What is Conservation Tillage?
Conservation Tillage (CT) is defined as “any form of tillage that minimises the number of tillage passes, where soil aggregate disruption is reduced, a minimum of 30% of the soil surface covered with residues, with the aim to reduce soil erosion” (CTIC) 2004. In one sense CT can be used as an umbrella term to describe crop establishment systems which aim to conserve soil and water relative to conventional tillage practices (i.e. ploughing).
A number of these establishment systems, such as Minimum Tillage, Strip Tillage and No-till/Direct Drilling may fall under the CT umbrella where the minimum requirement of 30% of the soil surface is covered by residues. Some would argue that 30% soil cover alone is not sufficient, and that a reduction in fuel usage by 50% or more compared to a conventional system is needed in order for cultivations to be considered conservation.
Internationally there are many, many definitions for the different establishments systems being employed by farmers across the globe. Non-inversion tillage, chisel ploughing, reduced tillage, minimum tillage, mulch tillage, conservation tillage, direct drilling, direct seeding, strip tillage, zero tillage and No tillage to name just a few. Some of these are distinct well-defined systems, whereas others are more regional descriptions of systems which have been modified to suit the local climate, soil type, cropping patterns and or farming system.
As already mentioned Min-till is used in Ireland as an overarching term to describe a myriad of establishment systems which have many differences and may or may not actually be Min-till. We need to carefully define any system being considered in terms of its cultivation depth and intensity but we also need to move beyond looking at establishment systems as simply cultivations and consider taking a more universal approach to defining establishment systems that includes other management factors also.