Organic Vegetable Production Research Articles

Sustainability and Strategic Positioning in Hydroponic Production

Objective: This study analyzes the strategic positioning of a family farming company, exploring intersections in support of the certification process for the organic production of leafy vegetables. Theoretical Framework: We adopt a qualitative approach to achieve the objective through a case study on a farm in Minas Gerais/Brazil. We present details on hydroponics, the sustainability tripod, and strategic planning. Method: We presented an analysis of strategic planning. We applied case studies and bibliographic research. We employed a qualitative approach based on information obtained through interviews and in-loco observations. Results and Discussion: The results present the analysis of the SWOT matrix that compares the internal conditions of the organization with market conditions. The results highlighted the potential of the company under investigation. The offensive capacity demonstrates excellent conditions for taking advantage of opportunities. The defensive capacity reported the vulnerability to repel threats. Research Implications: This case study highlights the potential of analyzing strategic positioning. By applying the SWOT matrix and calculating strategic positioning, a significant positive value that attests to the offensive capacity in relation to the external environment was observed. Originality/Value: This study discusses the applicability of strategic positioning analysis for hydroponic companie sthrough sustainability actions. The interest in this product is widely known and highlights the relevance of studies to foster the evolution of strategic management in this segment.

Biodegradable plastic film mulch increases the mineralisation of organic amendments and prevents nitrate leaching during the growing season in organic vegetable production

AbstractIntroductionOrganic vegetable production relies on inputs of organic forms of nitrogen (N). This presents a challenge as it needs to be mineralised by the soil microbial community. Difficulties matching the timing and rate of organic N amendments to crop demand could potentially lead to high rates of nitrate leaching. The use of plastic film mulch (PFM) has the potential to increase crop yield, accelerate N mineralisation, reduce rainfall infiltration and therefore N leaching. Biodegradable PFM reduces the risk of contaminating soil with plastics. Although these positive effects have been proven in major conventionally grown commodity crops, the effects of PFMs are poorly understood in organic vegetable crops, particularly in moist temperate climates prone to N losses via winter leaching.Materials & MethodsOur plot‐scale field experiment attempted to quantify the effect of biodegradable PFM on N leaching and N mineralisation in organic lettuce production in the presence and absence of biodegradable PFM. It took place in one season within a longer‐term experimental organic vegetable rotation.ResultsWe used two methods to measure the rate of carbon and N mineralisation: the buried bag method showed biodegradable PFM resulted in no additional N mineralisation; however, the ion exchange membrane method indicated an increase in N mineralisation of 30%. During heavy rainfall at the end of the growing season, nitrate leaching was observed only in the non‐PFM plots, leading to N losses equivalent to 6.3 g N m−2. This led to surplus mineral N at harvest of 18.1 g N m−2 in the PFM treatment and 8.6 g N m−2 in the corresponding unmulched plots. This did not lead to more leaching in the mulched plots in the following 6 months.ConclusionIn conclusion, our evidence supports the use of biodegradable PFMs to enhance the sustainability of organic vegetable production systems in temperate climates.

Mechanical Inter- and Intra-Row Weed Control for Small-Scale Vegetable Producers

Small-scale vegetable producers often do not have modern mechanical equipment; as a result, a significant amount of inter-row and all intra-row weeding is performed manually. The development of small, affordable machines increases the competitiveness of organic vegetable production, improves sustainable land use, and reduces dependence on unwanted herbicides. In this study, a simple modular lightweight e-hoe with the capability for both inter-row (1st degree of freedom) and intra-row (2nd degree of freedom) weeding was proposed. The e-hoe uses battery-powered in-wheel drives to move the platform (3rd degree of freedom) and additional drives to operate the tools. The e-hoe was evaluated in a small greenhouse using three different tools: a traditional hoe, an adjusted rounded hoe, and an adjusted spring tine narrow hoe. The experiments were conducted at four different tool rotation speeds, using specially designed 3D-printed models for crops and weeds for evaluation. The results indicate that the efficiency of the e-hoe rates up to 95% when the right tool design and rotation speed are combined. Based on the battery capacity, the machine can be operated for approximately 3.7 h, enabling the weeding of about 3050 plants.

Effect of Organic Granules on the Productivity, Quality, and Nutrient Uptake Level of Tomato and the Fertility and Microbial Population of the Soil

Organic vegetable production is needed worldwide to minimize the use of inorganic fertilizers, protect the environment, and produce healthy food. Accordingly, in the present study, the effects of organic granules on the productivity, quality, and nutrient uptake level of tomatoes and the fertility and microbial population of the soil were determined. Briefly, organic NPK granules and organic N, P and K-rich sources were compared with synthetic NPK granules and synthetic fertilizers administered at 100 and 75% of the recommended fertilizer levels. Among the various treatments applied, treatment with 100% of the recommended NPK using the synthetic NPK granules (Urea, DAP and MOP) led to higher growth, yield attributes, and yield (fruit yield, – 24.21 t/ha and stover yield, -15.01 t/ha) of tomato. This treatment also enhanced the nutrient uptake by tomato. However, quality parameters, such as total soluble solids (6.64% ), titrable acidity (0.62% ), ascorbic acid content (14.31 mg/100 g), lycopene content (3.54 mg/100 g), reducing sugars (3.11%), non-reducing sugars (1.02%), total sugar (4.13% ), and shelf life (15.76 days ) of tomato were higher with 100% of the recommended NPK from organic NPK granules than from synthetic granules. This treatment also enhanced the available nutrients and microbial population in the soil. Notably, the same trend was observed for tomatoes fertilized with 75 % of the recommended NPK. The lowest values were obtained with the absolute control. Based on the results of this experiment, the application of 100% of the recommended NPK using organic NPK granules is the best approach to improve the quality of tomato fruits and to enhance the soil fertility.

Phacelia and Buckwheat Cover Crops’ Effects on Soil Quality in Organic Vegetable Production in a High Tunnel System

Cover crops (CCs) are regarded as beneficial to agricultural practice as an option for soil quality improvement in field production systems. The main goal of this study was to assess the impact of spring phacelia (Phacelia tanacetifolia Benth.) and buckwheat (Fagopyrum Mill.) in a crop rotation (CC–leek–parsley, 2020–2021) on the physicochemical and biological properties of the soil in an organic high tunnel system. Soil analyses involved measurements of bulk density, water capacity, soil aggregation, soil organic carbon (SOC), available soil nutrients, as well as microbial abundance and diversity. Phacelia generated more aboveground biomass (58.2 t fresh matter ha−1) than buckwheat (33.0 t ha−1), and their biomass contained 161 kg N ha−1 and 67 kg N ha−1, respectively. A large quantity of elements, such as N, Ca, P, S, B, and Cu, were found in phacelia biomass. More Mg and Na were found in buckwheat plants. The results showed that CC biomass significantly improved some of the soil physical and chemical properties, such as soil organic carbon stock and wet aggregate stability, and decreased soil bulk density. Cover crop treatments changed the dynamics of soil bacterial and fungus populations in a high tunnel system. Phacelia increased the quantity of ammonifiers and nitrifiers in the soil substantially. Further research with a long-term focus is needed to assess the impact of cover crops on soil properties, soil quality, and subsequent crop yields in high tunnel crop rotation and management systems.

Bauran Pemasaran Komoditi Pakcoy Hijau Organik Di PT. Orgo Organic Farm Indonesia

PT Orgo Organic Farm Indonesia, located in Malang City, is a company specializing in organic vegetable production. To cope with increasing competition in the market, PT Orgo Organic Farm Indonesia needs to establish the right marketing mix strategy to boost sales. The aim of this journal article is to identify the company's internal and external conditions and analyze the marketing mix strategy implemented. The method used to describe internal and external conditions and analyze the marketing mix is descriptive method. Based on the analysis, it can be concluded that: (1) The external and internal conditions of PT Orgo Organic Farm Indonesia highlight the advantages of organic vegetable products with various benefits, but also indicate shortcomings such as incomplete product packaging, less intensive promotion, and suboptimal transportation infrastructure. (2) The marketing mix strategy implemented to increase product sales includes focusing on production development with emphasis on quantity, quality, and continuity (3K), developing the "GOGRIN" brand, pricing according to Cost of Goods Sold (COGS), distribution through direct distribution channels and retailers, and promotion through word of mouth, participation in bazaars, and utilization of social media

STRATEGI BAURAN PEMASARAN 7P DI CV. TANI ORGANIK MERAPI (TOM), KECAMATAN WUKISARI, KABUPATEN SLEMAN

This research discusses the implementation of the 7P marketing mix strategy at CV. Tani Organik Merapi is a company operating in the field of organic agriculture. This research also identifies the 7P marketing mix which includes product, price, promotion, place, people, process, and physical evidence, and how it is applied in the context of an organic farming company. This research aims to be able to analyze the SWOT to formulate an effective marketing strategy. The research results show that internal and external factors can influence a company, including strengths, weaknesses, opportunities and threats. This research method uses a mixed method by carrying out a research approach that combines quantitative and qualitative data analysis to obtain more comprehensive and accurate results. The analysis results show that CV's 7P marketing mix strategy. Merapi Organic Farming shows success in several aspects but requires improvement in the Promotion aspect. By using SWOT analysis, CV. Merapi Organic Farmers can develop 12 alternative strategies to improve performance and success in marketing organic vegetable products."

Improving marketable yield and phytochemical characteristics of N-fertilized tomato fruits with soil organic amendments through Azolla

ABSTRACT There is a growing demand for organic vegetable products. Increasing the marketable yield and quality of tomatoes through the use of optimal organic and inorganic fertilizers is a critical agronomic measure for crop productivity and soil health. However, little is known about the effects of Azolla on tomato productivity, fruit quality and soil organic changes. The aim of this study was to compare the effects of organic and inorganic fertilization on marketable yield and quality characteristics of tomato fruits. A pot experiment was conducted with four concentrations of Azolla and nitrogen in a completely randomized design. The results showed that Azolla has the potential to replace nitrogen and has a significant impact on fruit quality. The interactions of Azolla and nitrogen on the number of clusters per plant, the number of flowers per cluster, the proportion of fruit set, the number of fruits per cluster and the marketable fruit yield were significant. It can be concluded that the combination of Azolla and inorganic nitrogen fertilizer linearly increased the marketable yield and quality of tomato fruits.

Weed control, soil health, and yield tradeoffs of between-bed management strategies in organic plasticulture vegetable production

Planting a cover crop living mulch between plastic mulch beds in fresh market vegetable production can reduce soil erosion and runoff, and offers an opportunity to grow an income generating cash crop alongside a soil building cover crop. However, potential negative impacts on yield, variable weed control, unclear impacts on soil health, and limited management recommendations challenge adoption of this practice, despite grower interest. In a two-year study in southwest Michigan, living mulches were evaluated in the production of plasticulture organic summer squash (Cucurbita pepo cv. Lioness) and bell pepper (Capsicum annuum cv. Paladin). Strategies evaluated included three common grower practices (cultivation, dead straw mulch, mowing ambient weeds) and three mowed living mulch treatments (Italian ryegrass [Lolium multiflorum] monoculture, rye [Secale cereale] monoculture, and a Dutch white clover [Trifolium repens]/rye mixture). We determined the impact of these strategies on weed control, organic matter inputs, vegetable crop performance, nitrogen retention, and soil microbial communities. We found that cultivation and dead mulch provided superior in-season weed control, reducing weed biomass by an average of 86% compared to 18% among living mulch treatments, with associated reductions in the weed seedbank compared to living mulches and mowed weeds. In most cases, living mulch establishment was a challenge and weed biomass on average accounted for 99, 74, and 94% of organic matter inputs in rye, ryegrass, and clover/rye treatments, respectively. Squash performance was unaffected by our treatments, but pepper yield reductions ranged from 41 to 54% in all treatments relative to cultivation in one of two years. Living mulches and the weedy treatment showed the ability to reduce end-of-season potentially leachable nitrogen by 61% compared to cultivation and dead mulching. Soil microbial abundance and functional diversity were similar across treatments, but extracellular enzyme activity was higher in dead mulch, living mulch and weedy treatments compared to cultivation. Results from this study help quantify tradeoffs between common grower practices for managing weeds and soil between plastic mulch beds, highlight key challenges with living mulch alternatives, and identify areas for future research.

Evaluating the Soil Block Method and Growing Media in Organic Vegetable Transplant Production

Organic vegetable growers are interested in using the “soil block” method for transplant production as an alternative to plastic flats. The soil block method compresses growing media into a freestanding block in contrast to the cells of a plastic flat. Anecdotal evidence of soil block–grown transplants with increased vigor and root development exists, but limited research has been conducted to evaluate these claims. Furthermore, identifying commercial growing medium for certified organic transplant production is needed. The objective of this study was to compare growth parameters and root development of cucumber (Cucumis sativus) and pepper (Capsicum annum) transplants grown in soil blocks and plastic flats, in combination with four commercially available certified organic media (Beautiful Land Products “Soil Blocking Mix,” Purple Cow Organics “Seed Starter Mix,” Cowsmo “Green Potting Soil,” and Vermont Compost Company “Fort Vee”). A volume-based 50% peat, 25% compost, 12.5% perlite, and 12.5% vermiculite growing medium was also evaluated. A split-plot randomized complete block design with four replications was used with growing method as the whole plot factor and medium as the subplot factor. ‘Marketmore 76’ cucumbers and ‘Yankee Bell’ peppers were seeded in 50-cell flats and soil blocks made with Johnny’s Selected Seeds Stand-up 12 Soil Blocker. Data were collected on growth parameters by destructively sampling cucumbers 3 weeks after seeding, and peppers 5, 6, and 7 weeks after seeding. Root development was evaluated using WinRHIZOTM at the last sampling. Cucumber and pepper transplants performed differently in soil blocks and flats. Cucumbers grown in flats had a significantly greater dry weight than those grown in soil blocks, by 20% in 2022 and by 38% in 2023. In contrast, pepper transplants grown with the soil block method had between 50% and 130% greater dry weight in the final sampling in 2022. Cucumber and pepper transplants grown with Cowsmo “Green Potting Soil” performed poorly, with an up to 144% lower dry weight and up to 167% lower root surface area than transplants grown with the other media. Root development correlated with shoot development, without a specific advantage in soil blocks, although differences in root system architecture should be investigated. The evaluated Beautiful Land Products, Purple Cow Organics, and Vermont Compost Company media can all be considered suitable for growing certified organic vegetable transplants in both soil blocks and flats. Further research is warranted to better optimize the soil block technique, investigate optimum soil block bulk density, and inform growers of appropriate commercially available certified organic growing media for organic vegetable transplant production.

A soil health assessment tool for vegetable cropping systems in tropical soils based on beta-glucosidase, arylsulfatase, and soil organic carbon

Vegetable production is characterized by a strong dependence on external inputs and intense tillage, which can harm soil health (SH) by reducing organic matter levels, soil biota diversity, and overall ecosystem functions. Tools to assess SH affected by organic and conventional vegetable production systems are crucial and still scarce. This study aimed to develop a practical and reliable SH assessment tool for vegetable production systems in tropical soils by integrating Cornell's Comprehensive Assessment of Soil Health (CASH) with the four-quadrant model (4QM). Furthermore, the study evaluated the relationship between management practices and SH status. Arylsulfatase (ARYL) and β-glucosidase (GLU) activities, and soil organic carbon (SOC) were analyzed in 90 soil samples (0 to 10 cm depth) collected from 53 organic and conventional vegetable farms in the Federal District, Brazil. The adoption of practices aimed at improving or maintaining SH was significantly greater on organic farms than on conventionally managed farms, resulting in a SOC content and ARYL activity 27 % and 86 % higher in organic farms than in conventional systems, respectively (P < 0.05). ARYL proved to be more accurate in separating organic and conventional fields than GLU, highlighting its potential for SH evaluation in vegetable production systems. The integration of CASH and the 4QM, along with ARYL, GLU, and SOC measurements, effectively addressed the complexity of both organic and conventional vegetable production systems. This combined approach facilitated differentiation between systems based on varying levels of adoption of best management practices (BMPs). Further research is needed to assess the performance of this approach across different soil types and regions where vegetables are cultivated.

Development of a Bio-Fertilizer Machine (Holmon Egg) Integrated with NPK Sensor Technology for Enhancing Organic Vegetable Production in Sufficiency Community Enterprises

Development of a Bio-Fertilizer Machine (Holmon Egg) Integrated with NPK Sensor Technology for Enhancing Organic Vegetable Production in Sufficiency Community Enterprises

No-till system organic vegetable production under green manure: effect on yield and soil properties

No-till system organic vegetable production under green manure: effect on yield and soil properties

Analisis Faktor Pribadi Konsumen sebagai Pengaruh Perilaku Belanja Daring Produk Sayur Organik melalui Platform Digital Marketing

This research aims to analyze the influence of consumer personal factors which include gender, age, education, finances, and employment on buying interest and factual purchases of organic vegetables as well as analyzing the organic vegetable market segment by examining the characteristics of consumers who buy organic vegetables online in Palembang to become as a recommendation for marketing strategies for organic vegetables. The subjects were consumers who bought organic vegetables online at 20 shops that provided online purchases which was 200 respondents in total. The analytical method is K-Means Cluster analysis with the help of the SPPS 27 program and PLS 3.2 Structural Equation Modeling (SEM) analysis. The results show that there is a significant or positive influence of age, education, financial and employment factors on personal factors, and overall personal factors have a significant influence on purchase intention and factual purchases. The consumer market segmentation for organic vegetable products is consumers in productive age, 21 to 60 years old, highly educated, and work as private employees, entrepreneurs, and civil servants and from Palembangese, Javanese, Sundanese, and Malay origins, having a total income of IDR. 2–5 million in range. Moreover, this research is expected to be applied by online organic vegetable sellers to reach bigger market especially to those located in Palembang.

Status quo of fertilization strategies and nutrient farm gate budgets on stockless organic vegetable farms in Germany

Fertilizer management in stockless organic vegetable production is strongly affected by external nutrient purchases due to the high nitrogen (N) and potassium (K) requirements of vegetables. However, the database on nutrient flows and budgets in organic vegetable farming in Europe is very limited. Therefore, a survey based on semi-structured interviews was carried out comprising 12 organic horticultural farms in Germany. The results show that three different main fertilizer categories are used as inputs in different ratios by the inventoried farms: (1) base fertilizers (e.g., composts, solid farmyard manures), (2) commercial organic N fertilizers (e.g., keratins or plant products from food production or fermentation processes), and (3) commercial mineral fertilizers (e.g., potassium sulfate), all of which are approved for organic production. Ninety percent of the total nutrient inputs to the farms came from these fertilizers and biological N2 fixation, with the remaining 10% coming from other inputs, such as seeds or growing media. The estimated yearly average total farm budgets were nearly balanced across all farms with moderate surpluses (67.5 kg N ha−1, 2.06 kg P ha−1, and 0.26 kg K ha−1). However, large imbalances were found for most of the individual farms. These imbalances indicate the risk of nutrient accumulation or nutrient depletion in the soil, depending on the fertilization strategy and productivity of the farm. More specifically, increasing N share from base fertilizers led to increased P and K budgets, while strategies based on the use of large amounts of keratins led to the opposite—K and P depletion. We concluded that balanced nutrient management in organic vegetable production systems requires a thorough calculation and should combine the use of base fertilizers, commercial fertilizers with low P content, and increased N supply via BNF.

PENDAMPINGAN PENGEMASAN DAN PEMASARAN PRODUK SAYURAN ORGANIK DAN BUDIDAYA LELE SECARA AQUAPONIK DI YAYASAN HARAPANKU KOTA CIREBON

Harapanku Foundation is one of the Lecturer and Student ecosystems at Catur Insan Cirebon Cendekia University in carrying out Community Service (PkM) activities. The address of this foundation is Jalan Pekalangan No.74, Pekalipan District, Cirebon City. Harapanku Foundation is engaged in the social sector by empowering children with disabilities (with special needs) to produce organic vegetable products and aquaponic catfish farming. This Community Service (PkM) aims to provide knowledge and skills in packaging and marketing products made by children with disabilities (with special needs) at the Harapanku Foundation, Cirebon City. The PkM activity method consists of presentations, demonstrations, and individual and group practice. Community Service (PkM) can provide positive benefits for Harapanku Foundation managers in Cirebon City, because products in the form of organic vegetables and catfish can be marketed in good packaging. The results of this PkM activity greatly motivated children with disabilities and Harapanku Foundation administrators in carrying out marketing and packaging activities for organic vegetable and catfish products.

Presence of foodborne pathogens and survival of generic Escherichia coli in an organic integrated crop-livestock system

IntroductionIntegrated crop-livestock systems (ICLS) use animals to graze crop residues or cover crops before planting fresh produce and provide ecosystem services to support organic vegetable production. However, there is a risk of foodborne pathogen transfer to fresh produce because grazing may introduce enteric foodborne pathogens into the soil via animal feces, which may subsequently be transferred to the produce.MethodsTo examine the effect of cover crop use and the risk of cover crop grazing on the contamination of soil and produce by foodborne pathogens in ICLS, a three-year (2019–2021) experimental study was conducted in organically managed plots, which were assigned three different treatments (fallow without cover crop or grazing, cover crop without grazing, or cover crop with grazing by sheep) in a maize/tomato rotation. During the three years of the experiment, a total of 184 pre- and post-graze fecal samples and 96 samples of tomatoes were collected to test for foodborne pathogens (Escherichia coli O157, non-O157 Shiga toxin-producing Escherichia coli (STEC), and Listeria (L.) monocytogenes). Soil samples were collected monthly until 126–171 days after grazing (824 in total) to examine the presence of foodborne pathogens, and generic E. coli (MPN/g) was quantified to compare its persistence among the three treatments.Results and DiscussionWe did not detect any foodborne pathogens from harvested tomatoes in 2020 and 2021. One non-O157 STEC positive soil sample (0.1%, 1/824) was detected in the fallow treatment, and one L. monocytogenes-positive (1.1%, 1/92) was detected from the post-graze fecal samples. When assessing proportions of generic E. coli positive and counts of generic E. coli in the soil samples using mixed effect zero-inflated negative binomial models, soil samples collected in the graze cover crop treatment plot showed significant increases in the counts of generic E. coli until 61–82 days post grazing, but no difference was observed after 96–123 days, compared to the baseline of the fallow treatment. Findings from generic E. coli counts support the use of the United States Department of Agriculture (USDA) National Organic Program (NOP) 90- or 120-day interval rule between applying raw manure and harvesting in organic farming into ICLS. Additionally, we confirmed that commercial organic compost application before cover crop seeding in the winter had no significant effect on the proportions and counts of generic E. coli in the soil of the following growing seasons. This longitudinal field trial confirmed that the effect of sheep grazing on foodborne pathogen contamination in ICLS is minimal but further studies comparing the genetic associations between fecal and soil samples would be necessary to distinguish the source of foodborne pathogen contamination.

Environmental impacts and potential mitigation options for organic open-field vegetable production in Denmark assessed through life cycle assessment

A shift in food intake towards more plant-based options such as vegetables is emphasised for lowering the environmental impact of food consumption, and organic farming is promoted as a tool to meet European policy goals related to sustainability, environment and biodiversity. However, the current environmental impact of organic vegetable production is not well explored. Here we address the knowledge gap of environmental impacts from organic vegetable production in a life cycle perspective, locate primary impact sources and investigate potential mitigation option scenarios. The assessment focussed on pointed cabbage, cos lettuce and yellow onion in a mixed crop rotation, as common under commercial Danish conditions, and include estimation of soil carbon (C) and nitrogen (N) pools. The system boundary was set from cradle to farm gate, and included inputs to cultivation, soil C and N dynamics in the crop rotation, post-harvest cooling, packaging and storage. The data for modelling was collected from growers, consultants and the scientific literature. We report estimated global warming potential, marine eutrophication potential, land use, water consumption, mineral and fossil resource scarcity and cumulative energy demand from production. The analysis shows that environmental impacts stemmed from several activities dependent on the crop-specific characteristics of production. For summer-grown pointed cabbage, nitrous oxide emissions from high amounts of fertiliser and crop residue was responsible for 40 % of climate impacts, for cos lettuce the production of seedlings with peat as a substrate was responsible for 40 % of climate impact, and for transplanted yellow onion the post-harvest drying and storage was responsible for 27 % of climate impacts. The identified major mitigation options were an increase in harvest shares of hand-harvested vegetable crops, lower post-harvest loss from onion storage, optimised residue management and substitution of peat as substrate for seedling production. These are promising avenues for lower environmental impact.

Influence of Soil Type and Temperature on Nitrogen Mineralization from Organic Fertilizers

Organic vegetable producers in Georgia, USA, utilize a range of amendments to supply nitrogen (N) for crop production. However, differences in soil type, fertilizers and environmental conditions can result in variability in N mineralization rates among commonly utilized organic fertilizers in the region. In this study, the effects of temperature on N mineralization from three commercial organic fertilizers [feather meal (FM), pelleted poultry litter (PPL) and a mixed organic fertilizer (MIX)] in two soil types from Georgia, USA (Cecil sandy clay loam and Tifton loamy sand) were evaluated for 120 d. Net N mineralization (Net Nmin) varied with soil type, fertilizer and temperature. After 120 d, Net Nmin from the FM fertilizer ranged between 41% and 77% of total organic N applied, the MIX fertilizer ranged between 26% and 59% and the PPL fertilizer ranged between 0% and 22% across all soil types and temperatures. Incubation at higher temperatures (20 °C and 30 °C) impacted Net Nmin of FM fertilizer in the Tifton series soil. Temperature and soil type had a relatively minor impact on the potentially mineralizable N of the PPL and MIX fertilizers after 120 d of incubation; however, both factors impacted the rate of fertilizer release shortly after application, which could impact the synchronicity of N availability and plant uptake. Temperature-related differences in the mineralization of organic fertilizers may not be large enough to influence a grower’s decisions regarding N fertilizer inputs for vegetable crop production in the two soils. However, organic fertilizer source will likely play a significant role in N availability during the cropping season.

Comparison of cover crop termination methods for small-scale organic vegetable production: effect on soil fertility and health

Termination methods and the timing of the termination of the cover crops are critical factors determining the efficacy of cover crops in improving soil fertility and quality. We hypothesized that different termination methods will produce varying quantities of organic residue which will affect microbial diversity and thereby nutrient cycling and availability. The objective of this study was to compare termination methods (roller-crimper, flail mowing, rotary mowing, sickle bar mowing, and occultation using black tarps) for fall-grown cover crop combination (hairy vetch-cereal rye) under organic vegetable production. Field experiments were carried out in three consecutive years (2018–2021) and soil samples were collected from 0 to 15 cm and processed for analysis. Soil organic matter content, nutrients, health parameters, enzymes, and microbial diversity were measured. Flail mowing significantly enhanced the potentially mineralizable nitrogen, available phosphorus, and active carbon. Total Phospholipid Fatty Acid (PLFA) analysis showed a 24% increase for flail mowed, 17% for rotary mowed, and 15% for sickle bar mowed termination methods. There was a significant increase in active carbon content which ranged from 38.9% (rotary mowed), 25.4% (sickle bar mowed), 23.5% (flail mowed), 16.4% for crimper rolled method, and with 2.8% (occultation) respectively. Individual termination methods had varying effects on select enzyme activities. Results indicated that integrating cover crops has the potential to modify soil microbial community structure and increase soil enzyme activities. In this study, flail mowing appeared to be a good method for managing cover crops of choice in terms of soil microbial functionality and fertility.