Scientists tested whether compost made from vegetable waste could help cilantro plants grow better without expensive chemical fertilizers. They grew cilantro with different amounts of this homemade compost and measured how well the plants grew, how many nutrients they absorbed, and how many tiny pores (called stomata) were on their leaves. Plants that received the most compost grew the tallest, had the most leaves, and produced the highest harvest. The study suggests that using compost from food scraps could be a cheaper, more sustainable way to grow cilantro while reducing the need for expensive synthetic fertilizers.

The Quick Take

  • What they studied: Whether compost made from vegetable waste could help cilantro plants grow better and produce more food
  • Who participated: Cilantro plants grown in controlled garden plots with varying amounts of vegetable-based compost (no human participants)
  • Key finding: Plants that received the highest amount of compost (12 tons per hectare) grew 53 cm tall, produced 122 leaves per plant, and yielded about 36 tons of cilantro per hectare—significantly more than plants with no compost
  • What it means for you: If you grow cilantro at home or on a farm, using compost from your kitchen and garden waste may help you grow healthier, more productive plants without buying expensive chemical fertilizers. However, this study was done in a specific climate and soil type, so results may vary in your area.

The Research Details

Researchers conducted a controlled garden experiment where they grew cilantro plants in three separate garden blocks (sections). Each block received one of five different treatments: no compost, or compost at 6, 8, 10, or 12 tons per hectare (a hectare is about 2.5 acres). They added the compost 26 days after planting the seeds. This setup, called a Completely Randomized Block Design, helps scientists compare results fairly by testing each treatment multiple times in different locations within the garden.

After the plants grew, the researchers measured several things: how tall the plants got, how much they weighed, how many leaves they had, and how much cilantro they could harvest. They also tested the soil and leaves to see what nutrients the plants absorbed, counted the tiny pores on the leaves (stomata), and calculated how much profit farmers would make from each treatment.

The researchers used statistical tests to determine whether the differences between treatments were real or just due to chance. This careful approach helps ensure the findings are reliable and not just random variation.

This research approach matters because it tests a practical, real-world solution to a serious problem: the rising cost of chemical fertilizers is making farming more expensive and less sustainable. By using a controlled experiment, scientists can prove whether vegetable waste compost actually works better than no fertilizer, and they can figure out exactly how much compost works best. Understanding how compost affects plant nutrition and the tiny pores that help plants breathe helps explain why it works.

The study used a proper experimental design with repeated blocks, which strengthens the reliability of the results. The researchers measured many different outcomes (plant size, weight, nutrients, leaf pores, and profit), which gives a complete picture. However, the study doesn’t specify the exact number of plants tested, and it was conducted in one specific location with one type of soil and climate, so results might differ in other regions. The study appears to be well-documented with detailed measurements of nutrients and plant characteristics.

What the Results Show

The cilantro plants that received the highest amount of compost (12 tons per hectare) performed best across almost every measurement. These plants grew to 53 centimeters tall, weighed 67 grams each, had 122 leaves per plant, and produced a commercial harvest of about 36 tons per hectare. This was significantly more than plants that received no compost or smaller amounts.

The plants also absorbed more nutrients when given more compost. They consumed 355 kilograms of nitrogen and 454 kilograms of phosphorus per hectare. Interestingly, these high-performing plants had fewer tiny pores (stomata) on their leaves—only 353 per square millimeter—compared to plants with less compost. This might seem backwards, but it actually makes sense: fewer pores can mean the plant is more efficient at using water and nutrients.

From a farming perspective, the results were impressive. Farmers using the highest compost amount would make a 219% profit, meaning they’d earn more than double their investment. This is much better than using no compost or smaller amounts.

The study found that plants receiving no compost (the control group) had higher concentrations of certain nutrients like molybdenum, manganese, copper, zinc, and chlorides in their leaves. This suggests that when plants are stressed from poor nutrition, they sometimes concentrate certain minerals. However, this didn’t help them grow better overall. The high-compost plants had better iron concentration, which appears to have been more important for growth and productivity. The research also showed that the compost improved the plant’s ability to perform photosynthesis (turning sunlight into energy) and to move nutrients throughout the plant.

This study fits with existing research showing that organic compost can be a good alternative to chemical fertilizers. Previous studies have shown that plant-based compost improves soil quality and plant nutrition, but this research adds new information by specifically measuring how compost affects the tiny pores on leaves (stomata) and connecting that to overall plant productivity. The finding that more compost leads to better growth aligns with what scientists already know about how nutrients improve plant health.

The study has several important limitations to consider. First, it doesn’t clearly state how many individual plants were tested, making it hard to judge the sample size. Second, the experiment was conducted in one specific location with particular soil and weather conditions, so the results might not apply to cilantro grown in different climates or soil types. Third, the study doesn’t explain exactly what was in the vegetable waste compost or how it was made, so it’s unclear whether other types of compost would work the same way. Finally, the study measured stomatal density (pore count) but didn’t directly measure how much water the plants used, which would help explain why fewer pores led to better growth.

The Bottom Line

If you grow cilantro commercially or at home, consider using compost made from vegetable waste at rates around 10-12 tons per hectare (or proportionally less for smaller gardens). This appears to significantly improve plant growth and yield. Start with smaller amounts if you’re new to composting, and monitor your plants’ growth to find the right amount for your specific conditions. This recommendation has moderate confidence because the study was well-designed but was conducted in only one location.

This research is most relevant for cilantro farmers and gardeners looking to reduce fertilizer costs and improve sustainability. Home gardeners growing cilantro in containers or small plots should also find this helpful, though they’d need to scale down the compost amounts. Commercial farmers facing high fertilizer costs would benefit most from this approach. People concerned about sustainable agriculture and reducing chemical inputs will also find this valuable. However, if you live in a very different climate than where this study was conducted, you may want to test the approach on a small scale first.

You should expect to see visible improvements in plant growth within 3-4 weeks of adding compost, with maximum benefits appearing by the time plants are ready to harvest (typically 3-4 months for cilantro). The profitability benefits would be realized at harvest time. If you’re starting a composting system, plan ahead because making quality compost from vegetable waste typically takes 2-3 months.

Want to Apply This Research?

  • Track the amount of compost applied (in tons per hectare or cups per square foot for home gardens), plant height weekly, leaf count at harvest, and total yield weight. Record these measurements in a simple spreadsheet or app to see if your results match the study’s findings.
  • Start collecting vegetable scraps from your kitchen and garden waste. Create a compost pile or bin, and plan to apply finished compost to your cilantro beds about 26 days after planting. Begin with 8-10 tons per hectare (or about 1-2 inches of compost spread over your garden bed) and adjust based on your results.
  • Over multiple growing seasons, test different compost amounts on separate garden sections and compare plant growth, leaf count, and harvest weight. Keep detailed notes on weather, soil conditions, and compost quality to understand how these factors affect your results. This long-term tracking will help you optimize the approach for your specific location.

This research describes results from a controlled study on cilantro grown under specific conditions. Individual results may vary based on climate, soil type, water availability, and compost quality. Before making major changes to farming or gardening practices, consider consulting with a local agricultural extension office or agronomist familiar with your region. This study was conducted on cilantro specifically and results may not apply to other plants. Always follow local regulations regarding composting and agricultural practices.