Evaluation of some soil test methods in acid soils for available phosphorus for pea of Senapati district of Manipur (India)

Abstract

In an field experiment conducted on pea (Pisum sativum L.) during rabi season of 2013-14 in acid soil of Senapati district, Manipur, India phosphorus was given in the form of single super phosphate and levels of P2O5 kg ha-1 (0, 40 and 60) had significant influence on total dry matter yield, phosphorus concentration in plants and phosphorus uptake by plant. Six extractants were tried viz. Bray 1, Bray 2, Mehlich 1, Mehlich 3, Troug and Olsen to assess the available phosphorus status of the acid soils. The suitability of these extractants was in the descending order: Bray 1> Troug> Bray 2> Mehlich 3> Olsen (pH-8.5)> Mehlich 1. Bray’s P 1 extractable phosphorus showed the highest and positive correlations with dry matter yield (control) phosphorus content (control), phosphorus uptake (control), Bray’s percent yield and uptake. Therefore this extractant may be used as an index of available phosphorus for pea (Arkel) grown on acid soils of Senapati district, Manipur, the critical level being 14 ppm (mg /kg). The critical limit of phosphorus concentration in plant at 40 days of planting was 0.42% according to the graphical procedure of Cate and Nelson (1965) using a scattered diagram