| The protection of cultivated land resources is an important strategic issue related to China’s national grain security.Recently,non-grain production has become increasingly common in China with the social economic development.On the one hand,non-grain production is a voluntary choice of farmers under the market economy.Moderate development of non-grain production can promote the adjustment of agricultural structure and increase farmers’ income,which is conducive to the realization of rural revitalization strategies.On the other hand,some types of non-grain production could lead to severe damage to cultivated land and the ecological environment,and blind expansion may threaten national grain security.Therefore,there is an urgent need to systematically analyze non-grain production so as to provide a basis for reasonable guidance and control.Based on the general idea of “situation-mechanism-control”,this paper first analyzes the development status of non-grain crops on a macro scale through statistical data.Then taking three different counties and cities in Zhejiang Province as examples,based on the remote sensing interpretation information at parcel scale from 2000 to 2018,the changes in the quantity,type,and spatial distribution of non-grain production at different regions are characterized,and the driving forces of non-grain expansion are further explored.Using emergy and economic analyses,the difference in comprehensive benefits of non-grain production and other agricultural production are evaluated and compared.Finally,different functional zones of cultivated land are delineated based on the multi-functional evaluation of cultivated land and current layout of cultivated land protection,and differentiated development and control measures for non-grain production are proposed.The main research contents and conclusions of this research are as follows:(1)Based on the statistical data of the past years,we analyzes the planting situation of non-grain crops in Zhejiang Province and whole China from 2000 to 2017.The results show that:(1)During the study period,the overall sowing area of non-grain crops nationwide has only increased by 506 thousand hectares.The proportion of nongrain crops planted in major grain-producing provinces such as Shandong,Henan,and Anhui decreased by 9%,5%,and 6%,respectively,while the proportion of non-grain crops planted in southeastern coastal provinces such as Zhejiang,Fujian,and Guangdong increased by 19%,13% and 9%,respectively.The southeast coastal area is economically developed,and the huge market demand for non-grain crops such as fruits and flowers and their high economic returns have prompted local farmers to switch to non-grain production gradually.According to the grain import and export data of the customs,China’s grain production is currently in a tight balance.The self-sufficiency rate of staple grain(rice,wheat,and corn)is 99%,indicating that China’s staple grain can basically achieve self-sufficiency.However,considering the local expansion of non-grain production,it is necessary to strengthen the study of its spatial expansion characteristics and driving mechanism.(2)Zhejiang Province is the region with the most significant increase in the planting proportion of non-grain crops,with the planting proportion increased from 35% in 2000 to 54% in 2017.Among the main types of nongrain crops,the plantion of flower and nursery stock increased the most,from 2.59% in 2000 to 13.82% in 2017.Non-grain production in Zhejiang Province was initially developed in the most economically developed cities such as Hangzhou and Ningbo,and gradually expanded towards central and southwestern part of Zhejiang Province after 2010.(2)The parcel-scale non-grain information of the three typical counties in Tongxiang City,Xiangshan County,and Pingyang County in 2000,2010,and 2018 is extracted through multi-source high-resolution remotely sensed data.Based on this interpretated information,the changes of quantity,spatial distribution and landscape pattern of different non-grain types are analyzed.The results suggest that:(1)During 2000 and 2018,the areas of non-grain production of Tongxiang City,Xiangshan County,and Pingyang County increased by 4773.78 ha,6367.86 ha,and 8581.97 ha,respectively,equivalent to 12.40%,30.90%,27.54% of the respective cultivated land area in 2018.The degree of non-grain production in the interpretation result of remote sensing images is more informative than those of statistical analysis as fine scale remotely sensed data reveal greater information on current status of regional non-grain production.(2)There are obvious differences in the types of non-grain development in different study areas,which is closely related to local breeding practices,development foundations,farming conditions and other factors.The huge market demand brought by urban greening construction and the support policies of local governments have made nursery plantation the most advantageous non-grain production type in Zhejiang Province.(3)The spatial autocorrelation analysis show that a significant spatial agglomeration effect and obvious regional differences were observed in the spatial distribution of muitiple non-grain types.The agglomeration of a certain non-grain production type can further improve its production efficiency and competitiveness.(3)Using multinomial logistic regression model,the driving forces of the expansion of different non-grain types in three study areas during 2000-2010 and 2010-2018 are analyzed from the aspects of geography,distance,proximity and policy.(1)Tillage conditions have a significant impact on non-grain expansion.In the main,non-grain expansion tends to occur in places where transportation and water conditions are good and farming costs are low.In the study areas dominated by mountainous land,the nongrain conversion initially tends to occur in cultivated land with higher altitude and barren soil,and its production depends on the support of settlement networks such as rural settlements.However,such conversion inclines to occur in plain arable land with the development of non-grain production,and influencing factors such as transportation condition are no longer the main constraints.In addition,slope has different influences on the expansion of different types of non-grain production.For example,pond aquaculture tends to occur in plain areas with gentle slopes,while tea and bamboo are more likely to be planted in cultivated land with higher altitude and slope.(2)A significant agglomeration effect was observed in the expansion of multiple types of non-grain production.It can be inferred that the high incomes obtained by the pioneers of non-grain conversion have stimulated the “non-grain” followers of the surrounding farmers,or it may be that these pioneers rented the surrounding farmland to increase its operation scales after receiving high benefits.(3)An analysis of current policies for the protection of cultivated land has demonstrated that the basic farmland policy did not control the expansion of non-grain production as expected.This is ecause the main goal of the basic farmland policy is to curb non-agricultural construction activities on cultivated land.(4)Other policies such as grain production functional zone,highstandard farmland and agricultural park have a deterrent effect on the expansion of certain types of non-grain production,of which the grain production functional zone has the most significant inhibitory effect.In 2018,the ratio of non-grain production in the grain production functional zone of each research area was 7.30%-15.61%,far lower than that in the basic farmland of 17.65%-28.44%.(4)On the basis of economic analysis,the agricultural environmental pollution is incorporated into the emergy analysis to evaluate the environmental performance and comprehensive benefits of different agricultural production types more objectively and comprehensively.(1)Economic analysis results show that rice monoculture is the production type with the lowest economic benefit.The economic benefit of the integrated agricultural production system is 2.32-2.35 times that of rice monoculture,the economic benefit of the non-grain production system is 9.4-25.2 times that of rice monoculture.Duck rearing is the most profitable non-grain production type.This huge economic benefit gap explains the root cause of the booming non-grain production.(2)Emergy analysis results show that the current environmental loading ratio of non-grain production system in Tongxiang City is higher than other production systems partly due to excessive chemical fertilizers,pesticides and commercial feed which were utilized in the non-grain production systems for the pursuit of higher output and efficiency.In addition,unearthing nursery stock and pond excavation could damage the soil tillage layer and bring great difficulties to the future reproduction.(3)From the perspective of comprehensive benefits,integrated farming systems can strike a balance between environmental and economic benefits,thus,it is an appropriate way to achieve the multiple goals of grain production,rural revitalization and ecological civilization.However,farmers focus more on short-term economic benefits rather than long-term comprehensive benefits when making decisions.Hence,so reasonable guidance policies are needed for the promotion of integrated farming systems.(5)The idea of three-level and five-zone zoning management and control is proposed based on the multi-functional evaluation of cultivated land and the current cultivated land protection policy.The first level is the grain production core area,which is the main area to guarantee grain production,including grain production functional zone and cultivated land with the best evaluation of cultivated land production function.This area is crucial for subsidizing grain production.All non-grain production is prohibited in the area.Land plots that have already undergone non-grain production must be restored within a time limit.Remote sensing monitoring should be utilized to strengthen the monitoring of non-grain production prone areas.The second level consisits of three zones: ecological agricultural zone,integrated agricultural zone and leisure agricultural zone.These are the cultivated land in the basic farmland except the core area of grain production,focusing on protecting the production capacity of cultivated land,taking into account both ecological and economic benefits.Ecological agricultural zone is mainly located in ecologically important or sensitive areas.The zone allows moderate development of non-grain production with low environmental pollution,such as flower and nursery plantation.The integrated agricultural zone focuses on the development of integrated farming systems such as integrated rice-fish system and promotes green production.The leisure agricultural zone allows moderate development of leisure agricultural projects such as fruit and vegetable picking,flower sea sightseeing,and rural life experience without damaging the farming layer.The third level is the general farmland zone,which is the cultivated land outside the basic farmland.Non-grain production can be carried out in this sub-area to improve production efficiency and increase farmers’ income. |
PDF Full Text Request