Licenced hemp and marijuana growers have used Sustane 8-2-4 as part of their fertility programs, but in various ways. This is because some have chosen to rely exclusively on 8-2-4, to greatly simplify their input program, while others integrate that material with other inputs to maximize yields. So, let me give you a few examples of how Cannabis growers can succeed with 8-2-4.
In the first, a hemp grower in Kentucky wanted to know if 8-2-4 would provide good return on investment as an all purpose organic input. That grower's soil was in excellent shape, with >3% organic matter, a near ideal pH of ~6.5, and well balanced macro and micronutrient fertility. By applying 1000 lb/A of 8-2-4 to that field at planting, initial and final stands were increased by about 25% and yields were nearly double that of the unamended plots.
Another hemp grower used 8-2-4 as a sidedress for CBD hemp one month after transplanting. While the foundational fertility was quite high, the sidedress still increased the grower's yield and estimated returns by about $2000 per acre. Interestingly, that same grower tried side dressing with a competing product made from protein meals, but that material actually decreased yields because it seemed to promote greater plant disease in the test plot.
Amongst licenced marijuana growers, Sustane 8-2-4 has been used primarily to amend potting mixes at the time of transplant and as a top dress through the veg stage. By doing so, those growers were able to simplify their fertility management (less time spent mixing and measuring) and reduce costs (the Sustane programs cost significantly less than most fertigation programs). Indoors the yields were as good as their best hydro program. Outdoors the Sustane program has become their standard, yielding just under 2 lbs/plant, with 8-2-4 providing about 70% of the total nutrient input.
Safe, simple, and cost effective inputs-that is what Sustane provides Cannabis growers. Contact me directly for specific advice for your grow.