The COVID-19 pandemic changed the relationship of many Americans with food almost overnight. Many people are planting victory gardens to relieve the stress of grocery shopping in a safe manner and to ensure food security. This tradition is reminiscent of previous generations that cultivated home gardens throughout both World Wars.

Even before the pandemic, interest was high. The National Gardening Association found that 42 millions U.S. homes – or 1 in 3 – grew food either at home, or community garden.

Home gardening is not always easy. Poor soil quality can hinder vegetable growth and food production. Many gardeners in low-income areas, and especially those who are new to gardening, do not have the resources they need to improve their soil.

Scholars, we have studied the power of microbes within a variety of settings, including forest and permafrost soils, built environments and agricultural soils and digestive systems. Compost is a widely used gardening resource that should be given a major boost by the government.

Compost is made by microbes that break down organic matter, such as food scraps. Compost is so effective at improving soil health that it’s sometimes called “black gold”.

Compost feeds soils

Healthy soils are a living mixture of minerals, microbes and organic matter. They also contain water and air. In unhealthy soils, there may be fewer microbes and less organic matter. They become less active, and therefore less beneficial to plants. Poor soils are less able to hold water and decompose organic matter into building blocks that can be used for new growth.

The soil that is in good condition (right) feels, looks and smells differently than the soil that has been degraded (left). Sue Ishaq, CC BY-ND

feeds the microbes to make degraded soils more fertile. They require new organic matter, such as plant or animal tissue, that they can recycle.

Healthy soil contains some food that is produced by plants that fix the carbon in sunlight and pump nearly half of it into the soil as sugars. Microbes, in exchange, provide nutrients that the plants cannot acquire by themselves.

The soil microbes feed also on organic matter that is old, such as leaf litter and roots. New biochemical analyses indicate that these microbes die and become soil organic matter themselves.

Mix green organic waste like garden leaves, straw or vegetable peels with brown organic matter such as soil or manure to make compost. Over a period of weeks or months, microbes transform the mixture into compost that looks like soil.

The microbes release energy as they break down chemical bonds within the plant material. Compost piles reach temperatures of up to 170°F. This heat can kill microbial pathogens, which can be carried by manure.

Compost acts as a sponge when added to soils. Compost is also a source of micronutrients, such as nitrogen and phosphorus, that plants require to grow.

Compost of high quality, such as this batch made with horse bedding, looks remarkably like healthy soil. Gardeners use it to nourish microbes and help the soil retain nutrients and water. Kristen DeAngelis, CC BY-ND

Equity is a concern when it comes to accessing compost

Why don’t people use compost more often? Healthy soil is, in many ways, a luxury . It takes time to build a compost heap, and then it requires ongoing maintenance. This includes adding greens and browns at the correct intervals and watering and turning the pile weekly in the summer and monthly in the winter.

Composting requires tools and materials that are not always affordable to all gardeners. Composting requires a lot of space and a friendly regulatory atmosphere that allows residents to build compost piles. If not properly managed, these piles can attract pests and produce unpleasant odors.

These factors are driving interest in municipal composting, where a community collects organic waste from residents and processes it. These programs accept yard and food waste from residents and businesses, as well as restaurants and schools. They then create a professionally managed composting facility.

Municipal composting can save money by diverting waste food from landfills. It also promotes sustainability by reducing emissions of methane – a powerful greenhouse gas produced by landfills in the absence of oxygen. Combining a variety of wastes improves the breakdown and has more nutrition.

In exchange for their waste, many municipal programs provide participants with a certain amount of compost. Some programs offer pickup and delivery.

The municipal composting program in Tacoma, Washington.

Growing compost programs

We encourage those with the time and resources available to experiment with home composting. However, creating and promoting municipal composting will help reduce greenhouse gasses from food wastes and improve soil quality.

Local farms or community gardens sometimes offer composting. Many private companies provide local pickup services.

Residents and businesses in San Francisco are required to sort their waste into three categories: compostables, recyclables and trash. Residents and farms in the Bay Area can use food wastes composted. San Francisco Environment

Leaders in the promotion of city-scale composting include San Francisco and Seattle. Smaller cities, such as Burlington, Vermont, are also leaders. These programs are based on local ordinances, which either provide incentives to restaurants or other large food waste generators to compost their food waste rather than sending it to landfills.

Consumer support is needed to retain and attract funding for municipal composting. Land demand, particularly in urban areas, can lead city governments to sell community spaces that are underfunded or underutilized for commercial purposes. This is especially true if the local neighborhoods do not have enough social capital to advocate on their own.

Has many benefits when it comes to promoting community-based food production and composting waste. It improves soil, creates jobs, and increases access to fresh fruits and vegetables. It can also be used to mitigate climate change. The best part is that investing in local agriculture boosts the local economy. This helps people who are most in need, those seeking to access safe and nutritious foods.