农业开发与沙漠化防治(发展经济学-中国科学院研究生)

1、可持续农业开发与沙漠化防治内蒙古沙漠化地区的事例发展经济学石敏俊资源环境学院可持续农业开发与沙漠化防治社会经济条件的変化与土地退化土地利用変化及其驱动因素农户经济与沙漠化的关系农民对沙漠化防治技术的态度沙漠化防治技术的经济效益与环境保护效果引进适用技术,建立环境保护型土地利用方式可持续农业开发的外部支援政策科尔沁沙地土地利用（1950s-1990s）阿鲁科尔沁旗：家畜头数推移1947-1965：急增1965-1983：停滞1983-1996：増加阿鲁科尔沁：旱作农业1947-1965：急増1965-：停滞科尔沁沙地土地利用（1950s-1990s）奈曼：家畜头数推移1947-1965：急増19

2、65-：停滞1965-1970：减少,1970-1994：増加羊头数増加山羊减少（ 1965-）牛減少（1965-）奈曼：旱作农业1947-1960：急増1960-：減少 1960-1985：減少, 1985-1990：増加, 1990-1992：減少玉米种植面积扩大科尔沁沙地家畜头数与放牧强度変化1985-19951985-1995：家畜头数增加与放牧强度增大放牧强度超过合理放牧强度1970s-1980s：沙漠化土地面积扩大科尔沁沙地旱作农业 1985-1995耕地面积扩大趋势阿鲁科尔沁旗与开鲁县：耕地面积与播种面积显著扩大玉米种植面积扩大尤其显著科尔沁沙地土地利用変化第阶段：1950年代至

3、1960年代中期 农牧业急速扩大（家畜头数增加，旱地扩大），环境负荷大幅度增大。第阶段：1960年代后半至1970年代后期 农牧业停滞（1965年以后：山羊减少，家畜头数停滞；1960年初期：随着定居化，曾出现一时的开垦扩大，1960年代初期以后：旱作农业停滞，1970年代初期：随着农业学大寨运动，灌溉面积扩大）第阶段：1980年代以来 农牧业再次扩大（羊头数增加带动家畜头数增长；一部分区域旱地扩大，玉米单一作物化），放牧强度上升。内蒙古农业政策和制度的変化环境资源制约与沙漠化防治对策的实施草原保护、禁止开垦政策的背景（1960s）：环境资源的制约放牧强度加大草原退化沙漠化深刻沙漠化防治对策的

4、实施（1970s）植树造林流沙固定（草方格）市场变动价格变动与家畜头数的变化土地利用变化的驱动因素1950s-1965：家畜头数增加的原因制度政策起决定性影响1960年代后期至1970年代末期：畜牧业停滞原因环境资源的制约1980年代以来：受市场（价格）变动影响深刻沙漠化防治对策与土地利用调整-populous upland farming areas (Yaoledianzi)-土地利用结构调整 1)退化草地禁止放牧 2)退化耕地放弃耕作 3)基本农田集约经营 扩大灌溉面积 4)营造防风林land cover change in Yaoledianzi villageIntroducing

5、new technologies and alternativesIntroducing new technologies to raise productivityseeds,fertilizers,irrigationIntroducing alternatives to increase farm incomewheat, watermelon,riceSupplementary between economy and environment in populous upland farming areas(Yaoledianzi)放牧家畜减少玉米种植面积扩大引进小麦、经济作物、水稲等新

6、作物通过引进新技术新作物促使无差异曲线向右方移动改善农户经济与改善环境质量同步trade-off between economy and environment in remote pastoral areas(Babolihe)家畜增加放牧强度增大草地退化农户经济衰退转向旱作农业地表植被破坏沙漠化如何建立环境保护型土地利用方式对象区域土地利用変化 1996-2000旱作农业区域：旱作面积扩大放牧畜牧业区域：家畜减少，旱作面积扩大家畜减少原因 1996-2000资源制约：过度放牧引进草地退化畜产品价格下落导致畜牧业收益低下随着草地使用权长期化，外部成本内部化禁牧政策的实施旱地作物价格低落与旱作

7、收益低下旱作农业地区：期望高收益作物旱地作物价格下降导致收益低下农民期望发展高收益作物生产制约：有机肥不足与地力再生产低下旱作农业的地力再生产农户的农业经营意向放牧畜牧业地区牧民对畜牧业的执着缺乏新技术转向旱作农业从农法论看改进土地利用的方向脆弱的饲料基础畜牧业停滞地力再生产低下放牧地崩溃旱地引入饲料作物和牧草舍饲畜牧业改进地力再生产引进舍饲畜牧业减轻放牧强度的可能性 Background information of the study sites VillageYaoledianziSharitalaHousehold8437Population346163Total area (ha)1

8、,2831,235Cultivated land per household (ha)1.5 1.5 Rangeland per household (ha)6.1 20.5 Livestock per household (sheep equivalent) 10.5 41.7 Income per capita (Yuan)2,0502,264Sources of income Farm income (%)86.6 87.8 Crop income (%)76.1 31.5 Livestock income (%)10.5 56.3 Off-farm income (%)13.4 12.

9、2 Different households in Yaoledianzi Households with higher income cultivate more upland, which indicates that household income has higher correlation with the utilization of cultivated upland. household groupincome per capita (Yuan)source of income (%)cultivated land per household (mu)#rice field#

10、irrigable upland#non-irrigable uplandfarm income#off-farm incomeCroplivestockaverage86.58 76.07 10.51 13.42 21.95 5.34 12.90 3.71 A=400087.36 76.68 10.68 12.64 40.50 16.33 19.50 4.67 Different households in SharitalaHigher-income households raise more animals and cultivate larger area of crops. Ther

11、e is a significant correlation between household income and grazing pressure on rangeland. That indicates households who pursue higher income place more heavy pressure on rangeland. household groupincome per capita (Yuan)source of income (%)cultivated land per household (mu)#irrigable upland (mu)gra

12、zing animal per household (sheep equivalent)farm incomeoff-farm income#crop# livestockaverage87.82 31.51 56.32 12.18 21.91 13.29 41.69 A=400089.71 29.90 59.78 10.29 25.14 17.57 67.71 Impact of improving access to credit service on poor farmers behaviorNot poverty, but practices to reduce poverty pos

13、ed negative impacts on rangelandVillageHousehold typeCredit supporting availableOwn capital onlyIncome Grazing pressureIncome Grazing pressure(yuan)(sheep equivalent/ha)(yuan)(sheep equivalent/ha)YaoledianziPoor12,634 2.31 8,573 0.35 Better off 17,189 2.4117,189 2.41SharitalaPoor10,664 2.362,743 0.1

14、8Better off 12,936 2.4112,936 2.41Needs for regulation on rangeland useIf no restriction to grazing in pastoral areas or reclamation of rangeland in upland areas, households might raise more livestock herds or enlarge reclamation of rangeland. That gives a basis for regulations or norms on utilizati

15、on of rangeland, because rangeland as environmental assets includes nature of public goods with the function of environmental conservation. Policy scenariosActual policy implementYaoledianzi: grazing prohibition completely since 2000 (A)Sharitala: grazing prohibition half year since 2000 (B)Policy s

16、cenariosgrazing prohibition completely (A)grazing prohibition half year (B)restricting herds number and keeping grazing pressure less than 1 sheep equivalents per ha (C1)no restriction to grazing (D)SignScenario definitionEnvironmental regulations ATo prohibit grazing completely, and reclamation is

17、prohibited BTo prohibit grazing for half year, and reclamation is prohibited CTo restrict number of herds or keep a reasonable grazing pressure, and reclamation is prohibited C-1To keep grazing pressure less than 1 sheep equivalent/ha C-2To keep grazing pressure less than 2 sheep equivalent/ha C（5)T

18、o restrict number of herds less than 5 sheep equivalent per capita C(10)To restrict number of herds less than 10 sheep equivalent per capita DNo restriction to grazing, but reclamation is prohibited ENo prohibition on grazing or reclamationNew technologies0Using existing farming technologies1Introdu

19、cing sedentary beef cattle technologiesImpacts of conservation regulation on household incomeScenarioYaoledianziSharitalaIncomeGrazing pressureReclaimed landIncomeGrazing pressureReclaimed land(Yuan)(sheep equivalent /ha)(ha)(Yuan)(sheep equivalent /ha)(ha)A-0654,1220.00 0 153,1070.00 0 B-0736,9921.

20、58 0 283,9181.68 0 D-0764,4722.25 0 338,7662.41 0 F-01,036,3502.41 85.13371,2902.41 34.93C1-0694,7491.00 0 229,1141.00 0 C2-0735,3762.00 0 305,1212.00 0 C(5)-0760,5792.25 0236,7501.10 0C10-0764,4722.25 0 320,3932.20 0 Tradeoff between poverty alleviation and rangeland conservationHowever strict regu

21、lation to prohibit grazing completely has significant negative effect on livelihoods of the households. Rangeland conversation practices have posed negative impacts on poverty alleviation.A need for alternative policy to promote simultaneously rangeland conservation and poverty alleviation.Concept o

22、f Environmental Policy: Cross ComplianceRed Ticket设定合理的放牧强度基准值，对于家畜头数超过基准值，超载过牧的农户，按超过部分家畜头数处以罚款Green Ticket对于减少家畜数量，达到合理放牧强度基准值以下的农户，通过补贴等形式给予鼓励Reasonable policy alternativeRestriction of number of herds per capita (C5-0) or grazing pressure (C1-0) might be considered as alternative policy measures

23、 in pastoral areas.It may keep grazing pressure at a reasonable level with less negative impact on household income rather than prohibiting grazing completely (A-0) or for half year (B-0). Possible solutions to tradeoffUnder given technological condition, land use choices face a trade-off between en

24、vironmental conservation and economic interest, subject to resource constraints. The production possibility curve may be shifted outward through introducing new technology or changing constraints.Technological alternativesTechnological alternatives0: Based on actual practice1: Introducing sedentary

25、beef cattlePolicy scenariosA: Grazing prohibition and reclamation prohibitionB: Grazing prohibition, but no restriction to reclamationC: Restriction of number of herds or grazing pressureD: No restriction to grazing and reclamationSimulation on technical innovationIntroducing sedentary beef cattle g

26、enerate 52% income increase in Yaoledianzi under a complete grazing ban (from A-0 to A-1) and 78% income increase in Sharitala under a half year grazing ban (from B-0 to B-1).If restriction to keep grazing pressure at the level of 1 sheep equivalent per ha was implemented as alternative policy, intr

27、oduction of sedentary beef cattle may bring 48.7% income increase in Yaoledianzi and 52% in Sharitala.Improving poor farmers access to credit service availableIf sedentary beef cattle introduced, providing credit service to poor farmers may bring them 51% of income increase under restriction to keep

28、 grazing pressure at the level of 1 sheep equivalent per ha. If sedentary beef cattle introduced, providing credit supporting to poor livestock farmers may generate 416% of income increase under restriction to keep grazing pressure at 1 sheep equivalent per ha. Conclusion and implicationsRegulation on rangeland use is need