“Soil is the stomach of our world.” This statement by one of the speakers at the Global Soil Week, held in Berlin, Germany, in April, could serve as the guiding theme of a working group addressing the significance of grasslands and sustainable animal husbandry to maintain soil fertility and resilience building to climate change.
Across the world, pastureland management provides a livelihood for 1.2 billion people. At the same time, grasslands and pastures are the greatest carbon sinks, and are even more effective than forests, according to Tobias Reichert of the German NGO Germanwatch. Reichert quoted further statistics at the meeting in Berlin. The 3.5 billion hectares of pasture and fodder land world-wide represent 26 per cent of the world land area and 70 per cent of the world agriculture area. But pastureland is under threat from the intensification of farming and overuse by too intensive livestock production. Droughts in the tropics and the subtropics, which are becoming more frequent in the course of climate change, are a further threat.
But why should more attention be given to the significance of grasslands in resilience building to climate change? The participants of the working group at the Berlin Soil Week attempted to find an answer to this question, which was addressed especially by the representatives of the UK NGO Sustainable Food Trust (SFT), an organisation that sees soil as the “stomach of our world”. Soil fertility relies on a composition of thousands of microbes, but also on the bonding capacity of water; one gram of humus binds 20 grams of water, as the SFT experts stressed. They reported on field trials with mixed and grass farming involving small ruminants in the South of England that aimed at establishing an ecological balance and nutrient cycle. This form of pastureland management could represent an important contribution to the rehabilitation of degraded soils both in Europe and in other world regions, Patrick Holden and Richard Young of SFT maintain.
The experts refer to the intensification of agriculture, whether through intensive feedlot livestock production or through land-use change of pastureland into arable land, as the greatest challenge for the soil fertility of pastureland and grassland. They maintain that land use change is also the main cause of increases in CO2 emissions, for by ploughing pastureland, large quantities of CO2 are liberated that above all settle in the upper strata of the atmosphere. Therefore, Young called for a promotion of no tillage agriculture in land-use change programmes.
German expert Anita Idel also complained of a lacking awareness of the significance that grassland bears as a carbon sink and a guarantor of soil fertility. It was often forgotten that deeply rooted grasses optimised microbial life in soils as well as their capacity to absorb water. Furthermore, Idel criticised the claim that livestock production was one of the chief causes of methane emissions. Ecologically appropriate livestock grazing promoted the natural cycle. Only an overstocking in livestock production (feedlot) and the cultivation of soy in former pastureland as a consequence of this and its import from other regions were causing the oft-cited high levels of methane and other emissions, Idel stressed.
“Had we people in Australia built up on-time resilience to climate change, would there be so many bushfires?” farmer Walter Jehne asked, and reported on a recent initiative of the Australian government in co-operation with lead farmers to rebuild an organic balance in the drylands of Australian rangeland and to rehabilitate the land as carbon sinks by re-introducing the traditional nutrient cycle through a mobile digestion compost system; in Africa, this would probably be referred to as pastoralism.
The negative image of livestock husbandry as a cause of gas emissions and land degradation ought to be reassessed, albeit from the angle of an ecologically appropriate approach. The approaches from the UK, Australia and southern Africa that were presented in Berlin could provide a new perspective.
Angelika Wilcke, editor, Rural 21