Study on Phosphorus Adsorption and Application by the Major Soils of Ningxia
SUN Quan, HAN Xiou - yun, GUO Xiao - ning (1. Department of Agronomy, Faculty of Agriculture, Ningxia University. Yongning 750105; (2. Central Environment Supervising and Measuring Station of Yinchuan )
The characteristics of phosphorus adsorption isotherms by 10 soils of Ningxia were studied. The result indicated that the adsorption curves of the soils were fitted with Langmuir adsorption isotherm equation (IAE). The maximum P adsorption values were from 99. 0 to 666. 6 μg/g, being positively significantlg correlated with soil physical clay contents. According to the IAE, we predicted that the phosphoric fertilizer application amount was 54 to 77kg/hm2 in the major soils of Ningxia, being consistent with the amount defined by the methods of fertilizer efficiencies function.