Soil Health Principles- Understanding the Soil from Tes8ng to Field/ Farm Management

Transcription

1 Soil Health Principles- Understanding the Soil from Tes8ng to Field/ Farm Management Joseph Amsili Technician- Soil Health Lab Bob Schindelbeck Extension Associate

2 Soil Health Philosophy: A healthy soil is balanced and therefore provides for crop resiliency to stress. If we can 1) measure soil indicators to iden8fy constraints, then we can 2) op8mize our soil management. Physical SOIL HEALTH Biological Chemical Caveat: Increased soil health Increased profitability Iden:fy soil limita:ons Create opportuni:es for synergis:c management

3 Soil Sampling Considera8ons Iden8fy the ques8on. Is your purpose to: Assess general needs? Yield drag, rapid onset of crop stress Iden:fy constraints and manage them? Why is yield reduced in zone B versus zone A? Compare treatments? Tillage, crop variety, cover crop Get a baseline for monitoring? A Sample area 1 Use different approaches depending on ques:on being asked Uneven field- 2 samples B

4 soil penetrometer

5 A B Soil Management Planning begins with grower ques8ons.. Caveat: Increased soil health Increased profitability Iden:fy soil limita:ons Create opportuni:es for synergis:c management 1 4 Laboratory Analyses 2 SH Report Soil management plan 3 Table linking soil indicators to soil management

6 Soil Health => Understanding soil processes involved in op#mal soil func#oning Structural stability and resistance to erosion (water infiltration) Physical Chemical Nutrient storage and release Soil reaction (ph) Soil water storage and movement Aeration Physical root proliferation and organism movement Biological Roots/ debris feed microbial community OM decomposition N mineralization Pest suppression soil life

7 hzp://soilhealth.cals.cornell.edu

8 Model of Soil Structural Breakdown infiltration runoff a) aggregated soil b) soil crusts after aggregates break down Note that as a soil becomes compacted, the LARGEST pores are the most affected

9 Soil Structure Affects Many Processes- soil surface Large pores allow for rapid transfer of water and gases into and out of the soil. Surface crusts and surface seals forms when large pores become filled with small soil par8cles (compac8on). Dense surface restricts water entry increased runoff Reduced water intake less water storage, air exchange Drier soil is harder reduced root penetra:on Hard soil clods represent volumes of soil where water and nutrients cannot be accessed

10 Soil aggregate structure across different size scales Brady and Weil, The Nature and Proper8es of Soil, 2002

11 Collamer silt loam soil (Home soil) Large field with TWO contras8ng management histories Intensive cropping Moldboard plow Small grains Long- term SOD Grassed pasture

12 Wet Aggregate Stability Test infiltra8on, crus8ng, water storage, aera8on 16% stability Intensive cul8va8on 55% stability Plowed sod PLOW TILL Collamer silt loam

13 FIELD soil aggregate stability demonstra8on Collamer silt loam Iden8cal soil site 1 of rain applied A Runoff collected B Intensive Cul8va8on A Long- term SOD B A B Soil surface examined

14 Intensively cul8vated soil develops poor surface aggregate structure Large pores lost, water cannot enter quickly to be stored for later use by crop Soil dries HARD and roots cannot access water, nutrients

15 Soil Compac8on affects water intake and transmission, roo8ng, nutrient uptake surface crusting ok Tractors Field equipment Trucks 0-6 inch depth plow layer compaction (upper root zone) ok inch - depth Harvest - and - heavy - equipment - - Subsoil compaction

16 Add organic matter Increased biological activity & diversity Reduced soil-borne diseases, parasitic nematodes Pore structure improved Improved tilth and water storage Aggregation increased Humus and other growth promoting substances Decomposition Nutrients released Harmful substances detoxified HEALTHY PLANTS Adding organic matter affects soil processes Modified from Oshins, 1999

17 We recognize that soil biological processes are controlled by: the mix of active FUEL (living or fresh) and passive STABLE (very dead humus) materials the diversity of soil organisms and their activities The interaction of these components is controlled by moisture, temperature, mixing, inorganic nutrients (Nitrogen), carbon source, etc. We can affect these processes with our crop and soil management

18 All OM is Not Created Equal Fresh Material (crop residues, green manure) Green and animal manures provide both nutrients and energy- rich food for microorganisms living in the soil Breakdown products help to glue soil par:cles together to increase soil :lth Favors rapid bacterial popula8on increases which can lead to N immobiliza:on Composts (biosolids, biochar, municipal stockpiles) Bacteria/ bacterial by- products become a food source for next- level organisms More stable composts can lighten heavier soils and add water and nutrient storage capacity to coarser soils

19 There are three general types of organic mazer in soils: Living - soil organisms and plant roots Dead - recently dead soil organisms and crop residues provide the food (energy and nutrients) for soil organisms to live and func:on. Also called ac8ve or par8culate organic mazer Very Dead - well decomposed organic materials, also called humus. Humus contains very high amounts of nega:ve charge and has high water- holding capacity All three types of soil organic matter play important roles in helping produce high yields of healthy crops

20 Fungi colonize the plant rhizosphere Source: E.V. Johnson, University of Hawaii at Mãnoa Living (and dying) soil organisms break down organic debris release nutrients create/ release soil glues suppress pathogens provide food for other organisms

21 Root sec8on Root 8p Root hair Plant cells From: Life in the Soil Mokochi Okada Associa:on in Japan Plants contribute nutrients and cellular material to the rhizosphere (es:mates up to 20-40% of total plant energy) Root hairs are short- lived single cells expanding behind the root 8p can become infected by bacteria (Rhizobia nodula8on) can entwine with fungal mycelium to increase overall surface area for increased capture of nutrients and water die and burst and release compounds which modify the rhizoshere to facilitate new root hair explora8on

22 From: Life in the Soil Mokochi Okada Associa:on in Japan

23 Available or recently dead organic material Organic maber inputs provide the food (energy and nutrients) for soil organisms to live and func:on. Also called ac:ve or par:culate or rapid cycling organic maber.

24 Available or Ac<ve Carbon (C) (Weil et al., 2003) Permanganate oxidizable Carbon test: Frac8on of C and nutrients in total OM that is actually available for soil food web and plants The deep purple permanganate indicator solu:on chemically burns the easily oxidizable carbon. The purple solu:on is reduced and becomes lighter based on the amount of carbon that gets oxidized in the 10 minute test. Colorimeter measures color change against standard curve

25 The Effect of a Cereal Rye Cover Crop on Soil Health Soil or Crop Measurement Cover Crop Treatment No Cereal Rye Cereal Rye Soybean yield, kg/ha Active C mg/kg C respired in 2 days, mg/kg Mineralizable N mg/kg Stable aggregates % Overall Means of 6 sites in MD and PA with 2 to 6 years of rye cover crop in corn soybean rotation. This Table Represents Ray Weil s work

26 Cornell Soil Health Assessment Page 1 of 10 Assesses soil chemical, physical and biological func8oning Process oriented Measures indicators Uses scoring func8ons (see page 2) Overall score Targeted management sugges8ons (see pages 9-10) Modified Morgan soil extractant nutrient levels

27 Cornell Soil Health Assessment Page 2 of 10 Scoring Func8on strategy

28 Cornell Soil Health Assessment Pages 3-8 of 10 Defines the processes each indicator represents Rela8onship to soil management Interpreta8on of each test score Management priori8za8on Aggregate Stability is a measure of how well soil aggregates or crumbs hold together under rainfall or other rapid wegng stresses. Measured by the frac:on of dried aggregates that disintegrate under a controlled, simulated rainfall event similar in energy delivery to a hard spring rain, the value is presented as a percent, and scored against a distribu:on observed in regional soils with similar textural characteris:cs. A physical characteris:c of soil, Aggregate Stability is a good indicator of soil biological and physical health. Good aggregate stability helps prevent crus:ng, runoff, and erosion, and facilitates aera:on, infiltra:on, and water storage, along with improving seed germina:on and root and microbial health. Aggregate stability is influenced by microbial ac:vity, as aggregates are largely held together by microbial colonies and exudates, and is impacted by management prac:ces, par:cularly :llage, cover cropping, and fresh organic maber addi:ons. Your measured Aggregate Stability value is 33.3%, corresponding with a score of 16. This score is in the Low range, rela:ve to regional soils with similar texture. Aggregate Stability should be given a high priority in management decisions based on this assessment, as it is likely to be an important constraint to proper soil func8oning and sustainability of management at this 8me. Please refer to the management sugges:ons table at the end of this document.

29 Cornell Soil Health Assessment Pages 9-10 Available Water Capacity Low Surface Hardness High Subsurface High Hardness High Aggregate Stability Low Constrained and Subop8mal indicators are flagged in the Report management sugges8ons table Organic MaZer Low Soil Protein Index Low Root Pathogen Pressure High Respira8on Low Ac8ve Carbon Low

30 Soil Health Management Planning begins with grower ques8ons.. L Where is my soil strong or weak? What can I do to address these issues? How can I put it all together to make a sound soil management plan? Can someone help me with this?

31 Principles for Interpre8ng and Using the Cornell Soil Health Assessment Report The Cornell Soil Health Test iden8fies soil func8onal constraints. The goal is to combine this informa8on with the Grower s needs, skills and available resources to develop a soil management strategy for addressing these constrained soil processes The Soil Health Management Toolbox 1. Crop Rota:on/ hybrid choice 2. Growing cover crops 3. Organic/ chemical amendments 4. Reducing or modifying Tillage

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33 reduced 8llage, cover cropping, perennial forage rota8on crop, manure/compost Soil health reduced 8llage, cover cropping reduced 8llage cover cropping Green manure cover crop years Strip 8llage Combining the various management prac8ces that promote soil health can have an addi8ve effect

34 SH Management Planning Process Overview Grower strengths Grower goals, soil sampling Evaluate results Define op8ons Refine op8ons Implement, refine

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36 SH Management Planning Process Overview 1. Determine farm background and management history Young, crea8ve organic grain and seed grower. Diverse equipment inventory. Suppor8ve local farming community. 2. Set goals and sample for soil health Grower wants to transi8on rented land to organic. Looking for useful cover crops/ rota8ons to address soil constraints in the transi8on. 3. For each management unit: iden8fy and explain constraints, priori8ze Field history- con8nuous corn. Erosion in swales. Hardpan at 10. Soil ph low, soil biological processes stunted. 4. Iden8fy feasible management op8ons Fresh green manure needed to soken soil surface and s8mulate soil biological ac8vity. Adjust ph with broiler manure. Subsoil loosening needed to address hard layer. 5. Create short and long term Soil Health Management Plan Rent ripper implement to loosen soil to 12 depth. Broadcast cocktail of red clover, 8mothy, trefoil. Broadcast broiler manure to raise ph, s8mulate soil biology and add potassium. Tine weeder to 2 to incorporate seed/ manure. 6. Implement, monitor, and adapt