Strategies for agriculture with less water: back to the roots

Climate change is decreasing water content in many parts of the world. There is therefore a need to adapt by designed practices that save water and use less water. This can be done for instance by reduced tillage, mulching, selecting drought-tolerant cultivars and synchronizing plant demand with rainfall. Bodner et al. describe the most efficient strategies for better water management under dry climate. They found that selecting plant roots is a promising solution, yet still overlooked.


Water saved by wheat-maize relay planting with straw covering

Relay planting is planting seeds of a new crop among the plants of a mature crop so they will have a head start when the mature crop is done. As a consequence more crops per year can be brought to maturity in the same planting space. In northwestern China maize is planted about 40 days after wheat seeding, and this relay planting is popular for high yields. Yin et al. show that relay planting with reduced tillage and stubble mulching increases water use efficiency up to 46%.


Rice cultivation with less water

Rice is traditionally cultivated by transplantation by farmers in water. However there is an increasing scarcity of water in a time of climate change. Moreover, transplanting in water is costly because many workers are needed. Therefore dry direct-seeded rice cultivation appears as a promising alternative. Liu et al. have compared dry direct-seeded rice and transplanted-flooded rice. They propose that dry direct-seeded rice should successfully replace transplanted rice in Central China due to less water requirement, identical grain yield and higher resource use efficiency.


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.