Soil Fertility under flooded conditions Dustin Harrell Louisiana Ag. Technology & Management Conference Feb 12, 1014, Marksville, LA
Flooded Soil Changes physical and chemical soil properties Anaerobic (no oxygen) Management of fertilizer nutrients changes Phosphorus (P) Sulfur (S) Nitrogen (N) The Right Way to Grow Rice
Rice Research Station fertility and Agronomy Project Dustin L. Harrell
Taken from The Chemistry of Submerged Soils Ponnamperuma, Advances in Agronomy, 1972
Figure 9.22
Acid soils: Fe and Al-P Permanent flood ph P availability Calcareous soils: Ca-P Permanent flood ph P availability slightly increased
Rice Research Station fertility and Agronomy Project
Yield (lb/a) 10000 9000 a ab 8000 7000 bcd cd 6000 d d 5000 4000 3000 2000 1000 0 0 120 Planting 120 Preflood 120 Mid-Tiller 120 Green ring 120 50% Heading Rice Research Station fertility and Agronomy Project
Yield (lb/a) 10000 9000 LSD = 1643 CV = 12.7 A A A A A 8000 7000 6000 B 5000 4000 0 30 60 90 120 150 P 2 O 5 Rate (lb/a) Rice Research Station fertility and Agronomy Project
Yield (lb/a) 14000 12000 LSD = 2270 CV = 14 AB A A A 10000 BC 8000 6000 C 4000 2000 0 0 30 60 90 120 150 P 2 O 5 Rate (lb/a) Rice Research Station fertility and Agronomy Project
What is the best starter fertilizer for an alkaline (high ph) soil? DAP, MAP, or TSP-blend? 18-46-0 Rice Research Station fertility and Agronomy Project
Rice Research Station fertility and Agronomy Project 11-53-0
Rice Research Station fertility and Agronomy Project
Sources Only use SO4-S fertilizers Elemental S (90%) Not imm. Available Must be oxidized Ammonium Sulfate (21-0-0-24) Rates Base on soil test Rice Research Station fertility and Agronomy Project Soil Test Soil test Fertilizer Level Results Recommendation --ppm-- lb S per acre Low <12 20-25* Medium 12-16 5-15 High >16 none *Application of 100 pounds of ammonium sulfate will provide 21 lbs N and 24 lbs S.
Plant avaliable Nitrogen forms NH 4 + Plant available Stable under flood Moves by diffusion Correct N source for rice (NH 4 + forming sources, urea) NO 3 - Plant available Not stable under flood Moves by diffusion and mass flow Incorrect N source for rice LSU Kellogg s Master Rice Grower Program
Nitrogen Rules of thumb 1. Only use NH 4 + or NH 4 + forming fertilizers 2. Apply first application on DRY soil and flood ASAP. Approximately 2/3 of seasonal need 3. Apply 2 nd application at midseason Remaining 1/3 of seasonal need
Nitrogen NH 3 (gas) oxidized water urea NH 4 + oxidized soil anaerobic soil (no O 2 ) urea NH 4 + LSU Kellogg s Master Rice Grower Program
Rice Research Station fertility and Agronomy Project
Quantify ammonia volatilization losses and associated yield loss of N sources and treated urea products Rice Research Station fertility and Agronomy Project
6 N sources Evaluated Agrotain Agrotain Ultra-urea Arborite AG-urea NZONE Max urea AgExplorer NZONE Max is a nitrogen management aid that increases nitrogen availability and uptake in addition to reducing nitrogen loss Ca-Heteropolysaccharides, Ca-Aminoethylpiperazine, and Alkylarylpolyoxyethylene glycols NutriSphere-N SFP Manages Nitrogen Volatilization and Nitrification Active Ingredient - Partial calcium salt of maleic-itaconic copolymer Rice Research Station fertility and Agronomy Project
Cumulative N loss (% of total applied) 2013 Evaluation of Urea, Agrotain-urea, Agrotain Ultra-urea, Arborite AG-urea, Nutrisphere-urea, N-Zone MAXX-urea 20 15 10 5 urea Agrotain Ultra-urea (3 qt/ton urea) Agrotain-urea (3 qt/ton urea) ArboriteAg-urea (3 qt/ton urea) Nutrisphere-urea (2 qt/ton urea) NZoneMax-urea (3 qt/ton urea) Flood Applied A A B B B UREA 0 0 2 4 6 8 10 12 14 16 Rice Research Station fertility and Agronomy Project Time (days after application)
Urease Inhibitor Products Containing NBPT did significantly reduce volatilization losses Agrotain and Agrotain Ultra Arborite AG N-Fixx Factor 3:1 blend Urea/AMS, Amidas, NZoneMaxx, and did not reduce ammonium volatilization as compared to untreated urea alone (1 year data). 3:1 blend Urea/AMS and Amidas are beneficial fertilizer sources when S is limiting (1 year data). Rice Research Station fertility and Agronomy Project
What happens when a field is drained and reflooded? N 2 N 2 O (gas) (gas) NH 3 (gas) oxidized water urea NH + 4 nitrification NO 2 - NO 3 - oxidized soil anaerobic soil (no O 2 ) urea NH 4 + N 2 (gas) N 2 O (gas) NO 3 - denitrification LSU Kellogg s Master Rice Grower Program
What happens when you apply urea on dry, moist and flooded soils? Will using NBPT product help reduce volatilization? Can I add a higher rate? (Agrotain, N-Fixx, Factor, Arborite AG) How much total N loss will I have? Volatilization + nitrification/denitrification losses Total Nitrogen Use Efficiency (NUE) Rice Research Station fertility and Agronomy Project
Rice Research Station fertility and Agronomy Project
30 Volatilization NUE Yield Cumulative N loss (% of total applied) 25 20 15 10 5 Urea (Dry) Urea (Moist) Urea (Flooded) Initial rate higher Dry: 26.5 A Moist: 21.8 ab Flooded: 18 a 59% a 18% cde 2% ef 9319 a 7369 b 4167 c 0 0 2 4 6 8 10 12 14 16 Rice Research Station fertility and Agronomy Project Days (after application)
30 Cumulative N loss (% of total applied) 25 20 15 10 5 No benefit Same as untreated urea NBPT-Urea (Dry-HR) NBPT-Urea (Moist-HR) NBPT-Urea (Flooded-HR) Volatilization Some benefit Flooded: 18.6 b Dry: 8 c Moist: 6.3 c NUE 2% f 48% bc 34% d Yield 4780 c 9059 a 8394 ab 0 0 2 4 6 8 10 12 14 16 Rice Research Station fertility and Agronomy Project Days (after application)
The Right Way to Grow Rice Applying the Right Source at the Right Rate at the Right Time and in the Right Place
Questions Thank you James Leonards Jacob Fluitt Ron Regan