Reduced tillage - Non-inversion and shallow cultivation in organic systems (Reino Unido)

Non-inversion and ‘shallow’ ploughing cultivation strategies on an organic farm, where the use of herbicides for weed control is prohibited.

The shallow plough is used on land dominated by clay soils at an organically farmed estate, south of Cambridgeshire, UK. Previously, ‘conventional’ ploughs were used, which plough deeper than a shallow plough. However, ploughing deeper would often bring large chunks of raw clay from the subsoil to the surface. This would quickly solidify, locally referred as when the soil turns to ‘concrete’. Numerous cultivations were then required to reduce these ‘concrete’ soil chunks into a seed bed. It was a laborious, expensive task which sacrificed soil health to produce a less than satisfactory result. However, the farm still required a plough of some form as a means of weed control through inversion. As it is an organic estate, chemical sprays could not be used. A shallow plough was invested in as a way of striking the balance between overcoming the problems of creating a seedbed, but also maintaining the weed control benefits of inversion tillage. It has been very successful in reducing the input requirements, and at the same time increasing the quality of the output. Whilst shallow ploughing has challenges, such as full inversion of weeds in very dry conditions, on balance it is much better for the farming business than the previous alternative. We are able to do less damage to soil, and increase outputs which is important due to agricultural labour scarcity and smaller weather windows due to climate change.

Reduced tillage options have been a challenge to combat in organic systems where herbicides are prohibited. As such, trials of reduced tillage options have been explored. These include;
1)Non-inversion tillage where no ploughing is done and soil is cultivated to the first 100 mm.
2)Shallow ploughing where a specifically designed plough inverts soil to a depth of 125 mm, as opposed to traditional plough depths of 200 mm.

The purpose of this technology is to minimise soil disturbance to enhance the soil structure, biology and chemistry, whilst creating a seed bed and controlling weeds. The challenge on the specific site is there has been a history of annual plough, which has led to the proliferation of weeds that thrive on such systems. These include creeping thistle and common docks. As such, there was also the purpose of ‘disrupting’ the existing system in order to control these weeds. The only specific input required was a shallow plough, designed to invert soil from lower depths. For non-inversion tillage, a subsoiler and disc cultivator were used. The non-inversion tillage was done at two sites; one cereal stubble and one out of a fertility building two-year grass and clover ley.

Benefits/impacts/things land owners did/did not like:
Non-inversion tillage:
-Instead of ploughing, non-inversion tillage from the fertility ley allowed us to keep the soil structure from 2 years of grass/clover intact and in the right soil profile. We weren’t burying the friable, high-nutrient and porous top soil 200 mm under the ground and we weren’t lifting heavy, lower-aerobic soil to the surface where we wanted to plant.
-This meant that plants established quicker and we were able to drill later, despite the fields being very heavy, poorly drained fields.
-Weeds were killed, primarily through timely cultivations during a hot-spell, so that the cultivator brought roots to the surface to dry them.
-Drainage was evident after drilling as we were able to graze sheep on the wheat in March.
-Crops have tillered well and responded to nutrients.
-Establishment costs were approximately £30/ha cheaper.
-However, non-inversion tillage in cereal stubbles has not been as successful due to weed control, and whether the cheaper costs outweighs the weed burden remains to be assessed. The reason for this is not being able to cultivate during the hot weather (as this came before harvest).
-In addition, in cereal stubbles, we have seen less creeping thistles and docks, but more wild oats and cereal volunteers.

Shallow ploughing:
-Cheaper establishment costs through lower diesel usage (yet to be quantified).
-Better in many circumstances of inverting soil completely, but from a much lower depth.
-Did not bring up any large clumps of sub-soil which the conventional plough would. These result in much cultivations to break the clumps down.
-Ploughing ‘on-land’ meant that there was no smearing in the furrow from tyres.
-Lower HP requirement – 180 hp tractor ploughing 3.2 m to 125 mm on heavy land.
-Ploughing left over-winter did not require more than one cultivation before drilling as ploughed soil was friable from lower plough depth.
-That being said, there were favourable ploughing conditions in 2018. Regardless, we have sold our conventional plough because we like the shallow plough so much.

General benefits are:
-Reduced, prevented or restored land degradation
-Improved/preserved biodiversity
-Increased adaptation/resilience to climate change/extremes and its impacts
-A potential beneficial economic impact

The compilation of this SLM is a part of the European Interreg project FABulous Farmers which aims to reduce the reliance on external inputs by encouraging the use of methods and interventions that increase the farm’s Functional AgroBiodiversity (FAB). Visit www.fabulousfarmers.eu and www.nweurope.eu/Fabulous-Farmers for more information.

Lugar: Wimpole Estate, Reino Unido

No. de sitios de Tecnología analizados: un solo sitio

Difusión de la Tecnología: distribuida parejamente sobre un área (4.0 km²)

¿En un área de protección permanente?: No

Fecha de la implementación: 2018; hace menos de 10 años (recientemente)

• mediante la innovación de usuarios de tierras
• como parte de un sistema tradicional (> 50 años)
• durante experimentos/ investigación
• mediante proyectos/ intervenciones externas