Effects of wheat and fababean intercropping on available phosphorus of red soils and its relationship with rhizosphere soil pH

By determining rhizosphere soil availabe phosphorus and pH in different soil layers at the tillering-jointing, booting-heading, filling-milk stages of wheat in the wheat/fababean intercropping system and wheat monocropping system, a field experiment was carried out to study the effects of the intercropping on wheat rhizosphere soil available phosphorus concentration and pH and to investigate the interaction rule of available phosphorus and pH. The results show that compared with the monocroped wheat, the intercropping increases wheat yield significantly and improves rhizosphere soil available phosphorus concentration of wheat fields, and the intercropping effect is significant in 0 -10 cm, 10-20 cm soil layers at the tillering - jointing, booting - heading stages. The rhizosphere soil pH of intercropped wheat fields is significantly lower than that of the monocropped wheat in 10-20 cm at the tillering - jointing stage and in 0-10 cm, 10-20 cm, 20 -30 cm soil layers at the booting - heading stage. The rhizosphere soil available phosphorus concentration is negatively correlated with rhizosphere soil pH at the tillering - jointing, filling-milk stages. This research demonstrates that the decrease of rhizosphere soil pH in the intercroppig system is contributed to the increase of rhizosphere soil, available phosphorus concentration.