Organic fertilization and microbial dynamics

INFLUENCE OF LONG TERM ORGANIC FERTILIZATION ON THE SOIL MICRO-BIAL COMMUNITY FUNCTIONAL STRUC-TURE AND ENZYME ACTIVITIES IN PADDY SOIL

WORKSHOP ON ASIAN NETWORK FOR SUSTAINABLE ORGANIC FARMING TECHNOLOGYJuly 1-4, 2012

FERNANDO LOPEZ HALL, BUREAU OF SOILS AND WATER MANAGEMENT DILIMAN, QUEZON CITY PHILIPPINES

Venecio U. Ultra, Jr. Ph.D.College of Natural Sciences Catholic University of DaeguGyeongsan City, Republic of KoreaEvelyn F. Javier,

MSc.Philippine Rice Research In-stitute, Munoz City, Nueva Ecija, Philippines

LONG TERM ORGANIC ERTIL-IZER USE IN A PADDY SOIL

2003-present

Philippine Rice Research InstituteMaligaya, Science City of Muñoz, Nueva

Ecija

Project Goal:

To establish scientific information and data as basis for the develop-ment of technology of an organic-based rice production system

Sustainability of rice grain yield Sustainability of soil productivity

e.g. physical, chemical and biologi-cal aspect

Dynamic of Insect pest profile Differences in Grain quality and seed

vigor Environmental effects e.g. GHG

emission

CHEMICAL

PHYSICAL

BIOLOGICAL

SOIL HEALTH

SOIL PRODUCTIVITY; FUNC-TIONALITY

Objective:

•Determine the status of soil microbial community struc-ture and enzyme activities as a reflections of the im-pacts of organic fertilization on the biological properties and processes in rice paddy soil.

Original/Existing treatments:•Solo fertilizers treatment1.Control2.Full NPK rate/ha3.Half NPK rate/ha4.Rice straw5.Rice straw with EMBI6.Commercial organic fertilizer7.Chicken manure8.Green manure (T. diversifolia)

Original/Existing treatments:•Solo fertilizers treatment•Combined fertilizer treatment1.RS with full NPK2.RS with half NPK3.RSEM with full NPK4.RSEM with half NPK5.COF with full NPK6.COF with half NPK7.WSF with full NPK8.WSF with half NPK

Treatments for this particular study:1.Control or unfertilized plots2.Inorganic NPK fertilizers3.Commercial organic fertilizer4.Chicken manure5.Rice straw

Experimental Lay-out and design: RCBD with 4 replications

Data gathered: •Soil Enzyme Activities

–Acid phosphatase–Alkaline phosphatase–Dehydrogenase–Arylsulfatase–Urease

•Microbial Activity–FDA (flourescein diacetate hy-

drolyses)–p-D glucosadase activity–AWCD of Biolog EcoPlate

Data gathered:

•Soil Microbial Functional Diversity –Shanon-Weaver index (richness and evenness of response)–Carbon Utilization Richness (number of posi-tive wells on the ecoplate)

•Soil microbial functional struc-ture–Principal Component Analyses (substrate uti-lization physiologic profile)

Biolog EcoPlate inoculated with Paddy Soil to assess the Soil Microbial Physiologic Profile (Carbon Utilization Potential)

RESULTS

Treatments

Acid Phosphatase

Alkaline Phosphatase Dehydrogenase Arylsulfatase Urease

(μg urea hydrolyzed/

g soil / h)μg PNP/g soil /hr

Control 356±5 d 431±10 d 125±2 e 32±1 e 37±1 d

IF 435±13 c 531±16 c 193±5 d 49±1 d 53±1 b

COF 726±23 a 767±46 ab 285±10 a 74±2 a 62±2 a

CM 758±7 a 880±8 a 260±2 b 68±1 b 57±1 b

RS 597±5 b 728±7 b 210±2 c 54±1 c 45±1 c

P 0.000 0.000 0.000 0.000 0.000

Soil enzyme activities as affected bylong-term inorganic and organic fertiliza-tion

FDA hydrolyses

p-D-Glucosadase activity

Soil Microbial Activ-ities

Soil Microbial Activ-itiesBIOLOG ECOPLATE –Average Well Color Devel-opment

Microbial Functional Diversity

Soil microbial functional struc-ture

Soil Biological Parameters

Soil and Yield ParametersGrain Yield(tons/ha)

Avail P (ppm)

Exch K, (cmol/kg soils) SOM (%) Soil pH Avial N

2009 DS 2009 WS

Acid phosphatase 0.563* 0.033 ns 0.304 ns 0.319 ns 0.691** 0.066 ns -0.074 nsAlkaline phosphatase

0.523* 0.058 ns 0.288 ns 0.276 ns 0.669** 0.046 ns -0.066 ns

Dehydrogenase 0.644* 0.046 ns 0.298 ns 0.296 ns 0.681** 0.059 ns -0.067 nsArylsulphatase 0.564* 0.040 ns 0.312 ns 0.320 ns 0.697** 0.073 ns -0.068 nsUrease 0.548* 0.034 ns 0.300 ns 0.298 ns 0.685** 0.062 ns -0.071 nsFDA 0.555* 0.037 ns 0.304 ns 0.310 ns 0.687** 0.063 ns -0.076 nsp-D-Glucosidase 0.556* 0.034 ns 0.298 ns 0.312 ns 0.684** 0.061 ns -0.077 nsShanon-Weaver Index

0.565* 0.264 ns 0.545* 0.216 ns 0.540** 0.582** 0.521**

RICHNESS 0.555* 0.213 ns 0.366 ns 0.193 ns 0.586** 0.313 ns 0.334 nsPC1 0.873*** -0.124 ns 0.623** 0.580* 0.665** 0.743** 0.405 nsPC2 0.351 ns 0.107 ns 0.248 ns 0.171 ns -0.667** 0.029 ns 0.062 ns

Correlations soil and yield data Soil Biological Properties

Summary•Soil enzymatic activities in soils were generally higher in paddy soils applied with organic fertilizer particularly with COF and CM

–Phosphatase(acid and alkaline) in-creased with long term use of OF and resulted to enhanced P availability as indicated by the increased available P in the paddy soils.

•Organic fertilizer enhanced microbial activity in soils as shown by the in-creased FDA, pD-glucosidase, AWCD

Summary

•Soil microbial functional structure (using the Biolog Ecoplate sub-strate utilization physiologic pro-file) differs or showed distinct community structure among the fertilizer used in soils

Conclusion:

•Type of fertilizer applied in the paddy soils greatly affected mi-crobial properties which are con-sidered to be sensitive indicators of ecosystem responses and soil health.

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