نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی سابق کارشناسی ارشد مرکز تحقیقات کشاورزی استان قم
2 استاد بخش خاکشناسی دانشکده کشاورزی دانشگاه شیراز
3 استاد بخش خاکشناسی، دانشکده کشاورزی، دانشگاه شیراز
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Total copper (Cu) content of soil does not necessarily reflect its availability to plants. It is, therefore, important to find a suitable reagents which can predict the plant available Cu in soil to optimize fertilizer use. There is little, if any information available regarding Cu availability in calcareous soils of Iran. The availability of this nutrient is generally low in such soils. Therefore, it is very important to assess the status of Cu availability to plants by chemical extractants. In a greenhouse experiment, Nineteen surface soil samples (0 – 30 cm) with a wide range of physical and chemical properties from different filds in Fars Province for Determination of Available Cu for Rice were collected. The following extractants were used to extract available Cu: Mehlich-3 (MH3), ammonium carbonate - EDTA (AC-EDTA), ammonium bicarbonate-DTPA (AB-DTPA), ammonium acetate-EDTA (AA-EDTA), DTPA-TEA, ammonium acetate (AA), hydrochloric acid (CA), EDTA and Mehlich-2 (MH2). Copper extracted by AA and CA were lower than atomic absorption detection limit and thus was reported as nondetectable. The amount Cu extracted by other extractants were decreased in the following order: AC-EDTA > AA- EDTA > AB- DTPA > MH3 > EDTA > DTPA – TEA > MH2. Although, these methods removed different amounts of Cu from soils, they were significantly correlated with each other. However, the correlation between AC-EDTA and AB-DTPA was higher than the others. Multiple regression equations showed that the most influential soil properties affecting extractable Cu was organic matter (OM). The highest correlation coefficient was obtained between grain yield, and Cu concentration by the grain and top with DTPA. Inclusion of soil properties improved the coefficient of determination. Among the soil characteristics tested, cation exchange capacity (CEC), pH,calcium carbonate equivalent (CCE), and clay content correlated negatively with top dry weight and grain and straw yields. whereas, OM and pH related positively and CCE and CEC negatively with plant Cu concentration and uptake.
کلیدواژهها [English]