Industrial Crop Production Research Articles

Land degradation: Addressing the vulnerability of local people through the lens of transformative change

Land degradation (LD) is driven by many factors resulting from the intricate interplay between natural and socio-economic systems, which adds dynamism and complexity to this phenomenon. The study highlights LD as a source of social vulnerability in the Baragan Plain (Romania), often called the “granary of Europe” due to its century-long history of industrial crop production. We explore the community's perceptions of vulnerability due to LD and the community-based solutions to sustainable transformations through governance using a community-based causal-effect analysis (CBCEA). CBCEA is a participatory approach that uses systems thinking, engages key informants, and generates qualitative causal-effect diagrams to illustrate the system structure. Two workshops with local key informants revealed their views on the direct and indirect causes and effects of LD, strategies they proposed to reduce the community's vulnerability, and the conditions for making the agricultural land decision-making integrative, inclusive, adaptive, and participatory (IIAP). IIAP decision-making was considered a key to transformative governance. Key informants identified “Windbreaks construction” and “(Resilient) Irrigation system” as two effective, context-specific measures to address the causes and effects of LD. We advise caution when implementing the “Irrigation system” measure, as it may risk constraining the system to an undesirable state, commonly referred to as a “trap”.

Driving reactive nitrogen emissions in China: Competition between scale and efficiency

AbstractReactive nitrogen (Nr) emissions aggravate air and water pollution across the world. The factors influencing Nr emissions have not been clearly uncovered, especially for regions under rapid economic growth. Here we modeled total Nr emissions in mainland China and analyzed factors driving their growth during the decade (2000–2010) of fastest socioeconomic development. Results show that total Nr emissions increased from 24.9 terrogram (Tg) to 35.2 Tg, a 41.7% increase with an average annual growth rate of 3.5%. Agricultural activities, including crop planting and livestock and poultry breeding, together took a substantial but decreasing share, from 75.2% in 2000 to 61.4% in 2010. Industrial wastewater discharge, energy use, and crop production are the three largest sources contributing to the Nr emissions growth. Factors related to scale (e.g., the amount of industrial energy use) led to a growth in Nr emissions, and factors related to efficiency (e.g., industrial energy use per unit of economic output) contributed to reduction. The decreasing effect of efficiency gains, however, was still unable to overcome the increasing effect of the activity scale. More in‐depth research studies on mitigation strategies are required, to inform the decoupling between socioeconomic development and Nr emissions.

Pollination by bees in industrial crop production

In recent decades, beekeepers have faced challenges from the massive use of pesticides, climate change and the emergence of new diseases. Taking into account the fact that, as a result of the mass use of chemical plant protection products, the number of wild pollinating insects has significantly decreased, bees are the most effective performers of the pollinating function. In the last twenty years, Russian farmers have come to understand the role of bees in the industrial agrobiocenosis. It is economically advantageous to orient bees to efficient pollination, which requires a high concentration of colonies in a small area. The importance of bees in sunflower production goes beyond mere pollination. Studies have shown that plants visited by bees have a higher seed set, resulting in higher yields. In addition, the pollination process improves seed uniformity and quality. Since industrial crop production implies the placement of one monoculture on large areas, then, naturally, a large number of bees should be delivered to the sunflower array at once by the beginning of flowering. Only mobile beekeeping can cope with this task. Mobile beekeeping is a dynamic and adaptable approach to beekeeping, offering beekeepers increased flexibility, improved honey production.

Replacing peat moss with mixed hardwood biochar as container substrates to produce five types of mint (Mentha spp.)

Recent studies showed that biochar (BC) has the potential to partially replace peat moss-based commercial substrate as container substrates to produce crops, but the research of its use for industrial crop production is limited. To evaluate BC’s use as container substrate for valuable crop production, a greenhouse study was conducted with mixed hardwood BC incorporated with peat moss-based commercial substrate at different rates (20 %, 40 %, 60 %, 80 %, or 100 %; by vol.) to produce chocolate mint (Mentha×piperita L. ‘Chocolate’), peppermint (M. × piperita L.), Kentucky Colonel mint (M. spicata L. var. crispa), spearmint (M. spicate L.) and orange mint (M. aquatica Ehrh.). The peat moss-based commercial substrate was used as control. Results showed that all the different mint plants grown in BC-amended mixtures (except for 100 % BC) had similar soil-plant analyses development (SPAD) reading (except spearmint in 80 % BC), shoot fresh weight, and total dry weight (DW) compared with the control. The 100 % BC mixtures reduced plant growth indicated by the lower SPAD, nutrient contents, shoot fresh weight, total DW, as well as photosynthesis, which could result from the Magnesium deficiency caused by high pH, total porosity, and air space. In conclusion, 80 % (by vol.) of the BC mixed with 20 % of peat moss-based commercial substrate could be used for mint plant production.

Impact of oil palm-related activities on women’s empowerment in Ghana

The public debate over the effect of industrial crop production activities on women’s empowerment remains inconclusive. There are concerns that engagement in industrial crop (oil palm) related activities adversely affects females’ time allocation culminating in disempowerment. However, there is counter-argument that the improved income associated with women’s involvement in industrial crop production activities eventually increases their capacity to significantly contribute to household spending, decision making, and empowerment. Using a rich dataset from 416 farm households from Ashanti and Central regions of Ghana, we empirically quantify the effect of engagement in oil palm production activities on women’s empowerment. The extent of women’s empowerment is quantified using the scores in the five domains of empowerment (i.e. 5DE). The Propensity Score Matching technique is then employed to determine the impact of women’s involvement in the oil palm-related activities on their extent of empowerment. In this paper, we further identify and examine other potential determinants of women’s adequacy in the various indicators of empowerment as well as the overall extent of empowerment. While the study could not establish any significant impact of engagement in oil palm-related activities on women’s empowerment, the results clearly show that these activities contribute positively to empowerment. Also, we find that women with formal education, access to credit, formal training in agriculture or farming, and those engaged in off-farm income-generating activities tend to be more empowered irrespective of the community in which they find themselves. The paper offers suggestions on how women’s empowerment in rural or oil palm producing communities in Ghana could be enhanced.

Photosynthetic characteristics and chloroplast ultrastructure of welsh onion (Allium fistulosum L.) grown under different LED wavelengths

BackgroundThe optimized illumination of plants using light-emitting diodes (LEDs) is beneficial to their photosynthetic performance, and in recent years, LEDs have been widely used in horticultural facilities. However, there are significant differences in the responses of different crops to different wavelengths of light. Thus, the influence of artificial light on photosynthesis requires further investigation to provide theoretical guidelines for the light environments used in industrial crop production. In this study, we tested the effects of different LEDs (white, W; blue, B; green, G; yellow, Y; and red, R) with the same photon flux density (300 μmol/m2·s) on the growth, development, photosynthesis, chlorophyll fluorescence characteristics, leaf structure, and chloroplast ultrastructure of Welsh onion (Allium fistulosum L.) plants.ResultsPlants in the W and B treatments had significantly higher height, leaf area, and fresh weight than those in the other treatments. The photosynthetic pigment content and net photosynthetic rate (Pn) in the W treatment were significantly higher than those in the monochromatic light treatments, the transpiration rate (E) and stomatal conductance (Gs) were the highest in the B treatment, and the intercellular CO2 concentration (Ci) was the highest in the Y treatment. The non-photochemical quenching coefficient (NPQ) was the highest in the Y treatment, but the other chlorophyll fluorescence characteristics differed among treatments in the following order: W > B > R > G > Y. This includes the maximum photochemical efficiency of photosystem II (PSII) under dark adaptation (Fv/Fm), maximum photochemical efficiency of PSII under light adaptation (Fv′/Fm′), photochemical quenching coefficient (qP), actual photochemical efficiency (ΦPSII), and apparent electron transport rate (ETR). Finally, the leaf structure and chloroplast ultrastructure showed the most complete development in the B treatment.ConclusionsWhite and blue light significantly improved the photosynthetic efficiency of Welsh onions, whereas yellow light reduced the photosynthetic efficiency.

Food security impacts of industrial crop production in sub-Saharan Africa: a systematic review of the impact mechanisms

A number of industrial crops have been promoted in sub-Saharan Africa (SSA) to meet a range of policy objectives including economic growth, rural development, agricultural modernization and energy security. The food security impacts of industrial crop production have received extensive policyattention and have been widely discussed in the academic literature. There is, however, an overall lack of a clear understanding of these impacts due to thelarge diversity of industrial crops, and their varied modes of production, expansion areas, and impact mechanisms. This systematic review synthesizes theavailable knowledge on the interface of industrial crops and food security in SSA. In particular we identify key patterns with how different industrial cropsand impact mechanisms are represented and studied in the current literature, and how they intersect to affect food security. The current literature isfragmented, as most studies focus on single or small subsets of crops and impact mechanisms. Most studies capture mechanisms related to food access andavailability, rather than to food utilization and stability. A clustering analysis identified the main literature clusters that combine mechanisms related to foodavailability, access to food, and environmental impact. The overall analysis presented in this systematic review allowed us to identify priority policy andpractice domains that need to be targeted in order to improve the food security outcomes of industrial crop production in SSA.

A Conceptual Framework for Organisation of River Basin Developmentand Management in Nigeria

River Basin Development Authorities (RBDAs) in Nigeria were established since 1976 and they operate mechanized and capital intensive programmes. All the 12 RBDAs operate as separate Authorities, each with separate administrative and operational autonomy, but sharing the Basin Resources of the 8 Hydrological Areas. However, their performance was generally described as disappointing. This study first reviewed the existing organization of the 12 RBDAs in Nigeria. Thereafter, one of the 8 Hydrological Areas – the Komadugu-Yobe Basin (KYB) – which is the major inland drainage system in Nigeria was purposely selected for detailed study. Information on its major streams, tributaries and the main river; the hydrological area as well as the RBDAs sharing resources of the basin area, was gathered using ArcGIS version 10.0 and Erdas Imagine 9.2 software, as well as topographical and hydrological maps. This was processed and analyzed based on the principles of Stream Ordering and Logical Framework Analysis. The findings revealed that in establishing the RBDAs, basin-wide consideration of their sphere of operation was not taken into account. Dams were constructed before establishing the RBDAs. Runoff waters and spill ways were poorly controlled leading to flooding during rainy season and reduced water supply downstream during dry season, with serious environmental and socio-economic problems in the basin area. It was concluded that the RBDAs in Nigeria were poorly organized and have consequently failed to accelerate agricultural and rural development, and have also failed to boost food and industrial crop production as expected. The need was established for effective organization of River Basin Development and Management to improve their performance. To achieve this, a Conceptual framework for Integrated River Basin Development and Management was developed for adoption by river basin managers and other relevant stakeholders in Nigeria and around the globe to improve performance.

Conceptual Framework for Organisation of River Basin Developmentand Management in Nigeria

River Basin Development Authorities (RBDAs) in Nigeria were established since 1976 and they operate mechanized and capital intensive programmes. All the 12 RBDAs operate as separate Authorities, each with separate administrative and operational autonomy, but sharing the Basin Resources of the 8 Hydrological Areas. However, their performance was generally described as disappointing. This study first reviewed the existing organization of the 12 RBDAs in Nigeria. Thereafter, one of the 8 Hydrological Areas – the Komadugu-Yobe Basin (KYB) – which is the major inland drainage system in Nigeria was purposely selected for detailed study. Information on its major streams, tributaries and the main river; the hydrological area as well as the RBDAs sharing resources of the basin area, was gathered using ArcGIS version 10.0 and Erdas Imagine 9.2 software, as well as topographical and hydrological maps. This was processed and analyzed based on the principles of Stream Ordering and Logical Framework Analysis. The findings revealed that in establishing the RBDAs, basin-wide consideration of their sphere of operation was not taken into account. Dams were constructed before establishing the RBDAs. Runoff waters and spill ways were poorly controlled leading to flooding during rainy season and reduced water supply downstream during dry season, with serious environmental and socio-economic problems in the basin area. It was concluded that the RBDAs in Nigeria were poorly organized and have consequently failed to accelerate agricultural and rural development, and have also failed to boost food and industrial crop production as expected. The need was established for effective organization of River Basin Development and Management to improve their performance. To achieve this, a Conceptual framework for Integrated River Basin Development and Management was developed for adoption by river basin managers and other relevant stakeholders in Nigeria and around the globe to improve performance.

Human wellbeing outcomes of involvement in industrial crop production: Evidence from sugarcane, oil palm and jatropha sites in Ghana.

An extensive body of theoretical work has advocated the use of multiple human wellbeing indicators to assess the outcomes of agricultural investments in Sub-Sahara Africa (SSA). However, few studies have actually achieved it. This study investigates the human wellbeing outcomes of involvement in industrial crop production in Ghana by comparing the levels of different objective and subjective wellbeing measures for groups involved in industrial crop production as plantation workers and smallholders, and groups not involved (i.e. control groups). We use household income, adult consumption and the multidimensional poverty index (MPI) as indicators of objective wellbeing. We measure subjective wellbeing through self-reported levels of satisfaction with life, worthwhileness, happiness and anxiousness. Propensity Score Matching (PSM) analysis is used to assess whether involvement in industrial crop production increases household income and consumption. Overall, for most indicators of objective wellbeing industrial crop outgrowers, smallholders and independent smallholders are better off compared to other groups in their respective sites (in terms of mean scores), but involvement does not necessarily brings human wellbeing benefits (PSM analysis). On the other hand plantation workers are either worse off or have similar level of objective human wellbeing with control groups in their respective sites (in terms of mean scores), but involvement sometimes brings human wellbeing benefits (PSM analysis). However, workers tend to benefit from access to plantation infrastructure, which has a positive effect to their multi-dimensional poverty. In most cases the objective wellbeing measures do not correlate well with self-reported levels of subjective wellbeing. It is important to combine such indicators when evaluating the human wellbeing outcomes of agricultural investments in order to obtain a more comprehensive outlook of whether industrial crop production can become a valuable rural development strategy in SSA.

Smallholder-Based Oil Palm and Rubber Production in the Forest Region of Guinea: An Exploratory Analysis of Household Food Security Outcomes

The Guinean government has promoted the large-scale production of industrial crops such as oil palm and rubber through the Guinean Oil Palm and Rubber Company (SOGUIPAH). Smallholder-based production of these crops has also been promoted to boost rural development but the food security outcomes are unclear. This exploratory study assesses the food security outcomes of smallholder-based oil palm and rubber production at the household level using six standardized metrics of food security. We compare households involved in industrial crop production and households that only grow food crops under subsistence conditions through statistical tools such as Propensity Score Matching (PSM) and Endogenous Treatment Effect Regression (ETER). Overall, results suggest that oil palm and rubber smallholders perform better than subsistence farmers on metrics that capture perceptions of hunger and coping behaviors but perform worse for food diversity metrics. We hypothesize that this discrepancy can possibly be explained by the strong sense of security that steady income provides across time, which outweighs the shortcomings of diet diversity. The results of this exploratory study can inform the development of more detailed assessments of the food security outcomes of interventions implemented by SOGUIPAH in the area (and the mechanism through which these impacts emerge).

The effectiveness of development aid for agriculture in Sub-Saharan Africa

PurposeAgriculture is the major source of livelihood for the majority of population in Sub-Saharan Africa but its productivity is not only low it has started showing signs of decline since 2012. The purpose of this paper is to find out whether official development assistance for agriculture is effective.Design/methodology/approachThe data for development assistance for agriculture are broken down into the major agricultural sectors in receiving countries. The empirical evidence is based on the two-step system, i.e. generalized method of moments, to assess the degree of responsiveness of agricultural productivity to development assistance.FindingsThere is a positive relationship between development assistance and agricultural productivity in general. However, when broken down into the major agricultural recipient sectors, there is a substitution effect between food crop production and industrial crop production. Better institutions and economic freedom are found to enable agricultural productivity growth, and to increase the effectiveness of development assistance. The structural economic transformation associated with agricultural development assistance is also found to be weak.Practical implicationsAllocation of development assistance for agriculture is primarily determined by need, although expected effectiveness also increases the assistance receipts. Agricultural assistance policies could focus more on building productive capacity to reduce the need while boosting effectiveness.Originality/valueBreaking down data into agricultural recipient sectors and controlling for the potential spurious correlation under the assumption that more development assistance could be allocated, where agricultural productivity is already increasing due to some other factors.

Secondary treated effluent irrigation did not impact chemical composition, and enzyme inhibition activities of essential oils from Origanum syriacum var. syriacum

Environmental conditions, including irrigation water quality, are known to affect secondary metabolite production in plants and hence the composition and activity of essential oils of aromatic plants. The aim of this study is to evaluate the effect of irrigation with secondary-treated effluent, as compared with potable water irrigation, on the composition, biological activities and yield of essential oil (EO) from Origanum syriacum L. var. syriacum (OSS). The EO from OSS cultivated in Palestine under secondary treated municipal effluent compared with potable water irrigation were analyzed seasonally over a two-year period for oil quantity and composition, antioxidant activities 1,1- diphenyl-2-picrylhydrazyl (DPPH), 2,2 azino-bis (3-ethylbenzothiazloine-6-sulfonic acid) radical cation (ABTS), ferric reducing antioxidant power (FRAP), antimicrobial and inhibitory properties against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and porcine pancreatic lipase (PPL). The quality of the irrigation water did not affect the essential oil yield quantity and quality demonstrating the potential of this marginal water source for agri-industrial production of OSS. Under both irrigation water qualities, the EO contained 35 constituents, of which thymol (40.4–46.7%), and carvacrol (35.1–41.8%) were the most abundant. EOs from plants of both irrigation water qualities exhibited a strong free radical scavenging ability and reducing power activity, and high AChE, BChE, and PPL inhibitory activities. The EOs also showed a moderate antibacterial activity against most test bacterial strains, with high antibacterial activity against Staphylococcus aureus with 117 percent inhibition compared with chloramphenicol (30μg/disc). The high inhibitory activity of the EOs on AChE, BChE, and PPL, and its high antioxidant and antibacterial activities may be due to high concentrations of monoterpenes, especially thymol and carvacrol. The data demonstrate that secondary-treated municipal effluents can be successfully utilized for irrigation of industrial crop production setups for essential oil production from OSS (as a source of natural antioxidants, anticholinesterase, antiobesity and antistaphylococcal agents) without compromising yield quantity and bioactivities compared with potable water irrigation.

Is Aid for Agriculture Effective in Sub-Saharan Africa?

One of the key economic development challenges facing Sub-Saharan Africa (SSA) is its low agricultural productivity. Governments, donors, and foreign investors have underinvested in African agriculture even though research evidence shows that higher agricultural productivity would boost economic growth and poverty reduction. Solutions to the problem require a number of interconnected strategies, including, but not limited to, research on seeds and inputs, extension services, rural development, credit, institutional, and trade and price stabilization policies. We use the system two-step Generalized Method of Moments to examine whether official development assistance (ODA) for agriculture and rural development is helping to boost agricultural productivity. We find a positive relationship between ODA and agricultural productivity. However, when broken down into the main agricultural ODA recipient sectors, there is a substitution effect between food crop production and industrial crop production. While there exists a positive relationship between ODA for industrial and export crops output per worker (agricultural productivity), ODA for food crops has a negative relationship. Better public institutions and economic freedom are also found to enable agricultural productivity growth and to increase the ODA effectiveness. We correct the results for spurious correlation assuming that more ODA might be allocated where agricultural productivity is already increasing due to some other factors. Concerning the determinants of ODA allocation, we find that the allocation of ODA for agriculture is primarily determined by agricultural need, and that the expected effectiveness increases the ODA receipts. Finally, there is a weak ODA-led structural economic change effect in SSA. Labor released from agriculture to the urban sector(s) has a positive market effect on agriculture but is not engendering significant structural economic transformation.

Functional response of soil microbial communities to tillage, cover crops and nitrogen fertilization

Agricultural practices such as tillage, cover crops, and nitrogen (N) fertilization affect physico-chemical and biological soil parameters. However, these factors were often studied separately and their combined effects remain unclear, especially with respect to soil microbial functional diversity and carbon (C) and N content. Thereafter, we aim to assess the links between cropping systems and functional response of microbial communities by using a large range of soil chemical and biological measurements. A 5-yr field experiment was conducted in Northern France using a combination of three factors: i) no-till (NT) vs. conventional tillage (CT); ii) with or without winter cover crops (bare fallow; cover crops with a low prevalence of legumes; cover crop with a high prevalence of legumes); and iii) with or without N fertilization.C and N inputs from cover crops and crop residues, C and N content, enzyme activities, and microbial functional diversity in the topsoil (0–10cm) were measured over an industrial crop rotation: wheat, pea, corn, wheat, flax. No-till combined with any of the cover crops was characterized by increased total soil organic C and N contents by more than 20% between 2010 and 2015. Dehydrogenase and urease activities were significantly greatest under NT, irrespective of the presence of cover crops. Cover crops without N fertilization under no-till led to higher microbial functional activity (faster carbohydrate and phenolic compound degradation) and diversity. Bare fallow had lower soil microbial functional diversity and C and N contents compared with soil under NT and cover crops. On the other hand, NT associated with cover crops allowed to maintain the soil in both C and N, and to promote microbial activities without N fertilization. In conclusion, winter cover crops and/or NT are sustainable agricultural practices resulting in a greater soil quality index. These results demonstrate that NT and use of standard cover crops or cover crops with legumes for 5 years under a low biomass return in industrial crop production have a positive effect on: i) upper soil C content and microbial enzymes, irrespective of N fertilization regime; ii) soil microbial functional diversity in the absence of N fertilization.

Regional characteristics of market production of sugar beet and sunflower in Serbia

The paper analyzes the trends in the development of industrial crop production in the case of sugar beet and sunflower in Serbia from 1976 to 2013. Grouping of regions (4 regions without Autonomous Province of Kosovo and Metohija) and districts (25 districts) in Serbia in 2013, according to the characteristics of land capacity, production of sugar beet and sunflower and level of development, was carried out by cluster analysis. Based on the median value of the important characteristics of available land capacity, production volume and economic development in municipalities, I-distance method were ranked districts in Serbia from 1 to 25. Similarities between the sugar beet and sunflower production regions in Serbia were determined by the method of complete-linkage clustering, and the results were presented in the dendrogram. According to data for 2013 it was found that 99.8% of sugar beet production and 93.9% of sunflower production in Serbia comes from the Vojvodina region. The average yields per hectare for analyzed crops in the areas of the Vojvodina region, on average, were by up to 10% higher compared to the yields in Serbia. According to the characteristics of land capacity and production, areas of the Vojvodina region belong to the highest rank 1-7, while according to the characteristics of the development level, these areas belong to rank 2-13.

Between anti-smoking policies and tobacco farming subsidies: the case of Macedonia

The Balkan countries that produce oriental tobacco struggle to comply with the requirements of the World Health Organization (WHO) Framework Convention for Tobacco Control (FCTC) to reduce and reorient tobacco farming with other cultures.1 The shift of tobacco production is both resource demanding and requires strong political commitment and support. The Republic of Macedonia is classic example how these governments in parallel continue to have conflicting two-track policies on tobacco: strong anti-smoking policies and high tobacco farming subsidies to stimulate production. Macedonia is considered predominantly agricultural land with about 39% of the total area or 1.01 million hectares dedicated to agriculture.2 Agriculture accounts for 18% of total employment, which makes 9.7% of the Gross Domestic Product of the country. Around 70% of the Gross Agricultural Output is generated by crop production. Production of vegetables such as tomatoes, peppers and melons are dominant cultures.2 In addition to these, other important cultures are tobacco, fruits and grapes for consumption and wine production. Tobacco growing and production has a long history in Macedonia. Tobacco production comprises 78% of total industrial crop production covering 18 846 hectares of agricultural land.2 Tobacco represents one-quarter of the agricultural export of the country and for centuries has been deeply rooted in the economic and social culture of …

Impact of climate change on agriculture: An Indian perspective

India is the seventh largest country of the world. In India temperature will increase 3oC to 6oC and rainfall will increase 15-30% in 21 Centaury. While the global surface temperature is projected to increase by 1-4oC from 2100 for low emission scenario and 2.5-5.8oC for higher emission scenario in the atmosphere. This Paper has been prepared with the objects of provide key information on the impacts of climate on Indian agriculture. The greenhouses gas emissions increases day by day in the atmosphere from the many sources such as industrial sources crop production and fossil fuel combustion. These are the major sources for the climate change. The global increases in carbon dioxide concentration are due primarily to fossil fuel use and land use change, while those of methane and nitrous oxide are primarily due to agriculture. Currently Available general circulation models (GCMs) suggest that the area-averaged annual mean warming would be about 3°C in the decade of the 2050s and about 5°C in the decade of the 2080s over the land regions of Asia as a result of future increases in atmospheric concentration of greenhouse gases. In Rajasthan, a 2°C rise in temperature was estimated to reduce production of pearl millet by 10-15 per cent (Y S Ramakrishna et al.,). The state of Madhya Pradesh, where soybean is grown on 77 per cent of all agricultural land, could dubiously benefit from an increase in carbon dioxide in the atmosphere.

Optimal spacing and cultivation intensity for an industrialized crop production system

The overall design of an industrial crop production system should optimize the system's global parameters, such as total area required, intensity of cultivation and general production schedule. The key element is the optimal intensity of cultivation for the prevailing climatic and economic environments. A single-state-variable vegetative crop model (e.g. lettuce) was used to optimize a crop production system for two economic environments: quota- and area-limited production. A strictly uniform weather (every hour of the season) was assumed initially. Continuous spacing was a central control element. The main conclusions of the analysis with our model are: (1) plants of all ages can grow together in a single climatic compartment; (2) spacing should be scheduled to maintain a constant canopy density; (3) optimal canopy density is an increasing function of available light and a decreasing function of temperature; (4) where produce-price is high relative to the prices of rent and energy, the optimal cultivation intensity for an area-limited operation is higher than for a quota-limited operation; the opposite is true where rent is expensive; and (5) the marginal price to be paid for supplementary light is smaller where available natural light is more plentiful.

OPTIMAL SPACING OF A VEGETATIVE GREENHOUSE CROP

The design of an industrial crop production line involves finding the required area for a desired production rate. For any given crop, the required area depends on the chosen intensity of cultivation, expressed in terms of expenditure on capital, energy and other resources. The optimal intensity of cultivation depends on the prevailing climatic and economic environments. A single-state-variable vegetative crop model was used to derive the main features of the environmental-design for a quota-limited crop-growing operation. The main conclusions are: (1) Young and old plants can grow together in a single climatic compartment. (2) Spacing should be scheduled to maintain a constant canopy density. (3) Optimal canopy density is an asymptotically increasing function of available light and a decreasing function of temperature. (4) The marginal price to be paid for supplementary light decreases with available natural light.