Capacity for water retention improves
Ability to cycle nutrients increases
Not all soil is ideal for plant growth, which is why compost as a supplement for plant nutrition is useful and important. An even layer of compost allows an allotted area to contain a significantly increased amount of primary, secondary, and micro nutrients to plants. These nutrients are slowly released into the soil, with nitrogen taking from 3 to 4 years to be fully integrated, phosphate 3 to 5 years, and potassium releasing almost entirely during the first year of application.
As time goes on, the soil is able to retain water to a higher capacity which allows for a reduction of irrigation requirements, an increase of cation exchange capacity, and an improvement in the soil’s ability to hold onto nutrients. This process also allows for a reduction in soil compaction, enhanced microbial process, and improved nutrient cycling ability. Additionally, the added compost helps reduce soil-borne disease, reducing the need for pesticides.
To apply compost, first cultivate the soil to condition for planting. Then, uniformly apply the compost throughout the designated area using a traditional manure spreader or similar style of equipment. Add seeds to the mix, and water appropriately. Compost can also be applied over crop stubble prior to drill seeding, adding water during or after the process. In the case of crops that are harvestable multiple times during the season, apply compost when crop foliage is dry, watering it when possible.
Note that each crop will utilize compost differently, so choosing the right type of compost will be important to garner the best results for growth. For the most optimal results, lab test compost mixtures to decipher the nutrient makeup so that the crops are obtaining the appropriate level of nutrients.
Some of the information in this article came from the Compost Research & Education Foundations’ Compost Use Applications - A Return on Investment (ROI) factsheets. The full set of factsheets can be found here.