Improving Fertilizer Use Efficiency for Horticultural Crops. University of Florida

Transcription

1 Improving Fertilizer Use Efficiency for Horticultural Crops University of Florida

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5 Increase fertilizer use efficiency: Low P fertilizer formula Soluble vs. Controlled-release fertilizers Fertigation Foliar fertilization Snake oils Other practices

6 Low P fertilizer formula

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8 %$

9 *++,-*++ *++-*+++ * a a a Yield (bags/ac) P fertilizer rate (% of grower rate)

10 % Soil P (ppm) % 3.47% AB-DTPA extractable nonextractable

11 A ph - 1/2pCa 2+ Rockdale1 --Pineland Rockdale2 Rockdale3 Biscayne --Wetland Biscayne2 Biscayne3 Krome1 Vegetable field Krome2 Krome3 Chekika1 Chekika2 Krome4 --Fruit grove Krome5 Krome6 Pozo Blanco --Puerto Rico Fraternidad Guam1 Guam2 FA Ca 5 F(PO 4 ) 3 DCPD CaHPO 4 2H 2 O OCP Ca 8 H 2 (PO 4 ) 6 5H 2 O CRD CaAl 3 (PO 4 ) 2 (OH) 5H 2 O HA Ca 10 (PO 4 ) 6 (OH) 2 TCP β -Ca 3 (PO 4 ) 2 B DCPD CaHPO 4 2H 2 O FA Ca 5 F(PO4) 3 OCP Ca 8 H 2 (PO 4 ) 6 5H 2 O CRD CaAl 3 (PO 4 ) 2 (OH) 5H 2 O TCP β -Ca 3 (PO 4 ) 2 HA Ca 10 (PO 4 ) 6 (OH) 2 ph2po /pCa 2+ ph2po /pCa % 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Soil 7 Tomato Soil 11 Avocado Soil 12 Lime Soil 16 ENP Soluble P Exchangeable P Al-Fe P Organic P Ca-Mg P Residual P Percentage of Total P

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13 P K

14 Soil and Air Temperatures:24 hr. Jan. 26 to 27.(6 pm -5 pm) D eg rees C en tig rad e Hours G AIR

15 2m T min (F) Tsoil min(avg) -10cm (F) Mar-97 Jul-98 Dec-99 Apr-01 Sep-02 Jan-04 May-05 Oct-06 Feb-08 Jul-09 Year

16 2m T min (F) Tsoil min(avg) -10cm (F) Mar-97 Jul-98 Dec-99 Apr-01 Sep-02 Jan-04 May-05 Oct-06 Feb-08 Jul-09 Year! " #$% &' (' )* #+,% &- -( )&

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24 Water-soluble fertilizer

25 <Standard= N and P fertilizers are> >water-soluble. >plentiful. >lowest cost materials. >leachable.

26 Typical water-soluble N and P fertilizers used in horticultural production Nitrogen Ammonium sulfate Ammonium nitrate Urea Potassium nitrate Calcium nitrate Phosphorus Concentrated superphosphate Mono-ammonium phosphate Di-ammonium phosphate Ammonium polyphosphate

27 Nutrient release from CRF depends on temperature and moisture Water-soluble Slow/controlled-Release Non-coated Coated Ammonium nitrate Dissolves all at once Urea formaldehyde Slowly decomposes to soluble N Osmocote Nutrients leak through coating

28 Examples of slow and controlledrelease fertilizers Non-coated Nitroform Nutralene Nitamin IBDU (N sources only) Coated Osmocote Polyon Nutricote Syncote Polymer/Sulfur-coated fertilizers (N, P, K + others)

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30 4 5 #46 %

31 Polymer coating layer

32 PLANT RESPONSE to CRF depends on how well the release curve matches plant need.

33 8)%&/4!4!?* Improved nitrogen use efficiency by 10 50%

34 ") $& 0$' 14 A B BC CD CD D GROWTH RATE (kg/ha/d) IBDU SCU POLYON NITROFORM AS UAN NITROGEN SOURCE

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36 8)%&/4!4!? Fewer applications needed. (Decreased application cost.)

37 :%6%% 3-$-&) yr lbs-solids yield/tree 35 Conventional CR = 76% Escote Meister Sierra Nutricote Prokote CR = 94% CR = 100% CR = 84% Percentage of full N rate CR = 100% CR = 100%

38 8)%&/4!? Environmentally advantageous; less fertilizer loss. (Decreased nitrate leaching below root zone.)

39 %&'$& PERCENTAGE OF APPLIED N LEACHED (%) AS A B B C C C D E 8.1 UAN CORON POLYON NUTRALENE NITROGEN SOURCE SCU IBDU NITROFORM

40 8)%&/4!?2 Decrease salt damage

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42 High-volume use of controlled-release fertilizer is limited to> >turfgrass >greenhouse >nursery >landscape

43 Cost of materials for citrus (3 yrs ago)! 3-$ 5B7 /) 0 "% 5B7 ' *+6A 36A,62, *A6* A6 362* C * A6+ -0 A63 26 A62 '% 6 *6 **6

44 How does the relative COST OF FERTILIZER MATERIALS AND APPLICATION METHODS affect fertilizer selection by producers? Vegetables (3 yrs ago) Potato study: Cost of a water-soluble N fertilization program D $38 to $63 per acre. Extra cost to use a CRF program cost D $8 to $79 more than the most expensive soluble N cost. Extra cost could be offset by reduced application rate and/or providing cost-share to use CRF.

45 What do we know about CRF> >rates? >timing? >placement? >plant response? >leaching? >release rates as affected by temperature and moisture?

46 Fertigation

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48 Fertigation: What do we know about> >nutrient use-efficiency? >application frequency? >plant response? >leaching potential?

49 Fertigation improved N USE EFFICIENCY in bell pepper production. Yield at four pre-plant/fertigation N fertilizer combinations. Fert. application method Percent N applied pre-plant Percent N applied by fertigation Total fancy pepper yield Total marketable pepper yield tons/acre P-value

50 With good water management, fertigation APPLICATION FREQUENCY doesn t matter much. 6-year-old orange trees growing in lysimeters. Year Fertigation treatment Fertigations per year Relative amount of applied N that leached N uptake efficiency z % % 1999 Every irrigation Weekly Monthly Every irrigation Weekly Monthly %'%0$)0$ %'

51 Horticultural PLANT RESPONSE to fertigation is as good or better than the response observed with well-managed dry soluble fertilization. In both cases, irrigation (and sometimes drainage) water management is critical for success.

52 Why was there more leaching with fertigation compared with dry soluble fertilizer application? Estimated N leached below a ridge citrus grove root zone. N rate lbs/acre Dry soluble fertilizer Fertigation lbs N/acre/year CRF Study authors: This occurred purely because of unexpected prolonged irrigation or unexpected high rainfall following certain fertigation events in both years

53 Foliar fertilization

54 Can FOLIAR FERTILIZER APPLICATION improve nutrient use efficiency? Tree crops: Possibly Foliar uptake of urea can be 50% efficient; it has enhanced flowering and yield. Phosphite is recognized as a P source; it has increased flowering, fruiting, and lbs solids. Vegetables: No? Leaves cannot absorb enough N/P to correct a deficiency. Leaf burn is likely.

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57 Improve fertilizer use efficiency by: Develop a nutrient management plan Do a fertilizer trial by yourself Use appropriate application equipment. Use appropriate fertilizer sources and formulations Add organic matter to the soil whenever possible. Split fertilizer applications. Try to wet only the root zone when irrigating.

58 THANK YOU! Questions?