Sustainable production systems

Plant growth is decreased by the presence of salt in soils. In the world 20% of agricultural land and 50% of cropland is stressed by salt. This issue will increase with global warming and soil salinization is decreasing cropping land by 1–2% yearly. A potential solution is to favour  the development of some rhizobacteria, that are bacteria living in the root zone, named the rhizosphere. Paul and Lade review the beneficial effects of plant growth-promoting rhizobacteria for plants growing in saline soils. The photo clearly shows the poor growth of wheat in the saline zone at the bottom. Salt causes yellowing and death of wheat leaves.

Industrial agriculture has decreased the amount and diversity of soil life. However, soil life is essential for food production because some soil organisms help plants to grow by providing plant nutrients. For instance mycorrhizae are beneficial fungi that live in association with plant roots. De Beenhouwer et al. compared the diversity of mycorrhizae in wild and cultivated coffee plants. They observed that wild coffee plants had a much higher mycorrhizal diversity. Their findings reveal the conservation value of wild coffee and the possible application of mycorrhizae inoculation for producing coffee with few or without external fertilisers.

Drought is decreasing wheat yields in semi-arid regions. This issue may be partly solved by better forecasting wheat production. Bregaglio et al. improved wheat forecast by adapting two wheat models to the specific agro-climatic of Morocco.

Canola is a major crop for food as canola oil, and energy as biodiesel. Many factors control the yield of canola, but there is actually little knowledge on the influence of the spatial arrangement of canola plants. Gan et al. shows that uniform canola stands increase seed yield by up to 32% at low-yielding sites and by up to 20% at the high-yielding sites, compared to non-uniform plant stands. Yields can thus be increased by more uniformity, regardless of environmental conditions.

Producing safe food could be achieved in a sustainable way by changing agricultural practices.  However, there is actually a lack of suitable methods and indicators that measure sustainability. This lack of knowledge is particularly deep at the farm level in poor countries that represent most food production worldwide. In addition, actual indicators are defined only by scientists, thus not taking into account essential farmer knowledge. Using participatory indicators designed with farmers Yegbemey et al. reveal weaknesses of maize cropping in Benin. This knowledge can be used to set up sustainable cropping practices.

Industrial coffee production has increased greenhouse gas emissions because many forests have been converted to lightly shaded or full-sun crops. Indeed the huge amounts of carbon stored in forest trees and soil are decomposed then released into the atmosphere as carbon dioxide (CO2) upon deforestation. There is therefore a need for more ecological coffee production systems. Van Rikxoort et al. have compared the climate impact of four arabica coffee systems: unshaded monoculture, shaded monoculture, commercial polyculture and traditional polyculture. The authors provide advices for climate-friendly coffee production.

Olive oil is a major resource of the Mediterranean region. Olive oil production can be improved by understanding the reproductive biology of the olive tree on large areas, but research tools are actually missing. 

Therefore Oteros et al. developed six crop models adapted to the Mediterranean Basin, using data from 17 sampling points during the last 20 years. The results reveal better prediction of olive production.

Greenhouse plant nurseries commonly use vermiculite and peat moss for potting plants, thus threatening natural resources of vermiculite and peat moss. They can be replaced by biochar, which is a cheap product of organic wastes. However fresh biochar emits ethylene, a gas that has adverse effects on plant at high levels because ethylene is a plant hormone. Fulton et al. found a simple solution to get rid of ethylene emission.

Life on earth is impossible without plants and other photosynthetic organisms. Plants are the most important living organisms for the ecosystem because plant harvest sun energy and, in turn, all other living organisms feed on plant directly or indirectly. Plants are used for food, fiber and most recently for fuel. Pollinisators such are bees are necessary for the reproduction and survival of many plant species, including plants for food. However, industrial agriculture and the use of pesticides have strongly declined bees and other insect pollinators. This bee decline has already decreased global food production. A review article by Nicholls and Altieri discusses in detail the problems of pollinators and how to solve this problem with novel farming practices.

Agricultural production is more and more unstable as a result of complex issues related to climate, markets and public policy. Farmers must therefore develop new farming systems adapted to changing conditions. For instance in south-western France, during summer, farmers increasingly move livestock from lower plains to high summer pastures in the Pyrenees mountains. This adaptation based on ancestral know-how is due to the increasing scarcity of herbage in lower plains in summer. Martin et al. review 41 new ideas for farming systems adapted to changing conditions.