Agriculture

338 KiB

Open AccessFeature PaperArticle

Organic Contaminant Content and Physico-Chemical Characteristics of Waste Materials Recycled in Agriculture

by Hannah Rigby, Alan Dowding, Alwyn Fernandes, David Humphries, Rupert G. Petch, Christopher K. Reynolds, Martin Rose and Stephen R. Smith

Agriculture 2015, 5(4), 1289-1328; https://doi.org/10.3390/agriculture5041289 - 17 Dec 2015

Cited by 11 | Viewed by 7294

Abstract

A range of wastes representative of materials currently applied, or with future potential to be applied, to agricultural land in the UK as fertilisers and soil improvers or used as animal bedding in livestock production, were investigated. In addition to full physico-chemical characterization, [...] Read more.

A range of wastes representative of materials currently applied, or with future potential to be applied, to agricultural land in the UK as fertilisers and soil improvers or used as animal bedding in livestock production, were investigated. In addition to full physico-chemical characterization, the materials were analysed for a suite of priority organic contaminants. In general, contaminants were present at relatively low concentrations. For example, for biosolids and compost-like-output (CLO), concentrations of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) were approximately 1−10 and 5–50 times lower, respectively, than various proposed or implemented European limit values for these contaminants in biosolids or composts applied to agricultural land. However, the technical basis for these limits may require re-evaluation in some cases. Polybrominated, and mixed halogenated, dibenzo-p-dioxins/dibenzofurans are not currently considered in risk assessments of dioxins and dioxin-like chemicals, but were detected at relatively high concentrations compared with PCDD/Fs in the biosolids and CLOs and their potential contribution to the overall toxic equivalency is assessed. Other ‘emerging’ contaminants, such as organophosphate flame retardants, were detected in several of the waste materials, and their potential significance is discussed. The study is part of a wider research programme that will provide evidence that is expected to improve confidence in the use of waste-derived materials in agriculture and to establish guidelines to protect the food chain where necessary. Full article

(This article belongs to the Special Issue Recycling Organic Wastes in Agriculture)

505 KiB

Open AccessReview

Selenium Biochemistry and Bioavailability: Implications for Animal Agriculture

by Shaniko Shini, Asad Sultan and Wayne L. Bryden

Agriculture 2015, 5(4), 1277-1288; https://doi.org/10.3390/agriculture5041277 - 14 Dec 2015

Cited by 32 | Viewed by 12925

Abstract

Selenium (Se) is an essential trace mineral required for growth, development, immune function, and metabolism. Selenium exerts its biological effects as an integral component of selenoproteins (SePs). Deficiency or low Se status leads to marked changes in many biochemical pathways and a range [...] Read more.

Selenium (Se) is an essential trace mineral required for growth, development, immune function, and metabolism. Selenium exerts its biological effects as an integral component of selenoproteins (SePs). Deficiency or low Se status leads to marked changes in many biochemical pathways and a range of pathologies and disorders which are associated with SeP function. Animals, and presumably humans, are able to efficiently utilize nutritionally adequate levels of Se in both organic and inorganic forms. It is now clear that the bioavailability of Se varies depending on the source and chemical form of the Se supplement. There are a range of products available for dietary Se supplementation, however, organic sources have been shown to be assimilated more efficiently than inorganic compounds and are considered to be less toxic and more appropriate as a feed supplement. Yeast enriched with Selenohomoalanthionine (SeHLan) has recently become commercially available, and initial research suggests that it may be an efficacious source for the production of Se enriched animal products. Full article

(This article belongs to the Special Issue Nutritional Toxicology and Animal Nutrition)

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386 KiB

Open AccessReview

Challenges for Plant Breeders from the View of Animal Nutrition

by Gerhard Flachowsky and Ulrich Meyer

Agriculture 2015, 5(4), 1252-1276; https://doi.org/10.3390/agriculture5041252 - 12 Dec 2015

Cited by 23 | Viewed by 10435

Abstract

The question of how to feed the growing world population is very old, but because of the increase of population and possible climate change, currently it has an explosive impact. Plant breeding can be considered as the starting point for the whole human [...] Read more.

The question of how to feed the growing world population is very old, but because of the increase of population and possible climate change, currently it has an explosive impact. Plant breeding can be considered as the starting point for the whole human food chain. Therefore, high, stable and highly digestible yields of phytogenic biomass with low external inputs of non-renewable resources, such as water, fuel, arable land, fertilizers, etc.; low emissions of gases with greenhouse potential during cultivation; and high resistance against biotic and abiotic stressors, including adaptation to potential climate change, and a low concentration of undesirable substances in the plants are real challenges for plant breeders in the future. Virtually unlimited resources such as sunlight, nitrogen and carbon dioxide from the air as well as the genetic pool of microbes, plants and animals can be used to breed/develop optimal plants/crops. Biofortification of plants may also be an objective of plants breeders, but it is more important for human nutrition to avoid micronutrient deficiencies. A lower concentration of undesirable substances in the plants can be considered as more important than higher concentrations of micronutrients in plants/feeds. Animal nutritionists have various possibilities for feed additive supplementation to meet animal nutrient requirements. Examples to reduce undesirable substances in feed plants are discussed and shown in the paper. In summary, plant breeding has a large and strategic potential for global feed and food security. All breeding technologies may contribute to solving important global challenges, such as sustainable use of limited global resources, improved use of unlimited resources, adaption to climate change and lowering global greenhouse gas emission. More publically supported research seems to be necessary in this field. All methods of plant breeding that contribute to a more resource-efficient production of high and stable yields of available biomass should be used/combined. Full article

(This article belongs to the Special Issue Nutritional Toxicology and Animal Nutrition)

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294 KiB

Open AccessReview

Grain Sorghum: A Conundrum for Chicken-Meat Production

by Sonia Y. Liu, Glen Fox, Ali Khoddami, Karlie A. Neilson, Ha H. Truong, Amy F. Moss and Peter H. Selle

Agriculture 2015, 5(4), 1224-1251; https://doi.org/10.3390/agriculture5041224 - 08 Dec 2015

Cited by 29 | Viewed by 8715

Abstract

The inclusion of grain sorghum in diets for broiler chickens is quite common; however, under Australian conditions, the utilisation of starch/energy by birds offered sorghum-based diets appears inadequate. Various factors inherent in sorghum, including kafirin, phenolic compounds and phytate, may limit energy utilisation. [...] Read more.

The inclusion of grain sorghum in diets for broiler chickens is quite common; however, under Australian conditions, the utilisation of starch/energy by birds offered sorghum-based diets appears inadequate. Various factors inherent in sorghum, including kafirin, phenolic compounds and phytate, may limit energy utilisation. The recent quantification of kafirin, the dominant protein fraction in sorghum, has allowed its nutritional significance to be assessed. This is important as indirect evidence suggests that kafirin concentrations in local sorghums are increasing as an unintended consequence of breeding programs. Presently, Australian sorghums do not contain condensed tannin but, from analyses and assessments of other polyphenolic compounds and phenolic acids, “non-tannin” phenols appear to be negative influences. Anecdotally, white sorghums are considered to be superior to red varieties thus the fact that polyphenolic pigments are responsible for the “redness” of sorghum assumes relevance. Inclusions of sulphite reducing agents in broiler diets have generated promising responses but seem dependent on sorghum properties. Preliminary studies have shown the possibilities of using rapid visco-analyser (RVA) starch pasting profiles, promatest protein solubilities and grain textures to indicate sorghum quality and further studies are required to confirm these hypotheses. These assessments may indicate which sorghums will best respond to reducing agents such as sodium metabisulphite. Finally, the usually modest responses of broilers to exogenous feed enzyme inclusions in sorghum-based are considered in this review. Full article

(This article belongs to the Special Issue Nutritional Toxicology and Animal Nutrition)

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905 KiB

Open AccessArticle

Use of Insulated Covers over Product Crates to Reduce Losses in Amaranth during Shipping Delays

by Lizanne Wheeler, Lisa Kitinoja and Diane M. Barrett

Agriculture 2015, 5(4), 1204-1223; https://doi.org/10.3390/agriculture5041204 - 04 Dec 2015

Cited by 7 | Viewed by 6710

Abstract

Amaranth is a leafy vegetable with high nutrient content which is sensitive to temperature and low relative humidity. Delays in shipment to market may result in significant losses, therefore improved packaging to minimize mechanical damage and reduce moisture loss are desirable. Amaranth was [...] Read more.

Amaranth is a leafy vegetable with high nutrient content which is sensitive to temperature and low relative humidity. Delays in shipment to market may result in significant losses, therefore improved packaging to minimize mechanical damage and reduce moisture loss are desirable. Amaranth was stored in three types of consumer packages, bunches, clamshells and thin plastic bags, within vented plastic crates. Pallet loads were either covered with insulated material or not, while awaiting transportation. Results indicated covering pallets improved the color and overall quality while reducing weight loss and wilting. Covered crates had a “good” (7.6/9.0) overall quality while uncovered averaged 5.5/9.0 or “moderate” quality. There were significant differences in consumer package type, with the bagged amaranth having almost “excellent” quality (8.8/9.0) compared to “good-fair” quality in clamshells (6.2/9.0) and “poor-fair” quality in the control bunches (4.7/9.0). Amaranth stored in thin plastic bags was better in quality and color, with less weight loss and wilting, however, temperatures at the end of six hours of storage were higher and this may lead to microbial growth. Storage of amaranth in thin bags or clamshell packages, within plastic crates covered with insulated pallet covers while awaiting shipping resulted in improved overall quality and color. Full article

(This article belongs to the Special Issue Fresh Produce Wastage)

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216 KiB

Open AccessArticle

Aflatoxins, Fumonisins and Zearalenone Contamination of Maize in the Southeastern and Central Highlands Provinces of Vietnam

by Nguyen Hieu Phuong, Nguyen Quang Thieu, Brian Ogle and Hans Pettersson

Agriculture 2015, 5(4), 1195-1203; https://doi.org/10.3390/agriculture5041195 - 04 Dec 2015

Cited by 9 | Viewed by 6037

Abstract

A survey of the contamination of maize with aflatoxins, fumonisins and zearalenone was carried out in the Southeastern and Central Highland provinces in Vietnam. Four provinces were chosen for sampling maize: Dong Nai (22), Binh Phuoc (25), Dak Lak (30) and Dak Nong [...] Read more.

A survey of the contamination of maize with aflatoxins, fumonisins and zearalenone was carried out in the Southeastern and Central Highland provinces in Vietnam. Four provinces were chosen for sampling maize: Dong Nai (22), Binh Phuoc (25), Dak Lak (30) and Dak Nong (20). Aflatoxin B₁ (AFB₁), B₂ (AFB₂), G₁ (AFG₁), G₂ (AFG₂), fumonisin B₁ (FB₁), fumonisin B₂ (FB₂) and zearalenone (ZEA) were analysed by HPLC in 97 maize kernel samples. Fumonisins were the most common toxins found in all samples (67%), followed by aflatoxins (55.7%) and zearalenone (27.8%). The incidence of aflatoxin positive samples (61.7%) in the Southeastern provinces was higher than in the Central Highlands (50%), while fumonisins and zearalenone incidences were higher in the Central Highlands. The mean level of fumonisin B₁ in samples from the Central Highlands provinces (1757 µg/kg) was significantly greater (p < 0.05) than in the Southeastern provinces (740 µg/kg). Importantly, the percentage of positive samples (about 70%) that had over 20 µg/kg (ppb) aflatoxin was very high. Moreover, many samples (53%) contained more than one mycotoxin and this result highlights the difficulty of diagnosing mycotoxicoses in the field and the need for ongoing research to reduce the occurrence of mycotoxins in Vietnamese maize. Full article

(This article belongs to the Special Issue Nutritional Toxicology and Animal Nutrition)

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224 KiB

Open AccessArticle

The Effect of Supplementing Air-Dried Moringa stenopetala Leaf to Natural Grass Hay on Feed Intake and Growth Performances of Arsi-Bale Goats

by Aberra Melesse, Degnet H/Meskel, Sandip Banerjee, Aster Abebe and Amsalu Sisay

Agriculture 2015, 5(4), 1183-1194; https://doi.org/10.3390/agriculture5041183 - 30 Nov 2015

Cited by 6 | Viewed by 6980

Abstract

The most constraining factor in goat production in the tropics is underfeeding mainly attributed to limitations of feed both in quantity and quality. This study was conducted to assess the effect of supplementing different levels of air-dried Moringa stenopetala leaf (MSL) as a [...] Read more.

The most constraining factor in goat production in the tropics is underfeeding mainly attributed to limitations of feed both in quantity and quality. This study was conducted to assess the effect of supplementing different levels of air-dried Moringa stenopetala leaf (MSL) as a protein source on nutrient intake and growth performances of Arsi-Bale male goats. A total of 24 yearling goats with average initial body weight of 13.6 ± 0.25 kg were used in the study. The goats were blocked by live weight into four groups (n = 6 per group) and the groups were then randomly allocated into four supplemented treatments. All goats received a basal diet of natural grass hay ad libitum and 340 g/head/day concentrate. The treatments were the control diet with no supplementation (Treatment 1, T1) and diets supplemented with MSL at a rate of 120 g/head/day (Treatment 2, T2), 170 g/head/day (Treatment 3, T3) and 220 g/head/day (Treatment 4, T4). The duration of the experiment was 75 days. The results indicated that the average daily feed intake was (p < 0.001) higher in goats supplemented with T3 and T4 diets. The total dry matter, organic matter, and crude protein intakes of goats fed with T3 and T4 supplementations were (p < 0.001) also higher than those reared in T1 and T2 diets. Goats reared in T3 and T4 diets had lower (p < 0.05) feed conversion ratio than those fed with T1 and T2 diets. The final body weight in goats reared in T3 and T4 diets was 18.2 kg and 18.5 kg, respectively, being (p < 0.05) higher than those of T1 (15.8 kg) and T2 (16.3 kg). The average daily weight gain in goats fed with T3 and T4 diets was 111 and 114 g/goat/day, respectively, which was (p < 0.05) higher than those reared in the control (T1) (54.0 g/goat/day) and T2 (58.1 g/goat/day) diets. It can thus be concluded that goats reared at high level of MSL supplementation (T3 and T4) had better nutrient intake, feed conversion efficiency and growth performances, suggesting its potential as a good protein supplement to natural grass hay at the farmer’s management level. Full article

(This article belongs to the Special Issue Nutritional Toxicology and Animal Nutrition)

56 KiB

Open AccessReview

Aflatoxin Contamination of the Milk Supply: A Pakistan Perspective

by Naveed Aslam and Peter C. Wynn

Agriculture 2015, 5(4), 1172-1182; https://doi.org/10.3390/agriculture5041172 - 27 Nov 2015

Cited by 10 | Viewed by 7834

Abstract

Improving both quality and quantity of food available is a pressing need especially when one eighth of the world’s population consumes less energy than is required for maintenance and is exposed to contaminated food, both of which lead to greater susceptibility to diseases. [...] Read more.

Improving both quality and quantity of food available is a pressing need especially when one eighth of the world’s population consumes less energy than is required for maintenance and is exposed to contaminated food, both of which lead to greater susceptibility to diseases. The Pakistani population depends heavily on milk for nutritional needs and 10% of household income is spent on milk. This commodity requires continuous monitoring and care from its site of production by smallholder dairy producers through to urban consumers along tradition milk marketing chains. Feed ingredients used as concentrate feed to enhance milk production are often contaminated with mycotoxins, which, after ingestion, are transferred into milk. Aflatoxins can contribute to the causation of liver cancers, immune system disorders, and growth-related issues in children. Moreover, deaths in both humans and animals have also been reported after ingestion of aflatoxin-contaminated food. Studies have shown contamination of food and feed ingredients with mycotoxins, especially aflatoxins. This review places the dairy industry into context, summarizes how milk and milk products are contaminated with aflatoxins, and discusses the present legislative regulation of milk quality implemented in Pakistan. There is a need to eliminate fungus-susceptible animal feed ingredients, which are the source of mycotoxins so prevalent in the milk marketed to the consumer in Pakistan. Full article

(This article belongs to the Special Issue Nutritional Toxicology and Animal Nutrition)

553 KiB

Open AccessReview

Defoliation, Shoot Plasticity, Sward Structure and Herbage Utilization in Pasture: Review of the Underlying Ecophysiological Processes

by François Gastal and Gilles Lemaire

Agriculture 2015, 5(4), 1146-1171; https://doi.org/10.3390/agriculture5041146 - 25 Nov 2015

Cited by 87 | Viewed by 13735

Abstract

Sward structure affects herbage growth, pasture species dynamics, and herbage utilization. Defoliation management has a major impact on sward structure. In particular, tiller size-tiller density compensations allow for the maintenance of herbage growth. Tiller size and tiller density are determined by several major [...] Read more.

Sward structure affects herbage growth, pasture species dynamics, and herbage utilization. Defoliation management has a major impact on sward structure. In particular, tiller size-tiller density compensations allow for the maintenance of herbage growth. Tiller size and tiller density are determined by several major morphogenetical components. Defoliation affects these morphogenetical components, depending on its frequency and its intensity, through several direct and indirect physiological and environmental processes. Due to the implications of leaf area removal, defoliation has a direct effect on the mobilization of C and N reserves and their supply to growing leaves. In addition, defoliation has an indirect effect on leaf and tiller morphogenesis, due to its impact on the light environment within the canopy as well as plant responses to light signals (blue light, red far red ratio). Defoliation may also in some cases have a direct negative effect on leaf growth by damaging leaf meristems. Understanding the respective role of these various physiological and environmental processes requires studies where defoliation, photosynthetic active radiation and light signals are manipulated independently. Past and recent knowledge on these direct and indirect effects of defoliation on plant morphogenesis are discussed, leading to an overall integrated view of physiological and environmental processes that lead to adaptations of sward structure in response to defoliation management. Major consequences for herbage utilization efficiency are presented. Full article

(This article belongs to the Special Issue Forage Plant Ecophysiology)

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343 KiB

Open AccessArticle

Effects of Control Release Fertilizers on Nutrient Leaching, Palm Growth and Production Cost

by Pushpa Soti, Angie Fleurissaint, Stewart Reed and Krish Jayachandran

Agriculture 2015, 5(4), 1135-1145; https://doi.org/10.3390/agriculture5041135 - 18 Nov 2015

Cited by 6 | Viewed by 6244

Abstract

Objective of this study was to evaluate the effect of different controlled release fertilizer technologies on nutrient leaching and plant growth parameters of two palm species, Chinese Fan (Livistona chinensis) and Queen (Syagrus romanzoffiana). We compared Nutri-Pak (12-4-12 controlled [...] Read more.

Objective of this study was to evaluate the effect of different controlled release fertilizer technologies on nutrient leaching and plant growth parameters of two palm species, Chinese Fan (Livistona chinensis) and Queen (Syagrus romanzoffiana). We compared Nutri-Pak (12-4-12 controlled release packet) and Harrell’s (12-4-12 controlled release polymer coated urea) against Atlantic (8-4-12 controlled release polymer coated urea, coated sulfate of potash), the most commonly used palm fertilizer in South Florida. Plants were grown in 25 cm (11 L) pots under 70% shade, watered weekly, with pest and weed control done as required. Plant growth parameters: number of leaves, leaf length and width, and basal diameter, were measured every two months. Leachate was collected weekly after irrigation and a two-month composite sample was analyzed for nutrient concentrations. There was no difference in the growth parameters among the three fertilizers for Chinese Fan plants. However for Queen, Atlantic and Harrell’s had significantly thicker basal diameter than Nutri-Pak. Significant difference in the concentration of nutrients in the leachate was observed among the fertilizer types. Throughout the study period, Nutri-Pak had a lower concentration of nutrients in the leachate than Atlantic and Harrell’s. Our research indicates that Nutri-Pak control release fertilizer is comparable to other commercial fertilizers in Chinese Fan growth, but the larger Queen palms likely require an additional packet. Nutri-Pak fertilizer resulted in less nutrient leaching and could be a better environmental choice. Full article

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283 KiB

Open AccessReview

Carbon Assimilation, Biomass Partitioning and Productivity in Grasses

by Louis J. Irving

Agriculture 2015, 5(4), 1116-1134; https://doi.org/10.3390/agriculture5041116 - 10 Nov 2015

Cited by 57 | Viewed by 10236

Abstract

Plant growth correlates with net carbon gain on a whole plant basis. Over the last several decades, the driving factors shaping plant morphology and performance have become increasingly clear. This review seeks to explore the importance of these factors for grass performance. Briefly, [...] Read more.

Plant growth correlates with net carbon gain on a whole plant basis. Over the last several decades, the driving factors shaping plant morphology and performance have become increasingly clear. This review seeks to explore the importance of these factors for grass performance. Briefly, these fall into factors influencing photosynthetic rates directly, competition between plants in a canopy, and nutrient status and availability. Full article

(This article belongs to the Special Issue Forage Plant Ecophysiology)

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11865 KiB

Open AccessArticle

Biochar for Soil Improvement: Evaluation of Biochar from Gasification and Slow Pyrolysis

by Lydia Fryda and Rianne Visser

Agriculture 2015, 5(4), 1076-1115; https://doi.org/10.3390/agriculture5041076 - 05 Nov 2015

Cited by 87 | Viewed by 19411

Abstract

The growing need for food, energy and materials demands a resource efficient approach as the world’s population keeps increasing. Biochar is a valuable product that can be produced in combination with bio-energy in a cascading approach to make best use of available resources. [...] Read more.

The growing need for food, energy and materials demands a resource efficient approach as the world’s population keeps increasing. Biochar is a valuable product that can be produced in combination with bio-energy in a cascading approach to make best use of available resources. In addition, there are resources that have not been used up to now, such as, e.g., many agro-residues that can become available. Most agro-residues are not suitable for high temperature energy conversion processes due to high alkali-content, which results in slagging and fouling in conventional energy generation systems. Using agro-residues in thermal processes, therefore, logically moves to lower temperatures in order to avoid operational problems. This provides an ideal situation for the combined energy and biochar production. In this work a slow pyrolysis process (an auger reactor) at 400 °C and 600 °C is used as well as two fluidized bed systems for low-temperature (600 °C–750 °C) gasification for the combined energy and biochar generation. Comparison of the two different processes focuses here on the biochar quality parameters (physical, chemical and surface properties), although energy generation and biochar quality are not independent parameters. A large number of feedstock were investigated on general char characteristics and in more detail the paper focuses on two main input streams (woody residues, greenhouse waste) in order to deduct relationships between char parameters for the same feedstock. It is clear that the process technology influences the main biochar properties such as elemental- and ash composition, specific surface area, pH, in addition to mass yield quality of the gas produced. Slow pyrolysis biochars have smaller specific surface areas (SA) and higher PAH than the gasification samples (although below international norms) but higher yields. Higher process temperatures and different gaseous conditions in gasification resulted in lower biochar yields but larger TSA, higher pH and ash contents and very low tar content (16-PAH). From the feedstock data looked at in more detail, a few trends could be deducted in the attempt to learn how to steer the biochar characteristics for specific uses. Full article

(This article belongs to the Special Issue Effects of Biochar on Soil Fertility and Crop Production)

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875 KiB

Open AccessArticle

Effects of Biochar Blends on Microbial Community Composition in Two Coastal Plain Soils

by Thomas F. Ducey, Jeffrey M. Novak and Mark G. Johnson

Agriculture 2015, 5(4), 1060-1075; https://doi.org/10.3390/agriculture5041060 - 03 Nov 2015

Cited by 25 | Viewed by 7704

Abstract

The amendment of soil with biochar has been demonstrated to have an effect not only on the soil physicochemical properties, but also on soil microbial community composition and activity. Previous reports have demonstrated significant impacts on soil microbial community structure. These impacts are [...] Read more.

The amendment of soil with biochar has been demonstrated to have an effect not only on the soil physicochemical properties, but also on soil microbial community composition and activity. Previous reports have demonstrated significant impacts on soil microbial community structure. These impacts are modulated not only by the biochar composition, but also on the soil’s physicochemical characteristics. This indicates that soil characteristics must be considered prior to biochar amendment. A significant portion of the soils of the southeastern coastal plain are severely degraded and, therefore, candidates for biochar amendment to strengthen soil fertility. In this study we focused on two common soil series in the southeastern coastal plain, utilizing feedstocks endemic to the area. We chose feedstocks in four ratios (100% pine chip; 80:20 mixture of pine chip to poultry litter; 50:50 mixture of pine chip to poultry litter; 100% poultry litter) prior to pyrolysis and soil amendment as a biochar product. Soil was analyzed for bioavailable nutrients via Mehlich-1 extractions, as well as microbial community composition using phospholipid fatty acid analysis (PLFA). Our results demonstrated significant shifts in microbial community composition in response to biochar amendment, the effects of which were greatest with 100% poultry litter biochar. Strong relationships between PLFAs and several Mehlich-1 extractable nutrients (Al, Cu, Fe, and P) were observed. Full article

(This article belongs to the Special Issue Effects of Biochar on Soil Fertility and Crop Production)

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247 KiB

Open AccessArticle

Effect of Zinc-Phosphorus Interaction on Corn Silage Grown on Sandy Soil

by Saad Drissi, Abdelhadi Aït Houssa, Ahmed Bamouh, Jean-Marie Coquant and Mohamed Benbella

Agriculture 2015, 5(4), 1047-1059; https://doi.org/10.3390/agriculture5041047 - 29 Oct 2015

Cited by 24 | Viewed by 6286

Abstract

This study investigated the response of corn silage to different combinations of zinc (Zn) and phosphorus (P) soil supply when grown in sandy soil. The soil was naturally poor in extractable Zn and rich in plant-available P. The experiment was conducted in outdoor [...] Read more.

This study investigated the response of corn silage to different combinations of zinc (Zn) and phosphorus (P) soil supply when grown in sandy soil. The soil was naturally poor in extractable Zn and rich in plant-available P. The experiment was conducted in outdoor containers. The treatments consisted of soil supply combinations of 3 levels of Zn (0, 5 and 10 mg Zn kg⁻¹ of dry soil) and 4 levels of P (0, 12, 36 and 72 mg P₂O₅ kg⁻¹ of dry soil). The results showed the absence of a significant effect (at p ≤ 0.05) of Zn-P interaction on plant growth, plant mineral content or total aerial dry weight at harvest. P application depressed Zn shoot content, and conversely, Zn supply slightly reduced P shoot content. The total aerial dry weight at harvest was not enhanced by P application. However, it was significantly increased by Zn supply of 5 mg·kg⁻¹ only for the highest P (72 mg·kg⁻¹) application (at p ≤ 0.05). This increase was around 15% compared to no Zn soil supply. It was especially linked to kernel dry weight and particularly to pollination rate. For the highest level of P supply, Zn applications significantly enhanced (at p ≤ 0.05) the kernel dry weight and the pollination rate by 22.1% and 38.4% respectively, compared to no Zn supply. Full article

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Open AccessReview

Principles of Designing and Implementing Agricultural Extension Programs for Reducing Post-harvest Loss

by Paul E. McNamara and Joyous S. Tata

Agriculture 2015, 5(4), 1035-1046; https://doi.org/10.3390/agriculture5041035 - 28 Oct 2015

Cited by 5 | Viewed by 12922

Abstract

Post-harvest losses represent a significant threat to food security and farmer incomes worldwide. It is an inefficiency in the global food production system that is avoidable. In deducing principles of designing and implementing agricultural extension programs to reduce post-harvest losses, valuable lessons can [...] Read more.

Post-harvest losses represent a significant threat to food security and farmer incomes worldwide. It is an inefficiency in the global food production system that is avoidable. In deducing principles of designing and implementing agricultural extension programs to reduce post-harvest losses, valuable lessons can be gleaned from the handful of previous extension projects and programs addressing post-harvest loss. Abstracting principles from previous experiences and using this to inform future post-harvest loss prevention programs is an evidence-based approach to arrive at solutions to this problem. This paper reviews extension programs for post-harvest loss prevention, before presenting key principles abstracted from the review that should be taken into consideration for future post-harvest loss prevention programs. This paper aims to contribute to knowledge on the role of agricultural extension in the design of post-harvest loss reduction efforts in developing countries. Full article

(This article belongs to the Special Issue Agriculture and Rural Development)

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363 KiB

Open AccessReview

Fruit and Vegetable Co-Products as Functional Feed Ingredients in Farm Animal Nutrition for Improved Product Quality

by Eleni Kasapidou, Evangelia Sossidou and Paraskevi Mitlianga

Agriculture 2015, 5(4), 1020-1034; https://doi.org/10.3390/agriculture5041020 - 21 Oct 2015

Cited by 104 | Viewed by 14047

Abstract

There are significant environmental, economic and social factors favoring the reutilization of fruit and vegetable processing co-products in farm animal nutrition. Current evidence shows that fruit and vegetable processing co-products can be effectively used in farm animal nutrition as functional feed ingredients for [...] Read more.

There are significant environmental, economic and social factors favoring the reutilization of fruit and vegetable processing co-products in farm animal nutrition. Current evidence shows that fruit and vegetable processing co-products can be effectively used in farm animal nutrition as functional feed ingredients for the production of food products of improved quality. These ingredients comply with consumer requests for the production of “clean,” “natural” and “eco/green” label food products. The main parameters affecting extensive application of fruit and vegetable processing by-/co-products as functional feed ingredients in livestock nutrition are related to animal factors, logistics, and commercial value. Further research is needed to enable the commercial application of these products to livestock nutrition. Full article

(This article belongs to the Special Issue Recycling Organic Wastes in Agriculture)

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1921 KiB

Open AccessArticle

The Shortwave Infrared Bands’ Response to Stomatal Conductance in “Conference” Pear Trees (Pyrus communis L.)

by Raymond Struthers, Anna Ivanova, Laurent Tits, Rony Swennen and Pol Coppin

Agriculture 2015, 5(4), 1003-1019; https://doi.org/10.3390/agriculture5041003 - 12 Oct 2015

Viewed by 5608

Abstract

In situ measurements consisting of stomatal conductance, air temperature, vapor pressure deficit and the spectral reflectance in the shortwave infrared (SWIR) regions of thirty “Conference” pear trees (Pyrus communis L.) were repeatedly measured for eighty-six days. The SWIR was segmented into eight [...] Read more.

In situ measurements consisting of stomatal conductance, air temperature, vapor pressure deficit and the spectral reflectance in the shortwave infrared (SWIR) regions of thirty “Conference” pear trees (Pyrus communis L.) were repeatedly measured for eighty-six days. The SWIR was segmented into eight regions between 1550 and 2365 nm, where distances ranged from 40–200 nm. Each of the regions was used to describe the change in canopy water status over a period of approximately three months. Stomatal conductance of the water stress treatment was first determined to be significantly different from the control group nine days after stress initiation. The most suitable SWIR region for this study had wavelengths between 1550 and 1750 nm, where the first significant difference was also measured nine days after stress was initiated. After the period of water stress ended, forty-seven days after stress was initiated, all of the trees received full irrigation, where the SWIR region between 1550 and 1750 nm determined that stomatal conductance of the stress treatment lagged behind the control group for thirty days. Using a temporal sequence of SWIR measurements, we were able to successfully measure the beginning and the recovery of water stress in pear trees. Full article

(This article belongs to the Special Issue Remote Sensing for Crop Production and Management)

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238 KiB

Open AccessArticle

Removing Gaseous NH₃ Using Biochar as an Adsorbent

by Kyoung S. Ro, Isabel M. Lima, Guidqopuram B. Reddy, Michael A. Jackson and Bin Gao

Agriculture 2015, 5(4), 991-1002; https://doi.org/10.3390/agriculture5040991 - 30 Sep 2015

Cited by 40 | Viewed by 10428

Abstract

Ammonia is a major fugitive gas emitted from livestock operations and fertilization production. This study tested the potential of various biochars in removing gaseous ammonia via adsorption processes. Gaseous ammonia adsorption capacities of various biochars made from wood shaving and chicken litter with [...] Read more.

Ammonia is a major fugitive gas emitted from livestock operations and fertilization production. This study tested the potential of various biochars in removing gaseous ammonia via adsorption processes. Gaseous ammonia adsorption capacities of various biochars made from wood shaving and chicken litter with different thermal conditions and activation techniques were determined using laboratory adsorption column tests. Ammonia adsorption capacities of non-activated biochars ranged from 0.15 to 5.09 mg·N/g, which were comparable to that of other commercial activated carbon and natural zeolite. There were no significant differences in ammonia adsorption capacities of steam activated and non-activated biochars even if the surface areas of the steam activated biochars were about two orders of magnitude greater than that of non-activated biochars. In contrast, phosphoric acid activation greatly increased the biochar ammonia adsorption capacity. This suggests that the surface area of biochar did not readily control gaseous NH₃ adsorption. Ammonia adsorption capacities were more or less linearly increased with acidic oxygen surface groups of non-activated and steam-activated biochars. Phosphoric acid bound to the acid activated biochars is suspected to contribute to the exceptionally high ammonia adsorption capacity. The sorption capacities of virgin and water-washed biochar samples were not different, suggesting the potential to regenerate spent biochar simply with water instead of energy- and capital-intensive steam. The results of this study suggest that non-activated biochars can successfully replace commercial activated carbon in removing gaseous ammonia and the removal efficiency will greatly increase if the biochars are activated with phosphoric acid. Full article

(This article belongs to the Special Issue Effects of Biochar on Soil Fertility and Crop Production)

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232 KiB

Open AccessReview

Signal Grass (Brachiaria decumbens) Toxicity in Grazing Ruminants

by Susan G. Low

Agriculture 2015, 5(4), 971-990; https://doi.org/10.3390/agriculture5040971 - 29 Sep 2015

Cited by 29 | Viewed by 16462

Abstract

Signal grass (Brachiaria decumbens) is a highly productive tropical grass that is widespread through South America, Australia, Indonesia, Vanuatu and Malaysia due to its adaptation to a wide range of soil types and environments. Animal production from these B. decumbens pastures [...] Read more.

Signal grass (Brachiaria decumbens) is a highly productive tropical grass that is widespread through South America, Australia, Indonesia, Vanuatu and Malaysia due to its adaptation to a wide range of soil types and environments. Animal production from these B. decumbens pastures is highly variable due to sporadic outbreaks of photosensitisation associated with low growth rates of young animals, anorexia and wasting. The identification of B. decumbens toxicity through clinical signs may grossly underestimate the impact and severity of the disease. Affected animals without clinical signs have elevated serum liver enzyme concentrations resulting from blockage of the bile ducts by birefringent crystals, identified as calcium salts of steroidal saponins found in leaves and stems. The concentrations of the steroidal saponins vary through the year and within the plant. Young, green leaves contain 5–10 times the saponin concentration of mature leaves indicating that B. decumbens pastures are likely to be more toxic during sprouting and early growth. Previous exposure, selective grazing, and avoiding toxic leaves may partly explain apparent resistance of some animals to B. decumbens toxicity. Further research is needed to define growing conditions that produce elevated saponin levels and to investigate the impact of B. decumbens on rumen function. Full article

(This article belongs to the Special Issue Nutritional Toxicology and Animal Nutrition)

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Open AccessReview

Plant Bioactive Metabolites and Drugs Produced by Endophytic Fungi of Spermatophyta

by Rosario Nicoletti and Antonio Fiorentino

Agriculture 2015, 5(4), 918-970; https://doi.org/10.3390/agriculture5040918 - 29 Sep 2015

Cited by 101 | Viewed by 14850

Abstract

It is known that plant-based ethnomedicine represented the foundation of modern pharmacology and that many pharmaceuticals are derived from compounds occurring in plant extracts. This track still stimulates a worldwide investigational activity aimed at identifying novel bioactive products of plant origin. However, the [...] Read more.

It is known that plant-based ethnomedicine represented the foundation of modern pharmacology and that many pharmaceuticals are derived from compounds occurring in plant extracts. This track still stimulates a worldwide investigational activity aimed at identifying novel bioactive products of plant origin. However, the discovery that endophytic fungi are able to produce many plant-derived drugs has disclosed new horizons for their availability and production on a large scale by the pharmaceutical industry. In fact, following the path traced by the blockbuster drug taxol, an increasing number of valuable compounds originally characterized as secondary metabolites of plant species belonging to the Spermatophyta have been reported as fermentation products of endophytic fungal strains. Aspects concerning sources and bioactive properties of these compounds are reviewed in this paper. Full article

(This article belongs to the Special Issue Phytotoxic Fungal Metabolites)

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Open AccessCommentary

From Pandemic Preparedness to Biofuel Production: Tobacco Finds Its Biotechnology Niche in North America

by Joshua D. Powell

Agriculture 2015, 5(4), 901-917; https://doi.org/10.3390/agriculture5040901 - 25 Sep 2015

Cited by 12 | Viewed by 7196

Abstract

In 2012 scientists funded by the United States Defense Advanced Research Projects Agency (DARPA) produced 10 million doses of influenza vaccine in tobacco in a milestone deadline of one month. Recently the experimental antibody cocktail Zmapp™, also produced in tobacco, has shown promise [...] Read more.

In 2012 scientists funded by the United States Defense Advanced Research Projects Agency (DARPA) produced 10 million doses of influenza vaccine in tobacco in a milestone deadline of one month. Recently the experimental antibody cocktail Zmapp™, also produced in tobacco, has shown promise as an emergency intervention therapeutic against Ebola virus. These two examples showcase how collaborative efforts between government, private industry and academia are applying plant biotechnology to combat pathogenic agents. Opportunities now exist repurposing tobacco expression systems for exciting new applications in synthetic biology, biofuels production and industrial enzyme production. As plant-produced biotherapeutics become more mainstream, government funding agencies need to be cognizant of the idea that many plant-produced biologicals are often safer, cheaper, and just as efficacious as traditionally used expression systems. Full article

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Agriculture, Volume 5, Issue 4 (December 2015) – 21 articles , Pages 901-1328

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