4种宿根花卉北京地区水分蒸散规律与节水灌溉

为指导节水灌溉,2006年在北京市小汤山镇国家精准农业研究示范基地利用小型蒸渗仪研究了石竹、萱草、鸢尾、八宝景天4种宿根花卉人工控制条件下的蒸散规律。采用蒸散量反馈式灌溉原理设置了4个灌溉水平:100%ETc(ETc为充足灌溉水平下植物的实际蒸散量)、75%ETc、50%ETc、25%ETc。100%ETc灌溉水平下石竹和萱草出现7和9月蒸散高峰,鸢尾和八宝景天的蒸散曲线平缓,它们6—10月的总蒸散量分别为432.61、332.40、186.93和161.37 mm。根据2006年试验地的实际降雨情况,6—8月4种植物均不需补充灌溉,但9、10月需补充灌溉,补充灌溉量分别为185.38、154.32、48.52和42.15 mm。测量、记录4个灌溉水平下各种植物的生长和观赏指标,数据分析结果表明,相比100%ETc的充足灌溉水平,在75%ETc的轻微干旱胁迫下,石竹、萱草、鸢尾的生长没有显著差异,而八宝景天即使在50%ETc的水平下生长和观赏性状也没有显著变化,说明八宝景天的耐旱性最强。因此石竹、萱草和鸢尾可以采取75%ETc,而八宝景天采取50%ETc的节水灌溉标准,相比充足灌溉分别节水46.35、38.58、12.13和21.08 mm。

Evapotranspiration and water-saving irrigation of four perennial flowers in Beijing

In order to guide water-saving irrigation,evapotranspiration(ET_c) of four perennial flowers,Dianthus chinensis L.,Hemerocallis fulva L.,Iris tectorum Maxim.,and Sedum spectabile Boreau,was studied by mini-lysimeter under controlled condition in 2006 at National Precision Agriculture Research Station,Xiaotangshan,Beijing.Four irrigation levels were employed according to ET_c feedback irrigation principle as follows,100% ET_c,75% ET_c,50% ET_c,and 25% ET_c(ET_c here means the evapotranspiration of plant at ample irrigation).At 100% ET_c irrigation level,D.chinensis and H.fulva had two ET_c peaks in July and September,respectively,while I.fulva and S.spectabile had a gentle ET_c curve.The total ET_c was(432.61?mm) for D.chinensis,(332.40?mm) for H.fulva,(186.93?mm) for I.tectorum,and(161.37?mm) for S.spectabile from June to October.According to the rainfall amount at the experiment site in 2006,additional irrigation was unnecessary for the four plants from June to August,but it was needed in September and October;the irrigation amount was(185.38?mm) for D.chinensis,(154.32?mm) for H.fulva,(48.52?mm) for I.tectorum,and(42.15?mm) for S.spectabile.Growth and ornamental indexes of four species under four irrigation levels were measured and analyzed and results show that the growth of D.chinensis,H.fulva,and I.tectorum was not significantly influenced by the slight drought treatment at 75% ET_c in comparison to that of the ample irrigation level at 100% ET_c.Remarkably,S.spectabile showed strongest drought-resistance and its growth varied insignificantly even at the irrigation level of 50% ET_c vs.100% ET_c.In summary,D.chinensis,H.fulva,and Iris tectorum would save 46.34,38.58 and(12.13?mm) of irrigative water,respectively,by adoption of 75% ET_c irrigation,and S.spectabile would save(21.08?mm) if irrigated at 50% ET_c level.