Nitrogen (N) fertilisation is essential for crop and food production. However actual N fertilisation is not often very efficient and can induce pollution, e.g. by nitrates. There is therefore a need for indicators to compare farming systems. Scientists Godinot et al. developed a new indicator named ‘relative N efficiency’, which is specifically well suited to compare farming systems with different proportions of animals and crops.
Smart tactics of weed management in organic farming using rotation and no-tillage
Organic producers in the United States would like to no-till, but are concerned about managing weeds without tillage. Agronomist Randy Anderson shows that weeds can be controlled without tillage in experiments in the Great Plains of the USA. One favorable tactic is to include a 3-year interval of red clover in the rotation. Red cover suppresses both annual and perennial weeds, and it can be converted to cropland by fall mowing in the 3rd year (Photo). The complex rotation increases the impact of no-till on weed seed decay in soil and provide numerous opportunities for cover crops to replace tillage for controlling weeds. These benefits suppress weed growth and interference such that organic producers may be able to continuously no-till in their farming systems.
75% higher maize yield in maize-soybeans rotations using no till strip row farming
Industrial monoculture is often leading to the depletion of soil life and quality as a result of intensive tilling. New advanced techniques such as no-till and strip-till farming allow to restore soil fertility in the long run. No-till farming increases soil water, soil organic matter and decreases soil erosion. In strip till the farmer tills only the portion of the soil that will contain the seed row. Islam et al. studied no-till strip farming of maize-soybeans rotations. They observed a 75% increase of maize yield, amounting to 18.4 tons per hectare, after 5 year of cultivation.
Agroecological control of Cucurbitaceae flies
Conventional crop protection with toxic pesticides has often led to issues such as pollution, faunal imbalance, and resistance of pests after adaptation to the pesticides. Deguine et al. review safer, agroecological techniques to control Cucurbitaceae flies, a worldwide pest. Results show that farmers from the Reunion Island have reduced insecticide use with substantial cost savings using agroecological techniques. Such agroecological techniques are currently being extended to other countries of the Indian Ocean.
Solutions to grow maize on saline soils
The area of agricultural land on saline soils is increasing as a result of climate change and more frequent droughts. Since salt at high concentration is toxic to most plants, cultivation on such soils is becoming more and more difficult and induces yield losses. There is therefore a need for strategies to grow plants on saline soils. Farooq et al. review the mechanisms of maize resistance under salt stress. They propose solutions such as the use of arbuscular mycorrhizal fungi to improve plant nutrition.
Soil life does not like herbicides in olive crops
Industrial agriculture is known to decrease biodiversity and degrade soil structure. Agronomists Sánchez-Moreno et al. studied the impact of herbicides and soil management on nematodes – soil worms – and other soil life in Mediterranean areas. They found that soil life diversity is decreased by herbicides.
Social networks to share maize seeds
Many developing countries such as Timor-Leste are subject to extensive poverty and malnutrition but concurrently are rich in social networks. Scientists Lopes et al. explore the leveraging of existing social capital for development in community-based maize seed dissemination in Timor-Leste.
Legumes help cereal growth for bioethanol
Second generation biofuels from non-edible biomass, such as bioethanol from cereal straw, are more sustainable than first generation biofuels such as bioethanol from maize seeds. Sustainability could be further enhanced by cultivating both cereals and legumes, such as pea, because legumes are enriched in nitrogen that fertilises later the cereals. Nitrogen-rich cereal straw should facilitate yeast fermentation to produce bioethanol because yeast needs nitrogen to grow. Agronomists Pellicano et al. tested wheat, barley, triticale and oat grown in intercrop with pea. They found indeed that pea improves the N content of the straw mixture.
Earthworms are engineering soils for better food
Food production would not be sustainable without earthworms. Indeed, earthworms are major soil engineers. For instance earthworms transform organic residues into plant nutrients, and facilitate groundwater flow by tunnelling earth. Agronomists Bertrand et al. review the ecological services of earthworms, focussing on the effect of tillage, fertilisation and pesticide usage.
Rice-based crop rotations against global warming
Global warming is mainly due to the increase of carbon dioxide (CO2) concentration in the atmosphere. Agriculture highly influences atmospheric CO2 because plants and soils can sequester CO2 or release CO2. Researchers are thus trying to identify cropping practices, such as conservation tillage, that sequester CO2 in plants and soils in order to decrease atmospheric CO2 levels. Agronomists Motschenbacher et al. studied for the first time daily soil surface CO2 in rice-based crop rotations with corn, soybean, and winter wheat.
