![Sample our Environment & Agriculture journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5934/TOC-Subject-Sample-2021-Environment-Agriculture.jpg"})
ABSTRACT
Developing a fast and reliable soil testing method is critical for improving soil testing efficiency and ensuring reliable fertilizer recommendation. The objectives of this study were to evaluate Mehlich-3 (M-3) as a replacement for ammonium bicarbonate-diethylenetriaminepentaacetic acid (AB-DTPA) to extract phosphorus (P) and potassium (K) and to determinate the relationships between extractable P and K and their uptakes by crop in calcareous soils. M-3 and AB-DTPA were compared by using two approaches. In the first approach, the amounts of extracted P and K were compared by analyzing soil samples collected from agricultural production areas; in the second approach, snap beans (Phaseolus vulgaris) were grown in pot to determine the P and K uptakes by crop. There were significant correlations between M-3 and AB-DTPA for both soil test P and K based on soils collected from the agricultural field and the pot study. Soil test P and K by both extractants were significantly correlated with their uptakes by snap bean. The critical value of M-3-P regarding snap bean uptake was 47 mg kg−1 and was higher than that (18 mg kg−1) for AB-DTPA-P, whereas critical soil test K levels were similar between M-3 and AB-DTPA. M-3 was identified as an alternate improved extraction method instead of AB-DTPA in calcareous soils based on this study. However, more work will be needed to identify the correlation of the two extractants and crop responses under a field condition.