【作者】 黄利民；

【导师】 张安录；

【作者基本信息】 华中农业大学 ， 土地资源管理， 2009， 博士

【摘要】 20世纪90年代初以来,中国农地利用自东向西逐渐出现了农作物播种面积减少、复种指数降低、集约度降低等粗放利用的现象,2003年以来的农业税费减轻至2006年农业税费的取消,在一定程度上增加了中部农业区和西部地区的农地利用集约程度,但在东部地区和中部丘陵山区对农民种田积极性的激励效果并不明显。为了揭示农地利用发生这些变化的内在驱动机制及其对区域经济、环境产生的影响,本文以地处江南丘陵山区的湖北省通城县为例,在统计资料和实地调查取得的685份农户问卷调查资料的基础上,利用成本效益分析法、边际分析法、数理统计方法、实地考察与农户调查方法、生态系统服务价值评估等方法,研究了农地利用变化的驱动机制及其社会、经济和环境效应,并提出了提高农地利用收益,减轻农地利用负面影响的农地制度、农村税费制度、户籍制度和环境制度改革措施。研究表明:(1)农地边际化是一种受社会、经济、政策和自然环境等因素综合驱动作用的过程,一种在现有的土地利用和社会-经济结构条件下,农地变得不再具有经济生产能力的过程。农地边际化在区域土地利用变化中的表现形式主要有农地利用集约度变化、农作物播种面积变化、土地用途变化和土地经营制度变化。中国农地利用出现的农作物播种面积减少、复种指数降低、集约度降低等现象是农地边际化发生作用的结果。(2)农地边际化的主要诊断因子是纯收益。根据纯收益、结合总收益和实物产量的变化特征,可以将农地边际化的进程区分为初始边际化、中期边际化和完全边际化三个不同的发展阶段,完全边际化农地即边际农地。随着成本因素、价格因素、自然条件等的变化,农地不同边际化阶段之间是可以相互转化的。(3)不同类型的农地在同一时期的边际化进程不同。1985年至2006年,通城县水田出现了两次边际化现象,处于边际化阶段的时间为9年,旱地出现了3次边际化现象,处于边际化阶段的时间为11年,旱地的边际化进程明显快于水田。同时,通城县耕地面积减少,粮食作物播种面积减少,农地利用复种指数总体降低,农地利用集约度虽总体上升,但旱地潜在集约度也下降了,且农地利用集约度上升主要是由于经济增长、科技进步的推力和人口增长、耕地面积减少的压力,而并非农民内生的动力和农业内部的经济活力。(4)农地边际化对粮食安全的影响可从农地边际化引起的粮食作物播种面积减少、农地利用复种指数降低和农地撂荒三个角度对粮食产量的影响来衡量。1985年—2006年,通城县由于粮食作物播种面积减少引起的粮食产量总损失为28720.80吨,年均损失1305.49吨;由于耕地利用复种指数下降带来粮食产量损失为6343.18吨,年均每公顷耕地损失粮食产量15公斤。2006年,由于耕地显性撂荒造成的粮食产量损失为14464.67吨,人均31公斤;隐性撂荒造成的粮食产量损失为478.62吨,人均1公斤。(5)农地边际化对农地经营的影响主要表现在农地经营模式、农地经营方法、农地经营规模上。发生农地边际化时,农户在农地经营模式上的响应顺序按照其实现的难易程度一般为:承包经营→互换经营→代耕经营→转包经营→租赁经营→“公司+农户”经营→股份制经营等;在农地经营方式上,农户会作出减少劳动力的投入、用机械代替畜力耕种、减少农家肥增加化肥的施用等响应。在农地经营规模上,大农增大经营规模、小农减少规模而增加劳动力、物质成本的投入都可提高农地利用效率,从而减少边际化的损失。(6)农地边际化与农村劳动力迁移相互关联,农地边际化会导致农村劳动力的迁移,同时,农村劳动力的迁移会进一步加快农地边际化进程。但农地边际化对城市化没有明显的驱动作用。(7)农地边际化会降低区域种植业产值,降低农地利用经济效益,减少农户种植业收入。但农地边际化过程中,为弥补种植业的损失,农户一般会努力寻找其它就业机会和收入来源,于是农民从种植业以外的其它产业中得到的收入可能增加。(8)农地边际化对生态环境的影响主要表现在对土壤、生物多样性和农村景观的影响、农地利用变化引起的农地生态价值变化及农地边际化对区域生态承载力的影响。在农地边际化过程中,当农地继续作为种植业用地时,会导致土壤肥力降低、生物多样性减少、农地生态承载力降低等负面环境影响;而当农地完全边际化撂荒后,虽然也会带来杂草的蔓延、侵犯性物种的入侵,从而火灾发生的可能性增加而对某些物种造成毁灭性的破坏等负面环境影响,但农地撂荒也可增加土壤肥力、增加物种多样性、提高区域总体生态服务价值和生态承载力。(9)目前的农地制度、农村税费制度、户籍制度、环境制度都在一定程度上影响了农地利用收益的提高,为了提高农地利用收益、减缓农地边际化进程、减少农地边际化的不利影响和促进边际土地有效利用,需要有以农地制度为核心的各项制度的综合改革。如为促进农地流转的农地制度改革需要能提高农民非农就业、加快农民工市民化进程的户籍制度配合;提高农地经营收益的农地制度改革需要减少农民负担、规范农村公共产品建设和管理的税费制度、激励农民农地农用的环境制度配合。各项制度改革只有合理配合、齐头并进才能更好发挥制度改革绩效。更多还原

【Abstract】 Since the early 1990s, the phenomena of extensive cultivation such as the decrease of crop sowing area, the reduction of multiple-cropping index and intensity degree have gradually taken place in arable land use from East to West in China. Although there’ s increased degree of intensity of arable land use in agricultural area of middle region and west region ever since agricultural tax and fee lessening from 2003 and canceling in 2006, the encouraging effect of enhancing farmers enthusiasm of planting arable land was still insignificant in east region and middle hill region. Basing on the statistical data and 685 farmer field survey data collected from the case study of Tongcheng County (a hilly county in Hubei province), this paper has studied the driving mechanism of arable land use change and its social, economic and environmental effects through cost-benefit analysis, boundary analysis, mathematical statistics, field investigation and eco-service value evaluation method for the purpose of understanding these questions. In the end, the author has put forward some ideas of innovating agricultural land system, rural tax and fee system, household registration system and environment system to advance the net return of arable land use.Firstly, arable land marginalization is considered as a process driven by a combination of social, economical, political and environmental factors; a process that the farmland can not produce net return under an existing land use and socio-economic structure. Arable land marginalization is one of the driving factors of regional arable land use change, with the change of arable land use intensity degree, the change of crop sowing area, the change of land use and land management system as its forms, arable land use change in China is the result of arable land marginalizationSecondly, the main index to diagnose the marginalization of arable land use is net return. According to net return, total return and crop output, arable land marginalization course can be differentiated into three phases of early marginalization, middle marginalization and complete marginalization. Complete marginalization arable land is marginal land. Along with changes of cost factor, price factor as well as nature condition, the three different phases can realize mutual transformation.Thirdly, different types of arable land have different marginalization courses in the same period. From 1985 to 2006, paddy field in Tongcheng County befallened marginalization twice, which cost 9 years; dry land befallened marginalization three times, and the cost was 11 years; the marginalization course of dry land was faster than paddy field. At the same time, the arable land and crop planting area decreased, the multiple-cropping index of arable land use also reduced. Although the degree of intensity of arable land went up, dry land latency degree of intensity went down. Moreover, the increase of arable land degree of intensity ascribed to the thrust of economy development, science and technology advancement and the decrease of arable land, rather than the intrinsic motivation of farmers or the economic vitality of agriculture.Fourthly, the effect of arable land marginalization to food safety and security can be measured through three aspects, namely, crop sowing area decrease, multiple-cropping index of arable land use decrease and arable land abandonment. From 1985 to 2006, the total loss of food in Tongcheng County resulting from crop sowing area decrease is 28720.80 ton, the number of every year is 1305.49 ton; and the total number is 6343.18 ton due to the multiple-cropping of arable land use decrease, the number of every year every ha. arable land is 0.015 ton; the number is 14464.67 ton coming from explicit arable land abandonment; and 478.62 ton, implicit arable land abandonment.Fifthly, arable land marginalization affects arable land management in three aspects: the mode of arable land management; the way of arable land management and the scale of arable land management. When arable land is marginalizing, farmers will change their mode, way and scale of arable land management. Commonly, the procedure of mode change is : contract management - interchange management - fungible management -subcontract management - leasehold management - company and farmer management etc. The way change of arable land management will involve reducing labor, replacing animal power with machine, reducing muck and increasing fertilizer. As to the scale change, large-scale farmers will augment scale and small farmers decrease scale. All these ways can improve arable land use efficiency and reduce the loss coming from arable land marginalization.Sixthly, arable land marginalization and rural labor exodus are interrelated. Arable land marginalization can cause rural labor exodus, and rural labor exodus can quicken arable land marginalization. But arable land marginalization doesn’ t have obviously driven function on urbanization.Seventhly, arable land marginalization can depress the value of regional sowing industry as well as the economic benefit of arable land use, decreasing farmer income from sowing industry. Consequently, when arable land is marginalizing, most farmers will search other employment chance and income sources, and they may gain more income from other industry.Eighthly, the ecological environmental effect from arable land marginalization can be seen through the aspects of soil, biological diversity, rural landscape, ecosystem value of arable land and regional ecosystem carrying capacity. In the course of arable land marginalization, when arable land continues to be planted crop, some negative environmental problems, such as soil fertility decreasing, biology diversity cutting down and arable land ecosystem carrying capacity depressing will bring about. While when arable land is abandoned, the effect can be differentiated into two aspects: on one hand, it will cause weed to spread, aggressive species to inbreak, the possibility of fire happening to increase, thus causing the extinction of some species; on the other hand, arable land abandonment can also cause some positive environment effect, for instance, it can cause the increase of soil fertility and species diversity, region total eco-service value and ecosystem carrying capacity can also be advanced.Ninthly, the current agriculture land system, rural tax and fee system, household registration system and environment system all partially hindered the promoting of arable land use return. To increase arable land use return, slow down arable land marginalization speed, reduce the negative effect of arable land marginalization and effectively use marginal land, aforementioned systems, especially agricultural land system should be synthetically innovated. For example, agricultural land system innovation for accelerating arable land conversion should be in line with household registration system innovation for quickening the non-agricultural employment of farmers and citizenization of migrant workers. Agriculture land system innovation for advancing arable land return should go with rural tax and fee system innovation for reducing farmers’ burden, standardizing the construction and management of public production in rural area, plus environment system innovation for inspiriting farmers to use arable land for agricultural purpose. All correlative system innovations work in effect, better system innovation performance will appear.更多还原