Soil Fertility under flooded conditions

Transcription

1 Soil Fertility under flooded conditions Dustin Harrell Louisiana Ag. Technology & Management Conference Feb 12, 1014, Marksville, LA

2 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

3 Rice Research Station fertility and Agronomy Project Dustin L. Harrell

4 Taken from The Chemistry of Submerged Soils Ponnamperuma, Advances in Agronomy, 1972

5 Figure 9.22

6 Acid soils: Fe and Al-P Permanent flood ph P availability Calcareous soils: Ca-P Permanent flood ph P availability slightly increased

7 Rice Research Station fertility and Agronomy Project

8 Yield (lb/a) a ab bcd cd 6000 d d Planting 120 Preflood 120 Mid-Tiller 120 Green ring % Heading Rice Research Station fertility and Agronomy Project

9 Yield (lb/a) LSD = 1643 CV = 12.7 A A A A A B P 2 O 5 Rate (lb/a) Rice Research Station fertility and Agronomy Project

10 Yield (lb/a) LSD = 2270 CV = 14 AB A A A BC C P 2 O 5 Rate (lb/a) Rice Research Station fertility and Agronomy Project

11 What is the best starter fertilizer for an alkaline (high ph) soil? DAP, MAP, or TSP-blend? Rice Research Station fertility and Agronomy Project

12 Rice Research Station fertility and Agronomy Project

13 Rice Research Station fertility and Agronomy Project

14 Sources Only use SO4-S fertilizers Elemental S (90%) Not imm. Available Must be oxidized Ammonium Sulfate ( ) 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 < * Medium High >16 none *Application of 100 pounds of ammonium sulfate will provide 21 lbs N and 24 lbs S.

15 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

16 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

17 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

18 Rice Research Station fertility and Agronomy Project

19 Quantify ammonia volatilization losses and associated yield loss of N sources and treated urea products Rice Research Station fertility and Agronomy Project

20 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

21 Cumulative N loss (% of total applied) 2013 Evaluation of Urea, Agrotain-urea, Agrotain Ultra-urea, Arborite AG-urea, Nutrisphere-urea, N-Zone MAXX-urea 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 Rice Research Station fertility and Agronomy Project Time (days after application)

22 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

23 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

24 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

25 Rice Research Station fertility and Agronomy Project

26 30 Volatilization NUE Yield Cumulative N loss (% of total applied) 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 Rice Research Station fertility and Agronomy Project Days (after application)

27 30 Cumulative N loss (% of total applied) 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 Rice Research Station fertility and Agronomy Project Days (after application)

28 The Right Way to Grow Rice Applying the Right Source at the Right Rate at the Right Time and in the Right Place

29 Questions Thank you James Leonards Jacob Fluitt Ron Regan