کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5770638 | 1629420 | 2017 | 9 صفحه PDF | دانلود رایگان |
- Best estimations of plant available P (TAP) were achieved with anion exchange resins (AER).
- AER in bicarbonate form performed better than in chloride form.
- P extracted with bicarbonate-AER was related to most of the factors affecting TAP.
- Organic P related properties increased the performance of AERs to estimate TAP.
- Estimations of TAP are feasible with Olsen P if clay and carbonates are included in the model.
The sustainable use of P in agriculture, which is a non-renewable and strategic resource, relies on soil P tests. Traditional soil P tests, however, may not accurately assess plant-available P in soils ranging widely in properties. The main objectives of this work were: (i) the study of the accuracy of the widely used Olsen P in assessing available P to plants, and (ii) testing other extraction methods to assess phytoavailable P, in a representative group of soils from Mediterranean areas. To this end, a P depletion experiment was conducted using 18 soils to estimate total available P to plants in soil. In addition to Olsen P, other P extractions were performed to check their accuracy in predicting total available P to plants, including anion exchange resins in Clâ and HCOâ3 forms. Poor predictions of total available P with Olsen P (R2Â =Â 0.53, PÂ <Â 0.001) were improved when clay and carbonates were taken into account in a predictive model (R2Â =Â 0.8, PÂ <Â 0.001). The best estimations of total available P were obtained with resins, that in HCO3â form (R2Â =Â 0.87, PÂ <Â 0.001) performing better than that in Clâ form (R2Â =Â 0.77, PÂ <Â 0.001). Estimations with resins improved when potential organic P inputs to available P were taken into account. This reveals the role of organic P to the availability of this nutrient to plants. It can be concluded that single models based on Olsen P plus routinely determined soil properties, and single extractions with resins predict total available P in studied soils with sufficient accuracy.
Journal: Geoderma - Volume 297, 1 July 2017, Pages 10-18