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.

 

Positive effects of sustainable land management

Agriculture production in developing countries must be increased to meet food demand for a growing population. This issue may be solved by sustainable land management such as organic fertilization, lower soil disturbance, incorporation of residues, terracing, water conservation and agroforestry. From the review of 160 studies Branca et al. deduce positive effects of sustainable management, such as higher crop yield and soil carbon sequestration.

 

 

Genetically modified crops or agriculture biodiversity?

The growing world demand for food is a major challenge for humankind. Increasing food production will be more and more difficult due to fewer arable land, less water availability, pollution, warmer climate, and land competition of food production with biofuel production and cities. As a result there is a strong on-going debate on the best strategy to keep pace with global population growth and increasing food demand. One strategy favors the use of genetically modified crops, while another focuses on agricultural diversity. The review by Jacobsen et al. places genetically modified crops far down the list of potential solutions and recommend funding in other research areas of plant science.

 

 

Unexpected withdrawal from organic farming

Europe envision organic farming as a solution for sustainable agriculture. However the organic farming area has increased only from 1.8% in 1998 to 4.7 % in 2009 in European Union, still far from initial objectives. Worse, recent observations show cases of farmer withdrawal from organic farming. Madelrieux and Alavoine-Mornas studied organic farming withdrawal of 18 former organic farmers. Results show that withdrawal depends on the circumstances causing farmers to leave organic farming and what farmers learned by experience.

 

Ethylene-free biochar for plant nurseries

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.

 

The common tragedy of climate change and agriculture

Climate change is mainly due to the increase of greenhouse gases such as carbon dioxide (CO2) in the atmosphere. Industrial agriculture is partly responsible of atmospheric CO2 increase because industrial agriculture burns rapidly soil carbon, the ‘fridge’ that contains also nutrients for plants and other living organisms. Misuse of common resources has been well defined in the concept of The Tragedy of the Commons. The review article by Stavi and Lal emphasizes the relevance of this concept for agriculture. The article focuses on field crop production and livestock husbandry. Sustainable agriculture practices that sequester soil carbon are described.

 

Sustainable livestock farming

Livestock farming is very popular but causes regularly issues of food security and pollution. The long-term viability of livestock farming is critical for animal health, farm income, animal welfare and the environment. Therefore methods to assess the sustainability of livestock farming are needed. In a review by Lebacq et al. three different methods are analysed: the method-based approach, objective-driven approach and data-driven approach.

 

Soil compaction problems and solutions

Soil compaction is a major problem for farmers and soil scientists. Indeed soil compaction decreases the yield of most agronomic crops worldwide. The alteration of soil structure by compaction limits water filtration and air access, reduces root penetration and inhibits soil living organisms. Nawaz et al. review advances in understanding, quantification and prediction of the effects of soil compaction.  Sustainable remedies are also given.