Some consumers interested in hemp products will be interested in USDA Organic products having minimal agrichemical residues. Producers have interest in organic hemp because organic products typically sell for higher prices than comparable nonorganic products. The USDA National Organic Program (NOP) clarified in Instruction 2040 that hemp grown in accordance with state run hemp programs could be certified organic. This fact sheet will concentrate on outdoor production of organic hemp for cannabinoid extraction. Producers interested in organic production must be certified by a USDA accredited organic certifier.

Soil and Fertility Considerations for Hemp Production

Hemp is a warm season annual crop that prefers well drained soils with a pH range between 6.0 and 7.0. Soils that are wet, have high clay content, or are prone to crusting should be avoided. General fertility recommendations are given in Table 1. Nitrogen is often the most limiting nutrient for hemp and other Extension publications recommend a nitrogen rate of 100 - 120 lbs / acre for cannabinoid crops. Hemp needs nitrogen throughout its lifecycle but has greatest demand in the vegetative stage as plants devote their resources to getting bigger. Phosphorus and potassium are also important during early vegetative growth. Phosphorus demand is also high during flowering. Most farmable soils in Kentucky will provide adequate calcium, magnesium, sulfur, and micronutrients. Organic producers generally provide nutrients via animal manures, cover crops, and green manures in a multi-year crop rotation. Commercial products are available but these can be costly and producers should verify product NOP compliance with their certifier before use. Application rates should be based on soil test recommendations.

with their certifier before use. Application rates should be based on soil test recommendations.

Starting a Hemp Crop for Cannabinoid Cultivars

Cannabinoid crops are usually started from transplants or vegetative cuttings (clones). Kentucky producers should refer to the KDA Summary of Varieties (see references) to help make decisions on choosing cultivars that are compliant with the 0.3% THC threshold. In Kentucky, seeds should be started in a greenhouse in April or May. While certified organic hemp seeds must be used in organic production when available, organic seed availability is currently sparse in the U.S. Producers who cannot obtain organic seed may use untreated seed. Organic producers should start seeds in approved potting media and expect germination in 2 – 4 days at temperatures around 75circF. Producing clones is beyond the scope of this fact sheet but clones are a viable alternative to seed. Clones produce more uniform crops and eliminate the labor involved in culling male plants (see below). They are more expensive and growers should be aware that clones purchased from off-farm can be infested with greenhouse pests like aphids or spider mites. Anecdotal evidence suggests that plants started from seed develop more robust root systems than clones.

Young hemp plants need regular watering but overwatering is a very common mistake among new growers. While avoiding wilting, media should be allowed to dry out after watering. Care should also be taken to avoid plants becoming root-bound. Plants can safely be moved to the field when the second set of true leaves has developed (Figure 1). In Kentucky,

Table 1. Recommended fertility rates for selected macronutrients in cannabinoid hemp crops.

Recommendation

*Recommended N supply for a season. Organic growers should account for N being supplied by manure, cover crops or green manures before applying additional N.

† Additions of P, K, and S should be based on results of soil tests and soil type as well as previous field history. Additional information on soil testing and nutrient recommendations for Kentucky Growers can be found in University of Kentucky Extension's AGR-1 Lime and Nutrient Recommendations (See references).