Results of soil analysis carried out by Teagasc Environment Section last year show that 89pc of farms have soil nutrient problems.
Only one in eight dairy or tillage farms were found to have good overall fertility and less than one in every 11 drystock farms had essential nutrients at the recommended level.
Low acidity levels, and serious deficiency of P and K nutrients were found to be widespread in all farming sectors.
Tim Hyde, an environment specialist with Teagasc, has warned that target production for Food Harvest 2020 will be seriously impeded unless soil nutrient levels are restored.
"In recent years because of changes in legislation, and the cost of fertiliser, volumes applied have fallen substantially and the products used have changed too. In 2009 nationally P and K fertiliser use was at its lowest level in 20 years," he said.
"Soil fertility is the basis on which increases in productivity set out in Food Harvest 2020 will be delivered," he added.
Results from soil testing carried out in 2014, show that overall 11pc of soil achieved a good fertility.
Since 2008 the percentage of soil deficient in phosphorus (P) has increased from 29pc to 54pc.
While half the sample showed deficiency in potash (K) and 89pc had a serious deficiency, there has been some improvement since 2011.
Deficiency in potash was highest on drystock farms at 51pc of samples tested, while deficiency on dairy and tillage farms was 49pc and 45pc respectively.
Meanwhile, there is a bit of excitement in the fertiliser trade this week as a boat of quality granulated CAN into Dublin Port put downward pressure on prices.
A recent IFA price survey reported that CAN + S was trading for €320-350/t in Leinster and Munster.
Delivered big bag granular urea traded for €390/t to €430/t, with the most competitive prices in North Leinster (€385-415/t). In Munster prices ranged from €400/t to €425/t, while in South Leinster prices ranged from €390/t to €420/t. Prices in Connacht varied from €395/t to €430/t.
The survey found that CAN is moving for €306-350/t. The best of the prices were in North Leinster, where the €306/t was quoted. Bulk CAN was quoted at €285-295/t in Munster and €275-300/t in North Leinster.
Big bags of 18-6-12 varied from €390/t to €445/t, with prices at the lower end ranging from €400/t to €420/t.
Generally, delivered prices for 10-10-20 vary from €420/t to €440/t, while 27-2.5-5 is trading from €410/t to €440/t, with 24-2.5-10 selling for €410-440/t.
The IFA's Fintan Conway pointed out that the price gap between individual and group purchasing had widened considerably this season.
Mr Conway said bigger players in the market were aggressively chasing group and larger individual orders.
He pointed out that some purchasing groups and individual volume buyers were achieving prices significantly below those on offer to smaller co-ops and merchants.
Mr Conway said attempted price increases were being vigorously resisted by farmers.