Reducing the yield gap for organic agriculture


Agricultural land managed according to the organic agriculture methods world - wide covers about 37 million hectares. In Europe, this is almost 11 million hectares which represents 2.2% of the total European agricultural area.

Some EU Member States reach a high share of organic land, for example Austria 19.7%, while in absolute terms the largest surfaces can be found in Spain (1.6 million ha), Italy (1.1 million ha ), and Germany (1 million ha).

One review shows that organic is on average producing 80% of conventional yield but it also shows that wide variations (standard deviation 21%) between regions, systems and also between real farm data compared to experimental trials data.

Another analysis shows an average 75% of organic productivity compared to conventional, but stresses the fact that good management practices, particular crop types and growing conditions can bring organic systems nearly to the same yield as conventional.

In both studies the productivity gap is wide during very productive conditions and years, when the crop is brought to its maximum potential, but how it is narrow or even reversed (organic more productive than conventional) during less favorable conditions and years.

To overcome the gap, there are several elements of the farming system that have to be considered which differ depending on the region and the system. All the elements have to be matched within the crop rotation and the economic sustainability of the farm. The concept of eco - functional intensification may give guidance to achieving a more efficient use of natural resources and processes, improved nutrient recycling techniques, and innovative agro - ecological methods for enhancing the diversity and the health of soils, crops and livestock.

It is not just about more tons per hectare, better economic results are to be achieved sustainably which requires a thorough consideration of the quality of the product, production costs and environmental services provided by the farming system at farm scale and along the whole value chain.

What are the factors causing the yield gap?

Several factors may hold certain organic farmers back from reaching their full potential. Organic agriculture works as complex system managed by the farmer, who has fewer “emergency” tools to adjust production. The organic farmer needs a higher knowledge level to be able to foresee the evolution of the farm and of specific crops, and consequently plan the farm management as a whole.

The need for knowledge exchange among practitioners cannot be easily satisfied due to the still limited number of organic farms and their being spread out widely on a national and European scale, and with extremely limited knowledge networks acting as link.

Practical experience and scientific evidence allows us to identify the major factors causing a reduced yield and they are:

Inadequate nutrients supply

More skilled farmers usually introduce more legumes in the crop rotation (either as cash crop or green manure) and catch - crops to prevent leaching and nutrient loss. Where possible, innovative mixed - farming systems that allow recycling of animal waste are established.

As stockless arable farming is becoming the majority also in the organic sector, the mixed farming concept can be more easily implemented at landscape/valley/regional level, but how to do it, remains to be defined.

A very limited number of farmers use soil analyses or are simply able to “look” and decide consequently.

An investment in developing awareness and skills can be highly beneficial

Poor soil fertility management

The key point is the correct management of organic matter, by gathering locally available organic materials (cheap), fine - tuning soil labour, taking measures against soil compaction (ex. reduce pressure in tyres), tillage practices and the correct structuring of crop rotation

Insufficient weed management

It is a major obstacle especially for spring sown crops and crops with a slow early development (i.e. corn). It induces more problems in newly converted farms as appropriate crop rotation slowly but efficiently reduces the seed bank.

Nevertheless the need for specialisation in few crops (market pressure) often negatively affects the rotation and as a consequence the agronomic weed management. overall management (crop rotation, including cover crops, as first) is the main tool, but the attention to machinery is very high as well as the demand for more precise (close to the crop) weeding tools.

Several farmers adapt machines to their systems but there is room for technological development, as long as it leads to cheap machines which are not too crop - specific as organic farmers tend to grow more crops in their crop rotation and cannot invest in different machinery for each crop

Pest and disease pressure not sufficiently managed

Common bunt, phytophthora, corn borer and other pests and diseases are affecting organic crops usually with less strength due to the diversification of the farm and of the crops. Nevertheless, in areas and years with difficult conditions they cause huge losses.

This is due to the use of non - treated  seeds and the plant protection products allowed in organic have a preventive effect but their effect is limited when the pest or the disease is already attacking the plant. The first measure is prevention, starting from the choice of the appropriate crop/location combination and including rotation, fertilisation and irrigation policy, etc. Also the choice of varieties (or combination of varieties) that fit to the place of cultivation and resist to major pest and diseases have high relevance. Soil borne diseases are usually not so important thanks to the overall organic management, in case of need they are managed also with the use of cover - crops w ith sanitary effects

Variety choice

Organic farmers mainly use varieties selected for conventional systems There is insufficient availability of adapted genetic materials. This means materials resistant to major pest and diseases but also adapted to local climate and soil, to the organic cropping system, as well as qualitatively fit to organic demands and processing needs.

Locally and “organically” adapted seeds would contribute to solve the majority of these problems. Some seed companies have started to take an interest in organic breeding in the last few years but their supply is still insufficient. So several farmers have started to select their own seeds ‘on - farm’ or in cooperation with colleagues and local research stations. They are also increasing inter - crop biodiversity by seeding/planting combinations of varieties or populations. Legal issues however are major constraints in their search for solutions.

More at: