Commercial Monoammonium Phosphate Research Articles

Sweet Corn Phosphorus Uptake from Sandy Soil Amended with Anaerobically-digested Manure

ABSTRACT Anaerobic digester development on dairy, poultry, and swine confined animal feeding operations (CAFOs) reduce manure storage, produce energy and are poised to supply a variety of nutrient-rich materials. Field experiments were conducted in the Columbia Basin of South-Central Washington to evaluate the yield response and phosphorous (P) use efficiency of sweet corn (Zea mayes convar. saccharata cv. Sheba) to the application of P from anaerobic-digested manures. Treatments consisted of the application of 0, 10, 20, 40 kg P ha−1 from five sources, three from anaerobic digesters (AD); AD-dairy P fine solids; AD centrifuged poultry solids; and AD dairy-derived struvite-P compared to a commercial poultry fertilizer, commercial mono-ammonium phosphate, and a non-amended control. Sweet corn yields were not significantly different among P amendments or rates of application but were different between years and were greater than the No-P treatment in 2014. Phosphorus recovery efficiency defined as that percentage of applied P recovered by sweet corn averaged 138% among treatments receiving 10 kg P ha−1 and declined to 57% for higher rates of poultry materials and the commercial mono-ammonium phosphate (MAP) in 2013 and declined 50% in 2014 due to lower yields. Although yield was not different the uptake of P among treatments was significantly greater than the unfertilized control. The lack of yield differences among rates of P applied indicates that P was not limiting yield and suggests that under these production conditions the application of 10 kg P ha−1 of any of the amendments was sufficient. Abbreviations: AD: anaerobic digestion; ADD: anaerobic-digested dairy manure; ADP: anaerobic digested poultry manure; ADS: anaerobic-digested struvite; DM – dry matter; MAP – mono ammonium phosphate; PBP a commercial poultry fertilizer; PRD: percent P recovery efficiency difference method; PRB: percent P recovery balance method; PUE: Phosphorus use efficiency; AUE – Agronomic utilization efficiency.

Graphene oxide-Fe(III) composite containing phosphate – A novel slow release fertilizer for improved agriculture management

Abstract Novel materials offer opportunities to develop new types of fertilizers which could potentially increase efficiency of nutrient use in agriculture. Slow-release fertilizers can be more effective than traditional nutrient sources and simultaneously reduce negative impacts of nutrients to the environment. Using low-cost, abundant natural material, graphite rock, a functionalized graphene oxide (GO)/iron (GO-Fe) composite was synthetised and examined as a new carrier of phosphate ions in order to improve nutrient delivery to plants. The morphology of the composite was examined with scanning electron microscopy (SEM), and X-ray diffraction (XRD) was used to determine the presence of crystal phases. The composite was also characterised with thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR). We found that the presence of ferric ions was responsible for attachment of phosphate ions onto the GO-Fe composite, providing a loading capacity of 48 mg P/g. The kinetics of P release were examined using a column perfusion test while P diffusion in three different types of soils was examined using a visualization technique and chemical analysis. Compared with commercial monoammonium phosphate (MAP) fertilizer, application of GO-Fe composite loaded with phosphate (GO-Fe-P) resulted in slower release of P, thus reducing the possibility for leaching or runoff of soluble P to surface and groundwaters.

Growth and nutrient response of flax and durum wheat to phosphorus and zinc fertilizers

Flax (Linum usitatissimum L.) and durum wheat (Triticum turgidum L.) are important agricultural crops that enter the human food chain. Effective nutrient management considering nutrient interactions is important in order to increase crop yield and improve crop nutrient concentration. The objective of this study was to investigate the effect of P and Zn fertilizers on the yield and nutritional value of flax and durum wheat. A pot culture experiment conducted in a growth chamber using a calcareous clay-loam soil showed that P fertilizers can restrict flax growth due to an antagonistic effect of Zn fertilizer but can increase the seed yield of both crops by enhanced dry matter translocation to the seed/grain. Among the P sources, commercial monoammonium phosphate (CMAP) and commercial triple superphosphate (CTSP) had similar effects on growth and yield, but different impacts on the nutrient concentrations of both crops, indicating the importance of selecting P source to improve crop quality. Zinc addition with reagent grade P decreased the concentrations of P, K, Ca, Mg and Cu in flax but not in durum wheat. We conclude that proper combination of P and Zn fertilizers is necessary to optimize crop yields, but that P had a proportionally greater effect in promoting yield in durum wheat than in flax. In contrast, Zn had a greater impact on mineral composition in flax than in durum wheat, which can affect the nutritional quality of the crop as a component of the human diet. Key words: Flax, durum wheat, P and Zn fertilizers, nutrient, essential trace elements

Controlled-release P fertilizer concept evaluation using growth and P uptake of barley from three soils in greenhouse

Use of controlled-release P fertilizers to match the fertilizer P availability to crop requirement has potential for improvement of P uptake and crop production. Greenhouse experiments were conducted to evaluate the concept of controlled-release P fertilizer by using different coatings to regulate the release of P and to compare the growth and P uptake of barley (Hordeum vulgare L.) in three Alberta soils. Testing of different coatings in one experiment was followed by further evaluation of the promising treatments in two experiments. Commercial monoammonium phosphate (MAP) and diammonium phosphate (DAP) were coated with a polymer (thin-coated, 1.8% by weight or thick-coated, 2.2%) or enveloped in commercial packaging polyethylene film (shrink wrap, SW) with two, four or six pin-holes to control P release. Thin-coated treatment showed greater dry matter yield (DMY), P uptake (PU), net fertilizer P efficiency (NFPE) and net fertilizer releases efficiency of MAP compared to the uncoated, thick-coated or SW treatments in many cases. Coating of DAP did not consistently improve any of the above-mentioned parameters. In some cases, uncoated fertilizer had greater DMY, PU and NFPE than the polymer-coated treatments in early stages of crop growth (at the 13th, 26th, and 30th days), but coated treatments generally performed better during later stages of crop (at the 39th, 45th, 60th and 90th days). At 31.4 mg P pot-1 for example, thick-coated treatment had about 25% of its total PU during the 60th to 90th day, which resulted in greater spike yield accumulation in this treatment (8.4 g pot-1) compared to uncoated fertilizer (5.0 g pot-1). The P release rate was greater with thin-coated fertilizer than with thick-coated fertilizer during the 0 to 13th days (by 0.199 mg P kg-1d-1) and the 13th to 26th days (by 0.084 mg P kg-1d-1), but the opposite was true during the 26th to 39th days (by 0.112 mg P kg-1d-1) and the 39th to 52th days (by 0.064 mg P kg-1d-1). The polymer-coated, in particular the thin-coated, fertilizers delivered P in a manner that allowed the plants to use it more effectively than the uncoated MAP in several cases, which indicated a potential for improvement of fertilizer P efficiency and crop production. Key words: Barley growth, controlled-release P fertilizer, P uptake, yield

Availability of Phosphorus in the Water-Insoluble Fraction of Monoammonium Phosphate Fertilizers

Declining reserves of premium-grade phosphate rock (PR) have resulted in a reliance on lower grade ore to met the needs for phosphate fertilizer production. Elemental impurities, primarily Fe, Al, Mg, and K, are released from closely associated accessory minerals during acidulation of PR. These impurities result in the formation of sludge compounds in the wet-process acid, and in impurity compounds in commercial monoammonium phosphate (MAP, NH4H2PO4) fertilizers. Plus, these impurity compounds are generally water insoluble, thus reducing the level of water-soluble P in commercial MAP fertilizers. A greenhouse study was initiated to determine the availability of P in the water-insoluble fractions of MAP fertilizers. Seven commercial MAP fertilizers were selected to represent the major U.S. sources of PR (Florida, North Carolina, and Idaho). The water-soluble P was removed by washing with deionized water, and the remaining material having low water-soluble P was compared with reagent-grade MAP (100% water soluble). The water-insoluble-P-containing materials produced lower sorghum-sudangrass (Sorghum bicolor [L.] Moench) yield and less P uptake than water soluble reagent-grade MAP. Forage yields and P uptake were dependent on the source of the water-insoluble fraction. Phosphorus soluble in neutral ammonium citrate was not a reliable measure of short-term P availability in the water-washed fertilizer fractions.

Field evaluation of commercial monoammonium phosphate fertilizers

A field study was conducted for two years to evaluate 9 MAP fertilizers produced from the major sources of PR deposits located in Florida, Idaho and North Carolina compared with reagent grade MAP. Sources varied in chemical composition and had 81 to 100% of the A.O.A.C. available P water soluble. Each source was applied to a Norfolk (Typic Paleudults) and a Hartsells(Typic Hapludults) soil at rates to supply 0, 29 and 59 kg P ha−1. Forage yields and P concentrations in harvested forage were increased by the application of P (P ⩽ 0.05) to both soils during the two year study. The concentration of P in harvested forage was affected by the source of MAP only on the Hartsells soil in 1988. Nitrogen was not affected by the source MAP in any of the forage samples tested. Yield differences among sources were observed only in 1987 on the Norfolk soil and in 1988 on the Hartsells soil. Performance of the fertilizers was not related to the percentage of water soluble P or the content of metallic elements.