Description
DAP fertilizer is an excellent source of P and nitrogen (N) for
plant nutrition. It is highly soluble and thus dissolves
quickly
in soil to release plant-available phosphate and ammonium. A
notable property of DAP is the alkaline pH that develops
around the dissolving granule.
As ammonium is released from dissolving DAP granules, volatile
ammonia can be harmful to seedlings and plant roots in
immediate proximity. This potential damage is more common when the
soil pH is greater than 7, a condition that commonly
exists around the dissolving DAP granule. To prevent the
possibility of seedling damage, care should be taken to avoid
placing
high concentrations of DAP near germinating seeds.
The ammonium present in DAP is an excellent N source and will be
gradually converted to nitrate by soil bacteria, resulting
in a subsequent drop in pH. Therefore, the rise in soil pH
surrounding DAP granules is a temporary effect. This initial rise
in
soil pH neighboring DAP can influence the micro-site reactions of
phosphate and soil organic matter.
