How can I improve my soil?

In Central Kansas we often run into challenges with soil such as a high soil pH, low organic matter, heavy clay content, compaction, or construction related issues.

A soil test can help begin the process of understanding your soil. A soil test will provide a baseline to begin working from. We recommend selecting the gardeners package #2 that is offered through the KSU soil testing lab which tests the soil pH, nitrogen, phosphorus, potassium, and organic matter. Saline and Ottawa County residents can send in a soil sample through the Extension office for testing at a cost of anywhere from $9 to $15 per test. Click here for more information.

Nutrients are most available to plants at between a pH of 6.5 and 7 and knowing the pH can help you choose plants that will be successful in your soil

Any serious gardener must go ‘beyond’ the soil test though when developing a plan for soil health in the garden. The soil underneath our feet is an ecosystem that must be understood and cared for to build soil health for the long run.

Let’s make it as simple as we can though. There is one amendment that will improve ANY soil type. That is organic matter. Examples of organic matter include finished compost, composted manure, cotton-burr compost, shredded or rotten leaves, untreated grass clippings, peat moss, straw, and more.

Here are a few example scenarios.

Example SituationImproving soil
Starting a new vegetable garden or flower bed1. Clear off and remove existing vegetation if needed
2. Do a soil test and follow recommendations
3. Amend the soil with organic matter before planting. Spread 4-6 inches of organic matter (any kind) over the garden area in the fall before the first season of planting and work it 6-8 inches deep into the soil. If starting the new garden in the spring, spread 4-6 inches of a fully broken down form of organic matter such as finished compost, peat moss , or composted manure and incorporate it 6-8 inches into the soil before planting.
4. Mulch the garden with organic mulches or grow cover crops that will build soil over time, avoid excessive tilling which destroys soil structure
Maintaining an established vegetable garden1. Do a soil test every 2-4 years
2. Spread and incorporate 1-2 inches of organic matter into the garden soil each fall OR consider planting and growing a fall/winter cover crop in the garden that will cover the soil or be incorporated into the soil the following spring to improve soil organic matter.
Planting a new tree or fruit tree1. Do a soil test to help determine soil pH and what tree would be a good choice for the soil and site. Follow soil test recommendations.
2. Spread several inches of fully broken down organic matter such as finished compost, peat moss, or composted manure over a 10 foot x 10 foot area where the tree will be planted and incorporate it 6 to 8 inches deep. Then plant the tree and mulch around it with organic mulch (wood chips) to prevent weed competition.
3. We DO NOT recommend adding compost or organic matter to just the planting hole when you plant a tree. Amending only the planting hole can result in the tree settling too much over time and negatively influence water movement into or out of the root ball.
Raised bed garden soil1. We recommend a approximately equal mixture of 50% high quality top soil and 50% organic matter such as finished compost. There are various mixtures and percentages that can be used.
2. Organic matter can be added each year as needed to maintain a good level within the raised bed.

If you get serious about soil health there are other things to consider in managing your soil.

  1. Minimize disturbance…tilling destroys the soil structure and aggregates that create a healthy soil so it is best to till infrequently and only with a purpose.
  2. Maximize live roots…living roots are a hot spot for the microbes in the soil since they exude the carbon compounds they feed on. Maintaining live roots in your soil as long as possible is critical to long term soil health. Cover crops can be used in home gardens with great success to keep live roots in the garden soil throughout the year.
  3. Keep soil covered. Bare soil is a desert for the microbial life that keeps soil healthy by building soil aggregates. Always keep soil covered with plants or plant residues.
  4. Maximize biodiversity. Rotate vegetables and annual flowers to avoid growing the same plant in the same place over and over as this limits microbial life and beneficial microbes and increases opportunity for pathogens in the soil. A more diverse set of plants in a soil means healthier soil.