Impacts of Cultivated Land Conversion on Environmental Sustainability and Grain Self-sufficiency in China
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75China & World Economy / 75 92, Vol. 16, No. 3, 20082008 The AuthorJournal compilation 2008 Institute of World Economics and Politics, Chinese Academy of Social SciencesImpacts of Cultivated Land Conversion onEnvironmental Sustainability and GrainSelf-sufficiency in ChinaShuhao Tan *AbstractUsing provincial data, the present paper examines the impact of cultivated land conversion onagriculture and the environment. It is found that the grain production center is graduallymoving towards more fragile and water scarce areas, putting more pressure on the environment.Land conversion caused large losses in ecosystem service values in the 1990s, but large scaleecological restoration programs have been implemented since 2000 to compensate for suchlosses. The ecological restoration programs are concentrated in regions with relatively lowland productivity, whereas cultivated land conversion usually takes place in areas with relativelyhigh land productivity. Newly-cultivated land, especially that in areas marginally suit foragricultural production, is likely to have much lower productivity levels than the originalcultivated land. Because the stock of potentially cultivable land is almost exhausted, Chinasgrain self-sufficiency policy can only be maintained by preserving the available stock of arableland and increasing its productivity in a sustainable way.Key words: China, cultivated land conversion, environmental quality, grain self-sufficiency,land policyJEL codes: Q01, Q15, Q28I. IntroductionGrain self-sufficiency is an important agricultural policy goal in China.1 The Chinese* Shuhao Tan, Associate Professor, School of Agricultural Economics and Rural Development, RenminUniversity of China, Beijing, China. Email: Shuhtan68@gmail.com. The author is grateful for thefinancial support provided by the program of Natural Science Foundation of China (30571094), theprogram of National Social Science Foundation of China (07&ZD048) and the 973 Program of Ministryof Sciences and Technology of China (2004CB720401).1In this paper China refers to Chinese mainland.76 Shuhao Tan / 75 92, Vol. 16, No. 3, 20082008 The AuthorJournal compilation 2008 Institute of World Economics and Politics, Chinese Academy of Social SciencesGovernment has set a target of at least 95 percent grain self-sufficiency under normalconditions. Very limited land resources are available to feed its large population, whichreached 1.3 billion. Of the total land area, 960 million ha, only 13.5 percent can be used asarable land. As a result, only 0.10 ha per capita is available for agricultural production (NBS,2006).Chinas population is expected to stabilize at a level of 1.6 billion by 2030 (Zhong et al.,1999). In the coming years, the growing population will place a greater burden on thecountrys agricultural sector. Sustaining the agricultural production base and improvingagricultural productivity have been widely considered by researchers and the ChineseGovernment as the most effective ways of guaranteeing an adequate level of food productionin the long run. Strengthening the agricultural production capacity and developing a modernagricultural sector while sticking to the policy of food self-reliance have become nationalpolicy priorities since 2000 (State Council, 2007). Proposed measures include intensifyingthe conservation of arable land and improving the ecological environment, accelerating theconstruction of irrigation and water conservation facilities, stimulating the use ofenvironmentally-friendly fertilizers and pesticides, and investing in agricultural scienceand technology.In the long run, the agricultural production capacity in China might be greatlyrestricted by further reductions in the available arable land, resulting in overuse of thecurrent arable land, which, in turn, could lead to the depletion of the natural resourcebase through, for example, soil degradation, water scarcity and water pollution, andfurther reduce the efficiency of fertilizer application. This raises the question of whetherChina can maintain its grain self-sufficiency policy in the long run. In addition, what willbe the impact of this policy on environmental quality? An important issue causing concernis the conversion of cultivated land into, for example construction land. Shao and Xie(2007) show that 9.3 percent of the arable land was taken out of cultivation during theperiod 19962004, whereas 2.9 percent was added to the stock of cultivated land over thesame period.The present paper uses provincial and regional data to examine the impact of cultivatedland conversion on agricultural productivity and ecosystem services.2 Various studieshave addressed the cultivated land conversion issue in China. Many of these studiesexamine the link between cultivated land conversion and food self-sufficiency (e.g. Yang2 Ecosystem services refer to the goods (such as food or raw materials) and services (such as wasteassimilation or soil conservation) that are derived directly or indirectly by human beings from ecosystems.77Impacts of Cultivated Land Conversion2008 The AuthorJournal compilation 2008 Institute of World Economics and Politics, Chinese Academy of Social Sciencesand Li, 2000; Deng et al., 2006; Zhu, 2006).3 Other studies examine the environmentaleffects of cultivated land conversion (Tan et al., 2005), while Ash and Edmonds (1998)examine the relationship between land resources and both agricultural production and theenvironment. In the present analysis we take into account the uncultivated land that maybe cultivated in the future. The size of this stock could have a major impact on the arableland size and its quality in the near future. In addition, we use more recent data (up to 2004)that have been estimated with greater precision than the data used in most of the earlierstudies. Use of recent data is quite relevant because land use structure has changedgreatly during the last decade as a result of rapid urbanization and industrialization andincreasing welfare levels. The present study uses a method developed by Costanza et al.(1997) to estimate the value of the change in ecosystem services caused by cultivated landconversion.The present paper is organized as follows. Section II outlines the current situation andrecent trends in cultivated land and grain production in China; Section III examines the impactof cultivated land conversion on environmental sustainability using the change in ecosystemservice value as a measure of sustainability; Section IV examines the impact of cultivated landconversion on agricultural production by taking into account differences in productivitybetween land taken into agricultural production and land taken out of agricultural production.Section V concludes the paper and provides some policy implications.II. Cultivated Land and Grain Production in ChinaAlthough China has vast land resources, only a small portion can be used for cropping.Table 1 shows that 130 million ha (13.5 percent) of the total available land is cultivated land.Irrigated land accounts for 55 million ha, 42.2 percent of the cultivated land. The land thatis not cultivated, to a large extent, consists of forest land (18.2 percent of the total land area)and useable grassland (32.6 percent of total land area).From Table 1 it is evident that the total sown area is larger than the cultivated area,because more than one crop is planted per year in some regions. As a result, the multiplecropping index (calculated as the sown area divided by the cultivated land area) equals1.20. Approximately two-thirds of the sown area is planted with grain (cereals, soybeansand tubers). The three major grain crops, rice, maize and wheat, constitute just over half3 The term food security is commonly used in China to refer to food self-sufficiency. As the use of thisterm deviates from the commonly accepted definition of food security (access of all people at all timesto enough food for an active, healthy life), we will use the term food self-sufficiency (or self-reliance) inour study.78 Shuhao Tan / 75 92, Vol. 16, No. 3, 20082008 The AuthorJournal compilation 2008 Institute of World Economics and Politics, Chinese Academy of Social Sciences(50.2 percent) of the sown area. Other major crops are vegetables, oil-bearing crops (e.g.rapeseed and peanuts), fruit and cotton (NBS, 2006).Most paddy fields are located in areas with relatively high levels of rainfall (see Table 2).Approximately three-quarters of the paddy fields (75.7 percent) are located in areas withprecipitation levels of more than 1000 mm per year. In contrast, 79.2 percent of the dry landis located in areas with precipitation levels of less than l000 mm. Most cultivated land is flat(slope less than 5). However, 0.8 percent of the paddy land and 1.6 percent of the dry landis located on land with slopes of more than 25 (see Table 2).Comparing with the other regions of the world, agriculture in China is characterized by highexternal input and high labor intensity. As shown in Table 3, the chemical fertilizer use equals327 kg /ha. This level is more than twice the average level of the whole of Asia and is more thanthree times the global average. Use of tractors and harvest machines in China is very low. Thesize of the cultivated land per person working in agriculture is by far the lowest in China,confirming the great scarcity of land in China. These figures clearly show that China hasachieved its agricultural growth by adopting a biological pattern of agricultural intensification.Figure 1 shows the trend in the cultivated land area in China between 1988 and 2005.44 Note that the figures for cultivated land area for 2005 listed in Table 1 come from a different source(NBS, 2006) and cannot be compared with the estimates shown in Figure 1.Table 2. Natural Conditions of Cultivated Land, 2000 (%)Slope (degrees) 35 Total Paddy field 86.6 3.8 5.6 3.2 0.7 0.1 100 Dry land 80.9 4.8 7.7 5.0 1.3 0.3 100 Precipitation (mm) 1600 Total Paddy field 1.1 0.3 12.2 10.7 60.8 14.9 100 Dry land 5.1 9.0 54.3 10.8 17.8 3.0 100 Source: Zhang et al. (2003).Table 1. Composition of Total Land and Total Sown Area, 2005Composition of total land area Composition of total sown area Type Area (million ha) Share of total land area (%) Type Area (million ha) Share of total sown area (%)Total land area 960.0 100 Total sown area 155.5 100 Cultivated land 130.0 13.5 Grain 104.3 67.1 Irrigated land 55.0 5.7 Oil-bearing crops 14.3 9.2 Forest land 174.9 18.2 Cotton 5.1 3.3 Useable grassland 313.4 32.7 Vegetables 17.7 11.4 Other 341.7 35.6 Orchards and other 14.1 9.0 Source: NBS (2006).Note: Irrigated land has already been included in cultivated land. The reason that the irrigated land is listed here is toshow that high quality cultivated land, in particular, irrigated land, is very limited in China.79Impacts of Cultivated Land Conversion2008 The AuthorJournal compilation 2008 Institute of World Economics and Politics, Chinese Academy of Social SciencesBetween 1988 and 1995 the cultivated land area declined slightly. However, after 1995, itdecreased at a pace of more than 1 million ha per year, with the speed of decline beingparticularly rapid between 1999 and 2003.In contrast, grain production steadily increased during the 1980s and 1990s. As Figure 2shows, the production level in 1998 was approximately 1.26 times the grain production levelin 1987. From 1999 to 2003, grain production declined by more than 80 million tons. Thisdecline coincided with a rapid decrease in cultivated land area (see Figure 1). Since 2004,grain production has recovered and is now at a level close to that of the second half of the1990s. This, to some extent, can be attributed to the agricultural direct subsidy policyimplemented from the beginning of 2004.Table 3. Factor Use in Agriculture in DifferentRegions of the World, 2000Area Cultivated land area per person active in agriculture (ha) Number of tractors used per 1000 ha Number of harvest machines per 1000 ha Chemical fertilizer use (kg/ha) World total 1.1 19.0 3.0 99.5 Asia 0.5 14.6 3.8 146.8 Africa 0.9 3.1 0.2 21.4 North America 12.6 22.3 3.2 96.9 South America 3.5 11.2 1.3 78.9 Europe 8.8 37.3 4.0 82.2 Australia 19.8 7.2 1.1 51.4 China 0.2a 5.3 0.3 327.2 Source: Sun and Shi (2003).Note: aOwn estimate: Sun and Shi (2003) report a value of 0.1.Figure 1. Cultivated Land Area, 198820051161181201221241261281301321341988 1990 1992 1994 1996 1998 2000 2002 2004YearMillion haSources: Ministry of Land and Resources (19902000; 20012005).80 Shuhao Tan / 75 92, Vol. 16, No. 3, 20082008 The AuthorJournal compilation 2008 Institute of World Economics and Politics, Chinese Academy of Social SciencesThe geographical spread in grain production over north and south China (includingthe central-eastern provinces) is shown in Figure 3.5 The figure highlights that grainproduction has gradually moved northwards. In the beginning of the 1980s approximately60 percent of grain production took place in the south. Since 2002, this percentage hasdeclined to around 50 percent, with grain production in the north exceeding production inthe south for the first time in 2005. A similar shift in grain production was found in ananalysis of county-level data over the period 19801997 (You, 2006). Our data show thatthis trend continued after 1997.Within the northern region, grain production grew most in the northeastern region.The share of grain production in national production in the northeast grew fromapproximately 1011 percent in the early 1980s to more than 15 percent in 2004. However,grain production in both the northwestern and northern regions also increased byapproximately 2.5 percentage points during the same period. In the south, the decline ingrain production occurred mainly in the central-east region, the traditionally importantgrain production area. The share of this regions grain production in national productiondeclined from around 35 percent in the 1980s to around 27 percent in 2003. A similar processalso took place in the southeast, which saw its share of grain production decline by5 In this paper, north China comprises three sub-regions: northeast (Liaoning, Jilin, Hei Longjiang),north (Hebei, Henan, Shandong, Shanxi, Beijing and Tianjin) and northwest (Inner Mongolia, Shaanxi,Ningxia, Gansu, Qinghai and Xinjiang). South China includes three sub-regions: southeast (Fujian, Guangdong,Guangxi and Hainan), southwest (Sichuan, Chongqing, Guizhou, Yunnan and Tibet) and central-east(Hunan, Hubei, Jiangxi, Jiangsu, Anhui, Zhejiang and Shanghai).Figure 2. Grain Production, 1979200501002003004005006001979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005YearMillion tonsSource: Ministry of Agriculture (19792005).81Impacts of Cultivated Land Conversion2008 The AuthorJournal compilation 2008 Institute of World Economics and Politics, Chinese Academy of Social Sciencesapproximately 4 percentage points during the same period. Both the central-east andsoutheast are regions where rapid economic development has taken place since the mid-1980s. The share of grain production in the southeast area remained more or less stable ata level of 15 percent.These trends show that the major grain production areas have moved from the traditionalgrain growing areas in the south with relatively good production conditions towards northernregions, where rainfall levels are much lower. Hence, grain production levels in the nearfuture might be more erratic as a result of the more fragile ecological environment in thenorth regions.According to the land use change survey compiled by the Ministry of Land andResources (Huang, 2006) in 2002, on a land reserve of 88.7 million ha, 9.33 percent of thetotal land area is available. The land reserve consists of unused wetlands, wasteland andbare land. However, only 7.34 million ha of this land can be exploited as cultivated land asa result of natural limitations, such as water availability and ecological environmentalconditions. Only a small share of the land, 0.32 million ha, can be reclaimed under currentlyprevailing technological and economic conditions. The remainder, 7.02 million ha, would becultivable in the near future.The land reserve is distributed differently over the six major regions. The largest partof the land reserve is located in the northwest (almost 40 percent) and southwest (almost30 percent). Only 56 percent of land reserves are available in the central-east andsoutheast. Approximately two-thirds of the cultivated land reserve is located in theFigure 3. Geographical Shift in Grain Production, 197920050102030405060701979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005YearPercentageNorthSouthSource: Ministry of Agriculture (19792005).82 Shuhao Tan / 75 92, Vol. 16, No. 3, 20082008 The AuthorJournal compilation 2008 Institute of World Economics and Politics, Chinese Academy of Social Sciencessouthwest, as climatic and agro-ecological conditions in this region are more favorablethan in the northwest.III. Impact of Cultivated Land Changeon Environmental SustainabilityEnvironmental sustainability is fundamental to agricultural production. Cultivated landconversion can have important environmental effects. It causes a change in ecosystemservices and the values associated with such services because different land use typesprovide different ecosystem functions. Ecosystem service value is used here to indicateenvironmental sustainability. To derive the values provided by different land use types,non-marketed services should be valued by estimating the willingness-to-pay ofindividuals for these services. Using the methods of Costanza et al. (1997), Xie et al. (2003)estimate ecosystem services values of different ecosystem types in China from a survey of200 Chinese ecologists (see Table 4). Their estimation indicates that wetland and waterhave the highest ecosystem service values. Compared with farmland, forest land alsoshows a much higher ecosystem service value, while grassland value is only slightlyhigher. Only deserts have a much lower ecosystem value than farmland.Table 5 shows the sources of land taken into cultivation and the destinations of landtaken out of cultivation between the end of the 1980s and the end of the1990s, and derivesTable 4. Ecosystem Service Values of DifferentEcosystem Types in China (US$/ha per year)Source: Xie et al. (2003). Forest land Grassland Farmland Wetland Water Desert Gas regulation 387 89 55 199 0 0 Climate regulation 299 100 98 1891 51 0 Water supply 354 89 66 1714 2254 3 Soil formation and conservation 431 216 162 189 1 2 Waste treatment 145 145 181 2011 2011 1 Biodiversity 361 121 79 277 275 38 Food production 11 33 111 33 11 1 Raw materials 288 6 11 8 1 0 Amenity 142 4 1 614 480 1 Total 2417 801 764 6936 5084 46 83Impacts of Cultivated Land Conversion2008 The AuthorJournal compilation 2008 Institute of World Economics and Politics, Chinese Academy of Social Sciencesthe change in ecosystem service values related to these land conversions. The largest shareof the land taken into cultivation, 55.7 percent, came from grassland. The remainder of theland mainly came from forest land (28.7 percent) and unused land (10.8 percent). Using the perunit ecosystem values presented in Table 4, we estimate a total loss of ecosystem value of atTable 5. Change in Ecosystem Service Value for CultivatedLand Conversion, 19891999 Area (million ha) Per unit ecosystem service value (US$ per ha per year) Total value (million US$ per year) Land taken into cultivation by: Grassland 3.45 801 2765 Forest land 1.78 2417 4296 Unused landa 0.67 764 513 Water and wetland 0.29 6010 1729 Other landb 0.01 46 1 Total loss from the conversion 9303 Minus: Gain from the conversion 6.20 764 4737 Net loss of ecosystem service value 4566 Land taken out of cultivation for: Construction 2.14 0 0 Ecological restorationc 2.53 1609 4071 Destroyed by natural disastersd 1.19 632 752 Agricultural structural adjustment 0.83 764 634 Total gain from the conversion 5457 Minus: Loss from the conversion 6.69 764 5111 Net gain of ecosystem service value 346 Total loss of ecosystem service valuee 4220 Sources: Authors calculations based on Tian et al. (2002), Xie et al. (2003) and Ministry of Land and Resources(19902000).Notes: aFarmland value is used as an approximation for the value of unused land. The actual ecosystem service valueof unused land is higher because it is mainly located in Hei Longjiang, Jilin and Inner Mongolia. bDesert landvalue is used as an approximation for the value of other land. cLand taken out of cultivation for ecologicalrestoration becomes either forest land or grassland; the average value of the ecosystem service value of thesetwo land use types is used as an approximation of the per unit value of ecologically restored land. dCultivatedland destroyed by natural disasters is assumed to have the same per unit value as farmland value minus its foodproduction value and raw material value. eTotal loss of ecosystem service value (US$4220 per year) =Net lossof ecosystem service value (US$4566 per year) Net gains of ecosystem service gains (US$346 per year).84 Shuhao Tan / 75 92, Vol. 16, No. 3, 20082008 The AuthorJournal compilation 2008 Institute of World Economics and Politics, Chinese Academy of Social Sciencesleast US$4.566bn as a result of land conversion into new cultivated land. The conversion offorest land into farmland is the major factor leading to this ecosystem value loss.From the end of the 1980s to the end of 1990s, the land taken out of cultivation forecological restoration slightly exceeded the size of the cultivated land that was convertedinto construction land (38 and 32 percent, respectively). Almost 1.2 million ha (18 percent ofthe converted land) was destroyed by natural disasters, while more than 0.8 million ha wasmaintained for agricultural structural adjustment (i.e. producing horticultural products,fruit and livestock using modern techniques). The resulting change in the ecosystem valueduring this period was slightly positive (estimated at US$0.35bn), because land used forecological restoration has a much higher ecosystem service value per hectare than cultivatedland, whereas construction land is assumed to have a zero ecosystem value. Taking theestimated ecosystem values of land taken into cultivation and land taken out of cultivationtogether, we estimate that the total loss of ecosystem value caused by land conversionduring the period 19891999 was equal to US$4.22bn.Similar calculations have been made for the change in ecosystem value caused by thecultivated land conversion between 2000 and 2005. Because we could not find detailed datafor land conversion from non-farmland, we could only roughly estimate the gain and lossvalue between 2000 and 2005 (see Table 6). During this period a number of major ecologicalrestoration programs, such as the Sloping Land Conversion Program and the BeijingTianjinSandstorm Control Program, were implemented. In these programs, large areas of arable landin west and north China were and still are being converted into forest land and grassland toprevent soil erosion and dust storms. As is evident from Table 6, land conversion for ecologicalrestoration dominated the conversion of land during this period. It was responsible for 67percent of the land taken out of cultivation. As a result, there was a substantial gain inecological service value during this period, estimated at US$2.69bn (see Table 6).The estimated loss of ecosystem service value during the entire period 19892005equals US$1.53bn.6 The estimated loss of land conversion into construction land duringthis period is equal to US$2.61bn. Table 7 shows how the latter losses were distributed overthe six major sub-regions during the years 19992004. It shows that losses caused byconversion into construction land are much larger in the central-east and the north than inthe other four regions. In both the central-east and the north, the ecosystem value lossescaused by expanding construction land have been increasing over time. The other fourregions show relatively large losses in 1999 and 2004 and smaller losses in 20002003.In this section, the ecosystem service value is used to measure the impact of land6 This figure equals total loss of ecosystem service value in Table 5 (US$4220 per year) total gains ofecosystem service value in Table 6 (US$2686 per year).85Impacts of Cultivated Land Conversion2008 The AuthorJournal compilation 2008 Institute of World Economics and Politics, Chinese Academy of Social Sciencesconversion on environmental sustainability. This might not be a precise measure forestimating environmental quality change, but it does provide a measurable way of comparingthe environmental losses and gains caused by land conversion, and allows researchersand policy-makers to compare such changes over time and between regions for use indecision-making in the future. Because environmental quality is the basis of agriculturalproduction, the change in environmental quality caused by cultivated land change mightindirectly impact grain production, which is difficult to evaluate. The direct impact ofcultivated land change on grain production will be discussed in the next section.Table 6. Change in Ecosystem Service Value for Cultivated LandConversion, 20002005 Area (million ha) Per unit ecosystem service value (US$ per ha per year ) Total value (million US$ per year) Land taken into cultivation: 2.04 Loss from conversiona 2.04 1500 3060 Minus: Gain from conversion 2.04 764 1559 Net loss of ecosystem service value 1501 Land taken out of Cultivation for: 9.16 Construction 1.27 0 0 Ecological restorationb 6.14 1609 9879 Destroyed by natural disastersc 0.32 632 202 Agricultural structural adjustment 1.43 764 1100 Gain from conversion 11 181 Minus: loss from conversion 9.16 764 6994 Net gain of ecosystem service value 4187 Total gain of ecosystem service valued 2686 Sources: Authors calculations based on Ministry of Land and Resources (20012005) and Xie et al.(2003).Notes: aThe average per unit ecosystem service value of land taken into cultivation in Table 5 is used toapproximate the ecosystem service value of land taken into cultivation. bLand taken out of cultivationfor ecological restoration becomes either forest land or grassland; the average value of the ecosystemservice value of these two land use types is used as an approximation of the per unit value of ecologicallyrestored land. cCultivated land destroyed by natural disasters is assumed to have the same per unit valueas farmland value minus its food production value and raw material value. dTotal gain of ecosystemservice value (US$2684 per year) = Net gain of ecosystem service value (US$4185 per year) Net lossof ecosystem service gains (US$1501 per year).86 Shuhao Tan / 75 92, Vol. 16, No. 3, 20082008 The AuthorJournal compilation 2008 Institute of World Economics and Politics, Chinese Academy of Social SciencesIV. Impact of Cultivated Land Changeon Grain ProductionPopulation, resources and the environment are the major factors influencing grain self-sufficiency, which is considered to be an important goal of agricultural policies in China.Since 1995, the Chinese Government has put considerable effort into grain production. Itreached the highest point in 1998, but after that, the grain production decreased for 5 years.To improve grain production as well as to improve farmers income, from 2004, the centralgovernment abolished the agricultural tax, and implemented the direct subsidy policy in themajor grain production areas. However, grain self-sufficiency is still threatened by limitedcultivated land and decreased land productivity.Figure 1 shows the trend in cultivated land area during 19882005. In analyzing theimpact of land conversion on agricultural production, total cultivated area is not anincomplete indicator as it does not take into account differences in crop productivitycaused by precipitation, soil quality and other agro-climatic factors. The natural conditionsof newly-cultivated land differ significantly from those of the land already in cultivation.Hence, to examine the impact of cultivated land change on grain production we should notonly examine the size of the cultivated land but also its productivity. An important indicatoris the productivity coefficient p,7 defined as the average yield in a province divided by the7 In principle, the value of the productivity coefficient p is mainly decided by natural conditions like soiland climate (e.g. temperature, rainfall and radiation) and themultiple cropping index. Some economicactivities like fertilizing and irrigating also play roles.Table 7. Change in Ecosystem Service Value for CultivatedLand Conversion into Construction Use, 19992004(US$m per year)Region 1999 2000 2001 2002 2003 2004 Total Northeast 17 9 6 5 5 21 64 North 38 32 44 47 56 68 285 Northwest 13 9 9 13 13 14 71 Central-east 37 46 42 60 70 81 336 Southeast 18 12 10 11 13 16 79 Southwest 34 16 14 14 18 24 120 China 157 125 125 150 175 224 956 Sources: Authors calculations based on Ministry of Land and Resources (20012005) and Xie et al.(2003).87Impacts of Cultivated Land Conversion2008 The AuthorJournal compilation 2008 Institute of World Economics and Politics, Chinese Academy of Social Sciencesaverage yield in China.Table 8 shows the productivity coefficients of each province in China, and uses theseindices to divide the provinces into four groups: very strong production area, with pbetween 1.60 and 1.81; strong production area, with p between 1.20 and 1.60; mediumproduction area, with p between 0.90 and 1.20; and weak production area, with p below 0.90.The five provinces with the lowest ps are all located in northwest China.By multiplying the available data on land conversion per province with these coefficients,we can calculate the so-called standardized change in cultivated land since 1999.8 The resultsfor both absolute change9 and standardized change during 19992004 are presented inTable 9. Looking at the absolute change, cultivated area in the northwest has declined themost, and to a less extent in the southwest, north and central-east. If taking the landproductivity into account (standardized change), we find that the land taken out ofproduction in the central-east is much more productive than the land no longer cultivatedin the northwest. Even though the size of the land taken out of production in the northwestwas 2.7 times as large as in the central-east, the estimated impact on agricultural productionis relatively lower than in the central-east, where there is higher productivity. In total, thestandardized change in cultivated land (6.47 million ha) during the period of 19992004 is 12percent smaller (in absolute size) than the absolute change for China as a whole (7.32million ha). This shows that the cultivated land converted into non-cultivated use has alower productivity level than the average productivity level of all the cultivated land inChina, implying that the loss of land conversion and its impact on grain production aresmaller than the estimation based on the statistical data.8 Standardized change means the change based on the statistical data considering the productivity coefficientof each province.9 Absolute change means the change calculated from the statistical data, without distinguishing thedifference in productivity of each province.Table 8. Grouping of Provinces According toCultivated Land ProductivityVery strong production area (1.60 < p ? 1.81) Strong production area (1.20< p ? 1.60) Medium production area (0.90< p ?1.20) Weak production area (0< p ? 0.90) Hunan 1.81 Beijing 1.58 Chongqing 1.17 Hainan 0.70 Ningxia 0.53 Shanghai 1.76 Guangdong 1.51 Anhui 1.13 Hei Longjiang 0.64 Xinjiang 0.52 Jiangsu 1.73 Jiangxi 1.45 Hebei 1.05 Shaanxi 0.63 Inner Mongolia 0.48 Zhejiang 1.72 Shandong 1.42 Jilin 1.01 Tibet 0.62 Qinghai 0.43 Fujian 1.72 Sichuan 1.37 Tianjin 0.97 Guizhou 0.59 Gansu 0.42 Hainan 1.29 Liaoning 0.96 Shanxi 0.58 Hubei 1.27 Guangxi 0.91 Yunnan 0.55 Source: Zheng and Feng (2003).88 Shuhao Tan / 75 92, Vol. 16, No. 3, 20082008 The AuthorJournal compilation 2008 Institute of World Economics and Politics, Chinese Academy of Social SciencesFor land converted from cultivated land into land for construction use, the outcomesare quite different. The absolute change of conversion of cultivated land into constructionwas 1.25 million ha during the period of 19992004, representing only approximately one-sixth of the total land taken out of cultivation (see Table 9). Most of this land is located inthe central-east and the north. The productivity is relatively high, especially in the central-east. If we consider standardized changes in cultivated land, the land converted intoconstruction land makes up almost one-quarter of the total land taken out of cultivation. Asa result, the standardized change of land converted into construction land is approximately25 percent larger than the absolute change. This shows that cultivated land converted intoconstruction use has higher productivity and its impact on grain production is much larger,threatening grain self-sufficiency.To see the real change in the cultivated land more clearly, the present study uses theprovince-level productivity coefficient as an indicator of the productivity of cropland,which differs from analyses in existing published studies. Even within the same provinces,land productivity is also quite different as a result of, for example, location, topography andproduction conditions. Several case studies show that most high-yielding cultivated land(used for growing vegetables or rice) located in suburban areas has been converted intoconstruction land in the eastern coastal areas. Hence, the cultivated land converted intoconstruction use is not only mainly located in the provinces with higher productivitylevels, but also normally distributed in suburban areas with better production conditions(e.g. with fertile soil and good location). This can better reflect the impact of cultivated landconversion on grain production.The estimates above mainly focus on average values for land. Besides, differences inagro-climatic conditions between land taken into cultivation and already cultivated landmight also have an important impact on agricultural production. To this end, we comparethe natural conditions of land taken into cultivation between 1990 and 2000 (see Table 10)Table 9. Cultivated Land Change and Conversion, 19992004 (million ha)Cultivated land change Conversion into construction land Region Absolute change Standardized change Change ratio (%) Absolute change Standardized change Change ratio (%) Northeast 0.21 0.18 14 0.08 0.07 13 North 1.31 1.20 8 0.37 0.42 14 Northwest 2.80 1.49 47 0.09 0.05 44 Central-east 1.09 1.60 47 0.44 0.71 61 Southeast 0.39 0.54 38 0.10 0.15 50 Southwest 1.51 1.47 3 0.16 0.15 6 China 7.32 6.47 12 1.25 1.56 25 Sources: Calculated from Ministry of Land and Resources (19902000; 20012005).89Impacts of Cultivated Land Conversion2008 The AuthorJournal compilation 2008 Institute of World Economics and Politics, Chinese Academy of Social Scienceswith those of the cultivated land in the year 2000 (see Table 2 ). We find that newly-cultivated land is relatively flat. Only 11.6 percent of the land has a slope of more than 5degrees, as compared to 13.4 percent for the paddy land and 19.1 percent for the dry land,that is already in cultivation. However, rainfall levels are much lower for newly-cultivatedland. As much as 91.6 percent of the land receives less than 800 mm of rain per year,whereas for already cultivated land this share is 68.4 percent for dry land and only 13.6percent for paddy fields. This shows that newly-cultivated land is located in areas that areonly marginally suited for agricultural production, and that are likely to have much lowerproductivity levels. This finding reaffirms the conclusion of Lin and Ho (2003) that newly-reclaimed low-graded farmland in environmentally fragile frontier areas has never been ableto compensate for the loss of fertile farmland in the southeast area of the country. Inaddition, some research also shows that excessive reclamation of land in environmentallyfragile regions has brought damage to the natural environment, causing problems of soilerosion, desertification and deforestation (Ash and Edmonds, 1998; Yang and Li, 2000).In this section, four approaches have been used to examine the impact of cultivatedland change on grain self-sufficiency. First, the productivity coefficient has been used tomeasure the standardized cultivated land change, taking into account the natural conditionsthat might affect agricultural production and, therefore, grain self-sufficiency, given cultivatedland limitations. It is found that standardized cultivated land change, in general, is smallerthan the absolute value, implying that land converted into non-agricultural uses has lowerproductivity levels than the average productivity level of land in China as a whole. Second,an investigation into cultivated land being converted for construction use has beenconducted and it is found that the land converted into construction use has higherproductivity than the average level, mainly concentrated in north and central-east regions,where the productivity is normally higher. Third, a further analysis has been made byconsidering the difference of land converted into non-agricultural use within the provinces.More suburban high-yielding lands are converted into construction as a result ofTable 10. Natural Conditions of Land Taken into Cultivation,19902000 (%)Land with slope (degrees) 35 Total Share of the total land 88.5 3.9 4.3 2.5 0.7 0.2 100 Land with precipitation (mm) 1600 Total Share of the total land 10.9 14.8 65.9 2.1 4.6 1.7 100 Source: Tian et al. (2002).90 Shuhao Tan / 75 92, Vol. 16, No. 3, 20082008 The AuthorJournal compilation 2008 Institute of World Economics and Politics, Chinese Academy of Social Sciencesurbanization, threatening grain self-sufficiency. Finally, the natural conditions of slope andprecipitation for newly-cultivated land with the cultivated land in China in 2000 have beencompared, and it has been shown that the newly-cultivated land in general has worsenatural conditions, which might also threaten the basis of grain self-sufficiency in thefuture.V. Conclusions and Policy ImplicationsGrain self-reliance is an important goal of agricultural policies in China. However, whetherChina can maintain its successful grain self-sufficiency policy in the near future and whatimpacts of this policy will be on environmental quality is questionable. This paper hasexamined the impact of cultivated land conversion on environmental quality and grain self-sufficiency.Grain production has gradually moved northwards since the beginning of the 1980s.This is likely to put important constraints on grain productivity in the near future becauserainfall levels are much lower and the ecological environment is more fragile in the north ofChina than elsewhere in China.The concept of ecosystem service value developed by Costanza et al. (1997) is appliedto estimate the net changes in cultivated land. Between the end of the 1980s and the end ofthe 1990s it caused a total loss of ecosystem values worth of US$4.22bn. The losses causedby expanding construction land are largest in the central-east and the north, and have beenincreasing over time. Rapid urbanization and industrialization under imperfect land marketsand inappropriate government interventions have led to rent seeking in conversion, resultingin excess land conversion and negative environmental effects.Using the productivity coefficient as an indicator, we calculate standardized changesin cultivated land over the period 19992004 that take differences in productivity levels intoaccount. We find that the standardized change in cultivated land during this period was12 percent smaller than the absolute change for the whole of China. However, if wedistinguish the land in terms of its location within provinces, the impact of cultivated landchange on grain self-sufficiency will be more severe.Since the end of the 1990s, policy-making regarding land conversion has focused onthe balance in cultivated land areas. However, our study shows that such a policy causesa loss in agricultural productivity. Instead of reclaiming cultivated land from ecologicallyfragile areas, improving land productivity might be a more effective way to pursue grainself-sufficiency and to maintain the environmental base for agricultural production. Thisrequires that policy-makers: (i) strictly limit the conversion of cultivated land into91Impacts of Cultivated Land Conversion2008 The AuthorJournal compilation 2008 Institute of World Economics and Politics, Chinese Academy of Social Sciencesconstruction land, especially the cultivated land of high quality (flat, fertile, irrigated andsuitable for use of machinery), by increasing the intensity of urban land use, convertingsteeply sloped cultivated land into forest land or grassland, and avoiding development ofland with steep slopes; and (ii) pay more attention to land conservation and the improvementof technologies, especially land reclamation technologies, medium-yield and low-yield fieldimprovement technologies, water and soil conservation technologies, integratedtechnologies for small watersheds, and fertilizer-saving and water-saving technologies. Inaddition, stimulating land rental markets and land consolidation programs that reduce thehigh level of land fragmentation might also be effective policies for improving landproductivity without damaging the natural resource base of grain production.ReferencesAsh, Robert F. and Richard Louis Edmonds, 1998, Chinas land resources, environment andagricultural production, The China Quarterly, Vol. 156, pp. 83679.Costanza, R., R. Arge, R. de Groot, S. Farber, M. Grasso, B. Hannon, K. Limburg, S. Naeem, R.V.ONeill, J. Paruelo, R.G. Raskin, P. Sutton and M. van den Belt, 1997, The value of theworlds ecosystem services and natural capital, Nature, Vol. 387, pp. 25360.Deng, Xiangzheng, Jikun Huang, Scott Rozelle and Emi Uchida, 2006, Cultivated land conversionand potential agricultural productivity in China, Land Use Policy, Vol. 23, No. 4, pp. 37284.Huang, Xiaohu, 2006, Research on Land Management in China, Beijing: Contemporary ChinaPublishing House, pp. 41821. (In Chinese.)Lin, G.eorge C. S. and Samuel P. S. Ho, 2003, Chinas land resources and land use change: Insightsfrom the 1996 land survey, Land Use Policy, Vol. 20, No. 2, pp. 87107.Ministry of Agriculture, 19792005, Agricultural Statistical Yearbook 19792005, Beijing: ChinaAgricultural Press. (In Chinese.)Ministry of Land and Resources, 19902000, 20012005, Survey Report of Land Use Change,Beijing: China Statistics Press. (In Chinese.)NBS (National Bureau of Statistics of China), 2006, Statistical Communiqu of National and SocialDevelopment in 2005, Beijing: China Statistics Press. (In Chinese.)Shao, Xiaomei and Junqi Xie, 2007, Analyzing regional changes of the cultivated land in China,Ziyuan Kexue (Resources Science), Vol. 29, No. 1, pp. 3642.State Council, 2007, Several opinions of the Central Committee of the Communist Party of Chinaand the State Council on actively developing modern agriculture and pushing forward buildinga new socialist countryside in a down-to-earth manner, Xinhua News Agency [online; cited29 January 2007]. Available from: http://www.gov.cn/jrzg/2007-01/29/content_511847.htm.(In Chinese.)Sun, Han and Yulin Shi, eds, 2003, Agricultural Land Use in China, Nanjing: Jiangsu Science and92 Shuhao Tan / 75 92, Vol. 16, No. 3, 20082008 The AuthorJournal compilation 2008 Institute of World Economics and Politics, Chinese Academy of Social SciencesTechnology Press. (In Chinese.)Tan, Yongzhong, Cifang Wu, Qingri Wang, Liangqing Zhou and Dong Yan, 2005, The change ofcultivated land and ecological environmental effects driven by the policy of dynamic equilibriumof the total cultivated land, Ziran Ziyuan Xuebao (Journal of Natural Resource), Vol. 120,No. 5, pp. 72734.Tian, Guangjin, Quanbin Zhou, Xiaoli Zhao and Zengxiang Zhang, 2002, Spatial characteristics andecological background of neo-cultivated land in China, Ziyuan Kexue (Resources Sciences),Vol. 24, No. 6, pp. 16.Xie, Gaodi, Chunxia Lu, Yunfa Leng, Du Zheng and Shuangcheng Li, 2003, Ecological assets valuationof the Tibetan Plateau, Ziran Ziyuan Xuebao (Journal of Natural Resources), Vol. 18, No. 2,pp. 18995.Yang, Hong and Xiubin Li, 2000, Cultivated land and food supply in China, Land Use Policy,Vol. 17, No. 2, pp. 7388.You, Liangzhi, 2006, Land use and sustainability of Chinese grain production, paper presented atinternational seminar on Transition towards Sustainable Rural Resource Use in Rural Chinain Kunming, Yunnan Province, China, 2224 October.Zhang, Gongping, Jiyuan Liu and Zengxiang Zhang, 2003, Spatial-temporal changes of cropland inChina for the past 10 years based on remote sensing, Dili Xuebao (Acta Geographic Sinica),Vol. 58, No. 3, pp. 32332.Zheng, Haixia and Zhiming Feng, 2003, The quantity and quality analysis on dynamic equilibriumof the total cultivated land in China, Ziyuan Kexue (Resources Science), Vol. 25, No. 5,pp. 338.Zhong, Funing, Corlin Carter and Fang Cai, 1999, Chinas Ongoing Agricultural Reform, Beijing:Financial Economic Press. (In Chinese.)Zhu, Hongbo, 2006, On food security and cultivated land resource security, Nongye XiandaihuaYanjiu (Research of Agricultural Modernization), Vol. 27, No. 3, pp. 16164.(Edited by Zhinan Zhang)
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