中国农业科学 ›› 2018, Vol. 51 ›› Issue (23): 4496-4514.doi: 10.3864/j.issn.0578-1752.2018.23.009

• 土壤肥料·节水灌溉·农业生态环境 • 上一篇    下一篇

湖南不同季别稻作系统的生态能值分析

周江1(),向平安1,2()   

  1. 1湖南农业大学洞庭湖区域农村生态系统健康湖南省重点实验室,长沙 410128
    2湖南农业大学商学院,长沙 410128
  • 收稿日期:2018-04-21 接受日期:2018-08-24 出版日期:2018-12-01 发布日期:2018-12-12
  • 基金资助:
    国家科技支撑计划(2012BAD14B17);国家社科基金(11BJY028)

Ecological Emergy Analysis of Different Paddy Ecosystems in Hunan Province

ZHOU Jiang1(),XIANG PingAn1,2()   

  1. 1Rural Ecosystem Health Laboratory of Hunan Dongting Lake Area, Hunan Agricultural University, Changsha 410128
    2Business School, Hunan Agricultural University, Changsha 410128
  • Received:2018-04-21 Accepted:2018-08-24 Online:2018-12-01 Published:2018-12-12

摘要:

【目的】湖南稻作系统以一季稻和双季稻种植制度为主。论文通过评价稻作技术的调整对不同季别水稻种植效率的影响,期望为水稻可持续发展提供决策依据。【方法】通过相关统计年鉴资料获取2002—2016年湖南早稻、中稻和晚稻生态系统环境资源、经济资源的投入与产出原始数据,采用能值分析理论和方法,对三季稻作系统的动态发展状况及综合发展水平进行分析,再将其能值投入产出效率与传统经济利润率指标进行比较。【结果】2002—2016年湖南稻田生态系统中投入的自然资源能值相对稳定,投入能值大部分依赖购买能值并趋向增加;能值投入结构调整为机械>人工+畜力>化肥>农药或种子>燃料>有机肥,农业机械化逐渐代替了以人工、畜力为主的生产方式。系统每千公顷种植面积的购买能值投入中不可更新工业能值投入呈明显增长趋势,其中机械作业能值投入贡献率最高,化肥投入为中稻>早、晚稻且长年居高不下,农药投入为中、晚稻>早稻且趋向增加;可更新有机能值投入密度则趋向减少,其中人工能值虽显著下降,其贡献率仍最高,种子投入为早稻>晚稻>中稻且早、晚稻趋向增加,畜力能值投入转变为中稻>早、晚稻且趋向不断减少,有机肥投入能值不断减少;购买能值投入从2012年起转变为中稻>早稻>晚稻系统。系统单位种植面积的能值产出、生态和经济平均利润率均为中稻>晚稻>早稻;早稻种植面积始终低于晚稻。系统能值指标变化趋势为:能值投入率方面晚稻>早稻、中稻;能值产出率方面中稻>晚稻>早稻;系统对环境的压力较小,但环境负载率指标增长较快且晚稻>早、中稻系统;可持续发展指数已大幅下降至<2,2008年以后中稻>早、晚稻系统。【结论】湖南稻作系统生产方式日益现代化,系统富有活力但发展潜力日益下降。稻作经营仍属于粗放型方式,致使不可更新工业辅助能大量投入,造成短期内系统环境压力增大、生态和经济利润率不断下滑,不利于系统长期可持续发展。虽然湖南中稻生态系统的环境负载率、可持续发展指数、平均利润率仍优于早、晚稻系统,但由于系统投入了较多的人工、畜力、化肥和农药能值且其机械能值效率较低,致使其能值产出率、生态和经济利润率降幅较大并与晚稻系统基本持平,其竞争优势日益缩小。早稻系统种子能值投入较高且能值产出密度和利润率较低,晚稻系统购买能值投入产出综合效益较高。湖南稻作农业现代化的地域不均衡发展矛盾依然突出。无论哪个水稻季别,以市场价值作为评价依据的成本-收益分析法,低估了稻田生态系统的真实价值。政府需针对早、中、晚稻制定激励政策,以保障稻农的利益和实现稻作永续经营。

关键词: 水稻, 生态系统, 能值分析, 效率, 湖南省

Abstract:

【Objective】Hunan paddy ecosystem is mainly one- and double-cropping rice patterns ecosystem. By evaluating the effects of the adjustment of cropping patterns on the planting efficiency of rice grain in different seasons, this paper was expected to provide decision basis for the sustainable management of paddy.【Method】In this paper, raw data on the input and output of environmental resources and economic resources in the ecosystem of early rice, semilate rice and late rice in Hunan from 2002 to 2016 were obtained through relevant statistical yearbook. emergy analysis theory and method were used to analyze the dynamic development status and comprehensive development level of the different seasons paddy ecosystem. Then the input and output efficiency of paddy were evaluated by emergy analysis index and compared with the traditional economic profit rate index.【Result】From 2002 to 2016, the input emergy of natural resources in Hunan paddy ecosystem was relatively stable, and the input emergy was mostly dependent on purchasing emergy and tended to increase. The emergy input structure was adjusted to be mechinery>labor+animal>fertilizer>pesticide or seed>fuel>organic fertilizer. Agricultural mechanization gradually replaced the artificial, animal - based production mode. Purchasing emergy input per 1000 hm 2planting area: the density of unrenewable industrial emergy showed a significant growth trend, and the density of machinery operation emergy was the highest contribution rate in the unrenewable industrial emergy inputs. The density of fertilizer emergy inputs was the semilate rice ecosystem>early and late rice, and it stayed high for years. The density of pesticide emergy inputs was semilate and late rice ecosystem>early rice, and it tended to increase. Density of renewable organic emergy inputs had been tended to reduce. Although the labor emergy decreased significantly, its contribution rate was still the highest in the renewable organic emergy inputs. The density of rice seeds emergy inputs for early rice ecosystem>late rice>semilate rice, and early rice and late rice tend to increase. The density of animal emergy had been converted into semilate rice ecosystem>early and late rice, and the trend was decreasing. Organic fertilizer inputs tended to reduce unceasingly. The purchase emergy inputs had been converted into the semilate rice>early>late rice ecosystem from 2012. The emergy outputs of the unit planting area, ecological and economic average profit margin of rice were the semilate rice ecosystem>late rice>early rice. The planting area of early rice was always lower than that of late rice. The variation trend of the emergy index of Hunan paddy ecosystem was: the emergy input ratio (EIR) in the late rice ecosystem>early and semilate rice; the emergy yield ratio (EYR) in the semilate rice>late rice>early rice. The ecosystem puts less pressure on the environment, but the environmental load ratio (ELR) increases rapidly and it was the late rice ecosystem>early and semilate rice. The sustainable development index (ESI) had dropped significantly to<2, and converted into the semilate rice ecosystem>early and late rice after 2008. 【Conclusion】The rice production mode in Hunan paddy ecosystem had been modernized day by day. The ecosystem was dynamic but its potential was declining. The rice production mode belonged to extensive operation, which large inputs of industrial emergy cause short-term ecosystem pressure in environment, ecological and economic profit margins declining. It was not conducive to long-term sustainable development ecosystem. Although the semilate rice ecosystem’s ELR, ESI, average rate of profit is still better than the early and late rice ecosystem, but it’s EYR, ecological and economic profit margins were in the larger decline by using more labor, animal power, chemical fertilizers and pesticides and its mechanical emergy efficiency was low, leading to the competitive advantage to reduce. The seed emergy input of early rice ecosystem was high and the emergy yield density and profit rate were low. The comprehensive benefit of purchasing emergy of late rice ecosystem was higher. The contradictions in regional unbalanced development of modern paddy planting technology were still outstanding. Regardless of the grain in different seasons, the cost-benefit method which based on market value underestimates the real value of the paddy ecosystem. The different incentive policies should be formulated by government according to early, semilate and late rice, so as to safeguard farmers’ interests and realize sustainable paddy production.

Key words: rice, ecosystem, emergy analysis, efficiency, Hunan Province