Organic Farming: Essentials for Soil and Food Nutrition

How organic farming increases soil health and increases top soil?

Techniques used by organic farmers can help stop soil health degradation, or even restore soil health in previously degraded soils, because they replenish soil organic carbon and preserve underground biodiversity.

Organic farmers build soil life by adding compost and other organic materials, diversifying the crop rotation, growing cover crops, utilizing legumes to provide nitrogen (N), and integrating crops and livestock.

Cover crops are plants that are grown to benefit the soil rather than harvest income. They provide protection from soil erosion, nutrient losses, along with many other agroecosystem benefits. In organic systems, they can be used for weed suppression and are often a critical source of nutrients for cash crops through nitrogen fixation and green manure.

Organic farmers must rely on naturally-occurring fertilizers such as compost and manure for enhancing nutrient content in soils. The use of organic amendments has been shown to increase soil carbon sequestration, which may help to mitigate climate change by locking away carbon that could otherwise act as a greenhouse gas in the atmosphere.

Crop rotations—the sequence of crops grown on the same land in succession— are a critical component of maintaining healthy soils. They break pest and weed cycles, help cycle nutrients, and reduce economic risks associated with single cropping strategies. Organic farms tend to have longer crop rotations than their conventional counterparts, which leads to higher on-farm diversity.

How does organic farming increase nutrient density in food?

Organic farming increases mycorrhizal inoculum potential and AMF species diversity.

Arbuscular mycorrhizal fungi (AMF) are beneficial microorganisms that colonize almost all types of plants. They effectively extend the reach of plants’ roots, helping them to gather water and nutrients from a larger volume of soil.

AMF colonization has been shown to help crops thrive in dry conditions and in soils with elevated salt levels.

Crops grown with farmyard manure or compost contained more protein, vitamin C, phosphorus, potassium, calcium and iron.

Many studies concluded that organic practices produced more nutritious crop.

Also low levels of tillage on behalf of farmers, maintains or increases nutrients.

So we can conclude that organic farming practices that improve the variety of bacteria and fungi within the soil can make food more nutrient-dense.

What happens to soil over time in conventional ‘green revolution’ farming, and how?

Industrial agriculture has depleted soils worldwide and bred plants for size and rate of growth—not nutrition—in a narrow pursuit of ever-increasing yields.

Soil erosion and degradation of soil fertility have long been serious concerns among farmers and natural philosophers.

Regular tillage and liberal applications of synthetic nitrogen fertilizers influence soil life in ways that alter the abundance and community composition of soil bacteria, fungi, and larger life forms, like earthworms. Specifically, tillage and chemical fertilizers affect soil health through reducing soil organic matter and the diversity and abundance of soil life. Such changes can influence nutrient cycling, crop mineral uptake, and phytochemical production.

Tillage typically degrades soil organic matter by stimulating a burst of microbial activity. Tillage decreases the diversity of soil fungi and bacteria and particularly disrupts root-like fungal hyphae, reducing deliveries of mineral elements to plants from fungal symbionts.

Fertilizers use also affects soil life. Synthetic nitrogen fertilizers, for example, are known to reduce the abundance and diversity of mycorrhizal fungi.

A significant increase in the usage of pesticides, This causes a large amount of water pollution and damage to the soil.

A repetition of the crop cycle for increased crop production and reduced crop failure, depletes the soil's nutrients. Similarly, as there is no return of crop residues and organic matter to the soil, intensive cropping systems resulted in the loss of soil organic matter. To meet the needs of new kinds of seeds, farmers used increasing fertilizers as and when the soil quality deteriorated (Chhabra, 2020). The application of pesticides and fertilizers led to an increase in the level of heavy metals, especially Cd (cadmium), Pb (lead), and As (arsenic), in the soil.

Weedicides and herbicides also harm the environment. The soil pH increased after the green revolution due to the usage of these alkaline chemicals. The practice of monoculture has a deleterious effect on many soil properties, which includes migration of silt from the surface to subsurface layers and a decrease in organic carbon content.

Toxic chemicals in the soil destroyed beneficial pathogens, which are essential for maintaining soil fertility. There is a decrease in the yield due to a decline in the fertility of the soil. In addition, the usage of tractors and mechanization damaged the physicochemical properties of the soil, which affected the biological activities in the soil.

In the traditional methods, soil recovers in the presence of any kind of stressors However, this does not happen with these modern methods. In a study conducted in Haryana, soil was found to have waterlogging, salinity, soil erosion, decline, and rise of groundwater table linked to brackish water and alkalinity, affecting production and food security in the future.