Soil is the base of agriculture. Whether we practice conventional or organic growing, the journey always begins with soil. Maintaining soil health is essential for sustainable agriculture, ensuring that soil remains fertile, productive, and capable of supporting diverse plant life over time.
Soil is a living entity because of the presence of fungi, bacteria and other microbes and maintaining its health is very important. The soil's living population of microbes and other organisms are significant contributors to its fertility on a sustained basis and must be protected and nurtured for sustainable agriculture.
To build soils into sustainable systems, we often use the regenerative form of agricultural practices such as field fallowing, crop rotation, mixed cropping and intercropping or import concentrated nutrient sources in the form of manures or ready to use fertilizers.
Defined by the U.S. Department of Agriculture, Soil health is:
the continued capacity of soil to function as a vital living ecosystem that sustains plants, animals, and humans. Healthy soil gives us clean air and water, bountiful crops and forests, productive grazing lands, diverse wildlife, and beautiful landscapes. - (1)
The following are some key practices which we can apply to maintain soil health:
Read on as we explain each of the key practices.
Field Fallowing
Field fallowing is an agriculture practice where a piece of land is left uncultivated for a period to restore its fertility or to break the cycle of pests & disease. Fallowing soil is a method of sustainable land management that has been used by farmers for centuries in regions of the Mediterranean, North Africa, Asia and other places.
After years of monoculture, the soil recovers its moisture and fertility while its structure improves. In addition, by stopping cultivation, populations of enemies and pathogens are reduced.
Crop Rotation
Crop rotation is the practice of growing different crops in the same area across seasons to improve soil health, optimize nutrients, and reduce pests. If only one crop is sown in a particular field year after year, the roots of the crop extract nutrients from the same depth of soil every year, exhausting the rhizosphere and thus causing reduction in the crop yield.
To maintain the achievable yield potential, it is therefore necessary to take measures to improve soil fertility and productivity. (2)
Based on the residual effect on the soil, crops can be classified in two types:
Exhaustive crops:
These crops consume large amounts of nutrients which deplete soil fertility. Examples of heavy crop feeders include corn, tomatoes, cabbage and other Brassicas, peppers, lettuce, potatoes, strawberries, melons, wheat and rice. Soybeans are often heavy feeders even though they fix nitrogen, they still require phosphorous and potassium applications.
Restorative rotation:
These types of crops enhance or maintain soil fertility by improving soil structure, replenishing nutrients and add organic matter. Examples of restorative crops include alfalfa, clover, beans, peas, lentils, chickpeas, cereal rye, oats, barley, buckwheat and radish.
By practicing crop rotation, farmers can enhance their soil fertility and reduce their reliance on chemical inputs, promoting a more sustainable farming system. Rotating between exhaustive and restorative crops is effective to balance nutrient depletion and replenishment, improve soil structure and maintain long-term soil fertility. For example, rotate between corn and soybean, where corn depletes soil nitrogen, but soybean replenish it through nitrogen fixation.
Mixed Cropping
It is an agriculture practice where two or more different crops are grown simultaneously in the same field. Mixed cropping is usually done to reduce the risk of crop failure, maximize use of resources and improve soil health. The Mixed cropping concept is not new and has been practiced in many parts of the world to maximize land productivity in a specific area in a growing season.
Generally, the practice of planting two or more crops on the same field is more common in tropical regions where more rainfall, higher temperatures, and longer growing seasons are more favorable for continual crop production. Mixed farming system is helpful in decreasing the cost of production per unit area, increasing income and productivity and reducing the risk of farmers.
Mixed cropping is when two or more crops are grown on an equal amount of land at the same time. For example, growing wheat and chickpea crop on equivalent land at the same time is mixed cropping. This method helps to reduce the risk of crop failure by growing crops that have different maturity times and water needs. This way, the crops will be less likely to suffer from abnormal weather conditions. (3)
Intercropping
Intercropping is the practice of growing quite one crop on an equivalent field at an equivalent time during a definite row pattern. After one row of the most crops, three rows of intercrops are often grown. This increases productivity per unit area. Examples: Planting alternating rows of maize and beans or growing a cover crop in between the rows. (3)
The crops are typically chosen to complement each other in terms of growth habits, nutrient requirements, and other factors. Intercropping has repeatedly been shown to enhance ecosystem functioning, such as enhanced yield and stability, increased resource-use efficiency, enhanced soil fertility, reduced crop disease and pests, and minimized environmental costs. (4)
Well-designed intercropping operations efficiently use natural resources, increase biodiversity, manage pests, and in many instances, enhance crop productivity and quality, and natural soil fertility with reduced consumption of off-farm inputs. The primary consideration in intercropping is selecting compatible crops to minimize competitive inhibition, allow for ease of field management, and increase profit per land unit compared to monocultures. (5)
Cover Crops and Green Manure
A cover crop is a plant that is used primarily to slow erosion, improve soil health, enhance water availability, smother weeds, help control pests and diseases, increase biodiversity and bring a host of other benefits to your farm. (6) They are typically planted during the off-season or in between main crop cycles, when fields might otherwise be left bare.
Cover crops are an important component of sustainable agricultural development as they have been shown to improve soil health by enhancing the activity of microorganisms as well as their diversity and abundance.
Green manures are a specific type of cover crop that is grown and then tilled or incorporated into the soil while still green or shortly after flowering. The aim is to enrich the soil with organic matter, improve its fertility, and add nutrients.
Examples of some crop types frequently used as cover crop are
Leguminous broadleaves
Clovers, Cowpea, Faba bean, Lentil, Pea, Soybean, Sunn hemp
Non-leguminous broadleaves
Buckwheat, Flax, Radish, Rapeseed, Safflower, Sunflower, Turnip
Both cover crops and green manures are essential components of sustainable farming systems. While cover crops focus on protecting the soil, managing pests, and improving its overall health, green manures specifically aim to enhance soil fertility by adding organic matter and nutrients.
Manures and Fertilizers
Manure and fertilizers are the substances which can be added to the soil to enhance soil fertility and promote healthy plant growth. They both are significantly differ in their composition, source and method of application.
Manure refers to organic matter that is used as a fertilizer. It is derived from animal or plant waste and is used to improve the physical, chemical, and biological properties of the soil. Manure is typically rich in organic matter, nutrients, and beneficial microorganisms. The use of manures considerably improved the crop yield, macronutrients viz. nitrogen, phosphorus, potassium and micronutrients such as zinc, iron, manganese and copper, uptake in both the crops because of nutrient release from decomposed organic matter. The combined use of organic manure along with other fertilizers has great potential to improve soil quality and productivity of the crop. The application of organic manures such as farmyard manure (FYM), poultry manure (PM), press mud (PrM) and rice straw compost (RSC) in the soil acts as a nutrient reservoir and helps in recovering soil health. (7)
Fertilizers are substances, either organic or synthetic, that are applied to soil or plants to supply essential nutrients for growth. These fertilizers can be classified as:
Inorganic fertilizers
Organic fertilizers
Biofertilizers
Inorganic Fertilizers
Inorganic fertilizers, also known as synthetic fertilizers or chemical fertilizers, contain all the essential nutrients which are early accessible for plants. They are typically concentrated formulations of nutrients, such as nitrogen (N), phosphorus (P) and potassium (K), often referred to as NPK. Due to continuous use of inorganic fertilizers alone causes soil organic matter degradation, soil acidity or alkalization, soil deterioration and environmental pollution, so integrated or mixed inorganic and organic nutrient management system is an alternative system for the sustainable and cost-effective management of soil and the result is improve in soil properties and raising soil fertility without affecting environment. (8)
Organic Fertilizers
Organic fertilizers are derived from natural sources like plant materials, animal waste or compost that are used to improve soil health and plant growth. Organic fertilizer refers to materials used as fertilizer that occur regularly in nature, usually as a byproduct or end-product of a naturally occurring process. Organic fertilizers enhance the natural soil processes, which have long-term effects on soil fertility. (9)
Biofertilizers
Biofertilizers are substances which contains living microorganisms which, when applied to seeds, plant surfaces, or soil, colonize the rhizosphere or the interior of the plant and promotes growth by increasing the supply or availability of primary nutrients to the host plant. Biofertilizers keep the soil environment rich in all kinds of micro- and macro-nutrients through the process of nitrogen fixation, phosphate and potassium solubilization.
Nurture Growth Biofertilizer
Nurture Growth Biofertilizer is a microbial fertilizer which contains beneficial microorganisms. These microorganisms directly work on the plant as well as in the soil by adding beneficial microbes in the soil and contribute to increases the fertility of soil. These microbes build healthy soil by feeding the soil and balancing the soil microbiome to keep it healthy and living.
Nurture Growth Biofertilizer is widely implemented by farmers as an option to build soil health and resiliency because it adds beneficial microbes to the soil. When added as a foliar spray or through drip irrigation, the microbes interact with the plant to secrete hormones, metabolites and enzymes which interact with the microbes in the soil. As a result of the biological reaction, the plant and the soil communicate with each other to determine how many nutrients are required. For example, at the beginning of the growing season, more nitrogen is required, however, during the later part of the season, the plants may need other nutrients.
Our microbes help to determine how much N, P, or K is required and produce as much is required. It will not overproduce nutrients because the soil microbiome and our microbes will balance each other and will only produce what is required.
Soil health is crucial for plant growth, environmental sustainability, and a thriving ecosystem. By adopting regenerative farming practices and carefully applying manures and fertilizers, we can enhance and preserve the physical properties of the soil, boosting productivity while safeguarding its long-term health. This approach not only benefits crop yields but also ensures a sustainable, thriving agricultural system for future generations.
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Blogger Biography
Ankita is a Senior Science Officer at Nurture Growth Biofertilizer. She has over 9 years of experience in Agriculture research and extension. Her areas of specialization encompass Plant Pathology, Microbiology, Plant Protection, Organic farming, Biofertilizers, Organic Fertilizers, and Biocontrol agents.
She holds a Ph.D. in Plant Pathology and a master's degree in Botany with a specialization in Plant Pathology. Her doctoral research involved an in-depth study of lentil wilt and its management through various practices.
She has extensive experience in organizing training programs on Organic and Natural farming techniques for farmers, agricultural growers, students, and other stakeholders.
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