To plough or not to plough, that is the question
The debate amongst environmentalists whether to plough our fields or not, rattles on, particularly the tilling between olive and almond trees. It certainly can be said to look beautiful, especially her in Aragon where the stunning contrast of colours between light and shade of the ploughed fields are extraordinarily lovely. However, although European initiatives such as the conservation agriculture movement, strongly come out in favour of no tillage in areas of high erosion, subsidies for almond crops until recently insisted that the trees are pruned, fed with fertilisers and the fields ploughed, before grants were issued.
Conservation agriculture refers to several practises which permit the management of the soil for agrarian uses, altering its composition, structure and natural biodiversity as little as possible and defending it from soil erosion and compaction. The soil is protected from rainfall erosion and water runoff, soil aggregates are established, organic matter and fertility level naturally increase and less surface soil compaction occurs. Perhaps, even more importantly the contamination of surface water and the emissions of Co2 to the atmosphere are reduced, and biodiversity increases.
Conventional agriculture is generally harmful to the environment. It includes crop residue burning or deep soil inversion by tilling (ploughing) to control weeds and prepare seed beds. These techniques considerably increase soil deformation by compaction, erosion and river contamination with sediments, fertilisers and pesticides.
The ploughed olive fields may look like a beautiful zen garden but these techniques increase the emission of Co2 into the atmosphere contributing to global warming and reduce the sustainability of agriculture by lowering soil organic matter and fertility, alone with a decrease in biodiversity.
Conservation agriculture techniques can be adapted to different climatic and soil conditions. Direct drilling (the best technique from an environmental point of view) has been applied in countries as different as USA, Brazil, Austria and Ghana.
In southern Europe for example, in no till olive crops, a saving of 60-80 litres of fuel per HA annually and 3-5 hours of labour is estimated compared to conventional ploughing. Fewer passes on cereal crops save an estimated 97€ per ha on machinery depreciation and maintenance cost and a fuel annually compared to conventional tillage.
Extensive research has taken place in the last 20 years and has demonstrated the potential benefits of these alternative techniques. In all European countries there are pioneering farmers successfully using conservation agriculture methods.