One of the biggest ongoing debates in cannabis horticulture is whether to use organic nutrients or conventional (chemical) nutrients. Many organic purists swear that organically grown cannabis has more flavor, odor, and higher potency than conventionally grown cannabis. They also argue that the yield of an organically grown cannabis garden can be just as large as the yield of a conventionally grown cannabis crop. Growers that swear by conventional nutrients like the relatively low cost, the speed of growth, and the precise nutrition ratios. Most conventional growers believe the exact nutrient ratios of readily absorbed nutrients lead to larger yields and prolific growth. The truth of the matter is that both organic and conventional growing methods can produce a high quality end product, but each method comes with its own advantages and disadvantages.
Organic nutrients or fertilizers are derived from organic sources, such as animal or vegetable waste. A few examples of the organic fertilizers commonly used in cannabis production are bat guano, kelp extract, fish meal, and bone meal. Organic nutrients also include minerals and elements that are not considered “essential”. These include glacial rock dust, gypsum, and microorganism supplements (enzymes and beneficial microorganisms). Organic fertilizers can be individual ingredients or a combination of ingredients derived from organic sources.
The application of organic fertilizers will depend on the ingredients it contains and the form of the fertilizer (granular or liquid). Many organic cannabis growers rely on the “feed the soil and the soil feeds the plant” method. In this ideology, the soil is amended prior to planting with a variety of organic ingredients. As the microbes in the soil break down the organic matter, the plants are provided with the elements they need to grow. Another organic methodology is to apply liquid organic fertilizers on a regular basis throughout the lives of the plants. Although neither organic method will provide absorbable nutrients at the same rate as conventional fertilizers, liquid organic fertilizers offer a faster delivery of some nutrients when compared with granular organic fertilizers.
The biggest advantage of using an organic nutrient regiment is the reduced likelihood of burning or over-fertilizing the plants. In a way, organic nutrients are self-regulating (or regulated by the microorganisms in the soil). In other words, the rate at which the organic matter is broken down works in conjunction with the rate at which the plant requires nutrients. This slow release of nutrients protects the plants from over-fertilization or “burning”. Organic nutrients tend to stay in the soil longer and increase the diversity of microbial life over time. Organic nutrients also improve the soil’s structure (improved airflow and water retention). This equates to a very low run-off rate and makes organic nutrients more sustainable and renewable than conventional fertilizers. Outdoor growers will especially appreciate the way organic nutrients continue to build up the soil and improve its quality year after year.
The biggest disadvantage of organic nutrients is the rate at which they can be absorbed by the plants. Organic nutrients rely on the microorganisms to break down organic matter. This process can be slowed down due to environmental factors, such as temperature. For example, in colder temperatures, the rate at which microorganisms break down the organic matter is slowed. This, in turn, reduces the rate at which the plants are able to absorb essential elements. Another disadvantage of organic fertilizers is the possibility of introducing pest insects. Depending on where the organic products are sourced, there is a possibility that the product will contain unwanted visitors. This is why it is so important for cannabis growers to get their organic products from a reliable source.
Correcting nutrient deficiencies may be more difficult in an organically grown cannabis garden than a conventionally grown cannabis garden. As previously mentioned, it takes more time for organic nutrients to become available to the plants. If a quick fix is needed, let’s say for a phosphorus deficiency, it may take longer to rectify the problem with organic nutrients than it would with conventional fertilizers. The final disadvantage of organic nutrients is cost. It is very inexpensive to create ammonia; therefore, conventional fertilizers can be relatively inexpensive compared with organic nutrients.
Chemical nutrients are made in a laboratory and are synthesized and extracted to a specific chemical form. Nitrogen, phosphates and potassium are extracted from minerals and other impurities are removed entirely. The results of this process are highly refined, specific N-P-K quantities.
The biggest advantage of conventional (chemical) nutrients is rapid nutrition uptake. Since the microorganisms that are usually responsible for breaking down organic matter are bypassed, the rate at which the plants can absorb elements is increased. This rapid absorption can lead to increased growth rates and larger yields. The ability to create exact nutrient ratios is another advantage of chemical nutrients. This is especially true as our knowledge of plant physiology increases and we gain a better understanding of how specific ratios affect particular plant varieties. Put another way, chemical nutrients can be customized for cannabis plants or even for specific strains of cannabis plants depending on their particular needs. Lastly, relatively speaking, conventional fertilizers are affordable and easy to find.
Conventional nutrients and fertilizers are produced from non-renewable resources. This can mean a larger negative impact on the environment. Chemical fertilizers can leech also from the growing medium and impact the surrounding environments. Fertilizer run-off issues are almost entirely attributed to chemical fertilizers. Conventional fertilizers can also easily “burn” or harm plants when over-applied. All in all, conventional fertilizers supply nutrients to the plants quickly, but do not aid in the development of a healthy soil.
Studies have shown that although organic and conventional vegetables offer similar levels of many nutrients, including vitamin C and vitamin E, there is a significant difference in the levels of special compounds, including antioxidants. Recent studies have shown that organic fruits and vegetables deliver between 20% and 40% higher antioxidant activity than conventional fruits and vegetables. These antioxidant compounds include flavonoids and carotenoids which scientists believe can help protect cells from the effects of aging or from the sort of damage that leads to the development of cancerous cells. The reason why organic fruits and vegetables offer a higher percentage of antioxidants can be attributed to two factors. First, organic crops do not get treated with chemical pesticides so they are forced to fight off more pest insect attacks. The plants naturally make more antioxidants to protect themselves from such attacks. Second, conventional crops are heavily fertilized to grow bigger and at a faster rate. This can result in compounds being more diluted by extra moisture and carbohydrates.
It is safe to assume that some of the special compounds in cannabis would be affected in a way similar to fruits and vegetables. Many of the special compounds found in cannabis, including terpenes and cannabinoids, may be more prevalent in organically grown cannabis and more diluted in conventionally grown cannabis. This could be the main reason why many growers report organically grown cannabis to be more pungent, flavorful and potent than conventionally grown cannabis. Although cannabinoid tests show comparable THC levels in organically versus conventionally grown cannabis, it may be the ratio of specialized compounds that remains the significant difference between the quality of organically and conventionally grown cannabis
Deciding between organic and conventional gardening methods can be a difficult choice for cannabis horticulturists. From an environmental standpoint, organic nutrients offer a long-term advantage by actually increasing the health of the soil. This is especially advantageous for outdoor cannabis growers who will continue to grow their crops in the same soil year after year. Ultimately, it comes down to the grower’s budget and personal preference as to whether he or she uses conventional or organic nutrients. Many organic purists swear that organically grown cannabis is a higher quality product while cannabis growers who use conventional fertilizers swear by faster growth and larger yields. There is no doubt that the debate on this subject is far from over. As our understanding expands regarding the cannabis plant’s specialized compounds and how these compounds interact, we will come closer to being able to quantify the true difference between organically and conventionally grown cannabis.
Eric Hopper is a Professional Marijuana Grower Senior Editor.