Soil Testing for Crop Nutrient Recommendations and Management November 13, 214 Gulf Coast Research and Education Center, Balm Row Crop Responses to Nitrogen Rate, Application Timing and Irrigation Schedule Lincoln Zotarelli, Ph.D. - Horticultural Sciences Department Kelly T. Morgan, PhD Soil and Water Sciences Department University of Florida
1) Soil nutrient availability 2) Determination of cultivation area 3) Determination of nutrient need by the crop 4) Plant N requirement 5) Fertilizer Use Efficiency vs application timing 6) Timing of N application and rainfall 7) Placement of N-fertilizer 8) N-fertilizer application vs irrigation 9) Final Remarks
A soil probe is used to sample fields. (Tom Schultz)
Step 1) Soil sampling soil fertility test available: USDA Web Soil Survey
USDA WEB SOIL SURVEY - Main page http://websoilsurvey.nrcs.usda.gov/app/homepage.htm
Web Soil Survey provides: 1. Soil map of a area of interest understanding the soil properties and limitations 2. Acreage and linear measurement to be used for: A. more precise fertilizer calculation rate B. chemical calculation rate C. required info for fumigation documentation e.g. exact location of the area (coordinates) 3. Better yield estimation
N accumulation (plant + fruit) lb/ac 8 7 6 5 4 3 2 1 zucchini squash - N-plant accumulation 1 2 3 4 5 6 7 8 9 days after sowing
Daily N uptake rate (lb/ac/day) 2.5 zucchini squash - dialy N uptake 2 1.5 1.5 1 2 3 4 5 6 7 8 9 Days after sowing
Sweet corn marketable yield (lb/ac) 2 175 15 125 1 75 5 25 Y = -41.5 + 27.7x + 1.2x 2 -.36x 3 R 2 =.98 25 5 75 1 125 15 175 2 225 25 N-rate (lb/ac) 5 4 3 2 1 Sweet corn marketable yield (Crates/ac) 147 294 441 588 735 Ammonium nitrate (lb/ac)
EMERGENCE 6 lb/ac of NH 4 NO 3 28 DAE 6 lb/ac of NH 4 NO 3 Total applied: 18 lb/ac of N or 545 lb/ac of Ammonium Nitrate Fertilizer 42 DAE 6 lb/ac of NH 4 NO 3
Unaccounted 77% EMERGENCE 6 lb/ac of NH 4 NO 3 N-FUE:12% 28 DAE 6 lb/ac of NH 4 NO 3 Total applied: 18 lb/ac of N or 545 lb/ac of Ammonium Nitrate Fertilizer 42 DAE 6 lb/ac of NH 4 NO 3 Ear 7% Stover 5% Soil 9% Weeds 2%
Unaccounted 77% Unaccounted 6% EMERGENCE 6 lb/ac of NH 4 NO 3 28 DAE 6 lb/ac of NH 4 NO 3 N-FUE:12% 3% Total applied: 18 lb/ac of N or 545 lb/ac of Ammonium Nitrate Fertilizer 42 DAE 6 lb/ac of NH 4 NO 3 Ear 7% Ear 16% Stover 5% Soil 9% Stover 14% Weeds 2% Soil 8% Weeds 2%
Unaccounted 77% Unaccounted 6% Unaccounted 51% EMERGENCE 6 lb/ac of NH 4 NO 3 28 DAE 6 lb/ac of NH 4 NO 3 Total applied: 18 lb/ac of N or 545 lb/ac of Ammonium Nitrate Fertilizer 42 DAE 6 lb/ac of NH 4 NO 3 N-FUE:12% 3% 39% Ear 7% Stover 5% Soil 9% Weeds 2% Ear 16% Stover 14% Soil 8% Weeds 2% Ear 28% Stover 11% Soil 5% Weeds 5%
Potato production Current Practices 211/12 Placement Broadcast / Banding Timing 2-3 Seasonal Applications + Preplant Rate variable 2-3 lb/ac Source soluble fertilizer Irrigation method seepage
Treatments 3 common application timing 1. Pre-plant 2. Emergence 3. Tuber initiation Cultivated under seepage irrigation
Treatments kg ha -1 Trt. No. Total N pre-plant Emergence Sidedress 1 112 56 56 2 168 56 112 3 168 56 56 56 4 224 56 56 112 5 224 56 112 56 6 28 56 112 112 7 28 56 168 56 8 336 56 168 112 Increasing Total N single N-Rate 4 N-Rates 2 N-Rates
Weather 4 Planting Full Flower Harv PPN EMN SDN Temperature (ºC) 4 3 2 1-1 -2 21 211 212 Planting PPN EMN SDN Full Flower Harvest Temperature (ºC) 4 3 2 1-1 -2 Planting Full Flower Harvest PPN EMN SDN 5 1 GDD Dec Jan Feb Mar Apr May Date Temperature (ºC) 25 2 15 1 Rainfall (cm) -2 Temperature (ºC) 4 3 2 1-1 -2 Planting Full Flower Harvest PPN EMN SDN 1 GDD 11 GDD 12 GDD 33 cm 23 cm 15 cm 22 cm -1 5 cm 16 cm Dec Jan Feb Mar Apr May Jun Date 25 2 15 1 5 Rainfall (cm) 33 cm 23 cm 3 2 1 Rainfall (cm) Jan Jan Feb Mar Mar Apr Apr May M Date Date Crop Season precipitation 56 mm 37 mm 21 mm T avg (ºC) Rain cm 25 2 15 1 5 T avg (ºC) Rain cm
Soil Nitrogen Soil nitrogen (NO 3 +NH 4 ), mg kg -1 of soil 1 8 6 4 2 F * Main effect: Response to Emergence N-Rates 21 211 212 Soil nitrogen (NO 3 +NH 4 ), mg kg -1 of soil -6-4 -2 2 4 6 8 1 12 1 33 cm 15 cm F * 8 6 F * F * 4 2 F * 16-6 -4-2 2 4 6 8 1 12 Days after/before planting 2 F * 5 cm 4 F * 6 8 1 12 14 Rainfall (cm) F * F * 16-6 -4-2 2 4 6 8 1 12 2 4 6 8 1 12 14 Rainfall (cm) F * kg ha -1 56 kg ha -1 112 kg ha -1 168 kg ha -1 Rain cm
Soil Nitrogen Main effect: Response to Sidedress N-Rates 21 211 212 1 Soil nitrogen (NO 3 +NH 4 ), mg kg -1 of soil 8 6 4 2 2 4 6 8 1 12 14 Rainfall (cm) -6-4 -2 2 4 6 8 1 12 16-6 -4-2 2 4 6 8 1 12-6 -4-2 2 4 6 8 1 12 Days after/before planting F * 56 kg ha -1 112 kg ha -1 Rain cm
Atlantic - Plant Biomass Main effect: Response to Emergence N-Rates 21 211 212 Dry Biomass (Aboveground + Tubers) kg/ha 1 8 6 4 2 kg/ha 56 kg/ha 112 kg/ha 168 kg/ha a b a ab b b 2 4 6 8 1 12 2 4 6 8 1 Days after planting a ab bc c ns ns ns 2 4 6 8 1
Total and Marketable Yield 5 Main effect: Response to Emergence N-Rates 21 211 212 Yield Mg/ha 4 3 2 B ns AB AB A ns ns ns ns 1 56 112 168 56 112 168 56 112 168 Emergence N-rate (kg/ha) Total Yield Marketable Yield
Fresh Potato Yield (cwt/acre) 4 35 3 25 2 15 1 5 ns ns 5 1 Nitrogen (lb/ac)
No differences in potato yield, or biomass accumulation were observed due to emergence rates in low precipitation years; No difference in potato yield, or biomass accumulation were observed due to tuber initiation N-rates in any year at any location; Nitrogen rates above 2 lb/ac did not improve yield
Fertilizer Placement a success story of effective BMP practice Survey 211/12 67% growers broadcasted pre-plant fertilizer Placement Broadcast or Banding in Row Currently,5% of vegetable growers in the TCAA have adopted this technology in the last 3 years
92% 1% 17% 15% 8% 49.7% 1% 21% 21% 1% 44.7%.5% 1.8%.1%.8%.2% 1.4% 5.6%
Fixed irrigation Controlled irrigation TARGET WAS TO WET THE TOP 12-16 OF SOIL Source: Zotarelli et al 28. Scientia Horticulturae
Irrigation time 8am 1am 12pm 2pm 4pm Fixed Time Irrigation Soil Moisture Sensor N-rates of 75, 15 and 225 lb/ac weekly fertigation with calcium nitrate Source: Zotarelli et al 28. Scientia Horticulturae
Irrigation management affecting Nitrogen Use Efficiency 15 lbn/ac Controlled irrigation - FC 75 lbn/ac 2h fixed irrigation 15 lbn/ac 2h fixed irrigation 75 lbn/ac Controlled irrigation - FC Zotarelli et al. (28)
N accumulation (plant + fruit) lb/ac zucchini squash - N-plant accumulation 8 7 6 5 4 3 2 Contr Irr Fixed Irr 1 1 2 3 4 5 6 7 8 9 days after sowing
Daily N uptake rate (lb/ac/day) zucchini squash - dialy N uptake 2.5 2 1.5 1 Contr Irr Fixed Irr.5 1 2 3 4 5 6 7 8 9 Days after sowing
75 lbn/ac 15 lbn/ac 225 lbn/ac Average Zucchini marketable yield (lb/ac) Controlled irrigation up to 5 irrig. windows/day 22,389 25,422 26,135 24,649 A Fixed irrigation of 2h/day 15,525 19,535 19,891 18,316 B Average 19,955 B 22,478 A 23,13 A Means within columns/lines followed by the same lowercase letters are not significantly different (P.5) according to Duncan s multiple range test.
75 lbn/ac 15 lbn/ac 225 lbn/ac Average Zucchini marketable yield (lb/ac) Controlled irrigation up to 5 irrig. windows/day 22,389 25,422 26,135 24,649 A 1% Fixed irrigation of 2h/day 15,525 19,535 19,891 18,316 B Average 19,955 B 22,478 A 23,13 A 84% 1% 12% 74%
Effect of irrigation on solute displacement (injecting dye in fertigation lines) 24 hrs 3 days 7 days soil sensor based irrigation 16in fixed time irrigation schedule +38 in
Nitrogen management should be a combination of timing, placement, and rate; Roots are the target banding vs broadcast fertilizer N-rate is not the only factor that limits yield; Irrigation management plays an important role on yield and should be take into consideration in the fertilization management plan