Types of Soil

It is important to consider both the soil where you are planting hemp and the surrounding areas. Additionally, consider the climate of your area. You can consider growing hemp in non-ideal soil types only if the climate makes up for the soil condition. Here are some major soil types:

Growing in Clay Soil

Clay soils are generally heavier. It can retain water longer than other types of soils. Because of this, it can get dense which prevents water flow between the soil. Moreover, it can also decrease oxygen content in the soil due to its compact nature. Thus, this is one of the least favorable soil to grow hemp.

Clay soil is found in most parts of the world. You will need to prepare your plant bed to avoid clay accumulation especially in rainy areas where loose, loamy soil is easily washed off during wet seasons.

Growing in Sandy Soil

Sandy soil is usually common in drier climates and coastal areas. Other areas with tropical weather may also have sandy types of soils. It is more loosely packed which allows plenty of air and water movement. More importantly, it allows easier root growth. Hemp crops can find minerals through sandy soil easier as its roots can move much freely.

However, sandy soils cannot retain water as much as clay soil. Because hemp requires water to yield more growth, an advance preparation is needed to avoid drying up the soil. Some areas with generally warm, but moist weather may not worry as much. But, the temperature of the soil needs to be monitored as warm soil bed inhibits further growth.

A compost is necessary when growing hemp in sand soil. This will help the soil to stick together and retain water much longer. Mulch and fertilizer should also be added to aid plant growth and keep the soil relatively cool. This keeps the warm air from drying the soil too fast.

Growing in Loamy Soil

Loamy soil is perhaps the easiest soil to work with when growing hemp. It is loose yet heavy enough to retain water longer than sandy soil. It contains a balance of clay and sandy soil types. Typically, loamy soils are moist and fertile.

However, it is necessary to make sure that the soil contains the necessary minerals that the crop needs. Many make the mistakes of assuming that loamy soils need less preparation. Just like any type of soil, it must undergo proper examination and preparation before planting. Loamy soil is known to lose some nutrients easily because of over-planting, so it may be necessary to supplement it with necessary fertilizers.

Soil Mixture

A well-aerated loam soil is best for growing hemp. It should be fertile with a good amount of organic content. The soil should have a combination of clay and sand which both allows good water retention and flow. Moreover, it should have a pH of 6.3-7.8. The plant should be able to grow its roots easily through the soil. It should drain water fairly easy without losing too much as it may cause dry and warm plant bed.

It will be quite tough to find the “perfect” soil in most areas. Farmers often buy soil mixes to compensate if their field contains too much clay or too much sand. Also, mulch or compost can assist in adding much-needed nutrients to the soil. Moreover, it can help lessen the effects of having too much clay or sandy soil.

Soil Requirements

General Composition

An ideal composition of the soil would be loam with a balanced amount of sand and clay for water retention and oxygen flow. A good moisture is necessary for a proper seed germination. This is especially important during the first week after planting.

Soil pH level should be between 6.3-7.8. Moreover, it should contain at least 3.5% organic matter. But, it is better to have more organic matter to aid growth. Too much clay or soil can be compensated by mulch and compost to loosen up or hold water and nutrients in. It also adds more organic matter to the soil.

Texture

Hemp needs a good mix of both water and oxygen to grow and thrive. Too much water will cause lack of oxygen. However, too loose will stop retaining water and the plant will have a tough time finding water. Therefore, there should be a balance of compactness and looseness in the soil to yield maximum growth.

The soil should be dark and rich which signify a good amount of organic matter. However, the soil should be light and airy to the touched. It should be loose without being too sandy. Moisture shouldn’t make the soil lumpy. Additionally, being wet should not make it batter-like. It should hold water without becoming too muddy.

Water Drainage and Retention

Water is the most important element in growing any crop. Different crops require a different amount of water throughout its season. While hemp can practically grow in different soil, it has an ideal soil and water combination. Before considering the soil, the rainfall should be observed first. Ideally, hemp requires about 63.5-76.2 cm (25-30 inches) per year. Anything less or more than the ideal rainfall can be compensated with the soil type.

In ideal climate, a loose, airy soil is perfect for growing hemp. However, for warmer, drier weather, a bit of clay in the soil will help hold water much longer. However, it shouldn’t be too much that it hinders root growth and oxygen. On the other hand, for areas with more rainfall in the year, the soil could be a bit looser to avoid “overwatering.” Too much water in the soil will steal the much-needed oxygen and other minerals from it.

Temperature

Good moisture is required especially during the first weeks of growing season. A relatively wet weather is the perfect time to begin the growing of hemp. Approximately 25.4-33 cm (10-13 inches) of rainfall is ideal for seed growth. If not enough rainfall occurs at this stage, it is important to take advantage of the early soil moisture in the ground.

Seedlings are known to survive and germinate at temperatures above freezing, but the ideal soil temperature for germination is 7.8°-10°C (46°–50°F). A good rule of thumb is to plant hemp slightly before the planting of corn begins.

At this point, the soil needs water slightly above its regular content. This allows the grains to germinate faster and find water easily. However, as the roots grow, it shouldn’t be suffocated by compact soil. That is why it needs warmer temperature while it grows. Water should be monitored in the successive periods as the soil may lose too much moisture.

Soil Preparation

More often than not, the ideal soil cannot be found locally right away A good soil needs preparation and mixture. Loamy soil is a mixture of sand, clay, and silt. The idea ratio which can be followed when mixing is 40:40:20. This ratio allows water retention and drainage for hemp germination and growth.

The local soil can always be improved by purchasing high-quality commercial mixtures. Mixing manure, mulch, bonemeal, bloodmeal or other soil additives can improve not only the texture but nutrients as well. Some farmers may even use commercial soil exclusively by planting in pots or bags. But, this can be a bit expensive than conventional farming.

Adjusting pH Levels

The ideal pH level is between 6.0-7.8. Lower pH level means too much acid in the soil. This can be adjusted using agricultural lime (calcium carbonate) which reduces acidity. Too much alkaline will register high pH level. Sulfur is used to lower the alkaline. It is converted to sulphuric acid by the bacteria in the soil.

Soil Sterilization

The least talked about method is sterilization of the soil. More experienced farmers often do not need to sterilize the soil as the rotation of crops and proper fertilization often kills harmful bacteria and weed in the soil. However, planting hemp for the first time in the soil will need proper sterilization to avoid long-term issues with the plant.

A popular method is steaming the soil. However, this can be very expensive. A better option is solarization. It involves tilling the soil into fine parts, watering it, and covering it with a sheet of clear plastic. This amplifies the heat from the light of the sun. It should reach the temperature of 46°C (114°F) for around four to six weeks. It should be checked and re-tilled regularly to ensure consistency.

Soil Rejuvenation Techniques

Hemp can be planted on the same field for several years without any adverse effects on the land. A lot of farmers use it as one of the crops rotated with another. It may even improve soil health.

Some studies and experiences even show that hemp can remove toxins from the ground. Areas surrounding the Chernobyl nuclear disaster were planted with hemp. Apparently, it was highly effective in removing radioactive substances from the soil.

This proves that hemp is quite flexible and can be grown in different climates, areas, and regions. However, in order to yield the best crop each and every time, the soil must be rejuvenated.

Compost

Compost is one of the easiest ways to improve soil quality. It is commonly used to add nutrients to the soil even before planting any crops. In the United States, where growing hemp is still illegal in most states, using compost has been revolutionary as it replaces chemicals such as pesticides in most hemp farms. Because farmers in areas where hemp cultivation is allowed to some degree have no standard guide for the use of chemicals in cultivation, they have used chemicals with abandon. However, it raised concerns about harm to the soil which eventually led to a compost revolution among American hemp farmers.

Randy Ritchie, the co-founder of Malibu Compost, reports that the demand for compost among hemp farmers allows them to rejuvenate the soil instead of replacing it.

For most farmers, compost is a cheap way to help sustain hemp growth and to keep nutrients in the soil. This will allow continuous hemp cultivation in the area for years without adverse effects on the land.

Cover Crops and Rotations

The best way to keep the soil healthy is to rotate crops every few seasons or so. Growing hemp for too long will increase the risk of pest buildup suck as borers, rootworms, and rots. Because of this, farmers often use hemp to rotate with other crops such as wheat, bean, or alfalfa. It should be noted that hemp should not follow crops such as edible beans, soybeans, canola, or sunflowers as these plants are susceptible to white mold and other pests which hemp growing may bring to the soil. The best crop to rotate with hemp is wheat due to its hardiness and economic demand.

Some farmers may be apprehensive about rotating hemp due to its yield and income possibilities. Thus, they use other crops as cover crops between hemp seasons. Cover cropping is a technique where certain plants are used to rejuvenate the soil during planting seasons. These cover crops prevent erosion, mineral depletion, increase living matter, fix soil nitrogen, and control pests and diseases.

Cover crops are typically planted right after harvest and cut down and tilled into the soil before the next spring planting. It is important to keep the cover plants from growing seeds and spreading. Popular cover crops for hemp are mustard, legumes, and clover.

Conversely, hemp is also a good cover crop to rejuvenate the soil from planting other crops.

Intercropping

One drawback of plant rotation and cover cropping is the time required to accomplish it. The plants need to grow before starting the next season of hemp. Farmers cannot afford to lose profitability between the rotations and seasons. One thing to consider is intercropping.

Hemp can be a companion crop to another plant which can also yield another source of profit. It draws inspiration from the farming method of indigenous farmers where they plant several crops together. Typically, intercropping is done with the combination of cover crops as this allows maintenance of soil health without the need for plant rotation every few years.

Companion crops should not be susceptible to the same issues that hemp has. Moreover, it is best to avoid crops that will compete with hemp in terms of root growth. That means cucumbers and melons should not be planted with hemp at any time. Planting aromatic plants such as basil, garlic, or lavender can accomplish several things at once. These aromatics are not susceptible to the same pests and diseases as hemp, they will not compete with it, and can even deter pests due to their aroma.