Optimal Pollution Control in Agricultural Production: Biodegradable vs Plastic Mulches

——General Model and Application in  the Plastic Mulches

Jingze Jiang1, Tom Marsh1, and Eric Belasco2

1 School of Economic Sciences, Washington State University2 Department of Agricultural and Applied Economics, Texas Tech University

Outline

• Introduction and Motivation

• Purpose and Objectives

• Model

• Simulation (Plastic Mulches )

• Preliminary results

• Future work

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Introduction and Motivation--Studying the Widely Used Plastic Mulches

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Strengths Weaknesses

1. Increase production:(weed control, moisture

conservation, temperature modification)

2. Affordability(1.5$/lb-solid black)

Plastic Mulches Emission:1. productivity decreased2. Cost of disposing 3. Environmental problems:(wildlife

and livestock; carbon dioxide in the atmosphere)

Opportunities Threats

Improvement in Disposal Methods:1. Recycling2. Compositing Reduce cost and environmental

damage

New Materials-Biodegradable Mulches:1. Save disposal fee and labor fee2. Save environmentSo far the price is around twice

higher ; The quality is questioned.

Purpose and Objectives

• 1) By considering the cost of dealing with plastic mulch waste, what is the best choice for growers when choosing between conventional and biodegradable mulches?

• 2) What is the best choice among different mulches and waste disposal methods to achieve a social optimum?

• 3) Is government regulation necessary?

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Model-Growers’ Choices

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Model-Setup

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Objective—Maximizing Profit:

Model-Setup

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Constraints:

MP: BP: DC:

Solution:

Simulation (Plastic Mulches )-Model Adjustment

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• Plastic Mulches in Real World:

- 1. The illegal fine is from 5,000$ to 26,000$; The highest landfill tipping fee in WA is

0.056$/lb charged by LRI Landfill in 2010; The recycling fee is around twice higher than

land-filling tipping fee.(http://www.ecy.wa.gov);

- 2. If the grower does not deal with the used mulches, he would lose at least 2500$/acre, which is 73 times higher than the landfill tipping fee

- The grower once choose to use plastic mulches, he should prepare to pay for the disposal fee.

Simulation (Plastic Mulches )-first question

• What is the minimum increased yield caused by using plastic mulches to certify that the grower will use plastic mulches ? (not choosing 1.1)

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Simulation (Plastic Mulches)-Data• We choose one acre of tomatoes field as measure unit.

• The tomatoes 1989-2009 seasonal prices($/lb) in west US are collected from USDA website.

• The tomatoes 1989-2009 seasonal yield data (lb/acre) in WA are regress onto the US 89-09 yield data from USDA website.

• We use 1989-2009 LLDPE film seasonal real price data to measure ($/lb)

• Landfill tipping fee Data in WA is collected from Department of Ecology State of Washington and NSWMA’S 2005Tipp Fee Survey

• Other data, namely mulches usage (lb/acre), installing and removing mulches labor cost($/acre), are from surveyed farms.

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Preliminary result

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Preliminary results

• If the plastic mulches cannot increase the yield by 8.66%, the grower should not choose to use the plastic mulches.

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Future work

• Simulate the social cost for using the plastic mulches

• Simulate the conditions under which the biodegradable mulches can generate more benefit for growers

• Compare the difference of the social cost between using the plastic mulches and biodegradable mulches.

• Discuss the necessity of the government intervention balancing the individual interest and social optimum

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