Nutrition of Horticultural Crops. Monica Ozores-Hampton and Francesco Di Gioia University of Florida/IFAS/SWFREC Spring 2015

Transcription

1 Nutrition of Horticultural Crops Monica Ozores-Hampton and Francesco Di Gioia University of Florida/IFAS/SWFREC Spring 2015

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3 Enhanced Efficiency Fertilizer (EEF) Are products with characteristics that minimize the potential of nutrient losses to the environment, as compared to reference soluble fertilizers (AAPFCO, 2005)

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5 Enhanced Efficiency Fertilizer 1. Slow release fertilizer (SRF) Products that release nutrients (in a plant available form), slowely than reference soluble fertilizers, however the pattern of release is not well controlled. 2. Controlled release fertilizer (CRF) Products that release nutrient slowely than reference soluble fertilizers, in which the factors dominating the pattern of release are well-known and controllable during CRF preparation. 3. Stabilized fertilizer (SF) Products amended with an additive that reduce the transformation rate of fertilizer compounds, resulting in extended time of nutrient availability in the soil.

6 In the 1960s History To save labor and time, a single application of fertilizer that could release fertilizer over time. Mainly used in ornamental production and turf maintenance In the 1980s EEFs become tools to reduce the risk of nutrient losses while maintaining productivity (environmental protection) Currently Althought the use of EEFs has almost doubled in the last 50 years, it represent only 0.15 % of the global mineral market (Medina et al., 2009) The agricultural sector consumes represent only 10% of the total EEFs use, but demand has been increasing at annual rate of 10%.

7 Why to Use Enhanced Efficiency Fertilizer Improve fertilizer use efficiency Providing optimum levels of nutrients that match plants need Matching the pattern of plant nutrient uptake with the kinetics of nutrient release Reduce nutrient losses and environmental impact of agriculture Reduce losses of N by leaching, volatilization and denitrification Improve vegetables quality Reduce NO 3 -N concentration in leafy vegetables Avoid split applications Single basal application released at controlled rate over the season, minimizing cost for fluel, labor and save time

8 Crop Requirements and N Availability

9 1. Slow Release Fertilizer (SRF) SRFs contain N in a low-soluble, plantunavailable form that usually requires microbial degradation to release plant-available N. Thus N release is slower than conventional soluble fertilizers, but the release rate, pattern, and duration are not well-controlled.

10 Urea-formaldehyde (UF) % N These SRFs are condensation products of urea and formaldehyde in a reaction that includes water, sulfuric acid, sodium hydroxide, and surfactants. O H 2 N C NH 2 urea O + H C H formaldehyde base H 2 N CH 2 OH-HN O C + O C Monomethylol Urea (MU) NH-CH 2 OH NH-CH 2 OH Dimethylol Urea (DMU)

11 Urea-formaldehyde Condensation Products O O H 2 N C NH C HN NH 2 CH 2 O C H 2 N NH 2 urea O + H C H formaldehyde acid H 2 N O C Methylene di urea (MDU) NH HN + O C NH O C HN NH 2 CH 2 CH 2 Di - methylene tri urea (DMTU) + TMTU

12 Explanation of the fertilizer characteristics for urea formaldehyde (UF) and methylene urea (MU). Characteristics Total nitrogen Cold water soluble nitrogen (CWSN) Cold water insoluble nitrogen (CWIN) Hot water insoluble nitrogen (HWIN) Explanation The fertilizer grade typically 38% to 40% for UF and MU. This nitrogen fertilizer fraction is soluble in 71.6 F water and is available to plants immediately or within a few weeks. The CWSN fraction contains unreacted urea, methylene diurea, and dimethylene triurea. This is the slowly available and unavailable nitrogen fertilizer fraction that is not soluble in 71.6 F water. This nitrogen fertilizer fraction is not soluble in 212 F water, and may be reported indirectly through back calculation using the activity index. The HWIN may not be available to the plants during the season applied.

13 Urea-formaldehyde Release: Activity Index (AI): percentage of N insoluble in cold water that is solubilized in hot water. Provide an estimate of the fraction of relatively long-lasting release AI=[(CWIN HWIN) / CWIN] x 100 AI=[HWSN / (HWSN + HWIN)] x 100 Factors affecting N release: ph, temperature, soil moisture, soil property Microbial activity

14 Urea-aldehyde and Synthetic Nitrogen Compounds Isobutyliden Diurea (IBDU) 31 % N Reacting urea with isobutyraldehyde Mechanism of N release: Hydrolysis Factors affecting N release: Soil moisture (hydrolysis), particle size ph, Temperature

15 Urea-aldehyde and Synthetic Nitrogen Compounds Crotonyliden Diurea (CDU) 32 % N Reacting urea with acetaldehyde in acid conditions Mechanism of N release: Combination of hydrolysis and microbial activity Factors affecting N release: Soil moisture (hydrolysis), particle size ph, Temperature (microbial activity)

16 Controlled Release Fertilizer (CRF) Fertilizer products that release nutrient slowely than reference soluble fertilizers, in which the factors dominating the pattern of release are well-known and controllable during CRF preparation

17 Sulfur Coated Urea (SCU) % N Coating preheated urea granules with molten sulfur (156 C) and wax Mechanism of N release: Micro pores, holes, cracks Microbial degradation Factors affecting N release: Coating quality: thickness and uniformity Soil moisture, temperature

18 Sulfur Coated Urea (SCU) Damaged coatings with cracks (catastrophic release) Damaged coatings whose cracks are sealed with wax Perfect and thick coatings (locked-off)

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21 Water penetrates the coating through microscopic pores, dissolve the nutrients and increases the osmotic pressure within the coated core.

22 controlled release fertilizers The osmotic pressure stretch the coating, enabling the release of nutrient through pores and cracks

23 Catastrophic or failure release

24 Polymer Coated Urea (PCU) Resin-coated urea Alkyd resin (Osmocote) Polyurethane (Polyon, Multicote, Plantacote) Thermoplastic polymer-coated urea Polyvinyl chloride (PVC) Polyacrylamide (PA) Natural rubber (NR) (=lattex) Polylactic acid (PLA) Polyethylene (PE-impermeable) and Ehylene-vinyl-acetate (EVA - permeable)

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27 Polymer Coated Urea (PCU) Mechanism of N release: Diffusion Factors affecting N release: Temperature Coated membrane thickness

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29 Water penetrates the coating through microscopic pores, dissolve the nutrients and increases the osmotic pressure within the coated core

30 The osmotic pressure stretch the coating, increasing the micro-pores, enabling the release of nutrient through them

31 Leak-type release

32 Polymer Coated Urea (PCU) Coating thickness effect on N release

33 Polymer Coated Urea (PCU) Temperature effect on N release

34 Release Polymer Coated Urea (PCU) Release from a single coated urea: Diffusion vs. Failure Time

35 Manufacturer, trade name, control release fertilizer (CRF) type, coating description, and formulation of different CRFs. Manufacturer z Trade name Type of CRF Coating description Formulation examples Agrium, Inc. ESN Polymer-coated Flexible micro-thin polymer ESN (44-0-0) urea coating Agrium, Inc. Polyon Polymer-coated Ultra-thin ployurethane coating Polyon NPK ( ), Polyon (41-0-0) that uses patented Reactive Layers Coating Agrium, Inc. Duration Polymer-coated Micro-thin polymer membrane Duration (44-0-0), Duration ( ) Agrium, Inc. XCU Polymer/sulfurcoated urea Urea coated first with polymer and then sulfur and wax Chisso-Asahi Nutricote Resin-coated Resin coating with a special Fertilizer Co. chemical release agent Chisso-Asahi Meister Resin-coated Granular urea coated with a Fertilizer Co. polymer composition of natural products, resin and additives Everris, Inc. Osmocote Resin-coated Alkyd-resin coating made in a batch process from vegetable oil and resin Everris, Inc. Poly-S Sulfur/polymer- Urea coated first with sulfur and coated urea then polymer Everris, Inc. Agrocote Sulfur/polymer, and resin-coated Either 100% N or K potassium fully coated with polymer/sulfur and resin coatings Haifa Group Multicote Resin-coated Water-soluble nutrients encapsulated in a polymeric shell J.R. Simplot Florikote Polymer-coated Dual layer technology coats the fertilizer with a smooth exterior coating with no breaks XCU (43-0-0) Nutricote (28-0-0) Meister (21-7-4), Meister ( ) Osmocote Classic ( ), Osmocote Plus ( ), Osmocote Pro ( MgO+TE) Poly-S (37-0-0) Agrocote ( %S), Agrocote ( %S), Multicote Agri 4 (34-0-7), Multicote Agri 6 ( ) and (34-0-7), Multicote Agri 8 (34-0-7) Florikote ( ), Florikote ( ), Florikote (40-0-0)

36 Stabilized Fertilizer (SF) Fertilizer products amended with an additive reducing the transformation rate of fertilizer compounds, resulting in extended time of availability in the soil

37 Nitrification Inhibitor

38 Nitrification Inhibitor Stabilized fertilizers

39 Stabilized fertilizers Nitrification Inhibitor Chemical name Common or trade name Manufacturer 2-chloro-6-(trichloromethyl)-pyridine Nitrapyrin, N-serve Dow Chemical Co. 5-Ethoxy-3-trichloromethyl-1,2,4-thiadiazol Dwell, Terrazole, Etradiazo Uniroyal Chemical Dicyandiamide DCD SKW Trostberg AG 3,4-Dimethylpyrazole phosphate DMPP (ENTEC) BASF AG 2-Amino-4chloro-6-methyl-pyrimidine AM Mitsui Toatsu Co. 2-Mercapto-benzothiazole MBT Onodo Chemical Ind. 2-Sulfanilamidothiazole ST Mitsui Toatsu Co. Thiourea TU Nitto Ryuso

40 Stabilized fertilizers Nitrification Inhibitor Factors influencing the mobility, persistence and effectiveness of NIs: Inhibitor properties: - water solubility - volatility soil chemical and physical properties: - ph - organic matter - soil texture soil biological properties: - Genetic variability in Nitrosomonas strains Abiotic factors: - Temperature

41 Nitrification Inhibitor Factors influencing the mobility, persistence and effectiveness of NIs: NIs are more effective in: - Light-textured soils, - Low organic matter soils, - Low temperature ( 5 C) NIs are less effective in: - Heavy-textured soils, - High organic matter soils, - High temperature

42 Stabilized fertilizers Urease Inhibitor NH 3 + H + CO(NH 2 ) 2 + H + urease + H 2 O 2NH HCO - 3

43 Urease Inhibitor A large number of compounds with differing characteristics have been tested for their ability to inhibit urease activity Organic and inorganic compounds inhibit the enzyme: - Reacting with active sites on the enzyme - Interacting with a key functional group in the molecule - Changing the conformation of the active site - Complexing nickel in the active site (e.g. hydroxamates) - Being structural analogues of urea and competing for the enzyme (e.g. thiourea, methylurea, phosphoryl di- and triamides)

44 Urease Inhibitor The most effective compounds for the inhibition of urease activity appear to be the phosphoryl amides: - N-(n-butyl) phosphoric triamide - N-(butyl) cyclohexylphosphoric triamide

45 Urease Inhibitor The unique urease inhibitor commercially available is: N-(n-butyl) thiophosphoric triamide (NBPT - AgrotaiN)

46 Urease Inhibitor Urease inhibitors are expected to be most beneficial on soils when: (i) (ii) (iii) (iv) Loss of NH 3 from urea fertilizers is high Incorporation of urea is difficult There is little opportunity for the urea to move into the soil with infiltrating water The soil surface has a high urease activity due to lack of cultivation or the accumulation of organic matter.

47 Prices of enhanced-efficiency fertilizers for use in vegetable production Fertilizer Price ($/ton) Soluble urea 380 to 560 Soluble potassium nitrate 1,150 to 1,500 Methylene urea 750 to 1,000 Urea-formaldehyde 1,100 to 1,300 IBDU 1,400 to 1,600 Controlled-release urea (sulfur coated) 775 to 875 Controlled-release urea (polymer sulfur coated) 500 to 1,000 Controlled-release urea (polymer) 700 to 1,500 Controlled release NPK (polymer) y 810 to 2,000 Urease inhibitor Nitrification inhibitor 20 to 30 x 4 to 8 x x These products are marketed in 2.5 gallon containers. The listed price is additional to the price of the soluble fertilizer and does not reflect additional application costs that may be associated.

48 Enhanced Efficiency Fertilizer EEFs as BMP tool Are recognized as one of the few BMPs that have a direct impact on off-site nutrient movement and water quality. EEFs crop yield improvement Can certainly minimize the losses of nutrient in the environment if opportunely applied, however, their effectiveness in increasing crop yield must be evaluate case by case. Several studies report low or absent yield increase.

49 Enhanced Efficiency Fertilizer EEFs Economical benefits Use in agriculture must be supported from an economical convenience, currently the fertilizer prices are very instable, however EEFs are still more expensive compared to soluble fertilizers, therefore, their higher cost must be offset by reducing application cost and/or providing higher production EEFs classification and regulation An approved methodology is needed to estimate nutrient release properties from a broad range of materials Commercial label regulation is not complete

50 Literature Review Carson, L., M. Ozores-Hampton, K. Morgan, and J. Sartain Prediction of controlled-release fertilizer nitrogen release using the pouch field and accelerated temperature controlled incubation methods in Florida sandy soils. HortScience 49: Carson, L., M. Ozores-Hampton, K. Morgan, and J. Sartain Nitrogen release properties of controlled-release fertilizers in tomato production of South Florida. HortScience 49: Carson, L., M. Ozores-Hampton, K. Morgan, and S. Sargent Effects of controlled-release fertilizer nitrogen rate, placement, source, and release duration on tomato grown with seepage irrigation. HortScience 49: Carson, L., M. Ozores-Hampton, K. Morgan, and S. Sargent Effect of controlled-release and soluble fertilizer on tomato production and postharvest quality in seepage irrigation. HortScience 49: Carson, L. and M. Ozores-Hampton Description of enhanced-efficiency fertilizers for use in vegetable production. EDIS, HS1247, Carson, L. and M. Ozores-Hampton Factors affecting nutrient availability, placement, rate and application timing of controlled-release fertilizers for Florida vegetable production using seepage irrigation. HortTechnology 23: Carson, L., M. Ozores-Hampton, and K. T. Morgan Nitrogen release from controlled-release fertilizers in seepageirrigated tomato production in south Florida. Proc. Fla. State Hort. Soc. 126: Carson, L. and M. Ozores-Hampton Methods for determining nitrogen release from controlled-release fertilizers used for vegetable production. HortTechnology 22: Carson, L. and M. Ozores-Hampton Effect of controlled-release soluble fertilizer on tomato grown with seepage irrigation in Florida sandy soils. Proc. Fla. State Hort. Soc. 125: