刘美珍 蒋高明：草原养鸡可显著提高草原环境可持续性与经济效率

　　因过度放牧造成的草原退化，对畜牧业和生态环境可持续发展存在严重威胁，这在干旱地区特别是中国北方草地最为明显。尽管中国政府为恢复退化草地做出了巨大努力，但由于对当地社区的经济利益考虑不够，不幸的是，很多重大工程相在某种程度上成效不显或不幸失败。

　　本研究通过现场放养试验，验证了利用自然草地作可作为散养鸡理想栖息地，并满足部分饲料资源;用草原养鸡取代传统畜牧业，可提高环境的可持续性，增加牧民收入。草原养鸡可使地上植物生物量升高，从25克/平方米(绵羊)到84克/平方米(鸡)。在对比围栏(无放牧)内，草原养鸡不仅不会降低植株地上部分生物量，但却增加了60%根系生物量(P<0.01)。与传统绵羊放牧相比，草原养鸡显著提高了土壤表层(0～10厘米)含水量，从5%增加到15%。饲养鸡对土壤容重没有影响，而传统的绵羊放牧在0～10厘米的土层中增加了土壤容重35%(P<0.05)。更重要的是，当地牧民经济收入比传统养羊业提高了6倍左右。在草原生态学上，这种创新解决方案允许严重的退化草地自然再生。草原还提供了高品质的有机禽产品，可在大城市销售。

　　草原养鸡是增加环境可持续性和经济收入的创新战略，而不是对传统游牧牧区制度的挑战。该方法也可能适用于其他出现大规模退化的草地生态系统恢复。

　　Chicken Farming in Grassland Increases Environmental Sustainability and Economic Efficiency

　　Meizhen Liu, Bingxue Wang, Colin P. Osborne, Gaoming Jiang

　　Grassland degradation caused by overgrazing poses a threat to both animal husbandry and environmental sustainability in most semi-arid areas especially north China. Although the Chinese Government has made huge efforts to restore degraded grasslands, a considerable attempt has unfortunately failed due to an inadequate consideration of economic benefits to local communities.

　　A controlled field experiment was conducted to test our hypothesis that utilizing natural grasslands as both habitat and feed resources for chickens and replacing the traditional husbandry system with chicken farming would increase environmental sustainability and raise income. Aboveground plant biomass elevated from 25 g/m2 for grazing sheep to 84 g/m2 for chicken farming. In contrast to the fenced (unstocked) grassland, chicken farming did not significantly decrease aboveground plant biomass, but did increase the root biomass by 60% (p<0.01). Compared with traditional sheep grazing, chicken farming significantly improved soil surface water content (0–10 cm), from 5% to 15%. Chicken farming did not affect the soil bulk density, while the traditional sheep grazing increased the soil bulk density in the 0–10 cm soil layer by 35% of the control (p<0.05). Most importantly, the economic income of local herdsmen has been raised about six times compared with the traditional practice of raising sheep. Ecologically, such an innovative solution allowed large degraded grasslands to naturally regenerate. Grasslands also provided a high quality organic poultry product which could be marketed in big cities.

　　Chicken farming is an innovative alternative strategy for increasing environmental sustainability and economic income, rather than a challenge to the traditional nomadic pastoral system. Our approach might be technically applicable to other large degraded grasslands of the world, especially in China.

　　Liu M, Wang B, Osborne CP, Jiang G (2013) Chicken Farming in Grassland Increases Environmental Sustainability and Economic Efficiency. PLoS ONE 8(1): e53977. doi:10.1371/journal.pone.0053977.