Role of Soils in Water Quality. Mike Marshall Extension Associate Texas A&M-Institute of Renewable Natural Resources

Transcription

1 Role of Soils in Water Quality Mike Marshall Extension Associate Texas A&M-Institute of Renewable Natural Resources

2 Water Quality in Texas Water is a finite resource that can be impaired by pollution from sources across landscape. No one person, industry, or activity is to blame. Water pollution has lead to increased regulation in some watersheds in U.S. Producers should understand the issues and learn about ways to become part of the solution. Maintaining water quality isn t just about doing the right thing..clean water is vital to producers

3 Value of Clean Water Clean water is vital to producers in Texas: Irrigating crops Raising livestock Animal health Recreation

4 Value of Clean Water $100 billion of food each year Water is second only to oxygen as an essential nutrient to optimize: Animal gain Milk production Reproduction Excess levels of bacteria in water can lead to: Degraded ecosystems Limited agricultural production Increased regulation

5

6 Water Quality Water Quality = chemical, physical, and biological characteristics of water with respect to its suitability for a particular purpose or designated use. Chemical Physical Biological

7 Aquatic life Contact recreation Primary Secondary Public Water supply Fish consumption General uses

8 Key Chemical WQ Parameters A measure of the substances dissolved or in particulate form in H 2 O. 1. Nutrients mainly nitrogen and phosphorus. 2. Electrical Conductivity measure of the ability to conduct an electrical current. 3. ph measure of the acidity or alkalinity. 4. Dissolved Oxygen 5. Fecal Bacteria

9 What is the most common impairment in Texas?

10

11 WATER QUALITY IMPAIRMENTS IN TEXAS

12 Major Ag NPS Pollutants SEDIMENT FECAL BACTERIA Soil can carry all of these! NUTRIENTS HAZARDOUS/TOXIC CHEMICALS

13 Ag Activities That Can Degrade WQ Improper livestock manure and wastewater management Poor grazing management Improper fertilizer and pesticide management Removal of riparian vegetation Over-irrigation

14 Agricultural BMPs FUNCTION TO: Control surface runoff Minimize use of potential pollutants Ensure sound pest and nutrient management Optimize production RESULT IN: Improved water quality Increased efficiency and profits Increased property values Benefit to local community

15 Good Land Stewardship What we re really doing here is trying to create healthy upland watersheds through sound stewardship practices.

16 Characteristics of a Healthy Upland Watershed A Healthy Watershed is a catchment, i.e., rainfall is captured on-site. It acts as a sponge storing water to later release. High infiltration rates due to good vegetation cover and soil organic matter/structure and depth. Water flowing from the uplands as runoff & subsurface flow to springs and aquifers is clean and is slowly released down slope.

17 Unhealthy Watersheds? Most streams and rivers in Texas have been adversely affected by past human activities resulting in: Increasingly damaging floods Lower base flows High sediment loads Reduced reservoir storage capacity Invasion of exotic species Loss of natural riparian habitats Degraded water quality

18 Healthy

19 At Risk

20 Unhealthy

21 Sources of Nutrients

22 Nutrient Pollution Contamination by excessive inputs of nutrients Causes eutrophication of surface waters Excess Nitrogen or Phosphorus algal growth Nutrient Pollution leads to: Population effects-algal blooms Community effects-species composition shifts Ecological effects-food web changes Biogeochemical effects-eutrophication and hypoxia Human Health effects-via drinking water issues

23 Eutrophication

24 eutrophication

25 Management Practices Nutrient Management: Soil testing to determine the appropriate kind and rate of fertilizer to apply at the proper time to meet crop needs. Integrated Pest Management: Selecting the appropriate kind of pesticide and applying it at the proper rate and time to reduce the amount that moves into the environment. Grazing Management: Proper stocking rate and grazing distribution to enhance forage utilization and reduce potential bacteria and nutrients in runoff.

26 Vegetative and Tillage Practices Conservation Tillage: Practice of Cover Crops: Grasses, legumes leaving crop reside on the soil surface to reduce erosion. or small grains grown for temporary soil protection and improvement. Contour Farming: Aligning all Filter/Buffer Strip: Strips of grasses or farm tillage, planting and harvesting to the contour of the land to reduce erosion and runoff. other vegetation along streams or drainage areas to trap sediment, filter nutrients, and promote infiltration of water.

27 Structural Practices Sediment Control Basin: Trap sediment, control water flow within a drainage area, store runoff water, and increase infiltration. Grassed Waterway: Natural drainages that are shaped and planted to sod-forming grasses to help control runoff water from agricultural fields. Terrace: Soil embankments constructed on the contour of the land to control runoff and soil erosion.

28 Best Management Practices Nutrient Management Pest Management Vegetation Management Grazing Management Riparian Management The 5 Principles of Soil Health!

29

30

31 General BMPs for pesticide and herbicide use Read and follow directions Apply directly to plant Avoid applying during rainy or windy conditions Use extra caution when applying in areas where they can be washed into waterways Store in a covered area Dispose of leaking containers

32 Match the appropriate stocking rate to the grazing management unit. Implement grazing systems that allow for biological control of weed species. Adopt prescribed burning programs. Follow directions on pesticide labels.

33

34

35 Take Half Leave Half

36 Reduced water conservation.

37 Grazing Management

38 Rangeland health is directly related to the amount of forage ungrazed rather than the amount eaten.

39 Grazing Management Involves a Number of Decisions: Kind of animals Number of animals Grazing system

40 Kinds of Animals Cattle Sheep Goats Horses Exotics Wildlife

41 Number of Animals Landowner objectives Forage Weather Terrain Grazeable acres Water distribution

42 Grazing Systems High intensity low frequency Short duration Merrill Switchback Rotational Decision rotation Continuous

43

44

45

46 Proper Management Decisions With proper range management: you keep more water on your place grow more forage the water that does leave will be high quality

47 Proper Management Decisions With proper range management: you keep more water on your place grow more forage the water that does leave will be high quality

48

49 Riparian management Riparian areas are an important last line of defense for streams Vegetation acts as a filter Vegetation provides stream bank stabilization

50 Riparian management It s important not to overgraze riparian areas Fully exclude animals Partial exclusion Alternative watering sources Herbicide and pesticide use near streams In Texas, individuals or organizations may need to obtain a Texas Pollutant Discharge Elimination System (TPDES) general permit from the Texas Commission on Environmental Quality (TCEQ) before using pesticides in areas where the spray may leave a residue in a water body.

51 Pesticide use near streams The following would be authorized under Pesticide General Permit: Mosquito and other insect pests Vegetation and algae Animal pests Area wide pest (e.g. aerial) Forest canopy pests

52 Managing for runoff: Filter Strips Buffer strip Rainfall High evaporation and erosion Runoff velocity reduced Hillslope Water and dissolved nutrients taken up by riparian plants

53 Note the effectiveness of a vegetative filter strip in trapping sediment that would have wound up in the creek or reservoir. Nutrients, pesticides and bacteria were also trapped. Note denuded stream banks, sand depositions in creek, and algal bloom.

54 Effectiveness of filter strips in reducing fecal coliform levels under varying conditions. Fecal Coliform Reduction Slope Buffer Length Runoff Source 43% - 74% 9% 9m Poultry litter on no-till cropland >99% 4% 1-25m Manure on pastureland Reference Coyne et al Sullivan et al. 2007

55 Minimum width for vegetative filter strips. Source: Standards and Specifications No. 393, USDA-NRCS Field Office Technical Guide, Slope Minimum width of buffer strip

56

57 The Five Principles 1. Armor the soil 2. Minimize disturbance 3. Plant diversity (4 crop types) 4. Keep a living root year round 5. Livestock integration

58 Benefits of Healthy Soils Healthy soils hold more water and lose less water to runoff and evaporation Healthy soils reduce production costs and improve profits Healthy soils protect natural resources on & off the farm Healthy soils reduce nutrient loading and sediment runoff, increase efficiencies, and sustain wildlife habitats The nation that destroys its soils destroys itself --FDR

59 Implementing Ag BMPs Most farms/ranches need a combination of BMPs Some practices require engineering designs Some practices are expensive to implement Technical and financial assistance is available!

60

61

62 District Water Technician Funded by 319 grant through TSSWCB Provide technical assistance to agricultural producers for the development of Water Quality Management Plans (WQMPs) and implementation of Best Management Practices (BMPs)Stationed out of Gatesville Boone Herring Started in November 2014 Stationed out of Gatesville Work area is the entire watershed

63 Healthy Soils and Water Quality

64 Mike Marshall Leon River Watershed Coordinator office # ; cell # Leon.Watershed@gmail.com Website: leonriver.tamu.edu