小麦蚕豆间作对红壤有效磷的影响及其与根际pH值的关系

在云南红壤上采用田间小区试验,通过测定分蘖～拔节期、孕穗～抽穗期、灌浆～乳熟期不同土层深度小麦根际土壤有效磷(available phosphorus)含量和根际pH值,比较研究了小麦蚕豆间作对小麦根际土壤有效磷含量和pH值的影响,探讨了间作小麦根际pH与根际土壤有效磷之间的相互作用.结果表明,与小麦单作相比,小麦蚕豆间作显著地促进了小麦产量的提高.同时,小麦蚕豆间作促进了小麦根际土壤有效磷含量的提高,分蘖～拔节期、孕穗～抽穗期0-10 cm、10-20 cm土层单、间作差异显著；间作显著降低了分蘖～拔节期10-20 cm土层、孕穗～抽穗期0-10 cm、10-20 cm、20-30 cm土层小麦根际土壤pH.分蘖～拔节期、灌浆～乳熟期,单、间作小麦根际土壤有效磷含量与根际pH呈负相关关系.试验表明,在红壤上间作小麦根际土壤有效磷含量的提高与间作降低根际pH有密切关系.

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.