نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی دکتری دانشگاه تهران و عضو هیئت علمی مرکز تحقیقات کشاورزی و منابع طبیعی قزوین
2 دانشیار دانشکده کشاورزی دانشگاه تهران
3 استاد دانشکده کشاورزی دانشگاه شیراز
4 استادیار پژوهش موسسه تحقیقات خاک وآب
5 استادیار دانشکده کشاورزی دانشگاه تهران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Information about phosphorus fractions is important for evaluation of their status in soil and understanding of soil chemistry that influence soil fertility. To obtain such information, amount and distribution of P in different fractions of 20 soil samples of Qazvin province, Iran were determined by sequential extraction methods and their relationships with each other and with soil characteristics were investigated. Total P ranged from 700 to 1040 mg kg-1. The clay ranged from 18-52%, CEC from 14.5-33.5 c mol(c) kg-1 and the active CaCO3 from 2.9-19.4%. The amount of different P forms i.e. dicalcium phosphates (Ca2-P), octacalcium phosphates (Ca8-P), Al- phosphates (Al-P), Fe- phosphates (Fe-P), occluded-P (O-P), and P as apatite (Ca10-P) were found to range from; 1.6-42.3, 72-314, 14.5-54.8, 8.4-34.8, 5.9-33.4 and 262-697 mg kg-1, respectively. Simple correlation coefficients showed that Olsen-P had a significant correlation with soluble-P, Ca2-P, Fe-P and O-P. A significant correlation was also observed among different forms of P, which presumably reflects the existence of a dynamic relation between the chemical forms of an element in soil. Clay with Fe-P and O-P; total P with Ca8-P, Al-P and Ca10-P; and CEC with Al-P and O-P had positive and significant correlations. However, a significantly negative correlation was found for electrical conductivity (EC) with Ca8-P and Al-P; organic carbon (OC) with Ca10-P, and active CaCO3 with Ca10-P.
کلیدواژهها [English]