The Natural Farming Concept: A New Economical Waste Management for Small Family Swine Farms

Why Look at Inoculated Deep Litter Systems?

The most critical issue facing livestock and other small family operations nationwide is the development and implementation of cost effective pollution prevention technology. Our livestock producers, especially swine, continue to seek a best management practice (BMP) that is effective, economical, and practical, and in compliance with new US EPA laws. The Department of Health, Natural Resource Conservation Service, Hawaii Soil and Water Conservation Districts and the Cooperative Extension Service have been working diligently to address both federal and state waste management compliance needs of the local pork producer. As a result, the industry currently implements effluent irrigation, composting, deep litter technology, lagoon storage and solid separation as possible solutions for on-farm nutrient management. Unfortunately, due to new and revised EPA regulations, which now include nuisance odor and vector components, many of these strategies no longer meet federal criteria for BMPs.

In 2006, a system of waste management, with the potential to be implemented as a BMP under federal regulations, was discovered in Korea during a visit to the Janong Natural Farming Institution. The concepts of naturally collected micro-organisms, green waste deep litter, and a piggery design with strategic solar and wind positioning was being practiced in several countries in Asia and the Pacific Basin. Over the past six years, these concepts have been tested in Hawaiʻi to provide small swine farms with another BMP that is in compliance with current EPA regulations.

What did we do? 

For the past six years, the Extension Service has been touring many hog farms and conducting numerous educational seminars on the Inoculated Deep Litter System (IDLS). The number of IDLS piggery operators has increased dramatically due to farmers coming out of retirement, producers retrofitting and replacing their wash-down swine operations as well as new farmers trying their hand at raising hogs. A major factor of the great interest toward the IDLS piggery is the minimal labor and time to operate the system compared to the traditional style of raising hogs with daily wash downs of the pig pens. Other important factors include the concept of collected micro-organisms, a layering of the deep litter green waste system, and designing piggery housing with strategic solar and wind positioning to keep the facility cool and dry. The success of the IDLS system is exemplified by the following: 1) Low maintenance since litter pens never have to be cleaned, 2)has no odor or ve ctor problems if managed correctly and 3) development of cost effective housing.

What have we learned? 

IDLS incorporates four components: 1) self-collected, site-specific (or indigenous) micro-organisms (IMOs), 2) green waste, 3) natural ventilation, and 4) facility positioning relative to sunlight. The livestock facility is kept dry with natural ventilation and sunlight, which promotes proper fermentation of the pen litter (combination of green waste and livestock waste) thus preventing nuisance fly breeding and odors generated by proliferation of undesirable organisms.

Solar positioning. The building’s foundation is positioned from north to south, with the south end serving as the entrance to the facility. This takes advantage of maximizing sunlight traveling east to west, which provides adequate ultraviolet light, heating, and drying. Sunlight and ventilation help to promote drying, thus preventing liquid accumulation (from livestock waste, watering nipples or troughs, rain) in the litter, which deters the fermentation process from turning anaerobic, and eliminates conditions ideal for odor and fly breeding. (Note: orientation applies to the Northern Hemisphere and positioning should be reversed for application in the Southern Hemisphere.)

Natural ventilation. The building is designed with a high (14 ft H), vented roof, and walls (10 ft H) which have openings to the outside. Cool trade winds are allowed to blow through the building, forcing warm air to rise and be eliminated through the vented roof. This helps to dissipate heat generated from microbial fermentation in the litter, keeps the litter dry through constant air movement, and cools the facility during the hot season. During the rainy season, simple roll-down siding can be installed to keep rain out.

Deep Litter. In order to fulfill EPA regulations that require an impervious bottom to all waste handling facilities, there must be either a concrete slab or a thick (30 mil) plastic liner as the base of the building. Green waste, with a minimum depth of 4 feet, is then strategically layered to start the IDLS. The first layer consists of roughly a half foot of cinders mixed with bio-char (not charcoal briquettes). The second layer consists of 2 feet of cut logs. Logs should be at least 3 to 4 feet long and can range in diameter from 2” or more (larger, longer logs deter pigs from rooting them to the surface). The third layer is comprised of either leaves or fronds covered with assorted green waste. The next step is too lightly spread about one pound of IMO-4 and soil to every 50 square feet of surface area in the IDLS pen. For example, a 100 sq ft pen will require 2 pounds of IMO-4 applied in the third layer. The final step is to add about a half foot of sawd ust. Two weeks before introducing animals into the pens, activate the microbes once with a mist spray of lactic acid bacteria (LAB) and fermented plant Juice (FPJ). You can add animals to the pen once you smell a yeasty odor in the litter, a sign that the microbes have been activated and are at work in the pen.

Micro-organisms: The only micro-organisms used are self-collected by the producer from the specific site of the facility. The profile of indigenous micro-organisms may vary greatly from place to place, from windward to leeward coasts, and even between neighboring properties. The initial, one-time misting with lactic acid bacteria (LAB) and fermented plant juice (FPJ) activates the microbes to increase in numbers. To learn how to make these activators, please attend a Natural Farming Input-Making class, or contact the Hawaiʻi Cooperative Extension Service (

LAB and FPJ: These are self-made inputs. Go to CTAHR website for free publication

Future Plans 

Adaptation of concept overcome a major hurdle when the IDLS piggery became cost sharable with the federal government on November 15, 2012 and deemed a best management practice. Hog farmers who practice the IDLS are eligible in entering into a cost-share agreement with the U.S. Department of Agriculture (USDA) for Environmental Quality Incentive Program (EQIP) assistance and may file an application at any time and will further enhance the participation in the IDLSTo date nearly 50 retrofitted or new operations have been established in Hawaii. The IDLS has been introduced and being practiced in 11 states, Micronesia and various countries of the world. Future plans include implementing the technology to large scale operations, making of feed utilizing other natural farming techniques and evaluating the compost for organic plant propagation. The system is currently being tested with Poultry Production


Michael DuPonte, Extension Agent University of Hawaii at Manoa, College of Tropical Agriculture and Human Resources (CTAHR).

Additional information 


H. Park and M.W. DuPonte., 2010., How to Cultivate Indigenous Microorganisms, Biotechnology, CTAHR., June, BIO-9.

M. DuPonte and D. Fischer., Most Frequently Asked Questions on the IDLS Piggery, The Natural Farming Concept A New Economical Waste Management Stem for the Small Family Swine Farms in Hawaii., 2012., Livestock Management., Sept. , LM-23

D. M. Ikeda, Weinert Jr., E., Chang K.C.S., Mc Ginn, J.M., Miller S., Keliihoomalu, and DuPonte, M.W., 2013., Natural Farming: Fermented Plant Juice, Sustainable Agriculture, CTAHR., July, SA-7.

S. Miller, Ikeda, D.M., Weinert Jr., E., Chang K.C.S., Mc Ginn, J.M., Keliihoomalu, and DuPonte, M.W., Natural Farming: Lactic Acid Bacteria, Sustainable Agriculture, CTAHR., August, SA-8.


Kang Farms of Kurtistown, Hawaii, David Fischer (NRCS), Justin Perry III (NRCS) and Lehua Wall (CTAHR)

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