摘要
用根垫法研究了不同形态N源与P源对红松苗木根 土界面pH及磷有效性的影响 .结果表明 ,铵态N处理使根 土界面pH降低 ,硝态N处理使根 土界面pH升高 .不同N源处理引起根 土界面pH变化的幅度受P源种类及距根面距离的影响 ,施加矿物P时 ,铵态N引起的根 土界面pH下降的幅度明显减小 .不同P源处理时根 土界面有效P含量受N源种类的影响 ,铵态N处理时 ,加入易溶性P近根面处有效P含量显著增加 ,而加入难溶性P时仅距根面 0～ 2mm处有效P含量显著增加 ;硝态N处理时 ,仅在加入易溶性P时近根面处有效P含量显著增加 ,而加入难溶性P时 ,近根面处有效P含量与不加P处理时相近 ,表明铵态N处理引起的根系分泌质子是根 土界面处难溶性矿物P溶解的主要驱动力 .根
The effects of different nitrogen and phosphorus sources on pH and P availability in the root/soil interface of Korean pine seedlings were studied by means of the root-mat method. The results show that the addition of NH + 4--N decreases the pH in the root/soil interface, while the addition of NO - 3--N increases the pH compared with the control treatment. The type of P sources and the distance from the root plane reamarkably influence the changes of pH in the root/soil interface induced by the addition of the nitrogen sources. Compared with the addition of only NH + 4--N, the extent to which the pH in the root/soil interface decreases is obviously smaller when treated by NH + 4--N and rock P. When treated with different P sources, the contents of available P in the root/soil interface are affected by the types of the N sources. The content of the available P in the root/soil interface obviously increases when treated with NH + 4--N and soluble P, whereas the content of the available P increases only in the area 1--2 mm from the root plane when treated with NH + 4--N and rock P. When treated with NO - 3--N, the contents of available P in the root/soil interface increase only when applied with soluble P, whereas the contents of the available P change little when applied with rock P. The results above show that the protons excreted by the roots are the main activating force for the solution of the rock P in the root/soil interface. The concentrations of P in the root/soil interface are remarkably correlated with those in the needles of the seedlings.
出处
《北京林业大学学报》
CAS
CSCD
北大核心
2005年第2期23-27,共5页
Journal of Beijing Forestry University
基金
国家自然科学基金资助项目 ( 3 0 170 169)
关键词
N源
P源
根/土界面
PH
P有效性
红松
nitrogen sources, phosphorus sources, root/soil interface, pH, availability of P, Pinus koraiensis
