Estimation of suitable extractant of nitrogen for onion (Allium cepa L.) growing soils under temperate conditions of Kashmir valley

Abstract

A pot culture experiment was used to determine the suitability of five chemical extractants for nitrogen estimation: 2N KCl, hydrogen peroxide, acid dichromate, alkaline permanganate, and organic carbon. For this reason, soil samples with a range of physicochemical characteristics were gathered from nine (9) sites in the Kashmir Valley where onions are grown. Four doses of Nitrogen (0, 50, 100 and 120 kg ha-1 ) were used and two onion seedlings per pot were grown in order to calculate Bray’s percent yield at the time of harvesting. The results revealed that the relative efficiency of five chemical extractants for the extraction of available N were in the order of organic carbon > alkaline permanganate > hydrogen peroxide > acid dichromate > 2N KCl. Organic carbon and alkaline permanganate showed significant correlation with Bray’s per cent yield (r = 0.928 and 0.615) and nitrogen content (r = 0.914 and 0.538) in onion bulbs. Whereas, 30 per cent hydrogen peroxide is showing significant correlation (0.360) with Bray’s per cent yield and non-significant correlation (0.143) with nitrogen content. Both acid dichromate and 2N KCl are showing non-significant correlation with Bray’s per cent yield and nitrogen per cent in onion bulbs. It could be concluded that organic carbon and alkaline permanganate are the suitable extractants for nitrogen estimation.