Estimation of nitrogen and phosphorus in fertilizers found in Nepalese market and some soil samples

Abstract

Soil fertility is the basis for agriculture, soil acts as a crucial reservoir of plant micronutrients including the major elements such as nitrogen and phosphorus which largely determine plant health and crop productivity. The availability of nutrient absorption largely depends on the soil pH and soil moisture content as it affects the soil’s chemical, physical, and biological properties and plays a key role in agricultural productivity.

In this study, 15 soil samples were collected from Thecho, Gokarna and Pathivara Yangwarak to measure moisture content, soil pH, nitrogen and Phosphorus content and 6 samples of fertilizers from the Nepalese market were selected for their nitrogen and Phosphorus content. Soil moisture was found in the range of 16.57 – 28.40 % and soil pH was found in a slightly acidic to nearly neutral with pH value in the range of 6.5 – 7.0. Nitrogen content was estimated by the Kjeldahl method and phosphorus content was estimated by Olsen's method. Among 15 soil samples, phosphorus in 11 soil samples were found high value, 3 soil samples were found medium value and 1 soil sample were found low value and nitrogen in 5 soil sample were found high, 5 soil samples were found medium and 5 soil samples were found low value. In most of the fertilizers, nitrogen and phosphorus content were found much lower than labeled in the packet.