A study was undertaken for determining the effect of different levels of different fertilizers (diammoniu •.~ phosphate i.e. DAP, urea and potassium sulphate) on soil strength or soil penetration resistance under different conditions of compaction and moisture so as to select a fertilizer which reduces soil strength and conserves tractor power. The analysis of the data collected indicated that soil density and moisture affected the penetration resistance or strength of soil more than the fertilizers. It was further established that the strength of soil gradually decreased with DAP and increased with urea and potassium sulphate, suggesting thereby, that DAP is a better fertilizer for conserving tractor power at the time of seedbed preparation
Ghulam Sarwar Sheikh, Muhammad Shafique, M.S. Sabir. (1993) SOIL STRENGTH AS AFFECTED BY DIFFERENT FERTILIZERS UNDER DIFFERENT SOIL COMPACTIO~ AND MOISTURE CONDITIONS, , Volume 30, Issue 3.
