Agriculture

11 pages, 2765 KiB

Open AccessCommentary

Helping Agribusinesses—Small Millets Value Chain—To Grow in India

by Ademola Adekunle, Darwin Lyew, Valérie Orsat and Vijaya Raghavan

Agriculture 2018, 8(3), 44; https://doi.org/10.3390/agriculture8030044 - 17 Mar 2018

Cited by 22 | Viewed by 13896

Small millets, a group of highly nutritious food, have taken a back seat in the Indian agriculture landscape in recent years, due to government policies and failings in the value chain. In this commentary, the unusual decline of small millets in comparison to [...] Read more.

Small millets, a group of highly nutritious food, have taken a back seat in the Indian agriculture landscape in recent years, due to government policies and failings in the value chain. In this commentary, the unusual decline of small millets in comparison to its substitutes, and the repercussions thereof, were first presented as context. Thereafter, based on analysis of data from literature, survey, and stakeholder contributions, a cluster map for the Indian small millets value chain was designed, and its competitive state presented. This information was used to conceptualize an open innovation driven business model, and an ecosystem for the proposed model was discussed. This commentary provides the first cluster map analysis of small millets value chain in India, and a business model-based approach to stimulating its agribusinesses growth through a synthesis of stakeholders’ contributions and market data. Full article

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13 pages, 1651 KiB

Open AccessReview

Hungry Plants—A Short Treatise on How to Feed Crops under Stress

by Silvia H. Haneklaus, Elke Bloem and Ewald Schnug

Agriculture 2018, 8(3), 43; https://doi.org/10.3390/agriculture8030043 - 17 Mar 2018

Cited by 15 | Viewed by 6807

Abstract

Fertilisation is as old as is the cultivation of crops. In the 19th century, plant nutrition became an area of research in the field of agricultural chemistry. Liebig’s “Law of the Minimum” (1855) is still the basis for plant nutrition. It states [...] Read more.

Fertilisation is as old as is the cultivation of crops. In the 19th century, plant nutrition became an area of research in the field of agricultural chemistry. Liebig’s “Law of the Minimum” (1855) is still the basis for plant nutrition. It states that the exploitation of the genetically fixed yield potential of crops is limited by that variable, which is insufficiently supplied to the greatest extent. With a view to abiotic and biotic stress factors, this postulation should be extended by the phrase “and/or impaired by the strongest stress factor”. Interactions between mineral elements and plant diseases are well known for essential macro- and micronutrients, and silicon. In comparison, the potential of fertilisation to alleviate abiotic stress has not been compiled in a user-orientated manner. It is the aim of this chapter to summarise the influence of nutrient deficiency in general, and the significance of sodium, potassium, and silicon, in particular, on resistance of crop plants to abiotic stress factors such as drought, salinity, and heavy metal stress. In addition, the significance of seed priming with various nutrients and water to provide tolerance against abiotic stress is discussed. Underlying physiological mechanisms will be elaborated, and information on fertiliser application rates from practical experiences provided. Full article

(This article belongs to the Special Issue Plant Nutrient Dynamics in Stressful Environments)

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12 pages, 2073 KiB

Open AccessArticle

Exploiting Waste Heat from Combine Harvesters to Damage Harvested Weed Seeds and Reduce Weed Infestation

by Christian Andreasen, Zahra Bitarafan, Johanna Fenselau and Christoph Glasner

Agriculture 2018, 8(3), 42; https://doi.org/10.3390/agriculture8030042 - 17 Mar 2018

Cited by 13 | Viewed by 6061

Abstract

Weeds are mainly controlled with herbicides in intensive crop production, but this has resulted in increasing problems with herbicide-resistant weeds and public concerns about the unwanted side-effects of herbicide use. Therefore, there is a need for new alternative methods to reduce weed problems. [...] Read more.

Weeds are mainly controlled with herbicides in intensive crop production, but this has resulted in increasing problems with herbicide-resistant weeds and public concerns about the unwanted side-effects of herbicide use. Therefore, there is a need for new alternative methods to reduce weed problems. One way to reduce weed infestation could be to collect or kill weed seeds produced in the growing season. Crop and weeds are harvested simultaneously with the combine harvester, but most of the weed seeds are returned with the chaff to the field creating new problems in future growing seasons. During the harvesting process, the harvester produces heat. Under normal harvest conditions, the exhaust gas temperature measured directly behind the turbocharger of the engine of a combine harvester may reach between 400 °C and 480 °C depending of the size of the engine. These high temperatures indicate that there is a potential for developing a system which perhaps could be utilized to kill or damage the weeds seeds. We investigate how much heat is needed to damage weed seeds significantly and focuses on the germination patterns over time in response to these treatments. We investigated if heat treatment of weed seeds could kill the seeds or reduce seed vigour or kill the seeds before they are returned to the field. The aim is to avoid harvested viable weed seeds being added to the soil seed bank. During the threshing and cleaning process in the combine harvester, most weed seeds and chaff are separated from the crop grains. After this separation, we imagine that the weed seeds could be exposed to a high temperature before they are returned to the field. Seeds of nine common weed species were treated with temperatures of 50 °C, 100 °C, 150 °C, 200 °C, and 250 °C for 0, 2, 5, 10, and 20 s, respectively. Afterwards, the seeds were germinated for fourteen days. Seeds were differently affected by the heat treatments. We found that 50 °C and 100 °C was insufficient to harm the seeds of all species significantly at all durations. Heating with a temperature of 50 °C and 100 °C showed a slight tendency to break the dormancy of Alopecurus myosuroides Huds. and Papaver rhoeas L., but the results were not statistically significant. Seeds treated with 150 °C gave varying results depending on the duration and the weed species. The germination of A. myosuroides was significantly repressed when seeds were exposed to 250 °C for 5 s. Most species were significantly damaged when they were exposed to 250 °C for more than 10 s. Our results showed that there is a potential to explore how the waste heat energy produced by combine harvesters can be exploited to either kill or reduce the vigour of weed seeds before they are returned to the field with the chaff. Full article

(This article belongs to the Special Issue Weed Management)

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11 pages, 897 KiB

Open AccessArticle

Off-Farm Employment and Economic Crisis: Evidence from Cyprus

by Elias Giannakis, Sophia Efstratoglou and Artemis Antoniades

Agriculture 2018, 8(3), 41; https://doi.org/10.3390/agriculture8030041 - 15 Mar 2018

Cited by 20 | Viewed by 7169

Abstract

Off-farm employment is an important strategy for complementing farm household income and maintaining rural livelihoods. A multilevel logistic regression model was applied to investigate the effect of farm-level and regional-level factors on off-farm employment in Cyprus during the recent economic crisis period. The [...] Read more.

Off-farm employment is an important strategy for complementing farm household income and maintaining rural livelihoods. A multilevel logistic regression model was applied to investigate the effect of farm-level and regional-level factors on off-farm employment in Cyprus during the recent economic crisis period. The performance of nonfarm sectors positively affects off-farm employment; a one-percent increase in the share of the secondary and tertiary sector employment increases the likelihood of off-farm work by 9.5 times. The importance of location was also identified. Farm households located in rural areas are 70% less likely to engage in off-farm work than households located in urban areas. The positive effect of educational attainment and the negative effect of farm training confirmed the importance of human capital characteristics on off-farm labour participation. Farm structural factors are also significant determinants of off-farm employment. A one-hectare increase in the farm size decreases the odds of off-farm labour participation by 50%. Operators of crop farming holdings are 4.2 times more likely to work off the farm than operators of livestock and mixed-farming holdings. The results reveal the importance of adopting a multilevel and integrated approach for the analysis of off-farm employment. Full article

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13 pages, 910 KiB

Open AccessArticle

Limited Seed and Seed Yield Response of Calendula to Applied Nitrogen Does Not Justify Risk of Environmental Damage from High Urea Application Rates

by Jane M. F. Johnson, Russ W. Gesch and Nancy W. Barbour

Agriculture 2018, 8(3), 40; https://doi.org/10.3390/agriculture8030040 - 13 Mar 2018

Cited by 2 | Viewed by 4339

Abstract

Calendula (Calendula officinalis L.) seed, due to its high calendic acid content, is recognized as a potential environmentally safe substitute for volatile organic compounds. Agronomic guidelines for nitrogen (N) management to produce calendula seed oil on a commercial scale are limited. Post-harvest [...] Read more.

Calendula (Calendula officinalis L.) seed, due to its high calendic acid content, is recognized as a potential environmentally safe substitute for volatile organic compounds. Agronomic guidelines for nitrogen (N) management to produce calendula seed oil on a commercial scale are limited. Post-harvest soil N has the potential to move off-farm and contribute to water quality degradation (e.g., hypoxia in the Gulf of Mexico). Establishing N management guidelines should consider agronomic response and potential environmental risk. Calendula seed and oil yield, oil content, harvest index, N use, seed N use efficiency, oil N use efficiency, agronomic efficiency, vegetative growth, and the amount of residual soil-N following harvest response to five urea N rates (0, 34, 67, 134, and 202 kg N ha⁻¹) were assessed in a replicated field study repeated for two growing seasons. Seed yield increased with N rate, but because of the low N conversion efficiency, there appeared to be minimal yield gains in applying N beyond 34 kg ha⁻¹. The lowest amount of soil-N left underutilized in the soil was predicted to occur at 39 kg N ha⁻¹ and was adequate for seed and seed oil commercial calendula production on a Mollisol in the Northern Midwest United States. Full article

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7 pages, 691 KiB

Open AccessFeature PaperArticle

Weed Suppression Ability and Yield Impact of Living Mulch in Cereal Crops

by Roland Gerhards

Agriculture 2018, 8(3), 39; https://doi.org/10.3390/agriculture8030039 - 12 Mar 2018

Cited by 15 | Viewed by 5863

Abstract

Intercropping provides several benefits to the agro-ecosystem and plays an important role in Integrated Weed Management (IWM). In this study, we investigated the impact of living mulch in cereal crops on weed density and grain yield. Seven field experiments were conducted in Southwestern [...] Read more.

Intercropping provides several benefits to the agro-ecosystem and plays an important role in Integrated Weed Management (IWM). In this study, we investigated the impact of living mulch in cereal crops on weed density and grain yield. Seven field experiments were conducted in Southwestern Germany. Perennial ryegrass and white clover were sown on the same day as the cereal crop (early) and when cereals had produced 3–5 leaves or the first tillers (late). Average weed density in the control plots without living mulch was 45 weeds m⁻². Perennial ryegrass and white clover significantly reduced weed density to 22 plants m⁻² and 25 plants m⁻². Sowing date of living mulch had no effect on weed density. Grain yield was equal in all treatments. The results show that living mulch can suppress weeds without competing with the cereal crop. Full article

(This article belongs to the Special Issue Weed Management)

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10 pages, 1799 KiB

Open AccessArticle

Harvesting Method Affects Water Dynamics and Yield of Sweet Orange with Huanglongbing

by Said A. Hamido and Kelly T. Morgan

Agriculture 2018, 8(3), 38; https://doi.org/10.3390/agriculture8030038 - 10 Mar 2018

Cited by 3 | Viewed by 5707

Abstract

Changes in grove management practices may change crop water dynamics. The objective of this study was to estimate sap flow, stem water potential (Ψ_stem), and citrus yield as affected by harvesting methods in sweet orange (Citrus sinensis) trees affected [...] Read more.

Changes in grove management practices may change crop water dynamics. The objective of this study was to estimate sap flow, stem water potential (Ψ_stem), and citrus yield as affected by harvesting methods in sweet orange (Citrus sinensis) trees affected by Huanglongbing. The study was initiated in March 2015 for two years on five-year-old commercial sweet orange trees at a commercial grove located at Felda, Florida (26.61° N, 81.48° W) on Felda fine sand soil (Loamy, siliceous, superactive, hyperthermic Arenic Endoaqualfs). All measurements were replicated before and after harvest in four experiments (A, B, C and D) under hand and mechanical harvesting treatments. Sap flow measurements were taken on four trees per treatment with two sensors per tree. Sap flow measured by the heat balance method at hourly intervals during March and April of 2015 and 2016 significantly declined after harvesting by 25% and 35% after hand and mechanical harvesting, respectively. Ψ_stem measured after harvest was significantly higher than measurements before harvest. The average value of Ψ_stem measured increased by 10% and 6% after hand and mechanical harvesting, respectively. Mechanical harvesting exhibited lower fruit yields that averaged between 83%, 63%, 49% and 36% of hand-harvested trees under A, B, C and D experiments, respectively. It is concluded that the hand harvesting method is less stressful and less impactful on tree water uptake and fruit yield compared with mechanical harvesting. Full article

(This article belongs to the Special Issue Modelling for Water Management in Agriculture Systems)

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12 pages, 558 KiB

Open AccessFeature PaperArticle

Carbon and Nitrogen Content of Soil Organic Matter and Microbial Biomass under Long-Term Crop Rotation and Tillage in Illinois, USA

by Stacy M. Zuber, Gevan D. Behnke, Emerson D. Nafziger and Maria B. Villamil

Agriculture 2018, 8(3), 37; https://doi.org/10.3390/agriculture8030037 - 9 Mar 2018

Cited by 41 | Viewed by 7349

Abstract

Crop rotation and tillage alter soil organic matter (SOM) dynamics by influencing the soil environment and microbes carrying out C and N cycling. Our goal was to evaluate the effect of long-term crop rotation and tillage on the quantity of C and N [...] Read more.

Crop rotation and tillage alter soil organic matter (SOM) dynamics by influencing the soil environment and microbes carrying out C and N cycling. Our goal was to evaluate the effect of long-term crop rotation and tillage on the quantity of C and N stored in SOM and microbial biomass. Two experimental sites were used to evaluate four rotations—continuous corn (Zea mays L.) (CCC), corn-soybean (Glycine max [L.] Merr.) (CS), corn-soybean-wheat (Triticum aestivum L.) (CSW), and continuous soybean (SSS), each split into chisel tillage (CT) and no-till (NT) subplots. The CSW rotation increased soil organic carbon (SOC) content compared to SSS; SSS also reduced total nitrogen (TN) compared to other rotations. Levels of SOC and TN were 7% and 9% greater under NT than CT, respectively. Rotation did not affect microbial biomass C and N (MBC, MBN) while tillage reduced only MBN at 10–20 cm compared to NT, likely related to dispersion of N fertilizers throughout the soil. Despite the apparent lack of sensitivity of microbial biomass, changes in SOC and TN illustrate the effects of rotation and tillage on SOM dynamics. The inclusion of crops with high C: N residues and no-till use both support higher C and N content in the top 20 cm of the soil. Full article

(This article belongs to the Special Issue Sustainable Crop Production Intensification)

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12 pages, 2375 KiB

Open AccessFeature PaperArticle

A Protocol for Producing Virus-Free Artichoke Genetic Resources for Conservation, Breeding, and Production

by Roberta Spanò, Giovanna Bottalico, Addolorata Corrado, Antonia Campanale, Alessandra Di Franco and Tiziana Mascia

Agriculture 2018, 8(3), 36; https://doi.org/10.3390/agriculture8030036 - 1 Mar 2018

Cited by 16 | Viewed by 6678

Abstract

The potential of the globe artichoke biodiversity in the Mediterranean area is enormous but at risk of genetic erosion because only a limited number of varieties are vegetatively propagated and grown. In Apulia (southern Italy), the Regional Government launched specific actions to rescue [...] Read more.

The potential of the globe artichoke biodiversity in the Mediterranean area is enormous but at risk of genetic erosion because only a limited number of varieties are vegetatively propagated and grown. In Apulia (southern Italy), the Regional Government launched specific actions to rescue and preserve biodiversity of woody and vegetable crops in the framework of the Rural Development Program. Many globe artichoke ecotypes have remained neglected and unnoticed for a long time and have been progressively eroded by several causes, which include a poor phytosanitary status. Sanitation of such ecotypes from infections of vascular fungi and viruses may be a solution for their ex situ conservation and multiplication in nursery plants in conformity to the current EU Directives 93/61/CEE and 93/62/CEE that enforce nursery productions of virus-free and true-to-type certified stocks. Five Apulian ecotypes, Bianco di Taranto, Francesina, Locale di Mola, Verde di Putignano and Violetto di Putignano, were sanitized from artichoke Italian latent virus (AILV), artichoke latent virus (ArLV) and tomato infectious chlorosis virus (TICV) by meristem-tip culture and in vitro thermotherapy through a limited number of subcultures to reduce the risk of “pastel variants” induction of and loss of earliness. A total of 25 virus-free primary sources were obtained and conserved ex situ in a nursery. Full article

(This article belongs to the Special Issue Biodiversity of Vegetable Crops, A Living Heritage)

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14 pages, 254 KiB

Open AccessArticle

Determinants of Pesticide Use in Food Crop Production in Southeastern Nigeria

by Sanzidur Rahman and Chidiebere Daniel Chima

Agriculture 2018, 8(3), 35; https://doi.org/10.3390/agriculture8030035 - 28 Feb 2018

Cited by 33 | Viewed by 8735

Abstract

The present study examines pesticide use in producing multiple food crops (i.e., rice, yam, and cassava) and identifies the range of socio-economic factors influencing pesticide use by 400 farmers from Ebonyi and Anambra states of Southeastern Nigeria using a Tobit model. Results reveal [...] Read more.

The present study examines pesticide use in producing multiple food crops (i.e., rice, yam, and cassava) and identifies the range of socio-economic factors influencing pesticide use by 400 farmers from Ebonyi and Anambra states of Southeastern Nigeria using a Tobit model. Results reveal that 68% of the farmers grew at least two food crops. Overall, 41% of the farmers applied pesticides in at least one food crop, whereas 70% of the farmers producing both rice and yam applied pesticides. Pesticide use rates and costs vary significantly amongst farmers producing different food crops and crop combinations. Pesticide use rate is highest for producing yam followed by cassava estimated at 1.52 L/ha costing Naira 1677.97 per ha and 1.37 L/ha costing Naira 1514.96 per ha. Similarly, pesticide use rate is highest for the farmers that produce both yam and cassava followed by farmers that produce both rice and cassava. The inverse farm size–pesticide use rate exists in the study areas, i.e., the pesticide use rate is highest for the small farmers (p < 0.01). Farmers seem to treat pesticides as substitutes for labor and ploughing services, indicated by the significant positive influence of labor wage and ploughing price on pesticide use. Increases in yam price significantly increase pesticide use. Rice production significantly increases pesticide use, whereas cassava production significantly reduces pesticide use. Male farmers use significantly more pesticides. Farming experience is significantly positively related to pesticide use. Policy recommendations include land reform policies aimed at increasing farm operation size and investment in programmes to promote cassava production to reduce pesticide use in food crop production in Southeastern Nigeria. Full article

(This article belongs to the Special Issue Pesticides in Agriculture System)

17 pages, 1477 KiB

Open AccessArticle

Market, Policies and Local Governance as Drivers of Environmental Public Benefits: The Case of the Localised Processed Tomato in Northern Italy

by Francesco Mantino and Barbara Forcina

Agriculture 2018, 8(3), 34; https://doi.org/10.3390/agriculture8030034 - 28 Feb 2018

Cited by 17 | Viewed by 5583

Abstract

This article explores the role of a specific Localised Agri-food System (LAFS) in the provision of Environmental and social benefits (ESBs) in densely cultivated, industrialised, and populated areas by analysing the core of the processing tomato supply chain of northern Italy (Parma and [...] Read more.

This article explores the role of a specific Localised Agri-food System (LAFS) in the provision of Environmental and social benefits (ESBs) in densely cultivated, industrialised, and populated areas by analysing the core of the processing tomato supply chain of northern Italy (Parma and Piacenza). The research examines how the interplay of market drivers, public policies, and collective actions favoured farming, technological, and organisational innovations geared to support long-term economic growth and tackle, at the same time, environmental challenges. The tomato supply chain is characterised by a favourable convergence of attitudes, policies, and market conditions that over time allowed for fruitful interactions between private stakeholders and between the supply chain and public players. Decades of key stakeholders’ interconnections within the tomato supply chain led to a success story of economic growth and attention to a new balance between agro-industry and environment, for the benefit of producers/processors, consumers, and natural resources. Profitability strategies inevitably imply intensification of farming in order to maximise profit levels per hectare, however, the tomato supply chain found a collective motivation that could grant profitability and concurrently reward producers and processors for attention paid to safeguarding the environment—giving evidence that intensification does not necessarily conflict with requirements in support of sustainability. Full article

(This article belongs to the Special Issue Localized Agrifood Systems: Governance, Market, and Environmental Issues)

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8 pages, 2516 KiB

Open AccessArticle

Isolation of Mercury-Resistant Fungi from Mercury-Contaminated Agricultural Soil

by Reginawanti Hindersah, Khainur Rasyid Asda, Diyan Herdiyantoro and Nadia Nuraniya Kamaluddin

Agriculture 2018, 8(3), 33; https://doi.org/10.3390/agriculture8030033 - 27 Feb 2018

Cited by 11 | Viewed by 6719

Abstract

Illegal gold mining and the resulting gold mine tailing ponds on Buru Island in Maluku, Indonesia have increased Mercury (Hg) levels in agricultural soil and caused massive environmental damage. High levels of Hg in soil lowers plant productivity and threatens the equilibrium of [...] Read more.

Illegal gold mining and the resulting gold mine tailing ponds on Buru Island in Maluku, Indonesia have increased Mercury (Hg) levels in agricultural soil and caused massive environmental damage. High levels of Hg in soil lowers plant productivity and threatens the equilibrium of the food web. One possible method of handling Hg-contaminated soils is through bioremediation, which could eliminate Hg from the rhizosphere (root zone). In this study, indigenous fungi isolated from Hg-contaminated soil exhibited Hg-resistance in vitro. Soil samples were collected from the rhizosphere of pioneer plants which grew naturally in areas contaminated with gold mine tailing. The fungi’s capacity for Hg-resistance was confirmed by their better growth in chloramphenicol-boosted potato dextrose agar media which contained various HgCl₂ concentrations. Four isolates exhibited resistance of up to 25 mg kg⁻¹ of Hg, and in an experiment with young Chinese cabbage (Brassica rapa L.) test plants, two fungi species (including Aspergillus) were demonstrated to increase the soil’s availability of Hg. The results suggest that Hg-resistant indigenous fungi can mobilize mercury in the soil and serve as potential bioremediation agents for contaminated agricultural land. Full article

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14 pages, 2867 KiB

Open AccessArticle

Limits to the Biofortification of Leafy Brassicas with Zinc

by Philip J. White, Paula Pongrac, Claire C. Sneddon, Jacqueline A. Thompson and Gladys Wright

Agriculture 2018, 8(3), 32; https://doi.org/10.3390/agriculture8030032 - 27 Feb 2018

Cited by 28 | Viewed by 5788

Abstract

Many humans lack sufficient zinc (Zn) in their diet for their wellbeing and increasing Zn concentrations in edible produce (biofortification) can mitigate this. Recent efforts have focused on biofortifying staple crops. However, greater Zn concentrations can be achieved in leafy vegetables than in [...] Read more.

Many humans lack sufficient zinc (Zn) in their diet for their wellbeing and increasing Zn concentrations in edible produce (biofortification) can mitigate this. Recent efforts have focused on biofortifying staple crops. However, greater Zn concentrations can be achieved in leafy vegetables than in fruits, seeds, or tubers. Brassicas, such as cabbage and broccoli, are widely consumed and might provide an additional means to increase dietary Zn intake. Zinc concentrations in brassicas are limited primarily by Zn phytotoxicity. To assess the limits of Zn biofortification of brassicas, the Zn concentration in a peat:sand (v/v 75:25) medium was manipulated to examine the relationship between shoot Zn concentration and shoot dry weight (DW) and thereby determine the critical shoot Zn concentrations, defined as the shoot Zn concentration at which yield is reduced below 90%. The critical shoot Zn concentration was regarded as the commercial limit to Zn biofortification. Experiments were undertaken over six successive years. A linear relationship between Zn fertiliser application and shoot Zn concentration was observed at low application rates. Critical shoot Zn concentrations ranged from 0.074 to 1.201 mg Zn g⁻¹ DW among cabbage genotypes studied in 2014, and between 0.117 and 1.666 mg Zn g⁻¹ DW among broccoli genotypes studied in 2015–2017. It is concluded that if 5% of the dietary Zn intake of a population is currently delivered through brassicas, then the biofortification of brassicas from 0.057 to > 0.100 mg Zn g⁻¹ DW through the application of Zn fertilisers could increase dietary Zn intake substantially. Full article

(This article belongs to the Special Issue Plant Nutrient Dynamics in Stressful Environments)

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31 pages, 2638 KiB

Open AccessArticle

Recycling Improves Soil Fertility Management in Smallholdings in Tanzania

by Ariane Krause and Vera Susanne Rotter

Agriculture 2018, 8(3), 31; https://doi.org/10.3390/agriculture8030031 - 26 Feb 2018

Cited by 28 | Viewed by 7622

Abstract

Residues from bioenergy and ecological sanitation (EcoSan) can be utilized to sustain soil fertility and productivity. With regard to certain cooking and sanitation technologies used in smallholder households (hh), we systematically analyzed how utilization of the respective potentials to recover residues for farming [...] Read more.

Residues from bioenergy and ecological sanitation (EcoSan) can be utilized to sustain soil fertility and productivity. With regard to certain cooking and sanitation technologies used in smallholder households (hh), we systematically analyzed how utilization of the respective potentials to recover residues for farming affects (i) soil nutrient balances, (ii) the potential for subsistence production of composts, and (iii) environmental emissions. On the example of an intercropping farming system in Karagwe, Tanzania, we studied specific farming practices including (1) current practices of using standard compost only; (2) a combination of using biogas slurry, urine, and standard compost; (3) a combination of using so-called “CaSa-compost” (containing biochar and sanitized human excreta, Project “Carbonization and Sanitation”), urine, and standard compost. The system analysis combines a soil nutrient balance (SNB) with material flow analysis (MFA). Currently, nitrogen (N) and phosphorus (P) are depleted by −54 ± 3 and −8 ± 1 kg∙ha⁻¹∙year⁻¹, respectively. Our analysis shows, however, a clear potential to reduce depletion rates of N, and to reverse the SNB of P, to bring about a positive outcome. Composts and biogas slurry supply sufficient P to crops, while urine effectively supplements N. By using resources recovered from cooking and sanitation, sufficient compost for subsistence farming may be produced. Human excreta contribute especially to total N and total P in CaSa-compost, whilst biochar recovered from cooking with microgasifier stoves adds to total carbon (C) and total P. We conclude that the combined recycling of household residues from cooking and from sanitation, and CaSa-compost in particular, is especially suitable for sustainable soil management, as it mitigates existing P-deficiency and soil acidity, and also restores soil organic matter. Full article

(This article belongs to the Special Issue Energy and Agriculture)

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Agriculture, Volume 8, Issue 3 (March 2018) – 14 articles

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