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soil erosion, and thus barn feeding must be the dominate measures for husbandry
developing, with supplement of grazing animals in areas around the croplands
(Zhang et al. 2012 ; Li and Shen 2013 ). The grazing is not allowed on natural vegeta-
tion. Grassland and crop residues are the major sources of forage for barn feeding
sheep. Productivity of artificially cultivated grasslands is much higher than natural
grasslands, and it has become the dominated source of forage grass. As the alfalfa
productivity is significantly higher than other forage species and it also can fix nitro-
gen from the atmosphere as legumes, it becomes one of most important legume
forage for artificial grasslands (Zeng 2002 ; Shan et al. 2008 ).
Biomass productivity of sown alfalfa grassland is generally lower than that of
wheat at the same type of region (Table 3 ) (Du et al. 1999 ; Hao et al. 2004 ; Guo
et al. 2008 ; Jia et al. 2009 ; Jia and Li 2011 ), even if furrow-ridge with plastic film
mulching is used for alfalfa (Jia et al. 2006 , 2009 ). In the area with 300 mm average
annual rainfall, although grass yield may be higher than local wheat aboveground
biomass, it was still smaller than the half of maize aboveground biomass under the
ridge-furrow with plastic film mulching. Undoubtedly, alfalfa grassland is ineffi-
cient in providing the forage grass for the husbandry developing compared to maize
planting, or even it’s less efficient than wheat planting. Therefore, with dependence
only on the planting of alfalfa grassland to develop the animal husbandry, it is hard
to solve the food problem and feed the local people, and in improving people’s
income. This could be an important reason of the unwillingness of local people in
planting alfalfa for a long time.
The household survey further confirmed this view (Zhang et al. 2012 ). In the
North Mountainous area of Yuzhong County in Gansu (average annual rainfall of
about 300 mm). The study pointed out that the feeding sheep numbers or willing-
ness have significant negative correlation with the number of sold potatoes, and it
had also significant positive correlation with the maize dominated cereal produc-
tion, and no significant correlation with the alfalfa production (Fig. 5 ). This result
showed that planting alfalfa is insufficient to support the development of sheep hus-

Table 3 Aboveground biomass comparison between alfalfa and wheat in areas with various
annual mean precipitations

AMP

(mm) Survey site

Alfalfa

BPY (kg

ha−^1 , year)

Alfalfa

AAABY (kg

ha−^1 , year) Sources

Wheat B

(kg ha−^1 ) References

300 N Yuzhong 5527, 7 4471, 10 years Jia et al.

( 2009 )

5390 Jia et al.

( 2009 )

450 Guyuan 6368, 6 4533, 8 years Du et al.

( 1999 )

6179 EV

580 Changwu 7284, 5 4852, 6 years Hao et al.

( 2004 )

7500 Guo et al.
( 2008 )
Note: AMP is Annual Mean Precipitation; Alfalfa BPY is Alfalfa Biomass Peak and occurred Year
after sowing; Alfalfa AAAB is Averaged Annual Accumulated Biomass and occurred Year after
sowing; Wheat B is wheat biomass including straw and grain at the same site as alfalfa. EV is an
estimated value: (5390 / 300 + 7500 / 580) / 2 * 450 = 6179

Integrated Dryland Agriculture Sustainable Management in Northwest China