摘要
通过盆栽和大田试验研究了土壤水分对紫花苜蓿（金皇后）出苗与保苗的影响。盆栽试验结果表明：对于不同的土壤质地，苜蓿出苗和保苗所需的土壤水分不同，苜蓿出苗的土壤含水量下限：沙土为4．4％，粘壤土为7％；苜蓿保苗土壤含水量下限：沙土为4％，粘壤土为6％；无论是出苗还是保苗，栽植苜蓿所需的含水量沙土都低于粘壤土。大田沙地试验表明：随着苜蓿出苗时阃的延长，苜蓿根系不断向下延伸，对苜蓿死亡起决定作用的土层也不断增厚，播种出苗1～5d内，O～5cm土层含水量起决定作用；播种出苗6～9d内，影响苜蓿生命的土层达到5～10cm；播种出苗9～18d内，影响苜蓿生命的土层达到10～15cm。只有当整个根系层的土壤水分全部低于4％时，苜蓿才会死亡，局部水分低于4％时苜蓿仍可存活。
The effect of soil water on alfalfa emergence and keeping a full stand of seedlings was studied through pot trial and field trial. The pot trial results indicated that the soil moisture content for alfalfa emergence and keeping a full stand of seedlings was different with different soil texture, the lowest soil moisture was 4.4% in sandy soil, 7% in the clay; the lowest soil moisture for keeping a full stand of seedlings was 4% in sandy soil, 6% in the clay; the soil moisture in sandy soil for alfalfa emergence and keeping a full stand of seedlings was lower than in the clay. The sandy field experimental showed that with prolonging the emergence period, roots of alfalfa extended downwards, the soil layer which is critical to alfalfa survival become thicker, soil moisture in layer of 0-5cm had great effect on alfalfa survival in 1-5 days after emergence ; soil moisture in layer of 5-10cm had great effect on alfalfa survival in 6-9 days after emergence; soil moisture in layer of 10-15cm had great effect on alfalfa survival in 9-18 days after emergence. When the soil moisture content in all layers was lower than 4%, alfalfa can die, the partial moisture content was lower than 4%, alfalfa can still survive.
出处
《中国草地学报》
CSCD
北大核心
2009年第1期23-27,共5页
Chinese Journal of Grassland
基金
陕西省重大科技攻关项目“农业节水灌溉技术标准研究与示范”(2006Kz08-G3)
关键词
土壤含水量
出苗率
保苗率
紫花苜蓿
Soil moisture content
Rate of seedlings emergence
Rate of keeping a full stand of seedlings
Alfalfa
