Organic rice using fishes, ducks and frogs in China

Rice is a major food in China. However many pests, diseases and weeds cause losses of rice yield. The use of pesticides is no longer an option to solve a such problem because pesticides contaminate food and water. Non-chemical treatments are thus needed. Huang et al review non-chemical chinese practices that are successfully applied to rice cultivation. Practices include: growth of different resistance rice varieties to control blast, plant hoppers; leaf folder and sheath blight management by adjusting rice seeding and transplanting date; releasing fish and frog to control insect pests and weeds; rice-duck mutualism system to control multiple injurious insect and weeds, and also fertilize the soil.

 

Composted poultry litters fertilise soybean crops and increase soil quality

Composted and formulated poultry litters can be used as organic fertilizer for value added soybean crops such as edamame to maintain soil productivity and partially restore nutrients removed at harvest. However, applications may be limited by lack of understanding of properties and behavior in soil and impacts on plant and seed quality components in addition to yield. Greenhouse and field experiments by Blair et al. show that composted poultry litter is better for edamame production than formulated litters because composted poultry added a more stable organic substrate to soil.

 

Legumes are the future of food and fertilisation

Legumes are plants that do not need nitrogen (N) fertilisation because legumes are plants that are able to fix atmospheric nitrogen (N2). In addition legumes can be used as ‘green’ fertilisers because legumes are N-rich and thus cropping legumes provides the soil with a cheap, sustainable source of N fertiliser. Legumes are also an excellent source of protein for feed and food. Nonetheless legume cropping land in Europe represents only less than 4% of arable land. The grounds for such a low cropping surface are discussed by Voisin et al. who analyse the production of forage and grain legumes in France since 1950. The authors propose changes to improve legume production.

 

Models to predict Mediterranean olive 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.

 

Silicon-rich manure for sustainable rice production

Rice is a plant that needs silicon (Si) as a nutrient to grow well. Silicon is an element of silica (SiO2) found commonly in sand. Rice yields decrease when soils are depleted in available silicon. A possible solution is to add silicon-rich manure to soils. Song et al performed a 10-year field experiment and found that adding silicon-rich manure doubled the amount of available silicon in soils. Using manure brings the additional benefit of recycling organic waste and providing other plant nutrients such as nitrogen and phosphorus

 

Benefits and risks of anaerobic digestate fertilisers

Intensive soil fertilization with mineral fertilizers has led to several issues such as high cost, nitrate pollution, and loss of soil carbon. Fertilization with organic wastes such as anaerobic digestates is an alternative for sustainable agriculture. Conflicting results in the literature have questioned the effectiveness of anaerobic digestates as organic fertilizers. The review by Roger Nkoa demonstrates the fertilizer values of anaerobic digestates. However, anaerobic digestates emit amonia (NH3) and contain copper (Cu), Zinc (Zn) and manganese (Mn) that could pollute the soil and the atmosphere upon repeated soil applications.

 

Cropping and soil bacterial diversity

Soil living organisms are essential for food production by recycling organic matter and providing sustainable plant nutrients. Agricultural practices may degrade soil life, by actually precise knowledge on the impact of cropping is poorly known at the microscale, in micro- and macro-aggregates. The article by Constancias et al. reveals that cropping highly reduced bacterial density and diversity at the microscale, compared to bulk soils. The findings show that cropping practices that preserve aggregate stability should be favoured to preserve soil microbial diversity, and in turn fertility and food production.

 

Irrigation increases soil carbon and greenhouse gas N2O emissions

Irrigation controls food production as plant do not grow without water. The article by Trost et al. review the effects of irrigation on soil carbon and greenhouse gas N2O emissions. Findings include that irrigation increases soil carbon up to 500 % in  cultivated deserts and up to 35% in semiarid regions. In humid regions N2O emissions often increase after precipitation or irrigation.

 

Benefits of compost in agriculture

Climate change and most actual world food issues are linked directly or indirectly to soil loss of carbon and fertility. Here composting appears as a cheap and sustainable solution.The review by Martínez-Blanco et al. presents nine benefits of compost application to the soil. Composting practices are classified into short-term, mid-term, and long-term benefits.