Using fertilizer in a no till garden

Overuse of synthetic fertilizers causes immediate issues in our plants and soil.  

High nitrogen levels in the soil can cause plants to grow very quickly leaving them tender and susceptible to insect pressure and diseases. High nitrogen levels in the soil from artificial fertilizers can speed up the decomposition of organic material in the soil. As this process is sped up, carbon in the soil that is also a necessary part of plant growth, is used up faster as well. High nitrogen levels in the soil can also cause minerals to be blocked up and not available for plant use.

Nitrogen is soluble in water and is leached from the soil by watering. As the water enters the water pathways, nitrogen levels in ground water increases significantly. Nitrogen increases plant growth and plants in the water are no different than soil plants in that they too will start to grow faster vegetatively. As plants in the water increase their growth, they start to deplete the water of its oxygen levels which in turn affects the organisms living in the water. High nitrogen levels can also cause issues with algae blooms in water systems. These can be toxic to humans and animals alike.

 

Our prairie soils are very rich in minerals as they were created by a wide variety of rocks moving in glacial till. Due to the wide variety of rocks/minerals in the glacial till, a precursor to our prairie soils, our soils tend to have a rich variety of minerals and macronutrients for our plants. The majority of the nutrient shortages that prairie gardeners experience are not typically caused by a shortage of that specific nutrient in the soil. It could be that inconsistent watering prevents it from getting to the parts of the plants it is needed (blossom end rot) or the soil could be too saturated for the plant to pull the nutrient out (iron chlorosis) or the nutrient could be readily available in a form that is not available for the plant due to a lack of organic material in the soil. The addition of fertilizers will not help these issues, in fact it may just foster new issues!

Because our soils are so nutrient rich on the prairies, the addition of compost to our soil is not necessary to top up nutrients. Compost in prairie soil functions in a different role – it provides organic material to support the soil food web. As the organic material is broken down, it works to release nutrients already present in the rock minerals. Without organic material, the soil food web cannot convert these nutrients into usable forms for plants.

While artificial fertilizers are available immediately for plant use, compost needs to break down before it’s in usable forms for plant uptake. This makes compost the equivalent of a slow release fertilizer.

 

To add organic material to your soil, move the mulch to the side and place 1" to 2" of compost on the row and then recover with mulch. There is no need to work the compost into the soil, the earthworms will do this job for you! If you have poor soils, add 3" to 4" of compost and then mulch to help improve the soil health. It isn't necessary to add compost to the garden every single year. Incorporate compost into your crop rotations, add it only to the rows with the heaviest feeders like potatoes, tomatoes, peppers and eggplant. This way, a portion of your garden has additional organic material every few years.

To learn more about compost: click here!