Acid Soil Infertility Soil(lution)= Liming +Nutrient+Organic Matters Paul Reed Hepperly, PhD Fulbright Scholar/Rachel Carson Scientist

Rodale Farming Systems Trial Started in 1981 Eight Replicates Large Field Plots Input Agriculture compared to Biologically Based Side by Side

Transformation of Soil through Biologically Based Management Conventional Inputs Biological Based Management The Rodale Institute Farming Systems Trial shows that biological management including cover crops adds to soil color and texture.

Why should we Care? One third World Soil is acid or is prone to acidity One third is prone to excess salinity Acidity and salinity are key causes of infertility and poor agronomic and horticultural performance pH adjustment and Organic matter improvement work together To alleviate both excess Acidity and Alkalinity

Weathered Acid Soils Problematic on National and World Lands

Red Acid Soils Common In Older Soils from Humid Areas

Lime Eliminate Aluminum and Manganese Toxicities Provide Calcium, Magnesium and Micronutrient Increase Phosphorus, Molybdenum and Boron availability Better forage and grain production and quality Increase biological nitrogen fixation Increase microbial activity probiosis Improve soil structure

Australian Acidified Areas

Liming + Sub soiling = Synergy Coventry, E. 1985. Acid soils in Australia. Ruthergen Res. Inst., Victoria.

Glenelg Hopkins acidified catchment areas Glenelg Hopkins Soil Health Strategy 2009-2013

Descriptive Scale of Acidity Less than 3.5 Ultra Acid 3.6 to 4.5 Extremely Acid 4.6 to 5.0 Very Strong 5.1 to 5.5 Strongly Acid 5.6 to 6.0 Moderately Acid 6.1 to 6.5 Slightly Acid 6.6 to 7.3 Neutral 7.4 to 7.8 Slightly Alkaline 7.9 to 8.4 Moderately Alkaline 8.5 to 9.0 Strongly Alkaline

Acidity and Alkalinity Governs biological capacity Influences decay and synthesis of soil organic matter Integral to soil tilth or structure of fertility Gives exchange capacity for nutrients Removes toxicities

Most Crops are favored by near neutral pH of 5.5 to 7.0

Soil pH/Organic Matter Optimize Nutrient Availability

Nutrient Efficiency Influenced by pH

Root Extension shows Acid/Aluminum Toxicity

Acidic/Aluminum toxicity restricts root growth, plant growth and crop yield Dense root growth High yield Aluminium toxicity in acidic soils inhibits root growth Reduced yield Low yield

Mn Toxicity Mg Deficiency Acid Soil Infertility Toxicity and Deficiency Mn Toxicity Mg Deficiency

Sources Excess Acidity Ammoniated fertilizer Harvest Rainfall in excess Acid rainfall from emissions Irrigation water quality

Agricultural practices can increase soil acidification

Optimum pH Depends on Crop Species and Soil type Generally from 5.5 to 7.0 Liming under acid conditions Sulfuring for alkaline environments

Liming counteracts soil acidity

Lime Cost Effective Remedy Optimizes Soil Productive Capacity

Bag and Bulk Solutions are Available

Lime Factors Limestone sources different Magnesium can be important Fineness determines reactivity Lime needs spreading and incorporation

Limestone from different quarries vary considerably. When there is a need to correct Magnesium deficiency soil test of less than 100 Mg. Use dolomitic limestone for correcting the acidity of the acid soil.

Living Capacity of Soil Nutrient Cycles are geological, chemical and biological in nature Microbes are critical to soil’s capacity for providing nutrients and preventing toxicity Living soil from organic materials provides habitat, feeding and protection for nature’s labor force

Earthworms

SOIL BIOLOGY SUPPORTS HEALTHY PLANT GROWTH Cycles and retains nutrients Makes nutrient available to plants Builds soil organic carbon Builds soil structure Increases water infiltration and retention Promotes plant root systems Suppression of disease causing organisms Reduce soil acidity and break down toxins

The rhizosphere

What’s happening in the rhizosphere? Plants secrete "exudates" from the roots feeding bacteria and fungi Fungi extend hyphae threads through the soil, finding nutrients like phosphorus and carrying them back to the root Protozoa and nematodes eat the bacteria and fungi excrete nutrients feeding the plant The whole process is controlled by the plant

Organic Matter and Acidity determine Soil Fertility through Exchange Capacity Effects Helling et al. 1964. 60 Wisconsin soil tests SOM and Clay fractions separated

Optimizing Biological Nitrogen Fixation

Liming needed for Biological N Fixation

Mycorrhizal fungi Expand Root System Availability of Water, Phosphate, Zn and Cu

Overfeeding Kills Symbiosis

Formation and Persistence of Soil Particles based on Fungi

The Importance of putting Black Back

Biology holds the Chemistry Together

Biological Tillage and Amendment

Virtuous Cycle Microbes and earth worms promote humic material Humic material promotes chelation and absorption Microbes release nutrients, chemicals and hormone stimulants to promote plant health Stimulated plants are the source of new generations of organic materials, earth worms and microbial populations

A Virtuous Cycle When Life Begets Life Fertile Soil is the Dividend Photosynthesis produces plant food Plant food feeds fungal soil web Soil web feeds the soil and bines it together so it is not lost Clay is bound to organic matter through cationic mortar Calcium Persistent dark fertile soil yields Provision for plant nutrition Holds and supplies scarce water and nutrients Protects plants in stress environments Protects the Environment Improves economy and energy efficiency Tisdale and Oades how soil binds/holds 1981

Lime, Residue, Amendment work with biology to improve Soil Plant Residue Manure Compost Lime Earthworms Castings Soil Aggregation Increased Porosity Drainage and Aeration Root Exudate Soil Aggregation Improved Structure Lower Bulk Density

Improved Soil Road Map Test the soil completely Get the Acidity (pH) right Optimize Soil Organic Matter (SOM) Establish a SOM goal Create SOM tool box Devise SOM strategy Test, re-test, monitor and adapt methods Use Foliar Analysis to complement soil tests Look for positive biological changes from habitat development Test the soil completely Adjust the pH with lime or sulfur Adjust Macro and Micro nutrient deficiency Remove physical plow pans Eliminate mineral pesticide toxicity

Thank You for your kind Attention Any Questions? Comments?