Rice Straw Composting Guide 2026: How to Turn Dayami into Free Organic Fertilizer

Updated 2026  |  Organic Farming

Every wet season, rice farms across the Philippines produce more straw than most farmers know what to do with. Some of it becomes mulch, some becomes livestock feed, but a large share still goes up in smoke. This guide walks you through a simple, low-cost method developed by JICA and PhilRice that turns that leftover straw into compost using nothing more than urea, water, and a wooden frame, and explains why that choice is worth more to your farm than the ash ever was.

📚 Quick summary: rice straw composted with urea or ammonium sulfate reaches maturity in about two to two and a half months, compared to years of nutrient loss and air pollution from burning. This guide covers the science, the exact steps, and how to use the finished compost.

2 to 2.5

Months to mature compost

60 to 70°C

Pile temperature within 3 to 4 days

80:1

Raw C to N ratio of rice straw

1 kg

Urea per 100 kg rice straw

📋 Table of Contents

1. The Rice Straw Problem in the Philippines Today
2. Why Composting Beats Burning
3. The Three Essentials of Composting
4. Carbon and Nitrogen Content of Common Farm By-products
5. Materials and Tools You Need
6. Step-by-Step: Building the Compost Pile
7. Monitoring, Turning, and Timeline
8. Uses and Benefits of Finished Compost
9. Mistakes to Avoid
10. Frequently Asked Questions
11. More Organic Farming Guides

1 The Rice Straw Problem in the Philippines Today

Rainfed and irrigated rice areas across the Ilocos region generate a large volume of straw every cropping season. According to recent Philippine Statistics Authority figures, Ilocos Norte alone harvests rice on more than 60,000 hectares across its cropping seasons, producing well over 300,000 metric tons of palay a year. Rice straw yield generally runs close to the weight of the grain harvest itself, which means the province is left with a substantial volume of straw every season, whether it is used, stored, or burned.

Some garlic and onion growers use rice straw as mulch, and some farmers feed it to livestock, but a large share is still burned in the field simply because it is the fastest way to clear land for the next planting. Composting takes more time up front, but it converts that same byproduct into a fertilizer input the farm would otherwise have to buy.

2 Why Composting Beats Burning

Burning rice straw destroys almost all of its nitrogen, most of its sulphur, and a large share of its potassium, releasing them as smoke instead of returning them to the soil. It also contributes to the seasonal haze and respiratory irritation that many rice-growing provinces now regulate through local ordinances against open agricultural burning. Composting keeps those nutrients on the farm, builds organic matter in the soil over time, and produces a by-product you can either use yourself or sell to neighbouring growers.

💡 Local ordinances matter here. Several rice-producing provinces, including Ilocos Norte, restrict or prohibit open burning of agricultural residue under local clean air ordinances. Check with your municipal agriculture office before the next harvest so you are not caught off guard at burning season.

For decades, Trichoderma fungus activators recommended by government agencies and EM activators sold by private companies have been the standard way to speed up composting. Both work, but they are not always available in every municipality. The method in this guide, developed under the JICA-PhilRice Technical Cooperation Project, uses urea instead, a fertilizer nearly every Filipino farmer already has access to through local agricultural suppliers.

3 The Three Essentials of Composting

Composting is really just farming for microorganisms. Give the billions of fungi, bacteria, and other decomposers in the pile the right conditions, and they will do the rest of the work for you. They need three things to thrive.

Aeration

Aerobic composting microbes need oxygen to work efficiently. Rice straw is naturally good for this because it holds its shape and lets air move through the pile. Wet leaves, by contrast, mat down into slimy layers that block airflow and are poor material on their own. A mix of dry and green materials, plus regular turning, keeps oxygen moving through the pile. A poorly aerated pile decomposes slowly and starts to smell.

Moisture

Microbes multiply and spread fastest through a pile that is evenly moist. Too dry, and microbial activity stalls. Too wet, and the pile mats down, cuts off airflow, and starts to smell just like an under-aerated one. The pile is at the right moisture level when water drips between your fingers as you squeeze a handful of the material, but does not run freely.

Carbon to Nitrogen Ratio

Compost breaks down fastest when the carbon to nitrogen ratio of the material is below 40, with at least 1 percent nitrogen content. Rice straw on its own sits at roughly 80 parts carbon to 1 part nitrogen, far above that target, which is exactly why this method adds urea or ammonium sulfate to bring the ratio down into a range the microbes can work with quickly.

4 Carbon and Nitrogen Content of Common Farm Byproducts

Organic Matter	Total Carbon (%)	Total Nitrogen (%)	C:N Ratio
Rice straw	40	0.50	80
Wheat straw	45	0.38	117
Cattle manure	35	2.20	16
Swine manure	41	3.60	11
Poultry manure	35	4.00	9

Rice straw needs supplementary nitrogen to speed up decomposition. Add 1.0 kg urea, or 2.0 kg ammonium sulfate, for every 100 kg of rice straw.

5 Materials and Tools You Need

• Rice straw, shredded if a shredder is available, to speed decomposition
• Urea or ammonium sulfate as the nitrogen supplement
• A square wooden frame, roughly 1.5 meters on each side and 0.2 meters high, used to shape each layer
• Water source, enough to keep the pile evenly moist
• Animal manure, if available, to add extra nitrogen and reduce urea use
• Tarpaulin sheet, or opened and sewn polyethylene sacks, to cover the pile
• A soil or compost thermometer, useful but optional, to confirm the pile is heating properly

Grasses, broadleaf weeds such as hagonoy, and leguminous plants like peanut and bean residues can all be mixed in with the rice straw to add variety and nutrients to the finished compost.

6 Step-by-Step: Building the Compost Pile

1. Set the wooden frame on the ground where you plan to build the pile.
   
   
   
   
2. Pile rice straw evenly up to the top of the frame. Shredded straw decomposes faster than whole stalks.
3. Compact the first layer by pressing down along the corners of the frame. One layer is roughly 50 kg of rice straw.
   
   
   
   
   
4. Add 0.5 kg urea, or 1.0 kg ammonium sulfate, on top of each layer.
5. Water the layer until it is moist enough that water drips between your fingers when you squeeze a handful.
   
   
   
   
6. If animal manure is available, spread it on top of the layer. Manure is rich in nitrogen, so you can reduce the amount of urea applied depending on how much manure you add.
7. Lift the frame off the compacted layer and set it back on top to build the next layer.
8. Repeat the layering, urea, and watering steps until the pile reaches about 1.5 meters high.
   
   
   
   
9. Cover the finished pile with a tarpaulin sheet, or sewn-together polyethylene sacks, to protect it from evaporation and from nutrients leaching out during rain. If you use sacks, water the surface whenever it starts to dry out.
   

7 Monitoring, Turning, and Timeline

• Days 3 to 4: pile temperature should rise to between 60°C and 70°C. This confirms the microbes are actively decomposing the material. If the pile does not heat up, one of the three essentials, air, water, or nitrogen, is missing.
  
  
  
  
• Weeks 3 to 4: turn the pile over and rebuild it. Add 0.2 kg urea and water each layer again as you rebuild. Place the drier material toward the middle of the new pile so it gets the most microbial contact.
  
  
  
  
• Months 2 to 2.5: the compost matures. Finished compost does not smell bad, feels soft, and has turned a deep brown or black color.
  
  
  
  
• After harvesting: if you are not using the compost right away, pack it in plastic sacks and store it in a shady, dry place.
  
  
  
  

⚠️ If the pile is not heating up by day four, check moisture first. A dry pile is the most common reason composting stalls in the field. Add water, re-cover, and check again after 24 hours before assuming the nitrogen ratio is off.

8 Uses and Benefits of Finished Compost

Improves Soil Structure

In sandy soils, compost acts like a sponge, holding water and nutrients that would otherwise drain away. In clay soils, it improves porosity and drainage. Either way, the soil ends up better able to support healthy root systems.

Supplies Nitrogen, Phosphorus, Potassium, and Micronutrients

Compost is a common ingredient in seedling tray mixes for vegetables like ampalaya, tomato, and eggplant, where it feeds young seedlings while they are still in the tray. It is also applied as a basal fertilizer for cucurbits such as ampalaya, patola, squash, and upo, acting as a slow-release nutrient source through the growing season.

Inoculates the Soil with Beneficial Microorganisms

Finished compost carries a live population of bacteria and fungi into the soil, where they continue to extract nutrients and make them available to plant roots.

Works as Mulch

Spread on the soil surface, compost conserves moisture by shielding the ground from direct sun. As it eventually breaks down further, it adds another round of nutrients to the soil.

Buffers Soil pH

Repeated use of chemical fertilizer can push soil pH to extremes over time. Organic matter from compost helps buffer against that swing.

Supports Beneficial Insects

Soil rich in organic matter is a preferred habitat for spiders and other beneficial insects that help keep pest populations in check.

9 Mistakes to Avoid

• Skipping the urea or ammonium sulfate. Rice straw alone has too high a carbon to nitrogen ratio to decompose quickly on its own.
• Letting the pile dry out. A dry pile is the single most common reason composting stalls before it ever heats up.
• Building the pile too loosely. Compacting each layer as you build it keeps the pile dense enough to hold heat and moisture.
• Leaving the pile uncovered. Rain leaches nutrients out of an exposed pile, and sun dries it out just as fast.
• Never turning the pile. Without turning at the three to four week mark, the outer material never fully composts along with the center.

10 Frequently Asked Questions

Can I use commercial compost activators instead of urea?
Yes. Trichoderma-based activators and EM activators both work well and are recommended by government agencies and private suppliers. Urea is simply a more widely available alternative in areas where those products are harder to source.

How much rice straw do I need for a usable batch of compost?
A single layer inside the 1.5 meter frame uses roughly 50 kg of rice straw. A finished pile built to 1.5 meters high typically uses several hundred kilograms, so plan your batch size around what one or two farm workers can realistically turn and manage.

Is rice straw compost the same as liquid organic fertilizer like FFJ or FAA?
No. Rice straw compost is a solid soil conditioner that takes about two months to mature, while liquid organic fertilizers like Fermented Fruit Juice and Fish Amino Acid are fast fermented extracts used as foliar sprays. The two work well together. Spraying FFJ or FAA onto a rice straw pile can help speed up decomposition. See our Liquid Organic Fertilizer Guide for the full production process.

Why does my province restrict rice straw burning?
Open burning releases smoke and particulate matter that affect air quality and public health, which is why several rice-producing provinces, including Ilocos Norte, have local ordinances against it. Composting gives farmers a productive alternative that keeps nutrients on the farm instead of losing them as smoke.

✅ The rice straw composting formula: shredded straw, layered and compacted + urea or ammonium sulfate at the right ratio + consistent moisture + a full cover against sun and rain + one turn at three to four weeks = mature, usable compost in about two months, with none of the smoke.

11 More Organic Farming Guides

Rice straw compost pairs naturally with the liquid organic fertilizers already covered on this site. Use this section to keep building your organic fertility program.

🧪 Liquid Organic Fertilizer Guide
FPJ, FFJ, FAA, and Tea Manure production, costs, and application rates. Existing Guide →🌿 Browse All Organic Farming Guides
See the complete Juan Magsasaka organic farming library. Full Library →

Tags: Rice Straw Composting Philippines, Dayami Compost, Organic Fertilizer Philippines, JICA PhilRice Composting, Rice Straw Management, No Burning Rice Straw, Organic Farming Ilocos

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Source reference: composting method adapted from the JICA-PhilRice Technical Cooperation Project (TCP3) rice straw management technology. Regional rice area and production figures cross-checked against Philippine Statistics Authority quarterly Palay Production Survey data for Ilocos Norte. Always confirm current local ordinances on agricultural burning with your municipal agriculture office.