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ARS Home » Pacific West Area » Kimberly, Idaho » Northwest Irrigation and Soils Research » Research » Publications at this Location » Publication #186702
Title: MATRIX BASED FERTILIZERS REDUCE NITROGEN AND PHOSPHORUS LEACHING IN GREENHOUSE COLUMN STUDIES

Author
item Entry, James
item Sojka, Robert

Submitted to: Journal of Water Air and Soil Pollution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/13/2006
Publication Date: 11/8/2006
Citation: Entry, J.A., Sojka, R.E. 2006. Matrix based fertilizers reduce nitrogen and phosphorus leaching in greenhouse column studies. Journal Of Water Air And Soil Pollution. 180:283-292.

Interpretive Summary: We have developed matrix based fertilizer formulations (MBF) that reduce NH4, total phosphorus (TP), total reactive phosphorus (TRP) and dissolved reactive phosphorus (DRP) in leachate. These matrix based formulations cover a range of inorganic N and P in compounds that are relatively tightly bound (MBF1) to more moderately bound (MBF2) and more loosely compounds (MBF3) mixed with aluminum sulfate and ferric sulfate and with the high ionic exchange compounds starch, chitosan and lignin. When N and P are released from the chemicals containing these nutrients the new matrix based fertilizers likely bind N and P to a aluminum sulfate and ferric sulfate - starch - chitosan - lignin matrix. Glomus interadicies spores were added to the matrix to enhance plant uptake of N and P. Osmocoate (Registered) 16-16-16, a commercial slow release fertilizer (SRF) with aluminum sulfate and ferric sulfate (SRF+Al+Fe) and without aluminum sulfate and ferric sulfate (SRF) leached 78-84% more ammonium, 58-78% more TP, 20-30% more TRP and 61-77% more than MBF formulations 1, 2, and 3. The concentration and amount of nitrate leached among SRF and MBF formulations 1 and 2 did not differ. Total plant weight did not differ among fertilizer treatments. Arbuscular mycorrhizal infection did not differ among plants receiving SRF and MBF formulations 1, 2 and 3. Although field testing in necessary, results of this greenhouse test are promising.

Technical Abstract: When fertilizers are applied to soil, nitrogen (N) and phosphorus (P) use efficiency is low because only the soluble fraction of these nutrients can be taken up by plants. Land managers and home owners usually apply frequent applications of soluble forms of N and P as inorganic fertilizers in quantities greater than plants can take up. Thus many soils are fertilized with N and P in excess of plant requirements leading to nutrient leaching into the groundwater. We have developed matrix based fertilizer formulations (MBF) that reduce ammonium, total phosphorus (TP), total reactive phosphorus (TRP) and dissolved reactive phosphorus (DRP) in leachate. These matrix based formulations cover a range of inorganic N and P in compounds that are relatively tightly bound (MBF1) to more moderately bound (MBF2) and more loosely compounds (MBF3) mixed with aluminum sulfate and ferric sulfate and with the high ionic exchange compounds starch, chitosan and lignin. When N and P are released from the chemicals containing these nutrients the new matrix based fertilizers likely bind N and P to a aluminum sulfate and/or ferric sulfate - starch- chitosan- lignin matrix. Glomus interadicies spores were added to the matrix to enhance plant uptake of N and P. Osmocoate (Registered) 16-16-16, a commercial slow release fertilizer (SRF) with aluminum sulfate and ferric sulfate (SRF+Al) and without aluminum sulfate and ferric sulfate (SRF) leached 78-84% more ammonium, 58-78% more TP, 20-30% more TRP and 61-77% more than MBF formulations 1, 2, and 3. The concentration and amount of nitrate leached among SRF and MBF formulations 1 and 2 did not differ. The SRF treatment leached 34% less nitrate than MBF 3. Total plant weight did not differ among fertilizer treatments. Arbuscular mycorrhizal infection did not differ among plants receiving SRF and MBF formulations 1, 2 and 3. Although field testing in necessary, results of this greenhouse test are promising. Initially these new fertilizers may only be economically feasible to high value greenhouse or horticultural products, homeowner lawns, turf grass operations such as golf courses.