Soil fertility in conservation tillage systems

Authors: Young, Eric

Submitted to: Progressive Forage Grower
Publication Type: Trade Journal
Publication Acceptance Date: 12/6/2019
Publication Date: 1/1/2020
Citation: Young, E.O. 2020. Soil fertility in conservation tillage systems. Progressive Forage Grower. Volume 21, Issue 1. Pg. 25-26.

Interpretive Summary:

Technical Abstract: Soil forming factors (climate, biology, parent material, and drainage) and nutrient management practices heavily influence soil fertility. This article highlights the impacts of soil properties and tillage intensity on nutrient availability in agricultural soils. While organic matter and nutrients tend to be higher near the soil surface, reduced tillage can amplify this effect (termed stratification) due to a lack of soil mixing and accumulation of crop residues. Benefits of long-term reduced tillage include decreased erosion potential, improved soil structure and lower organic matter loss. However, spring nitrogen (N) availability can be reduced from lack of aeration with no-tillage, particularly for imperfectly drained soils. In fields managed strictly as no-till, organic matter, phosphorus (P), potassium (K) and other nutrients tend to concentrate in the upper 2 inches of soil. While studies indicate adequate crop nutrient uptake under no-till and other reduced-till systems, this assumes soil test levels (P and K) are optimum or above with sufficient N. One possible downside to highly stratified soils managed as conservation tillage is accumulation of P and soluble P release to surface runoff and/or leaching though macropores to tile drainage flow. Some degree of tillage may be necessary in highly stratified soils and/or soils receiving regular manure applications in P sensitive watersheds to mitigate runoff loss risk.