Sustainable Utilization of Humic Substances and Organic Waste in Green Agriculture

A special issue of Agriculture (ISSN 2077-0472). This special issue belongs to the section "Agricultural Systems and Management".

Deadline for manuscript submissions: closed (15 March 2023) | Viewed by 46249

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Guest Editor
Department of Chemistry, Inorganic Chemistry Laboratory, National and Kapodistrian University of Athens, Panepistimiopolis, 157 71 Athens, Greece
Interests: humic substances; aluminosilicate materials; fertilizers; adsorption; soil quality; clays and clay minerals; waste management; perlites
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Special Issue Information

Dear Colleagues,

Organic waste (OW), continuously created by agriculture, livestock farming, forestry and cities, is biodegradable matter, a plant nutrient source functioning—after processing—as effective fertilizer replacement.

Humic substances (HS), produced via physical, chemical and microbial processes during early diagenesis in the decay of biomass, are redox-active, refractory, dark-colored mixtures of heterogeneous organic compounds and represent an important source of organic carbon and nitrogen in terrestrial and aquatic ecosystems.

HS and processed OW have a beneficial effect on agricultural soil properties, pollutant sequestration, nutrient immobilization and transport. They also affect plant metabolism, thus greatly influencing water quality and green agriculture. OW management conserves energy and resources and contributes to a circular economy.

This Special Issue will focus on “Sustainable Utilization of Humic Substances and Organic Waste in Green Agriculture”. Original research articles, reviews, opinions, communications and letters are invited, introducing novel approaches to a range of hot topics, including but not limited to:

  • Green production processes, properties and uses of HS and OW;
  • HS interactions/complexation with compounds promoting sustainable agriculture;
  • Impact of HS, HS-contained materials and organic waste on the environment (soil, plants and living organisms, domestic animals and cattle included);
  • OW from industrial processes, e.g., molasses, cheese whey, slaughterhouse, leather;
  • Physical, chemical, biological OW treatments and recycling, e.g., retention, adsorption, composting, decomposer microorganisms, supporting green agriculture;
  • Management of the pollutants that accompany OW, e.g., chemicals, pharmaceuticals, drugs, dyes, pesticides, food additives.

Dr. Maria Roulia
Guest Editor

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Keywords

  • humic substances
  • organic waste
  • sustainable agriculture
  • organic/inorganic nutrients
  • plant growth
  • soil quality
  • fertilizer value
  • waste management
  • environment
  • toxicity
  • pathogens
  • organic contaminants

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Published Papers (15 papers)

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Editorial

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4 pages, 165 KiB  
Editorial
Sustainable Utilization of Humic Substances and Organic Waste in Green Agriculture
by Maria Roulia
Agriculture 2024, 14(1), 115; https://doi.org/10.3390/agriculture14010115 - 11 Jan 2024
Cited by 2 | Viewed by 1452
Abstract
Organic wastes (OW) comprise biodegradable plant, animal, and industrial and municipal waste; billions of tons are generated annually worldwide, and they are continuously produced as a result of prosperity, the increase in population, and the escalation of anthropogenic activities [...] Full article

Research

Jump to: Editorial, Review

12 pages, 1224 KiB  
Communication
The Effect of Dietary Humic Substances on Cellular Immunity and Blood Characteristics in Piglets
by Lukáš Bujňák, Alena Hreško Šamudovská, Dagmar Mudroňová, Pavel Naď, Slavomír Marcinčák, Iveta Maskaľová, Michaela Harčárová, Viera Karaffová and Martin Bartkovský
Agriculture 2023, 13(3), 636; https://doi.org/10.3390/agriculture13030636 - 8 Mar 2023
Cited by 5 | Viewed by 1690
Abstract
This study’s objective was to determine the impact of dietary humic substances on immune response and blood profiles in piglets. A total of 24 crossbred piglets (Slovakian White × Landrace; 35 days old; average body weight of 11.67 kg) were allotted to two [...] Read more.
This study’s objective was to determine the impact of dietary humic substances on immune response and blood profiles in piglets. A total of 24 crossbred piglets (Slovakian White × Landrace; 35 days old; average body weight of 11.67 kg) were allotted to two dietary groups with (experimental; 5 g·kg−1) or without (control; 0 g·kg−1) natural humic substances supplementation. In this study, we observed a significant increase of the proportion of CD4+CD8- lymphocytes (p < 0.001) in the experimental group. The results also showed a tendency for an increase of the phagocytic activity and the engulfing capacity of phagocytes and the numbers of the other monitored lymphocyte subpopulations (CD3+, CD21+, CD4-D8+, CD4+CD8+, CD4+CD25+) in piglets in the experimental group compared to the control group. Supplementation of humic substances increased serum alkaline phosphatase compared to the control group (p < 0.05). Other monitored blood parameters were not significantly affected by dietary treatment. It concluded that inclusion of humic substances in the diet of piglets could have a stimulating effect on cellular immunity, without a negative effect on haematological and biochemical parameters. Full article
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14 pages, 666 KiB  
Article
Fertilizer Performance of a Digestate from Swine Wastewater as Synthetic Nitrogen Substitute in Maize Cultivation: Physiological Growth and Yield Responses
by Eduardo L. Buligon, Luiz A. M. Costa, Jorge de Lucas, Jr., Francielly T. Santos, Piebiep Goufo and Monica S. S. M. Costa
Agriculture 2023, 13(3), 565; https://doi.org/10.3390/agriculture13030565 - 26 Feb 2023
Cited by 6 | Viewed by 2196
Abstract
Nitrogen (N) is the primary nutrient required for plant growth. During the last few decades, there has been extensive use of synthetic N-containing fertilizers in agriculture, resulting in increased environmental pollution. In this study, the feasibility of replacing synthetic N with biofertilizer in [...] Read more.
Nitrogen (N) is the primary nutrient required for plant growth. During the last few decades, there has been extensive use of synthetic N-containing fertilizers in agriculture, resulting in increased environmental pollution. In this study, the feasibility of replacing synthetic N with biofertilizer in maize cultivation was investigated. A liquid biofertilizer (digestate obtained from the anaerobic digestion of swine wastewater) was obtained and applied to large plots as a total (100%) or partial (50%) substitute for synthetic N fertilizer. Moreover, the most efficient fertilization mode, i.e., basal versus foliar application, was studied. Physiological growth indices, leaf nutritional status, and grain yield were assessed for each biofertilization treatment and compared with the conventional treatment with synthetic minerals. Compared with the conventional treatment, the total substitution of synthetic N by the biofertilizer (basal application) did not affect the growth parameters and grain yield of maize; the other treatments usually resulted in lower growth rates and yields, although not statistically significant (p ≥ 0.05). No difference was observed among the treatments for the contents of N, P, K, or Mg in the leaves. Generally, the highest means for Fe, Ca, Cu, Zn, and Mn contents in leaves were observed after in-row broadcast of synthetic fertilizers or basal application of the digestate as a total substitute for synthetic N, with a significant effect for Fe (p < 0.05). The mode of the biofertilizer application did not have any significant effect on either growth parameters or leaf nutrients. The data show that under the specific conditions of the study, the total substitution of mineral N with basal application of biofertilizer is the best strategy for minimizing the use of synthetic chemicals in maize cultivation without yield penalties. Full article
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11 pages, 270 KiB  
Article
Response of Maize Yield and Nutrient Uptake to Indigenous Organic Fertilizer from Corn Cobs
by Maria Theresia Sri Budiastuti, Djoko Purnomo, Bambang Pujiasmanto and Desy Setyaningrum
Agriculture 2023, 13(2), 309; https://doi.org/10.3390/agriculture13020309 - 27 Jan 2023
Cited by 9 | Viewed by 9174
Abstract
Indonesia’s corn harvest area is decreasing so that corn production is also decreasing. The use of suboptimal land can be done to increase the harvested corn area by adding nutrients with organic fertilizers. One of the organic fertilizer ingredients is corn cob waste. [...] Read more.
Indonesia’s corn harvest area is decreasing so that corn production is also decreasing. The use of suboptimal land can be done to increase the harvested corn area by adding nutrients with organic fertilizers. One of the organic fertilizer ingredients is corn cob waste. The aim of the study was to examine the role of corn cob fertilizer on the growth, yield and nutrient uptake of corn. The study used a completely randomized block design with one fertilization factor with six levels, namely chemical fertilizers and corn cob organic fertilizer at a dose of 2.5, 5, 7.5, 10 or 12.5 tons/ha. Corn cob organic fertilizer has met the standard as an organic fertilizer with an organic C content of 62.21% and organic matter of 85.71%, ranking it in the high category. The total nitrogen is 1.44%, total phosphate is 1.43% and total potassium is 2.17%. Corn cob organic fertilizer had an effect on the leaf area index, root length, levels of chlorophyll a and chlorophyll b, weight of 100 seeds, cob diameter and phosphate uptake. Doses of 12.5 tons/ha produced the highest changes in chlorophyll a and b, root length and phosphate uptake. Phosphate and potassium uptake correlated with plant biomass and root length. Therefore, the results of the present study suggest that corn cob organic fertilizer is able to support the growth, yield and nutrient uptake of corn in sub-optimum land. Several gaps and research priorities in soil fertility have been identified, which need to be addressed in the future. Full article
14 pages, 3207 KiB  
Article
Sustainable Utilization Strategy of Organic Waste via Fabrication of Bioelastomer with Antibacterial and Antioxidant Activities Using Mandarin Peel Extracts
by Kang Hyun Lee, Youngsang Chun, Ja Hyun Lee, Jong Uk Lee, Taek Lee and Hah Young Yoo
Agriculture 2023, 13(1), 161; https://doi.org/10.3390/agriculture13010161 - 9 Jan 2023
Cited by 8 | Viewed by 2360
Abstract
Mandarin peels (MPs), a food-processing residue, have several restrictions on their disposal and can cause serious environmental pollution. In this study, MP was used to fabricate a functional bioelastomer with antioxidant and antibacterial activities. Bioactive compounds were recovered from MPs in liquid form [...] Read more.
Mandarin peels (MPs), a food-processing residue, have several restrictions on their disposal and can cause serious environmental pollution. In this study, MP was used to fabricate a functional bioelastomer with antioxidant and antibacterial activities. Bioactive compounds were recovered from MPs in liquid form and added to the bioelastomer during fabrication to maintain the mechanical strength of the bioelastomer. The radical scavenging activities of the fabricated bioelastomer (B–MPE 15%) were 3.3% for DPPH and 20.8% for ABTS, respectively. In addition, B–MPE 15% exhibited antibacterial activity against gram-positive (Staphylococcus aureus), gram-negative (Escherichia coli), and antibiotic-resistant bacteria (Methicillin-resistant S. aureus and Vancomycin resistant Enterococcus). The chemical properties of B–MPE 15% were not significantly different from those of the control group (bare PDMS). Tensile strength, elongation at break, and water vapor transmission rate of B–MPE 15% were found to be 5.1 N/mm2, 649%, and 33.3 g/(m2 day), respectively. Therefore, the addition of MP extracts did not significantly affect the physical properties. The fabricated bioelastomer with antibacterial and antioxidant activities is expected to be utilized in the food packaging, pharmaceutical, and medical industries. Our research is expected to represent a future-oriented strategy for realizing carbon neutrality by upcycling food waste. Full article
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13 pages, 3186 KiB  
Article
Urban Agriculture as an Alternative for the Sustainable Production of Maize and Peanut
by José Luis Villalpando-Aguilar, Daniel Francisco Chi-Maas, Itzel López-Rosas, Victor Ángel Aquino-Luna, Jesús Arreola-Enríquez, Julia Cristel Alcudia-Pérez, Gilberto Matos-Pech, Roberto Carlos Gómez-García, Jesús Froylán Martínez-Puc and William Cetzal-Ix
Agriculture 2023, 13(1), 59; https://doi.org/10.3390/agriculture13010059 - 25 Dec 2022
Cited by 1 | Viewed by 1606
Abstract
Currently agriculture has difficulty keeping up with the demand for food around the world, which has generated a boom in the development of sustainable alternatives for producing food and caring for the environment. Therefore, the present study aims to show a backyard system [...] Read more.
Currently agriculture has difficulty keeping up with the demand for food around the world, which has generated a boom in the development of sustainable alternatives for producing food and caring for the environment. Therefore, the present study aims to show a backyard system comprising 50 cm × 50 cm pinewood boxes where maize and peanut were tested under control and compost conditions. The experiments were carried out for nine months starting from compost production and the sowing of the crops, which were irrigated with temporary rain. The compost was produced by converting ~213 kg of organic residues into ~300 kg of mature compost. The fertilizer treatment consisted of two doses of compost (1 kg doses). The developing plants were compared between conditions in both crops. In addition, the nutritional values of the compost and compost and soil were evaluated. Interestingly, the correlation analyses of the morphological properties of the soils showed that the effects of the nutrients were positively associated with the morphology of the crops studied. Finally, the yield produced for maize was 9 kg/m2 and 6.6 kg/m2 and that for peanuts was 184 g/m2 and 73 g/m2 under compost and control conditions, respectively. We consider that the development of new alternatives for producing food in times of crisis or situations of limited resources is necessary for the development of humanity and the care of the environment. Full article
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16 pages, 740 KiB  
Article
Deteriorating Harmful Effects of Drought in Cucumber by Spraying Glycinebetaine
by El-Saied E. Metwaly, Hatim M. Al-Yasi, Esmat F. Ali, Hamada A. Farouk and Saad Farouk
Agriculture 2022, 12(12), 2166; https://doi.org/10.3390/agriculture12122166 - 16 Dec 2022
Cited by 11 | Viewed by 2497
Abstract
In order to alleviate the shortage of irrigation water in dry regions, refining water use efficiency (WUE) is a key issue in sustainable productivity. Furthermore, glycinebetaine (GlyBet) is a vital osmoprotectant produced in crops for improving drought tolerance; however, little is known about [...] Read more.
In order to alleviate the shortage of irrigation water in dry regions, refining water use efficiency (WUE) is a key issue in sustainable productivity. Furthermore, glycinebetaine (GlyBet) is a vital osmoprotectant produced in crops for improving drought tolerance; however, little is known about its role in improving plant WUE under field conditions in non-accumulating plants such as cucumber. In order to elucidate the effectiveness of GlyBet concentrations (0, 2000, 4000, and 6000 mg/L) in mitigating the deleterious effects of drought (e.g., well-watered (1250 m3/fed), moderate drought (950 m3/fed), and severe drought (650 m3/fed)), field experiments were conducted at Elmia village, Dakahlia, Egypt in the 2020 and 2021 seasons on vegetative growth, some physiological attributes, as well as yield and quality. Drought considerably decreased vegetative growth, yield and its components, leaf relative water content, and photosynthetic pigment concentrations compared with well-watered plants while increasing electrolyte leakage. The most harmful causes were severe drought. However, exogenous spraying with GlyBet substantially boosted the mentioned attributes, but reduced electrolyte leakage within well-watering. Commonly 6000 mg/L contributed to the maximum growth and productivity, preserving cucumber plant water status above other concentrations or untreated plants. Under extreme drought, the application of 6000 mg/L GlyBet had a beneficial effect on moderating the damage of water deficit on cucumber plant growth and productivity. Overall, using GlyBet as a cost-effective and eco-friendly biostimulant six times (10, 20, 30, 40, 50, and 60 days from sowing) has the potential to mitigate drought damage while also increasing yield; however, more research is needed to determine the optimal rate and timing of application. Full article
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17 pages, 3376 KiB  
Article
Rabbit Manure Compost for Seedling Nursery Blocks: Suitability and Optimization of the Manufacturing Production Process
by Rangling Li, Hongying Wang, Enze Duan, Jiayu Fan and Liangju Wang
Agriculture 2022, 12(12), 2156; https://doi.org/10.3390/agriculture12122156 - 14 Dec 2022
Cited by 5 | Viewed by 4379
Abstract
Using rabbit manure to prepare growing media is an effective method to solve environmental pollution and realize resource utilization. The solution to rabbit manure management is the composting process which could produce compost suitable for seedling nursery blocks, which could improve transplanting efficiency [...] Read more.
Using rabbit manure to prepare growing media is an effective method to solve environmental pollution and realize resource utilization. The solution to rabbit manure management is the composting process which could produce compost suitable for seedling nursery blocks, which could improve transplanting efficiency and seedlings’ survival rate. Seedling nursery blocks were obtained by mixing rabbit manure compost, vermiculite, rice straw, and peat. The effect of cold pressing parameters, including moisture content (25–45%), binder content (1–5%), molding compression ratio (2.5–4.5:1), and strain maintenance time (0–120 s), were investigated on blocks quality (i.e., ventilatory porosity, relaxation density, compressive resistance, and specific energy consumption) through a general rotation combined experiment. These results showed there were significant interaction effects between molding compression ratio and moisture content, moisture and binder content, binder content and strain maintenance time, and molding compression ratio and binder content on block quality. The optimal parameters for manufacturing blocks were that the molding compression ratio, moisture content, binder content, and strain maintenance time were 4:1, 33.5%, 3.1%, and 60 s, and the relaxation density, ventilation porosity, and specific energy consumption were 363.31 kg/m3, 18.72%, and 0.44 J/g, which could achieve emergence performance. Full article
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19 pages, 3369 KiB  
Article
Chemical and Nutritional Characterization of the Different Organs of Taif’s Rose (Rosa damascena Mill. var. trigintipetala) and Possible Recycling of the Solid Distillation Wastes in Taif City, Saudi Arabia
by Esmat F. Ali, Hatim M. Al-Yasi, Ali Majrashi, Emad A. Farahat, Ebrahem M. Eid and Tarek M. Galal
Agriculture 2022, 12(11), 1925; https://doi.org/10.3390/agriculture12111925 - 16 Nov 2022
Cited by 4 | Viewed by 2032
Abstract
The objective of the current study was to examine the chemical composition and biological functions of the various Taif’s rose (TR) organs and floral solid distillation wastes (SDW). Additionally, it assessed the SDW’s potential use in animal feed and potential health applications. For [...] Read more.
The objective of the current study was to examine the chemical composition and biological functions of the various Taif’s rose (TR) organs and floral solid distillation wastes (SDW). Additionally, it assessed the SDW’s potential use in animal feed and potential health applications. For chemical and biological analyses, the plant stems, leaves, and flowers as well as the SDW of TR were gathered from four farms in the Al-Shafa highland region of Taif, Saudi Arabia. The highest levels of cardiac glycosides, flavonoids, and phenolics were found in the flowers (7.66 mg securiaside g−1, 16.33 mg GAE g−1, and 10.90 mg RUE g−1, respectively), while the highest carbohydrate and alkaloid contents were found in the TR leaves (2.09% and 9.43 mg AE g−1, respectively) with no significant differences from the SDW. Quercetin, apigenin, and rutin flavonoids, as well as isocorydine and boldine alkaloids, were found in larger concentrations in the flowers and floral SDW than in the leaves and stems. The various TR flower extracts were effective against Gram-negative and -positive bacteria but had no effect on fungal strains, but the SDW’s methanol extract was only effective against fungi. The plant stem had the highest N, K, and Mg contents (138, 174, and 96.12 mg kg−1, respectively), while the leaves had the highest P and Ca values (6.58 and 173.93 mg kg−1, respectively). The leaves had the highest contents of total carbohydrates and acid detergent fibre (59.85 and 3.93%, respectively), while the stems had the highest total protein and acid detergent fibre (8.66 and 24.17%, respectively), and the SDW had the highest fats and crude fiber (0.57 and 36.52%, respectively). The highest amounts of digestible crude protein, gross energy, and total dissolved nutrients (TDN) (4.52% and 412.61 Mcal kg−1) were found in the plant stem and flowers, respectively. The results of the current experiment showed that the TDN contents of the various organs and the SDW of TR are suitable for mature dry gestating beef cows. It was determined that, in addition to the SDW’s potential usage as an ingredient in animal feed, various plant parts and TR’s SDW can be utilized for a variety of medical reasons. Full article
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14 pages, 2287 KiB  
Article
Properties of Humic Substances in Composts Comprised of Different Organic Source Material
by Marge Lanno, Maris Klavins, Oskars Purmalis, Merrit Shanskiy, Anu Kisand and Mait Kriipsalu
Agriculture 2022, 12(11), 1797; https://doi.org/10.3390/agriculture12111797 - 28 Oct 2022
Cited by 14 | Viewed by 3264
Abstract
Reusing organic waste as fertilizer is one method to reduce the use of mineral fertilizers and minimize waste disposal in landfills. Regulations have been enacted for the processing of organic waste and for recycling end products, but the humic content of organic fertilizers [...] Read more.
Reusing organic waste as fertilizer is one method to reduce the use of mineral fertilizers and minimize waste disposal in landfills. Regulations have been enacted for the processing of organic waste and for recycling end products, but the humic content of organic fertilizers has been neglected. We studied seven composts with different organic input materials and technologies. Humic substances (HSs) were detected in all composts. The total organic carbon in the HSs constituted 8.7 ± 0.1% (SD)–27.0 ± 0.2% of the compost dry matter. Spectral differences between the studied samples in FTIR spectroscopy could be observed at 1700–1000 cm−1, indicating differences in compost precursor material. The EEM peak, associated with humic acids (HAs), was high in composts containing animal by-products (e.g., fish waste, horse manure, and kitchen biowaste). Kitchen biowaste, also when processed by Hermetia illucens larvae and vermicompost, exhibited slower organic material transformation with low humic acid/fulvic acid ratios (<1.60). The results show the importance of source material origin and amendments, which influence the composting process and final products. Our study emphasizes the role of humic substances in the comprehensive evaluation of composts. To maximize the added value of composts, marketing strategies should consider determining the share of humic substances besides the content of organic matter and nutrients. Full article
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14 pages, 863 KiB  
Article
Evaluating the Nutrient Contents and Nutritive Value of Taif’s Rose (Rosa damascena Mill var. trigintipetala) Waste to Be Used as Animal Forage or Soil Organic Fertilizers
by Tarek M. Galal, Esmat F. Ali, Ebrahem M. Eid, Hatim M. Al-Yasi, Ali Magrashi, Fayez Althobaiti and Emad A. Farahat
Agriculture 2022, 12(9), 1481; https://doi.org/10.3390/agriculture12091481 - 16 Sep 2022
Cited by 5 | Viewed by 2506
Abstract
This study aimed to evaluate the nutrient content and nutritive value of pruning waste of the Taif Damask rose for its potential use as an organic fertilizer or animal forage in the Taif region, Saudi Arabia. For this purpose, the pruning waste of [...] Read more.
This study aimed to evaluate the nutrient content and nutritive value of pruning waste of the Taif Damask rose for its potential use as an organic fertilizer or animal forage in the Taif region, Saudi Arabia. For this purpose, the pruning waste of Taif’s rose and soil samples supporting the plant growth at different ages were collected from four farms (F1: 4, F2: 10, F3: 12, and F4: 20 years old). The total aboveground biomass (AGB) of the plants, stems, and leaves were measured in addition to the stem height and crown diameter. The results showed that the maximum stem height and crown diameter (184.20 and 243.5 cm) were recorded in the oldest farm (F4). Moreover, the stem, leaves, and aboveground biomass (AGB) of the waste were maximal (3.91, 1.30 and 5.21 t ha−1) at F4. F1 had the highest N content (154.30 mg kg−1) in the plant leaves, while F2 had the highest stem N and P (172.33 and P 9.40 mg kg−1). Moreover, F3 had the highest concentrations of leaf P (7.17 mg kg−1), leaf and stem K (112.47 and 277.30 mg kg−1), stem Ca2+ (251.93 mg kg−1), and leaf and stem Mg2+ (122.27 and 123.57 mg kg−1). The stems had higher percentages of total proteins, fibers, ash, and NFE (total carbohydrates) than the leaves in F1 and F2, while the opposite was observed in F3 and F4. The leaves of F2 rose plants had the highest percentage of neutral detergent fibers (NDF), and their stems had the highest percentages of total proteins (10.71%). The leaves of F3 plants had the highest percentage of acid detergent lignin (ADL) and the lowest crude fibers (7.63 and 13.27%), while the stems had the highest NFE (72.71%). The plant–soil relationship expressed by the CCA biplot showed that all the measured plant parameters were at higher positions on the Mg axis, except for the plant height and crown diameter, which were at low positions on the N and NO3 axes, respectively. In contrast, Cl, NO3, HCO3, and SO42− had high positive correlations with axis 1 and negative values with axis 2, while EC, the total P, and Ca2+ had high positive correlations with, and pH had high negative values in relation to, axis 2. Due to its considerable high inorganic and organic nutrient contents, Taif’s rose could be used in the manufacturing of organic fertilizer. Additionally, the analysis of the nutritive value of the pruning waste supports its use as animal forage. We strongly recommend that further studies be conducted on the application of plant waste as a soil amendment and animal forage in the field. Full article
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14 pages, 1372 KiB  
Article
Biochar-Based Fertilizer Enhances the Production Capacity and Economic Benefit of Open-Field Eggplant in the Karst Region of Southwest China
by Meng Zhang, Yanling Liu, Quanquan Wei, Lingling Liu, Xiaofeng Gu and Jiulan Gou
Agriculture 2022, 12(9), 1388; https://doi.org/10.3390/agriculture12091388 - 4 Sep 2022
Cited by 12 | Viewed by 3397
Abstract
Biochar as an amendment has been widely applied to enhance crop productivity and improve soil quality. However, the effect of biochar-based fertilizer (BF) on the production capacity and economic benefits of open-field eggplant in the karst region remains unclear. A field experiment was [...] Read more.
Biochar as an amendment has been widely applied to enhance crop productivity and improve soil quality. However, the effect of biochar-based fertilizer (BF) on the production capacity and economic benefits of open-field eggplant in the karst region remains unclear. A field experiment was carried out in the karst region of Southwest China from 2020 to 2021 to study the ameliorative roles of different application rates (1875, 2250, 2625, and 3000 kg ha−1) of BF on the fresh yield, quality, fertilizer utilization, and economic benefits of fresh eggplant. The results show that BF increased the yield of fresh eggplant by 3.65–13.76% (2020) and 23.40–49.04% (2021) compared to the traditional fertilization practice (TFP). The application of BF reduced the nitrate content and increased the vitamin C (VC) and soluble sugar content of the fruits, which is beneficial for improving the quality of eggplant fruits. Meanwhile, the application of BF not only increased the nutrient uptake of the eggplant but also significantly improved the fertilizer utilization rates, especially the agronomic efficiency (AE) and recovery efficiency (RE). Moreover, BF could also significantly increase the output value and net income of fresh eggplant, which can help farmers increase their income. In conclusion, a BF application rate of 2544–2625 kg ha−1 could be used to improve the yield, fertilizer efficiency, and economic benefits of open-field eggplant and is recommended for managing agricultural production in the karst region of Southwest China. Full article
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16 pages, 2414 KiB  
Article
Taif’s Rose (Rosa damascena Mill var. trigentipetala) Wastes Are a Potential Candidate for Heavy Metals Remediation from Agricultural Soil
by Tarek M. Galal, Ali Majrashi, Hatim M. Al-Yasi, Emad A. Farahat, Ebrahem M. Eid and Esmat F. Ali
Agriculture 2022, 12(9), 1319; https://doi.org/10.3390/agriculture12091319 - 26 Aug 2022
Cited by 7 | Viewed by 2098
Abstract
The current study examines the bioaccumulation potential of Taif rose shrubs by analyzing the shrubs’ wastes. f. At Al-Shafa Highland, four farms with plants of different ages were chosen to collect soil samples and vegetative waste (leaves and stems) for morphological and chemical [...] Read more.
The current study examines the bioaccumulation potential of Taif rose shrubs by analyzing the shrubs’ wastes. f. At Al-Shafa Highland, four farms with plants of different ages were chosen to collect soil samples and vegetative waste (leaves and stems) for morphological and chemical analysis. The tallest stem and largest crown diameter (184.2 and 243.5 cm, respectively) were found in the oldest (20-year-old) shrubs, which also produced the highest biomass of pruning wastes of stems and leaves (3.9 and 1.3 t/ha, respectively). The 10-year-old shrubs gathered the highest concentration of Co and Pb (1.74 and 7.34 mg kg−1) in the stem and the highest Fe, Mn, and Ni (18.55, 18.60, and 9.05 mg kg−1) in the leaves, while the youngest plants (4 years) accumulated the highest Cr and Zn (0.83 and 13.44 mg kg−1) in their leaves. The highest contents of Cd, Cr, Cu, Fe, Mn, Pb, and Zn were found in the oldest Taif rose stem (34.94, 1.16, 36.29, 49.32, 51.22, 24.76, and 32.51 g ha−1), while the highest contents of Co and Ni were found in the stems of plants that were 10 and 12 years old (3.21 and 9.54 g ha−1, respectively). The Taif rose’s stem and leaves can absorb the majority of heavy metals that have been studied with BAF values greater than one. Significant relationships between various heavy metals in the soil and the same in the stems (Al, Co, and Pb) and leaves (Co, Fe, Mn, Ni, and Pb) of Taif roses have been observed. According to the current findings, the Taif rose is a promising viable and safe crop for heavy metals phytoremediation if it is grown in polluted soil because there is little to no risk of contamination in the use of its end products, high biomass of pruning wastes, and high efficiency of heavy metal removal. Full article
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Review

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16 pages, 965 KiB  
Review
Advances in Applications of Cereal Crop Residues in Green Concrete Technology for Environmental Sustainability: A Review
by Md Amir Suhail, Sandeep Shrivastava, Kunwar Paritosh, Nidhi Pareek, Andrey A. Kovalev, Dmitriy A. Kovalev, Yuri V. Litti, Vladimir Panchenko, Vadim Bolshev and Vivekanand Vivekanand
Agriculture 2022, 12(8), 1266; https://doi.org/10.3390/agriculture12081266 - 19 Aug 2022
Cited by 3 | Viewed by 2837
Abstract
Concrete is mainly employed as a construction material. Due to the manufacturing of cement and the extent of concrete usage, numerous environmental issues and water suction have presented challenges. There is an immediate need to overcome these problematic issues by substituting natural resources [...] Read more.
Concrete is mainly employed as a construction material. Due to the manufacturing of cement and the extent of concrete usage, numerous environmental issues and water suction have presented challenges. There is an immediate need to overcome these problematic issues by substituting natural resources with wastes and by-products of different biological processes in the production of concrete in order to make green concrete. Green concrete provides a relatively low-impact material to satisfy potential concrete demand and offers a cheaper, robust and highly reliable alternative that could fulfil future construction requirements in an environmentally safer way. The present review highlights the possible use of waste residues of agricultural origin from cereal farming in concrete as alternative materials to cement, fine aggregate and fiber reinforcement. The review also considers appropriate methods of treatment, the selection of residual resources and the blending ratios that may allow the development of next-generation green concrete with better physicochemical and mechanical properties. It also explores in-depth studies and the wider range of innovations in cereal farming residues for appropriate use in green construction for environmental sustainability. Green concrete could be an alternative material that could replace those used in conventional methods of construction and help make a further step towards environmental sustainability and a circular bioeconomy. Full article
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19 pages, 326 KiB  
Review
Biostimulant Effects of Waste Derived Biobased Products in the Cultivation of Ornamental and Food Plants
by Enzo Montoneri, Andrea Baglieri and Giancarlo Fascella
Agriculture 2022, 12(7), 994; https://doi.org/10.3390/agriculture12070994 - 10 Jul 2022
Cited by 10 | Viewed by 2776
Abstract
Soluble bio-based substances (SBS) may be isolated from the anaerobic digestate of the organic humid fraction of urban waste; from the whole vegetable compost made from gardening residues and from the compost obtained after aerobic digestion of a mixture of urban waste digestate, [...] Read more.
Soluble bio-based substances (SBS) may be isolated from the anaerobic digestate of the organic humid fraction of urban waste; from the whole vegetable compost made from gardening residues and from the compost obtained after aerobic digestion of a mixture of urban waste digestate, gardening residues and sewage sludge. These SBS can be used as sustainable and efficient plant biostimulants in alternatives to the commercial products based on fossil sources such as the Leonardite. The present review summarizes the main findings obtained from recent studies accomplished with the SBS applied on several ornamental (Euphorbia; Lantana; Murraya; Hibiscus) and vegetable species (tomato; red pepper; spinach; maize; bean; wheat; tobacco; oilseed rape) with the aim to evaluate their effect on plant growth; fruit and ornamental quality. The main results from these studies show that the non-commercial SBS are more efficient than commercial fossil-based products; at equal applied doses; in enhancing plant growth; leaf chlorophylls; photosynthetic activity; fruit ripening and yield and aesthetic effect; improving flower and fruit quality and optimizing water use efficiency. Depending upon the plant species, increases of the plant performance indicators ranging from zero to 1750% are reported for the plants cultivated in the presence of SBS, relatively to the control plants cultivated in absence of SBS added to the cultivation substrate. The review suggests that biowaste recycling is a sustainable and environmentally friendly source of plant biostimulants, as an alternative to existing fossil sourced agrochemicals. Full article
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