农牧交错带老芒麦的优化灌溉及对产量的影响

为了定量研究关键生育期灌溉和冬灌对老芒麦生产的作用,该文通过2005.10～2007.10在河北坝上地区田间定位实测的土壤水分、株高、叶面积指数、生物量和降水资料,分析了不灌溉、冬灌、关键生育期灌溉和冬灌结合关键生育期灌溉4个处理对老芒麦生长发育和产量的影响。结果表明:老芒麦的再生草生长缓慢,灌溉主要是影响了头茬草的生长。关键生育期灌溉能显著促进头茬草的生长发育,头茬草产量达4500kg/hm2以上,2a试验期间分别比对照处理提高104%和391%;冬灌使老芒麦返青期提前1周左右,使头茬草的产量分别提高53%和87%;而共同采用此两种灌溉的处理与单独关键生育期灌溉处理相比增产效果不明显。因此,在农牧交错地区,关键生育期灌溉是值得推荐的灌溉制度。另外,该文结果表明地上部生物量和叶面积指数均随植株高度呈线性增加,为老芒麦生物量和叶面积指数的模拟提供了依据。

Optimal irrigation of siberian wildrye grass in farming-pastoral ecotone of North China and its effect on yield

In order to investigate the effects of winter irrigation and irrigation during the key growing stage on crop growth and forage yield of siberian wildrye grass(Elymus sibiricus L.),field experiments were conducted in Bashang Plateau in the farming-pastoral ecotone of North China during 2005.10-2007.10.Rainfall,soil water content,plant height,leaf area index(LAI),biomass and forage yield were measured in field plots under no irrigation(CK),winter irrigation(W1),irrigation during key growing stage(W2),and the combination of W1 and W2(W3).The results showed that forage yield was dominated by the first cutting due to the poor regrowing ability.The single irrigation during the key growing stage significantly improved the plant height,LAI and biomass of the first harvest.Forage yield of the first cutting under W2 was above 4500 kg/hm 2,which was increased by 104%and 391%,respectively,in two years compared with CK.The grass under W1 turned green earlier in the following spring,and the forage yield of the first cutting was increased by 53%and 87%,respectively.There was no significant difference between forage yields under W3 and W2.Therefore,single irrigation during the key growing stage is recommendable for siberian wildrye grass in this region.In addition,the biomass and LAI increased with plant height linearly,which provides evidence for simulating the biomass and LAI of siberian wildrye grass.