Broadcast application of cattle slurry to grassland soils is a natural means of fertilisation. However this practice is actually not optimised and leads to nitrogen loss to the atmosphere and groundwater. Novel application techniques such as injection into the soil are therefore tested. Kayser et al. found that the type of application technique has no effect on nitrate leaching. Whereas the amount of applied slurry has an effect on nitrate leaching.
Global warming is partly due to increasing atmospheric CO2 concentrations. Global warming will probably increase drought periods. Plants assimilate CO2 by photosynthesis to build plant roots, leaves and shoots. There is actually little knowledge on how plants will respond to increasing CO2 and drought stress. Erbs et al grew maize under ambient CO2 concentration, of 380 ppm, and elevated CO2 concentration, of 550 ppm. Some maize plants were grown well-watered, others were under drought stress. Results show that maize is not altered under elevated CO2 if maize is well-watered, contrary to some other plant species. Maize is thus a promising crop for future climate, provided that maize is well watered.
Industrial agriculture has strongly altered soil life, and, in turn, decreased fertility. Alternative practices such as conservation agriculture and organic farming could restore better conditions for soil organisms. Henneron et al compared the effect of 14 years of conservation agriculture, organic farming and conventional agriculture on soil organisms such microbes and worms. They found that conservation agriculture and, to a lesser extent, organic farming improved all soil organisms.
Fostered by climate change the parasitic weed Phelipanche ramosa infests host crops such as tomato, hemp, tobacco and oilseed rape at an increasing rate. This weed can cause more than 80% yield loss of oilseed rape. To solve this issue knowledge on the way parasitic weeds infect oilseed rape is needed in order to design agroecological solutions. A report by Gibot-Leclerc et al. shows unexpectedly that the P. ramosa weed grows faster on slow-growing Brassicaceae – the oilseed rape family – than on fast-growing mouse-ear cress A. thaliana. This finding demonstrates for the first time that the growth of parasitic plants does not depend only of the growth speed of the host plant.
The production of cucumber, melon and watermelon is highly decreased by the root-knot nematode – a kind of worm – that causes dramatic galling on the roots of cucurbitaceous plants. A potential solution is to graft susceptible plant scions on nematode-resistant rootstocks. Liu et al. found a new grafted rootstock resistant both to root-knot nematode and to Fusarium wilt, another pest.
Green roofs recover green spaces in urban areas. Green roofs benefit the public, farmers and wildlife. Green roofs reduce stormwater runoff, mitigate urban heat island effects, absorb dust and smog, sequester CO2, produce O2, create space for food production, and provide natural habitat for animals and plants. Li and Babcock review the economic and environmental benefits of green roofs.
A catch crop is a crop planted between two regular crops grown in successive seasons or between two rows of crops in the same season. Catch crops are used in particular to reduce soil erosion and fertiliser leaching that occur when the soil surface is not planted. For instance nitrogen catch crops feed on nitrates and thus recycle soil nitrogen and decrease water pollution by nitrates. Catch crops are therefore a way to reduce the use of costly fertilisers. Tuulos et al. show that winter turnip rape, an oilseed crucifer, is an effective nitrogen catch crop adapted to the Nordic climate.
The glasshouse whitefly Trialeurodes vaporariorum is major worldwide pest of glasshouse crops. It does its damage by excreting plant sap which then grows black sooty mold fungus which spoils the appearance of the product. Tosh et al. reasoned that since plant volatiles – the odour of a plant – are usually harmless to humans but often harmful to insects, and since the glasshouse is an enclosed space, plant volatiles could be used to control whiteflies. The authors attempted to apply the well know ‘confusion effect’ – confusing animals with too much information – by bombarding the whiteflies with a super-abundance of host plant volatiles while they are feeding on tomato plants. Unfortunately the confusion effect does not have a strong impact on the whitefly. The confusion effect may be used in combination with other odour-based control methods for the glasshouse whitefly, but it is unlikely to be sufficient as a stand-alone control method.
Global warming is moving plant and animal species toward cooler areas, thus impacting agriculture and food production. In particular livestock farmers should adapt their pratices to climate changes, but there is actually few evidence of shepherd adaptation. Rigolot et al. surveyed shepherds from the French Auvergne. They found that shepherds clearly modify their use of collective mountain pastures in summer.
Urban agriculture is developping fast because more and more people live in urban areas. Moreover urban food production is local, cheaper and social. There is therefore a need for advanced indoor techniques to cultivate plants. Indoor techniques will also benefits people leaving in far northern and southern latitudes due to long yearly periods with no or little sunlight. As plants prefer some light colours, using specific colours might improve plant growth. Sabzalian et al. tested red, blue and white light-emitting diode (LED) to grow mint, lentil, basil, and four ornamental plants. Their experiments unraveled surprising performance and production of vegetables and ornamental plants.