張申 于存申 苗慶選 劉麗萍 劉業(yè)萍

摘要：為了解氮素供應(yīng)狀況（同時提供NH+4-N和NO-3-N）對草坪草生長和養(yǎng)分吸收特性的影響，以硝酸銨（NH4NO3）為供試肥料，通過盆栽試驗研究了不同氮濃度（0、2.5、10 mmol/L）下高羊茅的生長及養(yǎng)分吸收狀況。結(jié)果表明，添加外源硝酸銨高羊茅株高、干物質(zhì)累積量增加，根系平均直徑增大，總根長和根表面積降低，根系直徑在<0.3 mm和>0.9 mm范圍內(nèi)的根長顯著減少;與2.5 mmol/L氮處理相比，10 mmol/L氮濃度植株地上部干物質(zhì)累積量、根長、根表面積降低。隨外源氮濃度的升高，植株地上部氮、鉀含量和氮、磷、鉀養(yǎng)分吸收量呈上升趨勢，地上部氮、鉀的分配比例提高;地下部養(yǎng)分含量隨氮濃度的增加而增加，氮、鉀累積量各處理差異不顯著。增加氮濃度單位根長的氮、鉀養(yǎng)分吸收量提高，2.5 mmol/L和10 mmol/L氮濃度處理單位根長吸磷量差異不顯著。綜合分析高羊茅植株地上部和根系生長狀況，2.5 mmol/L氮濃度更有利于促進高羊茅植株生長，提高養(yǎng)分吸收量，節(jié)約氮資源。

關(guān)鍵詞：高羊茅;硝酸銨;地上部;根系;養(yǎng)分吸收

中圖分類號：S543+ .906文獻標識號：A文章編號：1001-4942（2019）04-0094-06

Abstract In order to understand the effects of nitrogen （N） supply （providing NH+4-N and NO-3-N simultaneously） on the growth and nutrition absorption characteristics of turfgrass， using ammonium nitrate （NH4NO3） as the test fertilizer， a pot experiment was conducted to study the growth and nutrition absorption of Festuca arundinacea at different nitrogen concentrations （0， 2.5， 10 mmol/L）.The results showed that the plant height， dry matter accumulation of shoot and root average diameter of Festuca arundinacea increased with exogenous N supply， while the total root length， root surface area and the length of roots in the range of <0.3 mm and >0.9 mm diameter decreased significantly. Compared with 2.5 mmol/L N treatment， the dry matter accumulation of shoot， total root length and the root surface area of plants decreased with 10 mmol/L N. With exogenous N increasing， the N and potassium （K） contents and the N， phosphorus （P）， K absorption of shoot increased， meanwhile， the proportion of N and K distributed in the shoot increased. The nutrients concentration in the underground of plant increased with the increasing of exogenous N， and no significant differences were found in N and K contents between treatments. The N and K absorption amounts per unit root length increased with the increasing of N supply， and there was no significant difference in the absorption amount of P per unit root length between 2.5 mmol/L and 10 mmol/L N treatments. Comprehensive analysis on the growth of shoot and root， 2.5 mmol/L exogenous N was more conducive to promote the growth and nutrition absorption of Festuca arundinacea， and save N resources.

Keywords Festuca arundinacea;Ammonium nitrate; Shoot; Root; Nutrition absorption

草坪是多年生低矮草本植物在天然形成或人工建植后，經(jīng)養(yǎng)護管理而形成的相對均勻、平整的草地植被，具有美化生活環(huán)境，調(diào)節(jié)小氣候，防止噪音、凈化空氣等作用，成為城市綠化不可缺少的組成部分[1]。草坪建成后，必須加強養(yǎng)護管理，才能使草坪生長健壯、整齊、美觀，達到一定的觀賞效果和使用目的[2]。合理施肥是草坪養(yǎng)護的重要技術(shù)措施之一，定期并適量地對草坪進行施肥管理，可促進草坪草生長發(fā)育，提高草坪質(zhì)量[3， 4]。