Abstract: Nutrient management is a significant measure to improve crop yield in modern agriculture.In order to find out the effect of fertilization on Ryegrass(Lolium multiflorum L.) physiology and yield relating to cold temperatures,a field experiment was conducted including five fertilization treatments: NPK,NP,NK,PK and CK(no fertilization).We tested leaf physiological indicators such as chlorophyll content,net photosynthetic rate,POD activities and MDA content during winter stage and harvested the grass yield.The result showed that nitrogen and phosphorus fertilizer could significantly increase the chlorophyll content of ryegrass(P<0.05),whereas potassium fertilizer did little.Nitrogen increased net photosynthetic rate in ryegrass significantly higher than phosphorus and potassium.Results also showed that the order of fertilizer effects on WUE of ryegrass was N>P>K.Content of chlorophyll,net photosynthetic rate and WUE showed as NPK>NP>NK>CK≈PK;Transpiration rate decreased significantly when applying nitrogen or phosphorus fertilizer.The general trend was NPK≈NP<NK≈CK≈PK.Nitrogen was the key effect factor of POD activities,while phosphorus and potassium could not influence yield increase without Nitrogen application;Nitrogen application reduced the ryegrass’s MDA content,and the range of reduction significantly higher than Phosphorus and Potassium;POD activities showed as NPK≈NP≈NK>CK≈PK while MDA content was completely opposite.Nitrogen,phosphorus and potassium application increased the ryegrass yield by 273.7%,73.2% and 22.4% respectively.Results indicate that reasonable fertilization can adjust cold resistance indicators which promote ryegrass yield.

Key words: Ryegrass, Chlorophyll content, Net photosynthetic rate, POD activities, MDA content, Yield of dry grass

摘要： 为研究肥料施用对越冬期多花黑麦草(Lolium multiflorum L.)生理指标及对产草量的影响,于2007年在大田试验条件下,设置氮磷钾全施(NPK)、不施氮肥(PK)、不施磷肥(NK)、不施钾肥(NP)和不施肥(CK)5个处理,测定了越冬期叶片的部分生理指标,并收获了全生育期产量。结果表明:氮、磷肥施用均可显著提高多花黑麦草叶绿素含量(P<0.05),而施钾对叶绿素的影响相对较小;施氮可提高光合速率,其效果明显高于磷、钾肥;肥料对多花黑麦草水分利用率的影响顺序为氮>磷>钾;各处理相比,叶绿素含量、净光合速率以及水分利用率均表现为NPK>NP>NK>CK≈PK;氮、磷肥的施用均显著降低多花黑麦草蒸腾速率(P<0.05),其变化趋势为NPK≈NP<NK≈CK≈PK;氮是过氧化物酶活力的主要影响因子,磷、钾肥需在施氮条件下才会发挥作用;施氮显著降低了丙二醛含量,且降低程度明显高于磷肥和钾肥;过氧化物酶活力表现为NPK≈NP≈NK>CK≈PK,丙二醛含量则呈相反趋势;与不施肥对照处理相比,氮、磷、钾肥分别使干草产量提高268.3%、53.3%、22.7%。结果说明,施肥可以调节多花黑麦草越冬期的相关生理指标,具有提高多花黑麦草抗寒和抗旱能力,从而达到提高产量的目的。

关键词: 多花黑麦草, 叶绿素含量, 净光合速率, 过氧化物酶活力, 丙二醛含量, 产草量