Search Results (29)

Climate change represents one of the most critical challenges, especially in the Mediterranean area. Using organic and localized fertilization could be an effective agroecological strategy to help mitigate the environmental impacts of climate change. Our study was carried out in an experimental field over a three-year crop succession including broccoli, sweet pepper and barley. A randomized complete block design was adopted, with two factors: (i) fertilization method (100% broadcast and 40% localized) and (ii) fertilizer type by testing: on-farm compost, two types of commercial compost and a mineral fertilizer. Environmental impacts per hectare and marketable yield were quantified using Life Cycle Assessment (LCA), considering abiotic depletion (AD), acidification (AA), eutrophication (EU), global warming potential (GWP), and photochemical oxidation (PO). The localized application of fertilizers achieved marketable yields comparable to the broadcast method, despite lower fertilizer inputs, suggesting an optimal nutrient-use efficiency. The LCA demonstrated that localized fertilization also enhanced environmental sustainability, decreasing Global Warming Potential (GWP) by 20% per hectare, compared to broadcast treatments. Moreover, considering only the fertilization phase, we observed a 59% reduction in GWP under the localized strategy. Even though localized fertilization emerges as an effective climate-smart strategy without compromising productivity, future research is recommended to assess its long-term impacts in site-specific conditions. Full article

The integration of different agroecological practices could significantly mitigate the impact of climate change. Therefore, a 2-year field experiment on organic zucchini was carried out to study the effects of clover (Trifolium alexandrinum L.) cover crop management (green manure, GM vs. flattening using a roller crimper, RC), compared to a control without cover (CT). This agroecological practice was tested in combination with the following different fertilizer treatments: T1. compost produced by co-composting coal mining wastes with municipal organic wastes compost plus urea; T2. compost produced with the same matrices as T1, replacing urea with lawn mowing residues; T3. non-composted mixture of the industrial matrices; T4. on-farm compost obtained from crop residues. The GM management showed the highest marketable yield and aboveground biomass of zucchini, with both values higher by approximately 38% than those recorded in CT. The T1, T2, and T3 treatments showed higher SOC values compared to T4 in both years, with a gradual increase in SOC over time. The residual effect of fertilization on SOC showed a smaller reduction in T3 and T4 than in T1 and T2, in comparison with the levels recorded during the fertilization years, indicating a higher persistence of the applied organic matter in these treatments. The findings of this study pointed out that combining organic fertilization and cover cropping is an effective agroecological practice to maintain adequate zucchini yields and enhance SOC levels in the Mediterranean environment. Full article

Despite growing interest in improving soil health on cocoa farms, applied research on the impacts of specific amendments on soil and plant outcomes is lacking. An integrated assessment of the impacts of two different organic amendments (compost and vermicompost) and a microbial biofertilizer on soil physical, chemical, and biological properties, as well as cocoa flowering, fruit set, and yield, was conducted in Guayaquil, Ecuador. Complementary culture-dependent and culture-independent methods were used to assess the impacts of amendments on microbial diversity, community composition, and specific taxa. Compost or vermicompost application affected soil chemical properties, including potassium, phosphorus, and sodium, and had small but significant effects on fungal beta diversity. Biofertilizer application slightly lowered soil pH and altered the total abundance of specific taxonomic groups including Azotobacter sp. and Trichoderma sp., with borderline significant effects on Azospirillum sp., Lactobacillus sp., Pseudomonas sp., calcium-solubilizing bacteria, and phosphorus-solubilizing bacteria. Amplicon sequencing (16S, ITS) identified 15 prokaryotic and 68 fungal taxa whose relative abundance was influenced by organic amendments or biofertilizer. Biofertilizer application increased cherelle formation by 19% and monthly harvestable pod counts by 11% despite no impact on flowering index or annual pod totals. This study highlights the tangible potential of microbiome optimization to simultaneously improve on-farm yield and achieve soil health goals on cocoa farms. Full article

As part of the European Green Deal, the Farm to Fork strategy was introduced with the idea that environment, agriculture and food are interconnected topics. Reducing the use of synthetic fertilizers by 20% before 2030 through the adoption of circular economy principles is one of the goals to be achieved. There are several bioproducts that can be obtained from the valorization of agro-industrial wastes used to increase crop yields under low-fertilizer applications. However, the aim of this review is to describe production methods and the use of compost tea on horticultural crops to understand its real potential in providing plant growth support. The effects of compost tea on crops can vary widely depending on the waste material used, compost quality, compost tea production process and parameters, and the interaction between horticultural species and compost tea application dose. Therefore, because of this heterogeneity, it is possible that we would achieve real, positive impacts on the environment and horticultural production if there were more collaboration between the research sector and private farms. This collaboration would allow the development of protocols for compost tea production and customized use according to real farm needs. This would reduce both the costs associated with the disposal of waste produced on the farm and reduce the costs associated with the supply of synthetic fertilizers. The adoption of on-farm guidelines for compost tea use would achieve a balanced trade-off between agricultural productivity and environmental sustainability. The literature review shows that the most-used dilution ratios, regardless of the type of starting compost, range from 1:5 to 1:10 compost–water (v/v). Although a complete understanding of the biostimulatory mechanisms activated by compost tea is lacking, the application of this bioproduct would improve the physiological and productive performance of many horticultural species of interest, especially under suboptimal conditions such as organic production. Full article

A compost program was developed on-farm, utilizing tree trimming biomass from a commercial pecan farm comprised of 14-year-old improved cultivar Western Schley pecan (Carya illinoinensis) tree stands. The direct soil application of shredded pecan tree biomass (P) and dairy manure (M) served as a standard on-farm practice. Three composts were produced using P and M with varying levels of other inputs and processing. The PM compost contained only P and M and its production included only weekly turning and watering. The other two composts included P, M, unfinished compost, and clay inputs, and either additional landscaping residues (A) (designated PM/A compost) or “green chop” (on-farm grown legumes, G) (designated PMG/A compost); production of PM/A and PMG/A composts included additional processing steps intended to improve compost quality per the recommendations of a compost consulting company. Soil samples were taken at three depths (0–15 cm, 15–30 cm, 30–61 cm) in November 2017 from the 1.3 ha study plot of trees. The standard practice and compost treatments were applied at approximately 18 t/ha in January 2018 and 2019 at a 15 cm depth. Soils were re-sampled at the end of the two-year study. Composts and soils were analyzed for: pH, sodium adsorption ratio (SAR), electrical conductivity, and total carbon, organic matter, magnesium, calcium, sodium, nitrate-N, total Kjeldahl nitrogen (TKN), available phosphorus, potassium, zinc, manganese, iron, and copper contents. Pecan tree leaf nutrient content, stem water potential, and leaf greenness were also measured one and two years after soil amendment application. While increases in several soil properties were observed with the treatments, only available phosphorus content was significantly different between pre and post at all depths. Electrical conductivity, TKN, Fe, Cu, SAR, and Na content showed significant differences in the upper soil layers. No differences in leaf properties were observed. This suggests that there are minimal differences in the outcomes for compost application compared to in-situ biomass application; additional compost inputs and processing did not provide additional short-term soil or plant benefits for pecan tree production. More work is needed to determine if there are long-term benefits to soil quality, plant health and performance, or carbon sequestration that impact the economic and environmental decision-making processes for composting and application of local organic wastes. Full article

Market gardening is a widespread practice of bio-intensive vegetable production characterized by direct marketing, small-scale farming structures, high crop densities, and innovative cultivation approaches. Currently, deep compost mulch (DCM) is a popular trend among related growing techniques. The combination of no-till and a permanent mulch of compost aims to improve soil fertility, regulate soil temperature, retain soil moisture, and control weeds. To address the problem of perennial weeds in organic no-till, deep mulch layers of typically 150 mm are used. The amount of compost required and the associated N inputs are immense and carry the risk of environmentally harmful N surpluses that can be lost through nitrate leaching or denitrification. The aim of this study is to evaluate the use of compost as mulch and to investigate N dynamics under DCM. For this purpose, a literature review was conducted, and soil inorganic nitrogen (N_min-N) was measured under on-farm conditions up to a soil depth of 900 mm in a market garden with DCM in Germany for one year. Furthermore, based on the collected data, the different N pathways were calculated using the N-Expert and NDICEA models and simulated for two additional scenarios. Results from field measurements showed a strongly increased N-surplus not taken up by the crops and a shift of N_min-N to deeper soil layers for municipal organic waste compost (MW), with an average accumulation of 466 kg N_min-N ha⁻¹ at 600–900 mm depth. N inputs from DCM can be significantly reduced by the use of green waste compost (GW) with low bulk density or wood waste compost (WW) with an additional high C/N ratio. Full article

Azolla spp. is a water fern that hosts Anabaena azolla, an N-fixing cyanobacterium, in its dorsal leaf cavities. Azolla occurs naturally in freshwater bodies in warm-temperate and tropical regions, and they have commonly been grown in rice paddies as a living fertilizer, providing N to the rice crop. We evaluated the potential use of Azolla harvested from freshwater bodies and applied as a biofertilizer to dryland vegetable crops. Two-thirds of the greenhouse gas emissions from crop production is attributed to N fertilizer, including fossil fuels used in fertilizer production and transportation. Azolla grown in on-farm ponds could remove CO₂ from the atmosphere and minimize the use of fossil fuels in fertilizer production and transport. A 140-d laboratory incubation was used to compare the N mineralization of Azolla biofertilizer with compost and cyanobacterial biofertilizer treatments. Azolla treatments had the greatest N availability at the end of the incubation (73.0%), with compost demonstrating the least N availability (15.5%), and the cyanobacterial biofertilizers moderate in N release (31.6%). A greenhouse study evaluated the N uptake and yield of kale (Brassica oleracea) receiving Azolla biofertilizer compared to urea and organic fertilizers. The nitrogen uptake by kale followed the same pattern as in the incubation study, with the Azolla treatments highest among the organic fertilizers, and urea the greatest overall. Compost yielded better than the control but was the lowest yielding among the fertilizer treatments. Finally, we compared the agronomic effect of Azolla biofertilizer with urea and manure applied at the same N rates to spinach (Amaranthus cruentus) and radish (Raphanus sativus) crops grown in the field on alluvial and peat soils. Fertilizer treatments affected the spinach yield at both locations but did not affect the radish yield. The manure treatment resulted in the highest spinach yields (18–27 t ha⁻¹), and the Azolla treatment applied at the same N rate as the manure yielded the same as the manure treatment on the peat soil and had the highest leaf and branch numbers. Azolla shows promise as a biofertilizer for dryland vegetable crops; however, an economic feasibility analysis is needed prior to encouraging the widespread adoption of on-farm Azolla production and use. Full article

On-farm composting of agro-livestock wastes can be considered the most appropriate method for their recycling. Pile turning (PW) is one of the most widely used aeration systems for composting. However, this system has long composting periods and is inefficient at supplying oxygen and controlling the temperature. To minimize these drawbacks, the combination of turnings with forced aeration (PR) is an option; in this work, this combination was compared to PW as an aeration system for the co-composting of vegetable waste with different manures. In this comparative study, the evolution of the process, the compost quality and the economic and environmental impacts of the process were evaluated. The PR system was more appropriate for obtaining sanitized composts (the temperature was ≥55 °C for at least three consecutive days) with an adequate degree of maturity. Furthermore, this system reduced the organic matter and nutrient losses, yielding composts with higher agronomic value and a higher total combined value of the nutrients than those obtained using the PW system. However, the energy consumption and associated CO₂ emissions were lower for the PW system, since this aeration system was based only on turnings without the use of forced aeration, as in the case of the PR system. Agricultural valorization of composts will offset this energy consumption and its impact, since it will contribute to reducing the use of synthetic fertilizers. However, more studies are required on the PR composting system and other agro-livestock wastes for the creation of centralized on-farm composting sites, where all steps of the composting chain are optimized. Full article

The management of municipal solid waste (MSW) and the reclamation of degraded sodic soils are two serious environmental and socio-economic problems experienced by the developing nations. To overcome these problems, a technology has been developed for the composting of MSW using earthworm and ligno-cellulolytic microbial consortia and its utilization for the sustainable reclamation of degraded sodic soils, as well as for harnessing their productivity potential. To standardize on-farm composting under aerobic conditions, the field experiment consisted of seven treatment combinations, replicated thrice with municipal solid waste (MSW) sole and in combination with agricultural wastes (AW) treated with earthworms (Eisenia foetida) and consortia of lingo-cellulolytic microbes such as Aspergillus spp., Trichoderma spp. and Bacillus spp. It was conducted at ICAR-CSSRI, Research farm, Shivri, Lucknow, India. The results revealed that the thermophilic phase was achieved at 60 days of composting and thereafter the temperature decreased. Marked changes in pH and EC were found and they changed from acidic to neutral. The reduction in total C, from initial to maturity, varied from 4.45 to 14.14% and the increase in total P and total K from 4.88 to 88.10% and 12.00 to 35.71%, respectively. The nutrient-rich quality compost based on the lowest C: N ratio, highest nutrient contents, microbial population (bacteria and fungi) and enzymatic activities was obtained from a mix of MSW and AW, enriched with earthworms and consortia of lingo-cellulolytic microbes. The efficacy of this enriched compost was evaluated for the reclamation of sodic soils and their potential for sustaining productivity of the rice-wheat cropping system was harnessed through combined application with a reduced dose of gypsum. The results indicated that the application of on-farm compost @10 t ha⁻¹ in conjunction with a reduced quantity of gypsum (25% GR) significantly (p < 0.05) improved the physico-chemical and microbial soil properties, and enhanced productivity of the rice-wheat cropping system over the use of only gypsum. This study proved that on-farm compost of MSW and its utilization for the reclamation of degraded sodic soils can be an alternate solution for useful disposal and management of MSW, thereby improving the health and productivity of sodic soils. Full article

Agriculture, and the related food systems, represents one of the sectors that use most of the available water resources and is responsible for a large part of the greenhouse gases increase in Earth’s atmosphere. The aim of the present research was to estimate the three dimensions of sustainability—identified by the 2030 Agenda—of the olive oil supply chain in a typical production area within Campania Region (South Italy), through the analysis of seven different olive oil systems: four certified as organic, two of which irrigated (BIO1, BIO2, BIO-IRR1, BIO-IRR2); two integrated (INT1, INT2); and one hobbyist (HOBB). The novelty of the research was the broad-spectrum sustainability evaluation of these systems, through the estimation of their water and carbon footprints, and some economic and social aspects, to classify them in sustainability classes. So, the Life Cycle Thinking approach was used to quantify the environmental impacts and the social issues, as well as the costs of production of 1 litre of packed oil produced. Environmental impacts were assessed thought the life cycle assessment methodology, with a focus on the global warming and the water footprint, using the SimaPro 9.0 software and Hoekstra methodology, respectively. The cost production evaluation was performed by the life cycle costing methodology, while a primordial approach of social sustainability estimation was built identifying the stakeholders involved and suitable impact categories. Results showed that, per litre of oil, HOBB and BIO2 were the systems that emitted less CO₂ eq (0.73 and 1.50 kg, respectively); BIO-IRR1 and BIO1 were the systems with the smallest water footprint (2.97 and 3.65 m³, respectively); HOBB and BIO1 were the systems with the lowest production costs (3.11 and 3.87 €, respectively). From a social point of view, INT1 and INT2 were the most pro-social systems. Overall, BIO1 was in absolute the most sustainable system under the various aspects considered. Hence the need to spread more and more (a) organic production methods, characterized by the use of self-produced fertilizers (on-farm compost); (b) more efficient machines use, for saving fuel; (c) balanced nitrogen fertilization to lower the water footprint. Full article

Increasing quantities of waste from using conventional plastic in agriculture and horticulture is one of the most pressing issues nowadays. Conventional plastic accessories (e.g., mulching films, clips, pots, strings, etc.) are typically fossil-derived, non-biodegradable and difficult to recycle after their use. Therefore, there is a need for biodegradable and bio-based alternatives with similar properties to conventional plastics, which can be disposed of through degradation in water, soil or compost under specific conditions. This work investigated the properties and the performance of biodegradable biochar-added and bio-based stem and arch support clips. In addition, the investigated clips were composted with tomato residues during 16 week laboratory composting. The scope of this work included: (1) the production of stem and arch support clips in a pilot installation using injection molding technology, (2) an analysis of their chemical composition, biodegradability, disintegration and phytotoxicity, (3) an evaluation of their performance in the greenhouse cultivation of tomatoes and (4) an evaluation of the composting of the clips with on-farm organic waste as an end-of-waste management method. The stem support clips during industrial composting (58 °C) degraded at 100% after 20 weeks, whereas during home composting (30 °C) the degradation was slow, and after 48 weeks the maximum weight loss was 5.43%. Disintegration during industrial composting resulted in 100% fragmentation into particles with sizes less than 2 mm. Phytotoxicity tests demonstrated that the substrates after industrial and home composting did not have a negative effect on the growth of the test plants (i.e., mustard, wheat, cuckooflower). The biochar-added stem support clips proved to be satisfactory alternatives to conventional non-biodegradable, fossil-derived clips and can be disposed of through composting. However, more work is needed to determine the optimal conditions for composting to ensure rapid degradation of the clips in relevant environments. Full article

Garden cress is a vegetable crop in the Brassicaceae family that is appreciated for its nutraceutical and taste-giving components in minimally processed food chains. Due to its very short cycle, which depends on the range of production from microgreens to baby-leaf vegetables, this crop is threatened by soil-borne pathologies developing within the initial stages of germination and emergence. This study aims to evaluate the suppressive bio-compost as an innovative means to counteract the main telluric diseases of garden cress and reduce the risks of yield loss by adopting sustainable remedies and decreasing the dependence on synthetic fungicides. Therefore, eleven green composts obtained using both previously distilled and raw aromatic plant residues were analyzed for suppressive properties against Rhizoctonia solani and Sclerotinia sclerotiorum on sown garden cress. The biological active component of the composts, detected by CO₂-release, FDA-hydrolysis and microbial counts, proved to be indispensable for pathogen control in vitro and in vivo, as demonstrated by the loss of suppressiveness after sterilization. Cross-polarization magic angle spinning ¹³C-nuclear magnetic resonance (CP-MAS-¹³C-NMR) was used to analyze the molecular distribution of organic C in composts. The results indicated the suitability of the feedstock used to make quality compost. The suppression levels shown by composts P1 (40% wood chips, 30% escarole and 30% a mixture of sage, basil, mint and parsley) and P2 (40% wood chips, 30% escarole and 30% a mixture of essential oil-free sage, basil and rosemary) are promising for the sustainable, non-chemical production of garden cress vegetables. Full article

Compost amendment is a widespread agronomic practice, but little information is available about the short- and medium-term effects on clay soils. In this investigation, we selected three soil compost rates (treatments, T), i.e., fertilizer (T2 = 1.5 kg m⁻²), amending (T3 = 15 kg m⁻²), and organic (T4 = 75 kg m⁻²), that were compared to a control (T1). Our research accounts for the effects reached on representative large boxes (about 0.75 m³), without crops and for about eighteen months. An overall assessment of the physical and hydraulic properties of the soil was made, including infiltration rate or saturated hydraulic conductivity (K_s), water content and water retention (θ) of the soil, bulk density and structure, and several physical quality indicators obtained from the water retention curve, accounting for the optimal balance between water/air into the soil, pore volume distribution function, and soil features in the inflection point of the soil water retention curve. Additionally, the temporal changes of K_s were evaluated. The main results showed that (i) after eighteen months, and regardless of T, θ significantly improved by a factor of 1.2–1.3, but these improvements (up to 1%) were detected only close to water saturation (i.e., until 6 cm of soil pressure head) when little (T2) or no compost (T1) addition was considered, while a larger range was detected (until 60 cm) when higher rates (T3–T4) were used; (ii) K_s determination allowed to establish that compost effects vanished after about eleven months, but it was not possible to verify that composting increased the permeability of the investigated clay soil within that time frame; (iii) some significant correlations between K_s and some soil physical indicators estimated from both the inflection point of the water retention curve or bulk density suggested possible improvements in soil permeability. Because some factors (water content of the soil above all) could have affected the comparison of K_s measurements, further research on this topic is needed. Full article

The perceived variability of plastic soil-biodegradable mulch (BDM) degradation has generated concerns about its functionality and sustainability, especially in climates and regions where biodegradation may be limited. This study evaluated the effects of surface-applied products (compost tea, dairy-based compost, humic and acetic acids) on the surface deterioration and visible degradation of three plastic BDMs (BASF 0.6, Novamont 0.6, and Novamont 0.7) and one cellulose paper mulch (WeedGuard Plus) in a Mediterranean climate. Deterioration was monitored for 10 months, and degradation was evaluated 6- and 12 months following soil incorporation. Deterioration varied between the two years of the study; however, the average deterioration for WeedGuard Plus reached 100%, BASF 0.6 and Novamont 0.6 achieved ≥80%, while Novamont 0.7 reached ≥70%. Application of humic and acetic acids increased BASF 0.6 deterioration, but only humic acid increased Novamont 0.7 deterioration. Scanning electron microscopy of mulch surfaces demonstrated evidence of microbial colonization; however, the surface-applied products did not enhance microbial counts. In-soil degradation of BDMs was inconsistent, but faster degradation occurred overall for starch- and polybutylene adipate-co-terephthalate (PBAT)-based BDMs. Future studies should continue to explore on-farm strategies to enhance in-soil degradation to meet the production system’s goals. Full article

Green agro waste can be turned into compost, which can then be used as an organic fertilizer, thus reducing the environmental impact of food and feed production. This research is focused on finding a feasible on-farm composting treatment of plant biomass to produce high-quality compost. Three different composting treatments were prepared and followed (with different additives at the start—biochar (BC) and effective microorganisms (EM), no additive (CON); covering and not covering the pile; different start particles size). Samples were analysed for nutrient concentrations, phytotoxicity and bacterial and fungal presence after seven months of composting. In 100 g of dry matter, the average compost contained 2.7 g, 0.38 g and 1.08 g of N, P and K, respectively. All investigated treatments contained more than 2% of total nitrogen in dry mass, so they could be used as a fertilizer. The highest nutrient content was observed in compost of small particle size (˂5 cm) and added biochar (11 kg/t fresh biomass). However, this compost had the least bacteria and fungi due to very high temperatures in the thermophilic phase of this pile. According to the radish germination index, the prepared composts have no phytotoxic properties and are stable and ready to use in plant production. Taking the cress germination test into consideration, they provided a nutrient-rich and biostimulative soil amendment. All three final composts were stable in terms of respiration rate, growth and germination tests. Results have shown that hop biomass after harvest has great potential for composting. Full article