Advances in soils Increasing Human sustainability through applied knowledge and technology - PowerPoint Presentation

1. Advances in soilsIncreasing Human sustainability through applied knowledge and technology

2. Jim AkinBS in Agriculture, SFASU, 1978MS in Soil Science, Texas A&M, 2001Emphasis: Environmental Soil Science23 years of research and practice in soil science

3. DisclaimerThe views expressed in this presentation are my own and do not represent the views of any company or governmental agency.This presentation is given in my personal capacity based on the totality of my training and experience.

4. Ultimate goal of agricultureProduction of enough food and fiber to feed and clothe humanity

5. The ChallengePopulation growthIncreasing but at a decreasing rateYield must increase as population increasesNorman BorlaugWheat breeding to double amount of grain per stalkSaved Third World from starvationNobel Laureate

6. Traditional Research PhilosophyLimit variables to as few as possible and preferably only oneIdentify correlationsExploit the correlations that increase yieldSets all other variables and conditions as constantsIf adverse results are noted in another area as a result, that becomes future research

7. Example of Traditional PhilosophyBreeding wheat to significantly increase yieldNo other factors considered in initial researchStalks were noted as too weak to hold the grain (broken stalks prior to harvest)Additional breeding done to increase strength of stalks to prevent lodging or broken stalks

8. Historical advances in Soil scienceMesopotamia or priorIf ground is broken, more seeds germinate, and yield increasesBronze Age EuropeLand continuously farmed loses yield over timeAddition of animal manure increases yield1920’s EuropeIG Farben synthesizes UreaChemical fertilizer affordable and available

9. Historical advances in Soil scienceModern day: Correlations are made between Nitrogen, Phosphorus, Potassium relative to plant growth Crops tested for their response to additions of fertilizerSoil tests for N, P, and K correlated to yield Optimum additions for soil conditions, specific crop and yield goals established based on soil testing

10. Emerging philosophyAn Holistic Approach (Soil Health/Sustainability)Considers additional factors beyond yieldEffects of fertilization of soil biotaEffects of plowing on available water, water holding capacityEffects of management practices on soil organic carbon and its relationship to soil biota, structure, water regime, nutrient fate and transport, erosionAs it is new, it is incompleteNo correlations to yieldNo economic correlations Expect changes, improvements, and refinements over the coming years

11. sustainabilityThe continual use of the soil resource without damage to the soil resource or other resourcesIn a larger sense it must do this while increasing yield to keep up with projected population growth AND be economically feasible on decreasing acres of landA very tall order indeed!

12. Large farm technologySub-meter soil mapping by aerial dronesNDVI (Normalized Difference Vegetative Index) on sub-meter scale1 inch accuracy GPS locations onboard harvesters to achieve high resolution yield maps Yield maps and soil maps correlated to provide high seeding rates in high yield areas, low seeding rates in low yield areasComputer controlled additions of water and nutrients to plants based on soil water availability in real time, plant growth stage, etc.

13. Large farm ResultsWaste not, want not – EfficiencyWater and Fertility = Money spent that could be used to support the familyUse of excess water is eliminated as much as practicableMinimizes the nutrients added to the fieldsField soil tests are often showing nutrients being “mined” (lower nutrient levels)Limits nutrients in runoffUse of seed drills reduces sediment load in streams, limits losses in soil structure

14. Soil Health MethodologyEstablish cover cropsUse rotational flash grazing of cover crops Seeding using no till methodsAllow harvested plants to stand until cover crop is established

15. Establishment of cover cropsCover crop shades ground, significantly reduces soil temperatures, reduces evaporationUse of deep rooted cover cropsAssists in destruction of historic plow pans Provides channels for water to access soil at greater depthsEspecially important given the 7 to 10 year drought cycleSevere droughts occur about every 50 years2 years in 12 will be “normal”Conservation of water at greater depths provides a reserve of water for crops in dry years

16. Use of seed drillsMinimal disturbance of soilExisting structure of soil preservedLosses of organic carbon added to soil by cover crop and standing stubble are minimizedMinimization of organic carbon losses allows net increase in organic carbon which promotes improved structure, increases in CEC, and biota (bacteria, beneficial fungi, worms (earthworms and nematodes)

17. Flash grazingReduces use of diesel fuel to lower the cover crop in advance of seedingConverts plant material into a more readily available form of fertilizerProvides a secondary operation and business for the farmTrampling of cover begins its degradation into organic matter while retaining its protection of the soil against rain, wind, and heat

18. Retention of plant stubblePlant stubble (stems) are retained primarily to reduce consumption of fuel and compaction of the soilRetention of stubble leaves roots in the groundA major pathway that water follows into the soil is by flowing down the stems and roots

19. Water, micropores, and MacroporesPeds have microporesVery small pores having capillary propertiesThese must be satiated before water moves by gravity through the soilMacropores are larger pores that do not have capillary propertiesIncludes root channels, the spaces between peds

20. StructureCrumbSubangular blockyAngular blockyPlatyMassiveEasiest for water to pass through; greatest macropore spaceMost difficult for water to pass through; fewest macropores

21. climateOne of the 3 active soil forming factorsClimate changesCyclicCan be extremeModels are most generally over simplified and not able to be used to “predict” known past events.All models are based on statisticsAll models contain errorWe cannot mitigate climate change but we can mitigate the effects of climate change

22. Cautions relative to climate modelsPeer reviewed papers are the best representation of the model(s)Someone with a degree in Journalism is likely not a good interpretive sourceAlways carefully read the materials and methods Keep lots of coffee available while doing this to prevent head and neck injuryAlways identify the assumptions being made and determine if they are valid in the “real world”Consider information from outside the climate community that have a bearing on the subject (Solar/Earth interactions, Geology)

23. Climate CyclesSevere droughts lasting 7 – 10 years recur on an approximate 50 year cycleTropical cyclones generally end the droughts and usher in several really wet yearsOnly 2 of 12 years is “normal”Houston floods…duh!!!Ice Age coming: All deep ocean currents moved to their ice age positions before the year 2000

24. Take home messagesAll science, even soil science grows and changesAccepted science is dangerous, if you disagree. Ask Galileo about his stand on the Copernican doctrineChallenge students to practice the triviumGrammar or rote memoryLogic – the use of good rational thoughtRhetoric – the expression of logical thought unemotionally and to express disagreements without being disagreeable

25. Take home messagesSustainability is a laudable goal, but it will take time, effort, and treasure to achieve it without devolving into a hunter-gatherer societySoil health, as it currently exists, is not successful on large scale operationsSoil health has been shown to be very effective at improving the soil condition, its water regime, sediment loads in runoff water, and improving nutrient availability on smaller farms where family provides the labor

26. Classroom ActivitiesPhysics – Demonstrate Stokes Law: Need a 1 L cylinder, Sodium Hexametaphosphate, soil, hydrometerIn a liquid larger suspended particles hit the bottom firstFinest particles (clays) don’t fall out as they are colloidsChemistry pH of soil; 2 parts water, 1 part soil, shake and measure with pH meterCaCO3 (limestone) buffers soil solution to about 8.3Electrical conductivity: make a saturated slurry of soil, filter it with a vacuum pump, and use an Ec meter to measure its conductivity (inverse of resistance); correlates to the amount of salts in the soil

27. Classroom ActivitiesBiologyCompare a “healthy” soil to one that has been annually disturbedNote the number of earthworms in eachFrom a mixture of soil and earth take samples and place on Agar plates to identify the types of colonies that growClimatologyExplore the weather data for your area for rainfalls, frequency of hurricanes, droughts, and then compare to sun spot activity

28. Last slideBooks: Nature and Properties of Soils, Brady, Niles C. and Weil, Ray R. Publisher: Prentice Hall.Weatherman’s Guide to the Sun, Davidson, Ben. ISBN-13: 978-1483588988 ISBN-10: 148358898XSoil is a dynamic natural body having properties due to the combined effects of climate and biotic activity, as modified by topography, acting on parent material over time.Dirt is a four letter word. Dirt is on the kitchen floor. We deal with soil!

29. ThanksAll y’all for listeningDr. Murray H. Milford, Professor Emeritus, Texas A&M University and according to his students, a consultant to God on the creation of soilsDr. Joe B. Dixon, Professor Emeritus, Texas A&M University; a consummate professional, fine teacher, and expert on clay mineralogyDr. Sam Feagley, Professor Emeritus, Texas A&M University for guidance in nutrient management