield of C.rotundifoliasowed in May was significantly higher than that sowed in March or April,while that of P.notatumsowed in May was significantly higher than all other times.Thus,it was concluded that May was ideal for seeding the grasses so that their seed germination rate,seedling growth,plant height,grass-coverage,and yield could achieve the optimal levels.