Farming systems as an approach to agro-ecological engineering

Ecological Engineering 11 (1998) 27–35

Farming systems as an approach toagro-ecological engineering1

Weili Liang *

Agricultural Uni6ersity of Hebei, Baoding, Hebei 071001, People’s Republic of China

Received 15 January 1997; received in revised form 18 November 1997; accepted 29 November 1997

Abstract

The relationship between agricultural ecological engineering and farming systems isdiscussed in this paper with a theoretical analysis and case study. The theory and approachof farming system design is implied in agricultural ecological engineering. Thus, farmingsystem as a theory and approach of agro-ecological engineering plays a very important rolein the management of agricultural systems. Farming systems are the bridge betweenagroecological engineering and agricultural systems. More comprehensive advanced researchon farming system theory and approaches employing ecological principles are needed toachieve more productive sustainable agricultural systems. New terms on eco-economic unitand eco-economic niche are explained in the paper. © 1998 Elsevier Science B.V. All rightsreserved.

Keywords: Farming system; Eco-economic niche; Agroecological engineering

* Corresponding author. Tel.: +86 312 2091276; fax: +86 312 2091217/2125635; e-mail:[email protected]

1 Paper presented at ICEE—International Conference on Ecological Engineering, Beijing, China,7–11 October 1996

0925-8574/98/$ - see front matter © 1998 Elsevier Science B.V. All rights reserved.

PII S0925-8574(98)00042-1

W. Liang / Ecological Engineering 11 (1998) 27–3528

1. Introduction

Chinese agriculture, with more than 5000 years of history and feeding a popula-tion which now exceeds 1.2 billion, is at its critical judgement point which willdefinitely have a critical effect on the nations future. Agricultural development inChina is now facing some difficult constraints, i.e. it has four contradictions toovercome: the contradiction between the increasing need for farm products anddeclining area of arable land; the contradiction between relatively inadequateresources and the requirement to increase yield; the contradiction between yield andprofit increase and sustainable development; and the contradiction between smallproduction scale and the necessity to increase profit of production. It is essential toincrease land productivity, labor productivity and capital productivity, with thepremise of increased resources use efficiency to overcome or diminish the aboveconstraints. The only way leading to that goal is to adopt and practice sustainableintensive agriculture.

The understanding of sustainable agriculture is a little different among peopleand nations, but the basic principle is the same: to develop agriculture that isecologically sound, economically profitable and socially responsible (Shi andCheng, 1994). Ecological engineering is an excellent approach to make agriculturalsystems better planned and more intensive. Sustainable agricultural developmentshould reach the three goals simultaneously at different levels of the system.Therefore, a systematic and integrative approach should be used in the design andmanagement of agricultural systems.

2. Farming system: An integrated method for the design and management ofagriculture system

A farming system (FS) (Fig. 1) is the existing structure and management of anagricultural production system dynamically arranged (designed) by the farmerdepending on his goals of production, priority of needs, and the regime of resourcesunder specific natural, social and economic conditions. It is a similar term toagricultural production system, emphasizing its artificial feature and the need forhuman’s management.

To increase the productivity and sustainability of an agriculture system means toimprove its structure and to make every part of the structure work well. Sinceagriculture production is the main function of an agricultural system and is acombined process of ecological and economic processes, and since the economicprocess is performed on the basis of good performance of ecological processes,sustainable agriculture development should undoubtedly concentrate its attentionon the elaborate design and proper management of agroecosystems. On the otherhand, as agricultural production is also an economic process, it is essential to paygreat attention on how to make the best profit by management at the premise ofefficient use of resources. Thus, the management of an agriculture system is amulti-purpose and multi-method subject. It is a farming system that combines

W. Liang / Ecological Engineering 11 (1998) 27–35 29

ecological, economical and social issues and integrates them into a systematictheory and approach for the design and management of agriculture system.

Furthermore, since agricultural ecosystems are almost artificial, they are moresimple and more fragile than natural ecosystems, and are more sensitive toenvironmental changes, including changes caused by management practices. Thisfeature brings both advantages and disadvantages. To get high net productivity, wemust maintain a simple system, i.e. at the early stage of succession. On the otherhand, to get multiple products and high-use efficiency of resources, we should keepor design the system with some complexity. It is the farming system approach thatbalances those two opposite aspects. Thus, the farming system approach is anintegrated method for the design and management of agriculture systems.

3. Farming system and agro-ecological engineering

3.1. Eco-economic niche—new concept

Since agriculture production is a combination of ecological and economic pro-cesses, all of its components have both ecological and economic features andfunction in both aspects. Thus, we can define the basic ecologically and economi-cally functioning components of an agriculture system as eco-economic unit (EEU).EEU can be a biological organization of a specific level (such as community,population, species and individual), and it can also be functioning components ofother types (a farm, for example).

Fig. 1. A schematic diagram of farming system—components and relationships


The adaptability of an EEU in an agriculture system, the status of the resourcesin the system that can be used by the EEU, and social requirements to the productof the EEU together decide the economic standing of the EEU (its price, potentialprofit and effects to people’s daily life and productive activities) in the system. Wedefine the regime of resources occupation by an EEU and its economic standingwhich is decided by its ecological adaptability and social requirement for itsproduct of the EEU as eco-economic niche (EEN). EEN indicates the position andfunction of an EEU in an agriculture system.

The concepts of EEU and KEN have both ecological and economic implication,thus those two terms are very helpful in understanding the proper application ofagricultural ecological engineering.

3.2. The role of agricultural ecological engineering: an explanation with EENconcept

The basic role of agro-ecological engineering (AEE) is to increase bioefficiencyand efficiency of use of resources and hence, the profit of an agroecosystem bymeans of proper design and management for system structure.

Agricultural species are much different to natural species. People always supplyagricultural species with their best satisfaction to get highest yields from them, i.e.to make the best adaptability of the species through fertilization, irrigation,greenhousing practices and so on. So, it is obvious that adaptability of anagricultural species can be changed by management practices, i.e. potential nichecan become realistic niche (Ma, 1990) by human’s interference. But, as an agricul-tural species has the attribution both of ecology and economics, whether itsadaptability will be interfered by people or not and the degree of interference isdetermined by its natural attribute—ecological adaptability and economic at-tribute—economic value. The better the ecological adaptability or the lower theeconomic value, the less interference is needed; The worse the ecological adaptabil-ity or the higher the economic value, the more interference is demanded.

To get the maximum benefit from the AEE, one should follow some principlesderived from the EEN theory:1. Make full use of the existing EEN and develop the potential EEN to get

integrative and efficient use of resources in all dimensions of time, space,quantity and quality in a system. The methods include introducing new EEUinto the system and increasing the grade of industrial chain (length of foodchain), etc.

2. Explore EEN. When an EEU does not adapt to a place where the requirementfor its product is great, it generally has a high economic value and can get greatprofit from improving its adaptability. For example, in winter in north China,farmers make great profit from growing warm season vegetables in greenhouses.In that case, the potential EEN of vegetables becomes existing EEN in green-houses.

3. Change fundamental EEN in certain dimensions. Natural species have devel-oped their adaptability for the need of existing and reproduction of their own,


and this may not meet the needs of the human. So, natural species have beendomesticated into crops and livestock animals that eventually become differ-ent to their natural relatives. There exist great potentials for changing thefundamental ENNs of (to domesticate) some species with modern techniquesto make them more suitable for human use.

4. Keep a proper number of EEU in a system. According to the principle ofcybernetics, it is essential to enlarge possibility space as much as possible inorder to achieve the desired result. It is necessary to occupy the existing EENcompletely by means of keeping a proper number of EEU in a system inorder to increase efficiency of the entire system. Too few EEU results inthe lack of stability (Odum, 1981) and inadequate use of resources. On theother hand, too many EEU intensify their competition for resources andincrease internal consumption, hence causing efficiency decrease of the entiresystem.

3.3. Farming system approach is an efficient skill of AEE

On a farm or a larger area, all the processes of ecology and economics andthe intension of the farmer’s consideration for the three aspects of sustainableagriculture development are realized by a concrete farming system.

China is now facing limiting factors to agricultural development with relatedmultidisciplinary issues. The only way to diminish those limiting factors is to usea multidisciplinary thinking and method (theory and practice). It is farmingsystem’s theory and practice that can just match the requirement. It is obviousthat all the farmers or any other practitioners design of an AEE will eventuallybe realized in a specific farming system. Thus, we can say that farming systemapproach is an efficient skill of AEE. There are two examples illustrating therelationship of FS and AEE.

3.3.1. Example 1: The technique series design of ‘one ton per mu’ (15000 kg ha−1)winter wheat–maize double cropping system

Winter wheat–maize double cropping system is the most important cropp-ing system of cereal production in North China. Before 1985, the annual yield ofthe system in Wuqiao county of Hebei Province was :11000 kg ha−1, and theprofit of annual production is �3150 Yuan ha−1 (375 US$ ha−1). From 1985to 1990, a group of scientists from China Agricultural University (the formerBeijing Agricultural University) did a series of experimental studies in the countyto increase the yield of the cropping system. They analyzed the status ofthe wheat–maize system of the county and found some problems with it. Basedon systematic thinking, they then designed a novel ‘technique series’ (Table1) that adequately solved those problems and hence, increased the yield to‘one ton per mu’ (Wang, 1991), made a profit of 4500 Yuan ha−1 (536 US$ha−1) from annual production and largely improved water use efficiency (Liang,1995).


Table 1Technique series of ‘one ton per mu’ wheat-maize double cropping system

(a) The actual yield of maize was much lower than its yield potentialProblems(b) The soil lacked phosphorus which severely limited the yield of the crops

Strategy Lengthening the growing period of maize: Postpone the sowing date of winterwheat 15 days and plant maize on wheat stubble to provide 250–300°C moreaccumulated temperature for maize grain filling.

TacticsWheat (a) Recommended fertilization: adjusting the nutrient ratio in fertilizer application

to the level of N:P2O5=2–2.5:1; adjusting the ratio of N application as baseapplication and top dressing to 3:2; top dressing N at 5–6 leaf stage; recommend-ing fertilizer application at the basis of soil testing(b) Improving sowing quality and deciding a reasonable seeding rate to ensurethe number of optimum ear per unit area(c) Choosing varieties of high tillering ability(d) Postponing spring irrigation stage on the basis of a heavy pre-sowing irriga-tion(e) Choosing varieties of middle or long seasonMaize(f) Increasing population density to an optimum level by decreasing individualspacing and increasing row spacing(g) Diminishing weak plants by increasing seeding rate and late thinning(h) Postponing the date of top dressing fertilization to 12 leaf stage(i) Fertilizing with potassium(j) Irrigation at grain-filling stage to increase photosynthesis rate and grain weight(k) Postponing harvesting time 15 days to let the grains completely fill andmature

3.3.2. Example 2: The de6elopment of an irrigated 3-year rotation cropping systemin Hexi Corridor, Gansu Pro6ince

An irrigated cropping area in Hexi Corridor, Gansu Province of NorthwestChina contributes half of the marketable cereal production in the province. Thearea is characterized with 586–670 kJ cm−2 y−1 of solar radiation, \3000 h ofannual sunshine, 1200–1600 m altitude, 7–8°C annual mean temperature, 150–160frost free days, 30–200 mm of annual precipitation, and 1900–33001 mm of PET.Therefore, there is no cropping without irrigation in this region. It is a typical ‘oasisagriculture’ area. The glaciers in the Qilian Mountains developed in modern timesand irrigate �540000 ha of cropping land. The traditional cropping system in thearea is one crop per year. The main crops are spring wheat, spring barley, barebarley, pea, cowbean, soybean, maize, potato, millet, rape, linseed, sugarbeet andsome fodder crops.

3.3.3. The main problemsThe main problems of the traditional cropping system are: (1) summer harvested

cereals (mainly wheat) take \73% of the total cropping area, which results in theinadequacy of labor and the waste of water resources. The glacier cannot provideenough water for more cereals in summer but supply an amount of water for


autumn harvested crops that exceed demand. (2) The monocropping system resultsin the waste of solar radiation. There are 90 days in the growing season or 1640°Cabove 0°C accumulated temperature after wheat harvesting and 85 days growingseason or 300°C above 0°C accumulated temperature that cannot be used by thetraditional cropping system. From 1978, a group of agronomists from GansuAgricultural University began to develop a more intensive and more profitablecropping system in the region.

3.3.4. Strategy(1) Decrease the percentage of summer harvested crops to 67% while increasing

the percentage of autumn harvested crops to 33%; (2) increase cropping index bychanging monoculture into intercropping; (3) increase the percentage of leguminousfodder crops by catch cropping and intercropping; and (4) rotate crops in asequence. In this way, a delicately designed intensive irrigated cropping system wasdeveloped (Table 2).

3.3.5. The ad6antagesThe advantages of the new cropping system are: Resources are utilized intensively

and equally both in aspects of time and space, the livestock system is linked withthe cropping system with the involvement of more leguminous fodder crops; waterand labor strains are relieved; annual yield of cereals increased by 30%, annualincome increased by 57%, and solar radiation use efficiency increased by 60.5%. Allof those make a more sustainable and profitable farming system.

The above two examples show that a delicate farming system design is to designa system structure that can make reasonable use of resources in all aspects of time,space, quality and quantity. That is what the AEE means.

Table 2Cropping pattern and rotation sequence of the irrigated 3-year rotation cropping system

I IIPlots/year III

Summer harvested cereals Maize+potato and soybean1 Wheat/leguminous foddercrops

Rape+potato and sugar-Wheat/potato and soy-beetbean

2 Summer harvested cerealsMaize+potato and soy-Wheat/leguminous fodderbeancrops

Wheat/potato and soybeanRape+potato and sugarbeet

3 Summer harvested cereals Wheat/leguminous fodderMaize+potato and soy-bean cropsRape+potato and sugar Wheat/potato and soybeanbeet

/, Relay intercropping; +, intercropping (Liu and Mu, 1993).


4. Toward a more intensive and more sustainable farming system

Farming systems in the world differ due to the variation of climate, soil andsocial-economic conditions, and so do people’s understandings of farming systemstheory and approach. However, farming systems as an approach to the design andmanagement of agricultural systems should have some general principles.

In the past years, agricultural scientists have done a lot of research on farmingsystems to develop its principles. They have achieved a lot, and their achievementshave greatly contributed to agricultural production. The situation now haschanged. The understanding of agriculture development and the requirement foragriculture by human society is much greater than years ago. For a world that isbecoming more and more populated, with more restricted resources and at the sametime, a more luxurious life style pursued, the agricultural system should supplymore products both in quantity and quality, while providing a better environmentfor human living and recreation (Loomis and Connor, 1992; Mei and Lu, 1995). Itis a great challenge, especially for developing countries, for the restrictions ofresources to agricultural production in those countries are usually more severe thanthose in developed countries. They should get enough food and other farmproducts while allowing farmers to become richer, they should feed and warm theirgreat populations while not damaging their environment and resources. There aregenerally several contradictions in agricultural development that developing coun-tries, such as China are facing. The contradictions are related to many social,economic and ecological factors. The demand for more farm products in limitedlands has meant that the development of agriculture should be intensive; and theneed for sustained increases in agriculture, while protecting environment qualityand the resources for human living and production, has required that the develop-ment of agriculture be sustainable. Thus, the theme of agriculture development inChina and many other developing countries should be intensive and sustainable. Aproper farming system that meets the multiple needs or goal of agriculturalproduction will no doubt be an effective approach that will perform the theme ofagriculture development efficiently. That farming system should be elaboratelydesigned with multidisciplinary theory and approach.

A farming system, ecologically sound, economically profitable and sociallyresponsible, should reflect three combinations: combination of farmers and thegovernment for social needs, combination of ecological and economic issues forbenefits, and combination of use and conservation of resources. That makes anoptimum farming system. Then, under the main principles, we can design the entiresystem at different levels from single crops to the crop–animal complex. For thispurpose, a farming system should be designed with the help of system approach.

The above two examples which the author experienced are both lacking insystematic data of resources and environment and need more advanced andcomplicated methods for decision making. Those are the tasks for intensive andsustainable farming systems research, and are also the tasks for agriculturalecological engineering (AEE).


5. Conclusion

A sustainable agricultural system depends on the optimum design of its structureso that it can perform its functions most efficiently and effectively. Farming systems(FS), a subject dealing with the structure and function of agricultural productionsystems with systematic thinking and integration of methods, have long beenefficient methods for both macroscale and microscale management, and haveproved to be successful as a theory and approach for agricultural system design. FSneeds further development to form a complete system of accurate theory andapproach.

There are one or several factors limiting the full play of system functions at eachlevel of an agricultural system. For effective management of the system, one shouldfind out and overcome or diminish the limiting factors with integrated methods inthe complex and coordinating system. Thus, the design of a sustainable farmingsystem should aim at the full play of the function of a agriculture system. That isthe role of farming system theory and approach, and is also an efficient skill ofecological engineering.

References

Liang, W.E., 1995. High-yielding, high-efficient and rational input. Agric. Mod. 5, 325–327.Liu, X.H., Mu, Z.G., 1993. Farming Systems in China. China Agricultural Press, Beijing.Loomis, R.S., Connor, D.J., 1992. Crop ecology: Productivity and Management in Agricultural Systems.

Cambridge University Press.Ma, Sh.J., 1990. Inquiry into Modern Ecology. China Scientific Press, Beijing.Mei, F.Q., Lu, L.Sh., 1995. Studies on The Sustainable Development and Comprehensive Productivity

of China’s Agriculture. Shandong Science and Technology Press, Jinan.Odum, E.P., 1981. Translated by Sun, R.R., et al. Fundamental Ecology. The People’s Educational

Press, Beijing.Shi, Y.Ch., Cheng, Xu. (Eds.), 1994. Integrated Resource Managementfor Sustainable Agriculture.

Beijing Agricultural University Press, Beijing.Wang, Sh.A., 1991. One Ton Per Mu Techniques—Research Papers on the Theory and Technique

Series of One Ton Per Mu Wheat–maize Double Cropping System. China Agricultural Press,Beijing.

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Farming systems as an approach to agro-ecological engineering