Bat guano: natural phosphorus

Bats gather in caves to sleep. They remain in the same cave for hundreds of years. Little by little, the bottom of these caves will be covered by huge layers of droppings, commonly termed bat guano. This guano has been a much appreciated fertiliser for centuries for its nutrient content and the beneficial effects it has on the soil. In the recent past, with the introduction of chemical fertilisers, it became outmoded. But its use is now again picking up with the growth of organic farming.

The nutrient content may vary depending on the diet of bats and the age of guano. Guano produced by insectivore bats has a higher proportion of nitrogen, while guano from fruit-eating bats has a high phosphorus content. Fresher guano has more nitrogen than that collected in old deposits.

Use in cannabis growing

In cannabis growing, bat guano is well known. Undoubtedly, it is one of the best natural sources of phosphorus, which is why it is quite popular among organic growers. Significantly, this is a slow-release type of phosphorus, meaning that plants will receive it throughout their lifecycle. Another reason for its good reputation is that it gives crops a sweet and natural taste, someone calls this “a touch of mango”.

On top of providing nutrients, guano is an excellent soil improver and both the structure and oxygenation of the substrate can be optimised. It contributes to pH stabilisation for its calcium content. It also improves the retention of water and liquid nutrients by the substrate. Other less known advantages include its nematocide properties for its chitin content; it is also used as a toxic waste cleaning agent in the soil. As soil improver, it works ideally if mixed with earthworm humus, as earthworm compost too is a great soil conditioner for its content of humic and fulvic acids, enzymes and microbial flora.

Guanokalong’s range of products

Guanokalong is one of the pioneering brands for the use of guano in cannabis growing. This company sources bat guano worldwide to offer a top-quality, mature product. Depending on the label, NPK is 1-10-1, but this is only designed to comply with minimum legal requirements. As a matter of fact, the NPK content is closer to 2-15-2 in marketed products, which also contain a large variety of micronutrients.

Guanokalong started to market slow-release bars as an ideal product to deliver nutrients throughout the full lifecycle in outdoor crops. Indoor growers used to crush bars to better dissolve the guano and facilitate its immediate uptake by the plant. In order to meet this demand, Guanokalong powder was put on the market as an easy-to-use version in all environments.

Another application for guano is the processing of ‘guano tea’ for a delivery of nutrients in liquid form. This application does not ensure the best exploitation of guano potentials, since achieving total dissolution is complex. In order to solve this problem, Guanokalong introduced a third product, Guanokalong extract, a supplement that improves the taste of crops and delivers enzymes and microelements. This product is vacuum-packed for perfect preservation.

Finally, they decided to enrich their range with additional products not based on bat guano, in order to meet all the needs of organic farmers. The first products to be marketed were Kalong Grow and Kalong Bloom, liquid fertilisers based on molasses and proteins and especially designed for use in combination with Guanokalong in the soil. Next to come on the market was the Guanokalong culture substrate - to which black and red peat, earthworm humus and bat guano can be mixed. Next they introduced the GK Organics line of organic products for soil preparation, such as fish meal, volcanic rock, palm ash, earthworm humus, cottonseed powder and seaweed meal. The last product to be released is Biogrow Complete Organics, an excellent soil conditioning agent that goes along with the full range of GK Organics and Guanokalong. It can ideally be used for simple growing on untreated soil. Now they are making preparations to release Guano Black, a mixture of bat guano with humic acid pellet, a real soil-life activator.

Healthiness

To save money some cannabis growers are brave enough to enter caves where bats live to collect guano. We absolutely advise you against this practice. It is illegal and could be punished by a fine for environmental crime. It may also cause health problems, as the combination of cave environment and excrements favours the transmission of diseases.

The use of Guanokalong is unproblematic, as it is collected and packed by professionals. In any case, it is not recommended to inhale guano powder when applying it to the substrate.

A few scared readers asked us if it is safe to use bat guano as they heard that bats can pass the Ebola disease. This fear is totally groundless, the collected guano is packed and sent to Holland and from Holland to the wholesaler selling it to your growshop. It is a long process whereas the activity of Ebola only lasts a few days. What is more, Guanokalong uses caves with guano dating back to a time that precedes by a considerable period the first appearance of Ebola.

Guanokalong: examples of use

My favourite form of application is Guanokalong powder, you only need to apply it to the soil and allow its contained microorganisms to act and macro and micronutrients to be released. The most well known use of bat guano is soil preparation. In addition to nutritional benefits, this type of application has a number of implied advantages, as the soil structure and life of the substrate are improved. Guano is also advantageously used in plant transplanting, as it contributes to the development of roots and the vigour of seedlings. Quantities may change, for instance in a 7 litre pot for indoor growing, 2 to 4 spoonfuls will suffice, while higher quantities can be applied outdoors; the recommended dose is around 100 g per plant, although much higher quantities can be added without any problem. When large plants are grown outdoors using a massive dosage of 400 to 500 g of bat guano per plant is possible without any risk of over-fertilisation. To prepare a substrate, 1 kg Guanokalong should be mixed for every 100 to 250 litres of substrate, depending on whether you need a more or less fertilised substrate.

Another type of use is to apply a thin layer of bat guano and earthworm humus on the soil surface, for it to incorporate into the soil with irrigation. This system is very useful when you go on holiday and leave someone in charge of your crop, as you would spare him the trouble of dosing several bottles of liquid fertilisers.

Another much talked-about type of product is guano tea. A way to prepare it is to leave a sock filled with guano in a basin full of water for it to dissolve little by little; as alternative systems, guano can be dissolved directly in lukewarm water, or mixed with water; the mixture is then stirred and left to settle overnight. In any case, it is more advisable to opt for pre-prepared Guanokalong extract, as achieving proper guano dissolution is something complex. Guanokalong extract can also be used to improve taste in crops with mineral fertilisation, including hydroponic crops. Guano can be used in aquaponics, or in hydroponics with fish. It is normally applied during flowering by introducing it into a sock, which is then placed inside a tank containing fish.

Conclusions

Bat guano is a fantastic product for cannabis growers, the most simple form is adding guano powder to the substrate and leave it to act. Bat guano is useful in all types of environments, as a source of phosphorus and a soil improver in organic crops, or as a taste improver in crops with chemical fertilisation.