不同磷水平对接种根瘤菌紫花苜蓿生长特性的影响

采用砂培方法,以NaH2PO4为磷源,设8个磷水平处理,研究了不同磷水平对接菌"甘农3号"紫花苜蓿生长特性的影响。结果表明,在接种根瘤菌并且在营养供应充分的条件下,紫花苜蓿的株高、叶片数、叶面积、叶绿素含量、地上生物量和地下生物量都随着营养液中磷水平的增大而呈现出先增大后减小的趋势,但各指标出现最大值时的磷水平并不相同。株高和叶片数在磷水平为500μmol/L时最大(P<0.05);地上和地下生物量在磷水平为1 000μmol/L时最大(P<0.05);叶面积和叶绿素含量在磷水平为1 500μmol/L时最大(P<0.05)。而根瘤数和根瘤重则随磷水平的增大而一直增大,并在磷水平为2 000μmol/L时出现最大值(P<0.05)。表明紫花苜蓿各器官对磷素的需求量并不相同,并且磷素并非越多越好,过多的磷反而不利于紫花苜蓿的正常生长。

Effect of different levels of phosphate on growth of rhizobium vaccinated alfalfa

The impact of different levels of phosphate on growth of rhizobium vaccinated alfalfa was studied.The results showed that plant height,blade number,leaf area,chlorophyll content,aboveground and underground biomass increased and then decreased along with the increase of the phosphate levels,but the phosphate level was different while different indices reached the highest value.Plant height and blade number were the highest under the phosphate concentration of 500 μmol/L(P<0.05);For aboveground and underground biomass,it was 1000 μmol/L(P<0.05);For leaf area and chlorophyll content,it was 1 500 μmol/L(P<0.05).However,nodulation and root nodule number increased along with the phosphate level and reached the highest under 2 000 μmol/L(P<0.05).It could be concluded that the demand of different alfalfa organs to phosphate was different.