Why Ploughing Is Such A Bad Idea
Tags: Global Warming, Environment, Ecology, Agriculture, Climate Change

Part of the series “Quest for Drawdown”. For anyone who has walked around farming areas, you’ll be aware that ploughing is an integral part of agriculture as we know it — widespread throughout many countries. However, what you might not know is that it has a very big negative impact on biodiversity and global warming.

There are many different processes involved in modern-day conventional agriculture. Ploughing (which comes in many forms) is a process whereby the top layer of soil is overturned — like flipping a pancake [1]. Tilling is another process, similar to ploughing, whereby soil is cut and broken into smaller pieces; like pulling a comb through the soil [1]. What these two processes have in common is that they both break up and disturb the soil causing a lot of disruption and problems — let me explain…

Firstly, when ploughing and tilling through the fields, the plants in the top layer of the fields rot and decompose, producing and releasing carbon dioxide and methane in the process [2]. Also, fields that are not tilled (so-called “zero tilled” fields) contain sub-soil fungi and plants with roots that extend deep and allow carbon sequestration (absorbing CO2 from atmosphere) [3]. Hence, by not ploughing or tilling, the potential for carbon sequestering (uptake of CO2 from atmosphere) is unleashed. Within the EU under current conventional farming methods, 5% of total greenhouse gas (GHG) emissions come from agricultural soils [4] (just soils, no animals!). That’s more than aviation and shipping combined [5],[6].

Difference between tilled and no-till ecosystems. From United States Department of Agriculture, USDA.

Secondly, by disturbing the top layer of soil small pores present in the soil structure that are responsible for the uptake of water are destroyed. In fact, tilling or ploughing a field often results in soil compaction [7]; which reduces overall soil porosity. This leads to reduced water holding capacity and an overall less hospitable environment for all life in the soil [7]. As a result, the farmer has to water more and there is an increased risk of flooding during heavy rains [8], [9].

Thus, thirdly the natural microbiome of the soil is compromised by the disruption and then subsequent compaction caused by tilling or ploughing. Soil, much like our guts, relies for its “health” on the biodiversity of naturally occurring organisms including bacteria, fungi, worms, and insects that are to be found there [10],[11]. All of these different organisms contribute to the stability and porosity of the soil structure, as well as to the richness of the soil in the forms of the organic matter broken down from plant and animal material. Mineral materials are also made more bio-available by these organisms to the plants grown as crops [10],[11]. Furthermore, these organisms form the bottom of the food chain for bigger animals such as voles and birds [12]; which in turn form a pyramid of biodiversity further outside the fields, and into the trees and hedgerows and beyond. All major disruptions to the soil mean major disruptions to the home of all these vitally important organisms [13].