Using crop green manures for cannabis cultivation can help to increase soil fertility, improve weed control and reduce water and fertilizer use. This is an excellent practice for any grower looking to keep their farm as natural as possible.
Long-term green manures like perennial ryegrass or lucerne are ideal for cannabis growing. These can be sown in the fall and plowed into the soil before spring planting.
Deep Rooting Green Manures
Deep rooting green manures scavenge nutrients from the soil and translocate them to the surface rooting zone. This increases their nutrient availability to subsequent crops and reduces the need for chemical fertilizers.
They also add organic matter, improve the structure of the soil and add fertility. This, in turn, results in greater yields and lower costs.
The best time to sow crop green manures is a few weeks before sowing or planting your next crop, or when they reach maturity whichever comes first. The earlier you do it, the sooner the manure will decompose and return to the soil.
You can sow a variety of different green manure mixes at different times of the year. Some are sown in autumn and cut back, others are sown in spring and allowed to grow throughout the winter before being dug in.
Some manures such as clovers and vetches, have flower buds which are attractive to bees and other beneficial insects. These flowers help to attract natural predators, such as hoverflies that feed on aphids.
Another benefit of some green manures is that they act as a cover crop, helping to prevent erosion during the winter. This is particularly important on sloping sites as the roots of the plant can anchor the ground in place.
There are a range of fast-growing, nitrogen fixing plants that can be sown as crop green manures. These include crimson and Persian clover, fenugreek, lupins, phacelia, buckwheat and white mustard.
These short-term, fast-growing crops can be sown between your main summer crop as catch crops or interplanted with the main crop. They can also be used as under crops to boost the growth of the crop and suppress weeds.
It is vital to remember that any crops sown at this time can also contribute to the development of harmful fungi and other soil-borne diseases, so it is important to choose the right types of green manure for your area.
Some winter cover crops, such as rye and wheat, fix nitrogen in the soil, preventing nitrate leaching during the cold weather. Other varieties, such as common vetch and tares, have high levels of glucosinolates that disrupt pest life cycles and prevent re-infestation by these pests.
Nitrogen Fixing Green Manures
Nitrogen fixing green manures are plants that improve the nitrogen levels in the soil by trapping excess nitrogen from the air. They can be legumes like peas and beans or non-legume plants such as buckwheat, mustard, alfalfa, lupins and sweetclover.
When grown in good nutrient rich soil, green manures can add up to 40 to 200 pounds of nitrogen per acre. However, this is dependent on the species of legume and cultural and environmental conditions. For example, a delayed planting date, poor stand establishment, or drought can reduce the amount of nitrogen in cover crops.
Legumes such as beans, fava beans, lupins and fenugreek are ideal nitrogen fixers as they have roots that work with the bacteria in the soil to bind the nitrogen. These plants can also smother weeds and deter pests when planted in combination with other green manures.
Often, legumes such as beans are included in crop rotations. This allows the roots of a green manure to draw up nutrients from the subsoil and bring them up to the surface rooting zone, where they become available to the following crop.
The roots of some green manures such as rye, tares, vetches and fodder radish, also have the ability to extract phosphorus from the soil. This is a very valuable source of P for the soil and helps to build organic matter.
Another advantage of green manures is that they can be used to create a natural habitat for beneficial insects, which help control disease and pests. They can also be used to attract and shelter predators such as hoverflies, which are important for controlling aphids, which infect vegetable crops.
Some green manures, such as lupins and clovers, are also considered nutrient conservers. These plants minimize nutrient leaching and add additional nutrients into the soil, improving water infiltration and retention and increasing aeration.
They can be sown at any time, but many grow best from late fall to spring. They can be sown on heavy to medium soils and will germinate well even when temperatures are dropping in mid-autumn.
Depending on your needs, you can plant a wide range of green manures. Some of the most common include field beans, lupins and clovers. Other choices, which are often more difficult to plant, include rye, tares, smother peas and vetches.
Green manures can help improve the nutrient content of soils, reducing weed populations and pests. When applied at the right time and amount, green manures can also prevent diseases and nematodes from spreading to crops.
In addition, incorporating crop green manures into the soil can improve its drainage and aeration, resulting in better water retention. It can also encourage the growth of beneficial microorganisms and other organic matter that are necessary for healthy soil organisms.
Many cannabis growers use a variety of soil fertilizers to ensure optimal plant health and growth. These can include commercial soil blends, liquid nutrients, and homemade preparations.
Liquid fertilizers are commonly used for indoor growing. They can be pushed through misters, drip lines, and hoses for quick and easy delivery to the plants. They are usually a mix of nitrogen, phosphorus, and potassium (NPK), the three basic macronutrients required by plants.
Nitrogen and phosphorus are the primary nutrients for the vegetative stage of marijuana growth, while potassium is essential during flowering. When using liquid nutrients, it is important to apply them at the proper time to avoid nutrient lockout, which can lead to poor yields and damaged growth.
Generally, it is recommended to start adding nutrients to your potting soil when the plant’s roots are starting to grow rapidly. This is the same strategy used for other houseplants, and it’s a great way to avoid burning out the plants or damaging their growth.
If you’re a newbie to growing cannabis, consider purchasing a soil nutrient blend that is specially designed for the cultivation of marijuana. These mixes are often made with high-quality compost and other organic materials, which can ensure a more nutritious and sustainable growing experience.
When choosing a soil nutrient, it is best to make sure that the formula contains all of the key macronutrients (nitrogen, phosphorus, and potassium) for your cannabis strain. These nutrients are important for root and stem development, as well as air and water transport.
In addition, soil nutrient formulations should be balanced to ensure that all the macronutrients are available at the correct times in the growing cycle. During the seedling and vegetative stages, cannabis plants can absorb far more nutrients than a typical houseplant. In order to ensure the highest quality buds, it’s important to add nutrients as soon as the plants reach this phase, rather than wait until later on.
Organic matter is a vital component of any healthy soil system, as it provides essential macro and micro nutrients that cannabis plants need to grow. It also contains beneficial microbial life forms that break down and make these nutrients available to your plants.
Soil amendments made with compost, pumice, earthworm castings, kelp meal, perlite, bat guano, fish emulsion, or peat moss are some of the most common ingredients you can use to improve your soil. They will help build a living ecosystem that supports the growth of beneficial microorganisms, such as mycorrhizal fungi and bacteria.
Another important benefit of using organic matter is that it doesn’t contain the salts and chemicals found in synthetic fertilizers and pesticides. These chemicals can cause problems for cannabis plant health and can enter the body of a consumer when they are inhaled, leading to negative effects.
Nitrogen is a key component of chlorophyll, which allows your cannabis plants to use sunlight to convert carbon dioxide and water into oxygen and glucose (energy). It’s essential for photosynthesis, respiration, cell division, and plant growth and maturity.
Phosphorus is another critical nutrient that plays a big role in plant growth, flowering, and development. It helps your plant absorb the energy from the sun, store it in their cells, and use it to create bigger, healthier buds and florets.
If your soil is deficient in phosphorus, you can add it with animal manure, blood meal, compost, or fish meal. You should monitor your plants’ growth to see if they are getting enough of this nutrient, and take steps to correct any deficiencies as quickly as possible.
Many organic growers prefer to avoid commercially available chemical fertilizers and pesticides as much as possible. This is because these toxins are toxic to the human body and can cause adverse effects in both humans and the environment.
There are a number of other benefits to growing organically, including higher yields and enhanced flavour. These are due in part to the fact that your plants will have access to a greater variety of natural micronutrients than with non-organic cultivation techniques.