404
bandry industry, and maize as one of main food crops. However, the production
capacity determines the size of feeding livestock. As potato stalks and tubers cannot
be directly used as feeding forage, so the most of the area under potato will induce
the smaller scale feeding sheep.
Mowing is the most common form to use alfalfa pasture. In another aspect, the
soil fertility restoring ability of mowing alfalfa land is an important reflection of the
productivity of alfalfa grassland. Our research indicates that soil organic carbon
(SOC), soil total nitrogen (STN) and soil SOC/STN ratio showed a slow downward
trend in a conventional mowing alfalfa land. It implied that the mowing alfalfa was
unable to improve soil quality, so that it cannot restore the farmland fertility through
rotation between crop land with this type of mowing alfalfa grassland (Jiang et al.
2006 ; Wang et al. 2006 , 2009 ).
Vegetation restoration is an important way to improve the ecological environ-
ment of the semi-arid areas. Returning farmland to grassland or forest is the main
vegetation restoration policy. According to 6 years’ continuous field observation of
vegetation restoration process with three methods: planting alfalfa (Medicago sativa
Linn.); biennial sweet clover (Melilotus officianalis Linn.) and natural recovered
abandoned land (Yuan et al. 2015b), it was found that abandoned land biomass is
only 1000 kg ha−^1 within the whole experiment period; sweet clover biomass above
2000 kg ha−^1 in the majority of the years, except decreased significantly in the third
year. The alfalfa biomass more than 2000 kg ha−^1 in the third year, furthermore, it
Fig. 5 Logistic regression analysis of influencing factors of local farmer household adopting rais-
ing sheep indoor in North mountain area (annual precipitation 300 mm, annual mean temperature
6.5 °C) of Yuzhong County, Gansu Province. Wald X^2 indicated that farmland and grain production
influenced positively on the adoption but the influence of alfalfa land has negatively influence trend
to the adoption although this influence is not statistically significant. (Data from Zhang et al. 2012)
F.-M. Li et al.