Hemp farmers gained long-awaited clarity this week on chemical testing and safety-net programs for their crop.

USDA on Tuesday announced the regulations implementing part of the 2018 Farm Bill, which opened hemp to commercial production.

Here are some of the key questions that the rules answer.

How will hemp be tested?

The Farm Bill requires that hemp contain less than 0.3% of THC, the high-inducing chemical associated with hemp’s illegal cousin, marijuana.

Under the new rules, THC testing must be done by a laboratory registered with the Drug Enforcement Administration.

Tests must be conducted within 15 days of expected harvest by a USDA-approved sampling agent or a law enforcement officer, said Greg Ibach, the Ag Department’s marketing undersecretary, in an Oct. 29 conference call with reporters.

Samples will be taken from the flower of the plant.

To account for variation in sampling and testing procedures, labs must provide the measurement of uncertainty for their results.

If a laboratory reports the THC content as 0.35% with a measurement of uncertainty of +/- 0.06, the range is 0.29% to 0.41%.

Because 0.3% is within that range, the crop is legal.

If the crop exceeds 0.5%, the farmer will get a notice of violation and a corrective action plan. The grower will have to file compliance reports with USDA periodically for at least the next two calendar years.

Growers who rack up three of these “negligent violations” in a five-year period won’t be able to grow hemp for the next five years.

Negligent violations are not subject to criminal enforcement, but USDA will report unlicensed hemp growers to the Justice Department.

What kind of federal aid will be available?

Starting in 2020, USDA programs available to hemp growers will include crop insurance, Whole-Farm Revenue Protection, the Environmental Quality Incentives Program and other conservation offerings, and a limited selection of loan programs.

Programs may not be available in all areas.

In places where crop insurance is not offered, farmers may be able to purchase Noninsured Crop Disaster Assistance, said Bill Northey, USDA’s farm services undersecretary.

Crops that have to be destroyed because of excessive THC content will likely not be covered by crop insurance, Northey said.

Hemp farmers who participate in USDA programs will need to file an acreage report after spring planting with their local Farm Service Agency office.

The procedure will be the same for filing acreage reports for corn or soybeans.

How will the states be involved?

The Farm Bill allows states and Indian tribes to choose whether hemp production will be allowed within their borders.

While many states have legalized hemp, the crop remains illegal in some places, such as South Dakota, where the governor opposes the crop.

Where hemp farming is legal, the state department of agriculture generally regulates hemp and licenses growers.

States can also legalize hemp but leave oversight of the crop to USDA, Ibach said.

In any case, legal hemp states will have to revisit their regulatory plans to make sure they comply with USDA’s new rules.

States may impose rules that are stricter than the Farm Bill, but states cannot be less restrictive, Ibach said.

What happens next?

The interim final rule goes into effect immediately but comes with a public comment period.

USDA will use the feedback it gathers to revise the regulations as they are being put into practice.

“We will use the 2020 growing season as a chance to test drive the interim rule,” Ibach said.

The agency’s goal was to publish the rules in time for growers to make their 2020 planting decisions, said Ag Secretary Sonny Perdue.

It’s hard to say how much hemp the U.S. will produce next year under the new rules.

In 2018, when the crop could only be grown for research, the U.S. had about 120,000 acres of hemp.

With commercial growing allowed this year, production surged to an estimated half-million acres, Ibach said.

Regulatory clarity will help farmers manage their businesses, but the market for this year’s crop will likely indicate whether hemp production continues to grow, Ibach said.