growing hemp

8/7/2019 Growing Hemp

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Growing Hemp in 2011

Hemp is a fibrous plant grown throughout the world. Depending on where you are, hemp has differentdefinitions. Commonly, hemp with <1% THC value is considered a non-drug form of the plant (most drugforms of cannabis contain 10+% THC). Hemp, when smoked will more likely produce a headache and no

euphoria! Hemp has a wide variety of well-documented applications; today, we are going to explore thelegal farming of this great crop.

Non Toxic Agriculture

Hemp is grown in a very similar way to the drug-use cannabis plant. It looks the same and it grows thesame. Environmentally friendly, hemp crops require no added pesticides or herbicides. Compared tocotton, this is important, a crop which uses about 24% of the world's pesticides, but they form only 2.4%of global crops!

Yields

Well-fertilised soil is required for a good yield. Hemp can be grown in a variety of soil types but bestresults come from sandier soils. In general, the better the soil quality, the higher the yield. As with allcrops, nutrition comes from the soil itself. This is one reason why some believe hemp has not becomemainstream. Mono-cultured fields soon deplete their nutrients and chemical additives are the onlyother answer.

This is the reason that hemp farming is most successful as part of a sustainable permaculture thatincludes rotation farming. To extract nutrients from deep in the soil, hemp has a large tap root system.Soil health is maintained as the leaves from the plant fall during harvesting/flowering and are recycledinto nutrients. A hectare of hemp can provide 9 tons of hemp fibre and 2 tons of seed in only 120 daysor less! Yields are optimal when healthy seed is used and correct spacing is observed during planting.The latitude of the plantation has an important part to play when choosing seed variety. The existing soilcondition should be investigated before the first crop is sown.

Harvesting

At the ideal time of harvesting, which is dependent upon the seed maturity and/ or ideal leaf defoliationthe crop is harvested. A combine harvester is the usual means of gathering seed, whilst fibre is collectedby mowing/cutting machinery. Harvest time can be affected by both the hemp variety and the intendedtarget crop. There are a number of harvesting alternatives;

Baling

The whole plant is compressed into a bale similar to straw, ready for pulping. For some uses includingfibre/hurd/shiv production, the hemp stalk must be complete.

Retting



Separation of the fibre from the hurd/shiv is a natural process called retting. A good ret will enable ahigher fibre quality to be produced which in turn will enable easier manufacturing. There are severaltypes of retting in common use;

Dew retting

Water Retting

Chemical Retting

Crailar Enzyme retting

It can take up to 5 weeks to complete hemp retting depending on the methodology employed. Timingthe length of the retting process carefully is an important step in ensuring high quality hemp fibre and ahealthy yield. Before baling and storage, even retting can be attained by turning the windrows. Beforebaling and storage, even retting can be attained by turning the windrows. Using an in-field chaffer/sieve(or similar machinery) a cross-contamination rate of 25% can be expected between hurd and fibre.

Decortication

Hemp fibre and hurd are separated in the decortication process, usually in a purpose built facility.Decortication facilities have to enjoy a high throughput in order to be profitable and can cost up to $10to build. Globally there are only 10 major decortication facilities. A disk refiner is required whenproducing MDF. For textile production, scotching, hackling and combing are usually required.

Harvesting Operations

Hemp should be cut in the early flowering stage for textile applications or whilst the main pollenshedding process occurs, before the seeds are set. Fibre that is harvested after a seed crop has maturedwill be lignified and is only suitable for use in limited non-woven fibre applications. Fibre that isharvested after a seed crop has matured will be lignified and is only suitable for use in limited non-woven fibre applications. This results in lower fibre yields if the stalks are cut after seed has matured. Amodified combine harvester operating at high speed can harvest by cutting the seed heads andthreshing them. To reduce blockages during harvesting, a narrowed chopper can be utilized. Bothconventional and axial-flow harvesting machines can be used to gather a hemp crop. Stalks are left afterretting to dry in the field. They are then mown, cut to length and baled.

Weather Implications

Hemp crops are susceptible to the weather, particularly at the start and finish of the flowering cycle.Insufficient rain at the beginning adversely affects growth. Excess rain at the end of the growth cycle canresult in a lower yield with losses due to a retting and rotting process.

Processing & Storage



Seeds should be cleaned in the field with a winnower. The clod sieve size will depend upon the variety of the hemp seed grown. A recommended size would be 5-6mm slits and 2mm elongated slots. If seeds areimproperly treated, it is hard to remove the protective husk (pericarp); if producing hemp oil, this iscrucial in ensuring a low THV content. A 12% moisture content is an ideal target for drying process, alow-humidity, dark and cool (4oC) storage area is the best way to keep seed over time. This should

ensure an 80%+ germination rate for 2 years, with rates going down significantly in following years. Theremaining few centimetres of stem on the field are tilled into the soil again to provide nutrients andimprove the condition of the soil for future crops. All parts of the hemp plant are utilized commerciallyor recycled into the environment. Even the dust residue of processed hemp may be used for fuel orplastic production.

Find Out More About Hemp

To find out more information about hemp from all aspects including agriculture, construction andmanufacturing, check out these in-depth books by Paul Benhaim;

How To Build A House of Hemp

How to Grow Hemp for Profit

Hemp Fuel and Hemp Biodiesel Guide

The Hemp Textile Industry Secrets

The Hemp Plastics Industry

Hemp - From Food to Fibre

The Hemp Bodycare Industry

Medical Marijuana Industry

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