科尔沁沙地沙打旺草地衰退规律与恢复技术研究

科尔沁沙地沙打旺草地发育可划分为3个时期:形成期(生长1年)、高产期(生长2、3年)、衰退期(生长4年或5年之后)。衰退草地表现为植株矮小,分蘖能力下降,枝条减少直径变细,根颈中央有坏死组织出现,枝条多沿着根颈的外围长出,单株重明显下降,群落中沙打旺株丛减少,仅有3～4株/m²,杂草占绝对优势。沙打旺草地经济利用期为2～3年,生态有效期4～5年。选择衰退初期的沙打旺草地进行施肥可明显地提高产草量(中耕结合施肥比撒施效果更好),并可延长利用期。

Research on Decline Law and Recovery Technique of Astragalus adsurgens Meadow on Kerqin Sand Land

The growing of A. adsurgens meadows was divided into three periods. They were forming period, high yield period and declining period. Decline meadow showed the characters of small plant, shooting reduction, branch diameter thinning and both weight of per plant and forage yield of per area reduction. The dominance of A. adsurgens in community decreased, while weed increased in decline meadow. A. adsurgens meadow was 2 3 years of economic utilization period and 4 5 years of ecological effective period. The fertilizer could increase forage and seed yields in early decline period.