Researchers from the American Society of Agronomy found that compost could improve apple orchard sustainability and tree health.

Due to recent increases in climate change effects, farmers have become more aware of the environmental impacts of orchard management and sparked their interest in sustainable nutrient management practices. Farmers have been searching for a way to improve soil health without harming the environment or risking their crops.Apple trees in commercial orchards are grafted plants. The above-ground portion of the desired apple tree is attached to a healthy root system. Source: Greg Peck

Soil is different from orchard to orchard. Healthy soil depends on many factors, including the microbial community living in the soil. Microbial communities are made up of bacteria, nematodes and fungi. Some microbes convert soil nutrients into forms that apple trees can then use. In the soil, microbes and plant roots have a beneficial partnership. Plants release fluids from the roots into the soil, and the fluids serve as a food source for the microbial community and the microbes in turn help the apple trees. Bacteria recycle nutrients to promote plant growth and alter plant metabolisms.

During the study, the team applied compost to apple orchards and studied soil health and crop health. They found that adding compost increased the number of soil bacteria associated with recycling nutrients. Compost provides an additional food source for the bacteria, which allows bacteria to thrive. Larger microbial activity leads to more nutrients for the trees. Applying compost could reduce the amount of fertilizer needed, which lowers costs and negative effect on their environment.

Some fertilizers come from non-renewable resources. Adding compost to nutrient management plans would reduce dependence on these non-renewable resources while also providing sustainable use for materials that would otherwise be considered waste. Farmers can integrate compost with quicker release fertilizer sources. This is a big step in farm sustainability, but it’s not the singular solution.

In the future, the team hopes to replicate this study in different regions with different soil characteristics. They also want to take a deeper look at the roles of fungi in microbial communities of orchard soils.

The study was published in Soil Science Society of America Journal.