Nutrient Use Efficiency vs. BMPs in Florida. G. David Liu Horticultural Sciences Department IFAS, University of Florida

Transcription

1 Nutrient Use Efficiency vs. BMPs in Florida G. David Liu Horticultural Sciences Department IFAS, University of Florida HOS4283C-Advanced Organic and Sustainable Crop Production PSF 5, Friday, March 19, 2014

2 Internship opportunities Working on snap bean/tomato If interested, please your CV to me at

3 Most soils in Florida are sandy in nature Hastings Live Oak Belle Glade Parrish

4 Sandy soils are water repellent Courtesy of P. Hallett

5 Problems associated with water repellent soils 1. Rapid leaching of fertilizers 2. Poor water and nutrient holding capacity 3. Uneven distribution of nutrients and water 4. High soil evaporation 5. Severe runoff 6. Soil erosion 7. Low productivity March 02, 2013

6 Challenges Environmental 1. The impairment of Florida s waters: 53% of river miles, 82% of lake acres; 32% of estuaries as of Air pollution such as PM 2.5 resulted from NH 3 volatilization Economic 1. Energy prices rise 2. Fertilizer prices escalate 3. Producers operate on very thin profit margins Resource Phosphate rock will be run out: 1. In 25 years in Florida 2. In 50 years over the world Liu et al Comparing Gibbs Energy Relationships for Ammonia Volatilizations from Agricultural Soils for Potato Production. American Journal of Environmental Science (in press)

7 Environmental Challenges

8 Florida has 52,000 river & stream miles 800 lakes 700 springs 4,500 sq. miles of estuaries Courtesy of T. Obreza

9 Vegetation shift caused by high P levels in water Vegetation shift in the Everglades Sawgrass Cattail

10 Economical Challenges

11 $/ton Bean price ($/100 lb) Prices of beans and selected fertilizers Urea TSP MOP Source: National Agricultural Statistics Service/USDA

12 Resource Depletion

13 Years remaining Years remaining to deplete phosphate 60 rock resources and peak P curve US Canada World Cordell et al., 2009 USGS, A new OPEC, an Organization of Phosphate Exporting Countries, may arise E. Epstein, 2005

14 Current Situation (NE Florida)

15 Live Oak HF1 HF2 HF3 HF4 HF5 HF6 HF7 HF8 HF9 HF10 HF11 HF12 HF13 HF14 HF15 HF16 HF17 HF18 HF19 HF20 HF21 HF22 HF23 HF24 HF25 HF26 HF27 HF28 HF29 HF30 HF31 HF32 P content (mg/kg) 700 P level in soil (Mehlich 3) IFAS recommendations: low, 25; high, 41 mg/kg

16 Soil test P and Ca Rates 1. P 2 O 5 : 120 (lbs/a) 2. Gypsum (32.6% CaO): 1000 to ,964 lb Ca/acre (2750 lb CaO/acre): 56-fold > the requirement. Ca3( PO4 ) 2( s) -calcium +calcium 3Ca 2 ( aq) 2PO 3 4 ( aq)

17 Calcium rate trial 0 lb/acre 500 lb/acre 1000 lb/acre 2000 lb/acre

18 Potato yield (lb/acre) Tuber yield and specific gravity Nonmarketable Marketable Gypsum rate (lb/acre) Specific gravity Gypsum rate Specific gravity

19 Crop Production vs. Water Pollution

20 Crop Production vs. Water Pollution Leaching Runoff Soil erosion These are all related to water and nutrient management

21 Seasonal Changes in P Concentration (mg/l) of Water in the Everglades Courtesy of Y.C. Li

22 What Is the Extent of the Problem in Florida? As of miles of rivers and streams 350,000 acres of lakes 900 square miles of estuaries were impaired by the nutrients nitrogen or phosphorus. As of ,587 miles of rivers and streams 919,000 acres of lakes 1,795 square miles of estuaries were impaired by the nutrients nitrogen or phosphorus.

23 Vegetation shift caused by high P levels in water Vegetation shift in the Everglades Sawgrass Cattail

24 Cleaning Florida s Impaired Water Bodies: How do we go from good intentions to actions on the ground?

25 DACS s definition of Best Management Practices Best management practice means a practice or combination of practices determined by the coordinating agencies, based on research, field-testing, and expert review, to be the most effective and practicable on-location means, including economic and technological considerations, for improving water quality in agricultural and urban discharges.

26 What s BMP? BMPs = Best Management Practices BMPs are specific cultural practices that aim at reducing the loads of specific compounds while increasing or maintaining economical yields. BMPs are tools to achieve the TMDLs

27 What s TMDL? TMDL = Total Maximum Daily Load A TMDL is a calculation of the maximum amount of a pollutant that a water body can receive from point and non-point sources, and still meet water quality standards for its intended use (fishing, swimming, drinking).

28 Ag BMP program examples Nursery Vegetable/ Agronomic Citrus Sod Golf course Courtesy of E. Simonne

29 UF/IFAS Research and Extension programs Soil testing laboratory BMP Regulatory Agencies (DACS, FDEP WMD) Ag suppliers (Fertilizer, irrigation., Pest control) Courtesy of E. Simonne

30 Functionalities of parties FDACS: responsible for producing a Florida BMP manual FDEP: responsible for confirming that BMPs actually work UF/IFAS: responsible for supplying most of the science behind BMPs Producers: responsible for implementation of BMPs

31 Notice of Intent to Implement BMPs

32 Nutrient Management Strategies 1. 4R nutrient stewardship 2. Schedule irrigation 3. Biochar/Surfactant application 4. Nutrient-balancing 5. Profit yield maximization 6. Controlled release fertilizer application 7. Soil ph management

33 4R Nutrient Stewardship International Plant Nutrition Institute

34 Nutrient Management Precision application Good housekeeping Courtesy of T. Obreza

35 Schedule Irrigation Irrigation scheduling Courtesy of T. Obreza

36 Irrigation scheduling based on Evapotranspiration (ET) Potato Growth Curve in Hastings, FL

37 Biochar Application What s biochar? Why biochar works? How do we apply biochar?

38 What s Biochar? Biochar, Agrichar, Biomass-Derived Black Carbon

39 Soil Improvement Biochar Soil Amendment (from IBI)

40 Surfactant Application What s surfactant? Why surfactant works? How do we apply surfactant?

41 What is a Surfactant? Surfactant is a surface-active agent also known as a wetting agent that, in a small quantity, distinctly affects the surface characteristic of a system. Chemical structure of a soap, sodium stearate

42 Why Surfactants Work?

43 Surfactant Effect on Canopy

44 Surfactant Effect on Tomato Yield

45 Nutrient Balancing

46 Liebig's Law of the Minimum Justus von Liebig, Liebig's barrel Water capacity is limited by the shortest stave. Potato yield is determined by the shortest stave.

47 Potato yield (Mg ha -1 ) p < 0.01 Relative P-use efficiency (%) N Balancing vs. P-Use Efficiency Potato Yield A Relative P-use efficiency A B B 0 Imbalanced Balanced 0 Imbalanced Balanced

48 Take-home Message (I) Water and nutrient management is one of the primary components for BMPs BMP is the key for cleaning Florida s impaired water bodies BMP can enhance the sustainability of crop production and environment

49 Take-home Message (II) Techniques for nutrient management: 1. 4R nutrient stewardship 2. Schedule Irrigation 3. Apply biochar/surfactant 4. Balance all of 17 essential nutrients 5. Use controlled release fertilizers 6. Manage soil ph appropriately

50 Guodong David Liu (352) E: