Fertilizer Amendments Research Articles

Synergistic use of cattle bile, compost and fertilizer amendments in enhancing the bioremediation of hydrocarbon-contaminated soils

This study investigated the degradation of hydrocarbon-contaminated soil using compost, NPK 20:10:10 fertilizer, and cattle bile as biostimulants. In this study, 1000 g of homogenized contaminated soil was amended with 10.50 g of NPK fertilizer and 107.50 g of compost to achieve a nitrogen concentration of 0.2 %. To establish a 0.4 % nitrogen concentration, 23.90 g of NPK fertilizer, 243.54 g of compost, and 2 ml of cattle bile were used. These amendments were applied in various combinations to create the following microcosm treatments: A, B, C, D, A2, B2, C2, D2, and a control. The microcosms, along with the control were incubated for 6 weeks in triplicate. Throughout this period, several parameters were monitored every two weeks, including pH, nitrogen (N), potassium (K), phosphorus (P), moisture content, organic carbon, organic matter, total heterotrophic bacterial count (THBC), and total petroleum hydrocarbon (TPH) concentration. The results showed significant differences (p < 0.05) in TPH content across the microcosms during the four sampling periods. By the end of the 6-week incubation, the TPH residual concentration varied between 1.58 mg kg-1 and 20.61 mg kg-1, corresponding to degradation rates of 98.43 % and 79.58 %, respectively, from an initial TPH concentration of 100.91 mg kg-1. Microcosm B2 demonstrated the highest hydrocarbon removal efficiency (98.43 %), while the control showed the lowest efficiency. The order of degradation efficiency among the microcosms was B2 > B (94.89 %) > C (94.64 %) > A (94.13 %) > D2 (93.62 %) > A2 (93.51 %) > C2 (92.45 %) > D (91.44 %). The study also found that pH and nitrogen levels were related to the reduction in hydrocarbon content. Microcosms with a 0.4 % nitrogen concentration showed a higher rate of nitrogen consumption compared to those with a 0.2 % concentration. Additionally, changes in pH were observed as hydrocarbon degradation progressed. This study further applied cluster analysis, Bayesian statistics, and multiple linear regression to evaluate the effects of treatments on soil quality over time. Cluster analysis showed increasing dissimilarity between merged clusters, while Bayesian analysis revealed positive trends in parameter estimates in Weeks 2 and 4. Regression analysis indicated significant impacts of Weeks 2, 4, and 6 on Week 0, with F-statistics of 8.475 (p = 0.016), 9.804 (p = 0.004), and 3.759 (p = 0.037), though multicollinearity reduced the predictive power of individual coefficients. Overall, Microcosm B2 emerged as the most effective treatment option. The findings suggest that biostimulation using a combination of moisture, compost, NPK fertilizer, and cattle bile is an effective approach to achieving high efficiency in TPH degradation in hydrocarbon-contaminated soils.

Irrigation Regime Optimization Plays a Critically Important Role in Plastic-Shed Vegetable Production to Mitigate Short-Term and Future N Leaching Pollution

In northern China, plastic-shed vegetable production significantly contributes to nitrogen (N)-induced groundwater eutrophication due to excessive fertilization and irrigation. However, the impact of optimized farming practices on N leaching has seldom been systematically examined. We conducted a four-season field study to evaluate the impacts of optimal farming measures on tomato yield, water percolation, N concentration in leachate, and total N (TN) leaching. The treatments included conventional fertilization and flood irrigation (CON), fertilization decreased by 20% and flood irrigation (OPT1) or drip fertigation (OPT2), fertilization decreased by 30% and drip fertigation (OPT3), and no fertilization with flood irrigation (CK). Compared with the CON treatment, the optimal treatments significantly reduced annual TN leaching by 9.92–50.7% without affecting tomato yield (57.1–98.2 t ha−1 for CON and 48.1–106 t ha−1 for three optimal treatments). Drip irrigation contributed 73.8–79.0% to the mitigation of TN leaching. The N originating from soil and irrigation water exhibited a similar contribution to TN leaching (45.4–58.6%) to that of fertilizer N. The daily TN leaching at the basal fertilization stage was much greater than that at the top-dressing stage, due to over-fertilization. Optimizing fertilization, particularly basal fertilization, in combination with drip irrigation could substantially reduce N leaching in plastic-shed vegetable production. Other optimal practices, such as decision support systems (DSSs) and fertilizer amendments, could also be investigated to further mitigate the N leaching.

Process and mechanism of termite impact on soil and plant.

Termites, as a kind of nesting social insects, are often confused as worldwide "pests" because some of their groups have great destructive effects. The vast majority of termites can regulate ecosystem functions and ser-vices by participating in biogeochemical cycles, known as "ecosystem engineers". We reviewed studies on the effects of termites on the physical, chemical and biological characteristics of mound soil ecosystems and the composition and diversity of plant communities. Termites could form unique soil "biogenic aggregates" and "resource heterogeneity patches", which affect microbial community structure, extracellular enzyme activity, physicochemical property and greenhouse gas emission, thereby affecting plant growth, community composition and structure, and vegetation productivity. However, this effect significantly differed among termite groups and functional groups, and was dependent on regional soil environment and microclimate conditions. Meanwhile, termite-mound could effectively improve ecosystem adaptation or resistance to environmental stress through the above process. Future research should focus on the following directions: 1) studying the trophic cascading effect of termite-centered soil multilevel biological network and the potential effect on biogeochemical cycle from microscale (aggregate level) to macroscale (landscape level); 2) exploring the potential of termite mound soil as a fertility amendment in tropical regions, and mining beneficial microbial functional genes to develop related products for termite control.

Elimination of microplastics, PFAS, and PPCPs from biosolids via pyrolysis to produce biochar: Feasibility and techno-economic analysis

Biosolids from municipal wastewater treatment contain many contaminants of emerging concern, including microplastics (MPs), per- and polyfluoroalkyl substances (PFAS), pharmaceuticals and chemicals from personal care products (PPCPs). Many of these contaminants have very slow biotic or abiotic degradation rates and have been shown to have human and ecological health impacts. Application of biosolids to agriculture, a common disposal method, can result in extended environmental contamination. An approach for eliminating the contaminants is pyrolysis, which can also generate biochar, enhancing carbon sequestration as a side-benefit. We pyrolyzed biosolid samples from an operating facility at various temperatures from 400 to 700 °C with a 2-hour residence time. We then evaluated contaminant removal, which in many cases was 100 %, with only a few residuals. No trace of PFAS was detectable even at 400 °C. Overall mass removal of PPCPs, including PFAS, was over 99.9 %. MP removal via pyrolysis ranged from 91 to 97 %. The biochar contains significant amounts of Fe and P, which make it a useful fertilizer amendment. The techno-economic analysis indicates that pyrolysis may generate significant cost savings, and revenue from the sale of biochar, sufficient to more than cover the investment and operating costs of the dryer and pyrolysis unit.

Bio-inoculant consortia modulated plantain (Musa × paradisiaca L.) growth, rhizosphere pH, acid phosphatase and urease activity

Fertilizers influence biochemical interactions in the rhizosphere that can affect crop performance. This study evaluated the interaction of plantain (Musa × paradisiaca) growth with soil pH, acid phosphatase and urease activities under different fertilizer amendments in Buea with mono-modal and Akonolinga with bi-modal rainfall patterns in Cameroon. The two experiments were setup in June 2021 following a randomized complete block design with NPK (nitrogen, phosphorus, and potassium), bio-inoculant consortia (plant growth-promoting bacteria – PGPB, Beauveria, Trichoderma, PGPB + Trichoderma), and untreated control, with four replications each. Soil samples were collected on 30th September 2021 and 30th April 2022 for analyses of soil physico-chemical and biological properties. Higher plantain performance occurred in Buea than Akonolinga across samplings, while treatments modulated plantain performance. Significant correlations occurred between plantain height or stem girth with rhizosphere pH, acid phosphatase and urease activities. The soil in Akonolinga is clayey with 38 % higher clay content than Buea, while Buea was clay-loamy with two times more silt than Akonolinga. The pre- and post-planting soil pH in Buea were strongly acidic as compared to extremely acidic soil in Akonolinga, with significant variation of post-planting pH across treatments, sampling time, and field sites. The positive correlation of soil pH, acid phosphatase and urease activities with plantain growth strongly indicate functional relationships that highlight fertilizer effects, sampling time or site-specific variations, and their interactions on plantain performance. Thereby, highlighting the role of locally formulated bio-inoculants in improving crop performance. These findings open up avenues for further studies on the role of bio-inoculants on crop nutrient uptake, and control of crop pests and diseases, in order to promote a holistic management approach that integrates bio-inoculants, crop type, and site-specific factors.

Comparative Effects of Site-specific and Blanket Fertilizer Application on Soil Physicochemical properties and Maize (Zea mays L.) Yield at Mikalango in Chikwawa District, Southern Malawi

Malawi's economy predominantly relies on agriculture. However, continuous soil degradation threatens crop production, food security, and nutrition. The use of fertilizers in soil fertility amendment has not been as effective due to blanket application, which does not adequately address Malawi's diverse soil nutrient deficiencies. This can also lead to over-fertilization, which can generate greenhouse gas emissions contributing to climate change. The experiment, set up in a randomized complete block design, compared site-specific and blanket fertilizer applications having 5 treatments and 5 replications, where a single maize seed variety was planted uniformly. Data was collected from the site's soil physicochemical properties, maize growth, and yield components and analyzed using JMP SAS software version 14.0.0. Results indicated that site-specific fertilizer application significantly differed from blanket fertilizer application at a 5% level of significance. Phosphorus (0.31 ppm), Sulphur (24.2 ppm), and Zinc (1.92 ppm) were significantly higher due to site-specific fertilizer application. Similarly, plant biomass (3.41 t/ha) and grain yield (7.03 t/ha) were also significantly higher due to site-specific fertilizer application. Hence, the study concluded that site-specific soil fertility management is ideal for efficient nutrient replenishment and attaining optimum yields while mitigating climate change in maize farming systems

Interactive Effect of Fertilization and Biochar on the Growth of Juniperus scopulorum under Various Shading and Irrigation Conditions

The global demand for landscape trees has been amplified with the increasing anthropogenic activity. South Korea has also witnessed a surge in demand for landscape plants, among others, Juniperus scopulorum gaining popularity for its ecological, economic, adaptability, and management attributes. However, the optimum management practice for high-quality Juniperus seedling production in South Korea remains unknown. This research was conducted on the one-to-two-years-old two cultivars of J. scopulorum, namely Blue Angel and Blue Heaven seedlings, to investigate the combined impacts of varying fertilizer concentrations (0 ppm, 150 ppm, 300 ppm) and biochar content (0% and 20%) under contrasting shading intensities (0%, 35%, 55%) and irrigation levels (200 ml, 400 ml, 800 ml). The study revealed that biochar and fertilizer amendment significantly (p &lt; 0.01 and p &lt; 0.05) enhanced the height and root collar diameter growth in Blue Angel and Blue Heaven in light shade intensity (0–35%) and higher irrigation (400–800 ml) conditions. Similarly, seedlings planted in 20% biochar and 300 ppm fertilizer yielded higher foliar, stem, and root biomass in low shade and higher irrigation conditions. The amount of shade and irrigation and their interactions significantly affected the morphological growth of seedlings for both cultivars, causing positive interaction with soil amendment (biochar and fertilizer application). These findings suggest that efficient seedling production of J. scopulorum management should focus primarily on light shading and moderate irrigation under biochar and higher fertilizer application. The research contributes valuable insights toward optimizing management practices and reducing costs associated with J. scopulorum seedling production in the region. Keywords: biochar, fertilizer, irrigation, Juniperus scopulorum, shading

Microarthropods improve oat nutritional quality and mediate fertilizer effects on soil biological activity

AbstractSoil biological processes are important drivers of crop productivity in agroecosystems. Soil microarthropods play key roles in nutrient cycling and plant nutrient acquisition, though little is known about how these effects manifest in crop production under different organic fertilizer amendments. We explored the interactive effects of microarthropods and fertilizers on crop productivity in two greenhouse experiments: experiment one involved a single Collembola species, and experiment two involved diverse microarthropod communities. Oats were grown as a model crop in both experiments under one of three initial fauna abundance levels (none, low, and high). In both experiments, four organic fertilization treatments were compared: alfalfa green manure, Kreher's Poultry Litter Compost, Chilean nitrate, and a nonamended control. Oat growth and development were evaluated weekly. During each experiment, 48 pots were selected randomly for destructive harvest at two separate times to mimic forage and grain harvest stages. At each harvest, multiple soil metrics (microarthropods, microbial biomass, microbial enzymes, and soil carbon and nitrogen) and plant metrics (biomass, reproduction, and tissue carbon and nitrogen content) were evaluated. Our findings indicated that microarthropods, both single species and diverse communities, stimulated nitrogen cycling and enhanced crop nutrient status. As microarthropod abundance and diversity increased, microarthropods exerted more effects on soil microbial activity. The effects of the microarthropods enhance the breakdown of fertilizers, ultimately making fertilizer choice less important for soil processes and plant nutrient availability. Our findings suggest that microarthropods drove oat production yields primarily through their effects on soil biological processes.

Insights into the distribution characteristic of microbiota in alkaline–sandy soil with inorganic and organic fertiliser treatments: contrasting abundance, structure and functionality

ABSTRACT Fertiliser amendment is the most direct method for improving soil properties of ecologically vulnerable areas (e.g. desertification soil area), and then, understanding the response of microbial community activities and growth to different fertilisation treatments is of great significance in sandy soil restoration. Here, a field experiment with different fertiliser treatments in typical alkaline–sandy soil was conducted. In this study, the difference of physicochemical property, microbial communities and functions in different treatments of no fertiliser (CK), (ii) fly ash chemical fertilisers (CF), (iii) humic straw organic fertiliser (OF), (iv) functional microbial fertiliser (FMF), (v) sulphate-reducing bacterial (SRB) fertiliser (MF) and (vi) humic straw organic fertiliser + functional microbial fertiliser + SRB fertiliser (CMF) were evaluated. The result showed that the contents of soil total organic carbon, NO3-N, P and K in the FMF were highest. The abundance of keystone taxa (Gemmatimonadetes and Thaumarchaeota) increased significantly in the treatments of microbial fertiliser. Microbial fertiliser boosted genes for aerobic nitrite oxidation, nitrogen fixation, ammonia oxidation and aromatic compound degradation. The number of methylotrophy and dark sulphur oxidation genes was reduced. The bbove results indicated that the treatments with the inoculation of functional microbes are better than the others for the restoration of alkaline–sandy soil.

Soil Organic Matter Input Promotes Coastal Topsoil Desalinization by Altering the Salt Distribution in the Soil Profile

Organic amendment is an effective method to reclaim salt-affected soil. However, in coastal land with shallow saline groundwater, it is limited known about the mechanism of organic amendment on soil desalinization. Thus, to examine the effect of topsoil organic matter content on soil water/salt transport and distribution, two-year field observations in Bohai coastal land, North China, and soil column experiments simulating salt accumulation and salt leaching were conducted, respectively. There were different organic fertilizer amendment rates in 0–20 cm topsoil, 0% (CK), 50% (OA 0.5), and 100% (OA 1.0) (w/w) for soil column experiments. Field observation showed that after organic amendment (OA), the soil’s physical structure was improved, and less of the increase in topsoil salt content was observed, with more salt accumulated in deep soil layers during the dry season. In addition, OA greatly promoted salt leaching during the rainy seasons. The results of the soil column tests further indicated that OA treatments significantly inhibited soil evaporation, with less salt accumulated in the topsoil. Although there was no difference in soil water distribution between the CK and OA 0.5 treatment, the topsoil EC for the OA 0.5 treatment was significantly lower than that for CK. During soil water infiltration, the OA 0.5 and OA 1.0 treatments significantly increased the infiltration rates, enhanced the wetting front, and promoted salt leaching to deeper soil layers, compared with CK. The improvement of soil organic amounts could make the soil more self-resistant to the coastal salinization. The findings of this study provide some insights into soil water/salt regulation in heterogeneous soil masses and on the permanent management of coastal saline farmland.

Agro-technologies for greenhouse gases mitigation in flooded rice fields for promoting climate smart agriculture

We investigated methane (CH4) and nitrous oxide (N2O), two important greenhouse gases (GHGs) emissions using the closed chamber method from a flooded rice field in Brahmaputra valley of Assam, northeast part of India. We tried to understand the factors responsible for the emission and identify appropriate agro-technologies for their mitigation. Various factors like water level, drainage management, soil organic carbon management, crop management, fertilizer amendment, cultivar type etc. affect the GHG production and emission from the flooded rice soil. In this study, six treatments were employed, namely, farmer's practice (FP), recommended fertilizer dosage (RDF), direct seeded rice (DSR), intermittent wetting drying (IWD), use of efficient methanotrophs (MTH), and use of ammonium sulfate as a nitrogen source for real-time nitrogen management using leaf color chart, (AS). GHG flux was measured through the static closed chamber technique. Soil temperature, pH, and redox potential (Eh) and other soil physico-chemical and biological properties that have a potential role in GHG emission were also assessed. The lowest CH4 flux was observed in IWD treatment. The highest CH4 but lowest N2O flux was observed in RDF thus portraying a tradeoff relationship among these two GHGs. The highest N2O flux was observed in AS. Changes in Eh strongly altered CH4 and N2O emissions. The CH4 flux for the growing season varied from 62.5 to 86.3 kg ha−1 with an average of 72.4 kg ha−1. The average N2O flux was 0.89 kg ha−1 with values fluctuating between 0.72 – and 1.08 kg ha−1. The findings of this study could assist in understanding the factors affecting the source, production, and sink of these two important GHGs. IWD, along with judicious N-based fertilizer use, could provide significant respite from GHG emissions in rice-based agriculture. These climate-smart strategies not only reduce emissions but also have the potential to improve yield.

Soil pH and phosphorus availability regulate sulphur cycling in an 82-year-old fertilised grassland

The application of lime and mineral fertiliser is known to mitigate soil acidification and improve soil quality in improved grasslands. However, the long-term effect of simultaneous lime and fertiliser amendments on soil carbon (C) and sulphur (S) cycling is still poorly understood. To examine if soil pH or nutrient availability are the dominant factors regulating C and S cycling, we evaluated the biodegradation of methionine (organic S), gross S transformation, and microbial S utilisation using 35S and 14C dual-labelling. Soil samples (0–10 cm) were collected from one unfertilised control and five annual limed (Ca) treatments with or without nitrogen (N), phosphorus (P), potassium (K) and sulphur (S) fertilisers (Ca, CaN, CaNP, CaNPKCl, CaNPK2SO4) in an 82-year-old upland grassland experiment in Rengen, Germany. Long-term lime application increased soil pH values but significantly (p < 0.05) decreased soil organic C content. Fertilisation had no significant effect on microbial utilisation of 35S-labelled methionine, while microbial immobilisation of 35SO42− in the limed soils was significantly reduced compared to the control. This is attributed to either the increased soil pH or decreased C availability after liming. Microbial carbon use efficiency (CUE) was significantly higher in soils with applied P fertiliser (i.e., CaNP: 0.66 ± 0.02, CaNPKCl: 0.68 ± 0.02, CaNPK2SO4: 0.65 ± 0.01) compared to the CaN treatment (0.58 ± 0.01). Moreover, compared to CaN, CaNP and CaNPKCl treatments significantly increased gross S turnover, while no significant effects were observed in the CaNPK2SO4 treatment. Soil P deficits decreased microbial CUE and S bioavailability. Although P fertiliser addition alleviated microbial P limitation when N fertiliser was added, S fertiliser (CaNPK2SO4) present constrained S transformation rates. Overall, the importance of P availability for global S cycling in grasslands is shown, especially under N-enrichment conditions. However, the subsequent potential for C loss from long-term liming should be carefully considered in grassland management.

Responses of nematodes to oil contamination in a mangrove sediment: A microcosm study

The effects of oil pollution on nematode assemblages were investigated in a mangrove sediment. Microcosms comprised 350 mL plastic jars filled with 250 g sediment. In the oiled treatments (O), 15 mL oil were added to the soil. In the oil and fertiliser treatments (O + F), oil and fertiliser (N: P: K: 3: 2: 5) were added to the soil. After four weeks, nematodes were extracted and identified. The number of nematode taxa was highest in the C (61), intermediate in the O + F (59) and significantly lower in the O (25) treatment. Taxa present in the C but absent in the O treatment were oil-intolerant. Taxa present in the O treatments were oil-tolerant. Five taxa survived oiling probably due to fertiliser amendment. Oiling eliminated oil-intolerant taxa and favoured those that were resistant. In the O+ F treatment, the number and species of nematodes increased significantly.

Site properties, environmental factors, and crop identify influence soil bacterial communities more than municipal biosolid application

Reducing the environmental impact of Canadian field crop agriculture, including the reliance on conventional synthesised fertilisers, are key societal targets for establishing long-term sustainable practices. Municipal biosolids (MSB) are an abundant, residual organic material, rich in phosphate, nitrogen and other oligo-nutrients, that could be used in conjunction with conventional fertilisers to decrease their use. Though MBS have previously been shown to be an effective fertiliser substitute for different crops, including corn and soybean, there remain key knowledge gaps concerning the impact of MBS on the resident soil bacterial communities in agro-ecosystems. We hypothesised that the MBS fertiliser amendment would not significantly impact the structure or function of the soil bacterial communities, nor contribute to the spread of human pathogenic bacteria, in corn or soybean agricultural systems. In field experiments, fertiliser regimes for both crops were amended with MBS, and compared to corn and soybean plots with standard fertiliser treatments. We repeated this across four different agricultural sites in Quebec, over 2021 and 2022. We sampled MBS-treated, and untreated soils, and identified the composition of the soil bacterial communities via 16S rRNA metabarcoding. We found no indication that the MBS fertiliser amendment altered the structure of the soil bacterial communities, but rather that the soil type and crop identities were the most significant factors in structuring the bacterial communities. Moreover, there was no evidence that the MBS-treated soils were enriched in potential human bacterial pathogens over the two years of our study. Our analysis indicates that not only can MBS function as substitutes for conventional, synthesised fertilisers, but that they also do not disrupt the structure of the resident soil bacterial communities in the short term. Finally, we suggest that the use of MBS in agro-ecosystems poses no greater concern to the public than existing soil bacterial communities. This highlights the significant role MBS could potentially have in reducing the use of conventional industrial fertilisers and improving agricultural production, without risking environmental contamination.

Soil amendments reduce CH4 and CO2 but increase N2O and NH3 emissions in saline-alkali paddy fields

Limited research has been conducted on ammonia (NH3) volatilization and greenhouse gases (GHGs) emissions in saline-alkali paddy fields, along with complex interaction involving various genes (16sRNA, amoA, narG, nirK, nosZ, and nifH). This study employed mesocosm-scale experiment to investigate NH3 volatilization and GHGs emissions, focusing on bacterial communities and genic abundance, in saline-alkali paddy fields with desulfurized gypsum (DG) and organic fertilizer (OF) amendments. Compared to the control (CK) treatment, DG and OF treatments reduced methane (CH4) and carbon dioxide (CO2) emissions by 78.05 % and 26.18 %, and 65.84 % and 11.62 %, respectively. However, these treatments increased NH3 volatilization by 26.26 % and 45.23 %, and nitrous oxide (N2O) emission by 41.00 % and 12.31 %. Notably, NH3 volatilization primarily stemmed from ammonia nitrogen (NH4+-N), rather than total nitrogen (TN) in soil and water. N2O was mainly produced from nitrate nitrogen (NO3−-N) in soil and water, as well as NH4+-N in water. The increase in NH3 volatilization and N2O emission in DG and OF treatments, was attributed to the reduced competition among bacterial communities, rather than the increased bacterial activity and genic copies. These findings offer valuable insights for managing nutrient loss and gaseous emissions in saline-alkali paddy fields.

Evolving dynamics of insect frass fertilizer for sustainable nematode management and potato production.

Potato production faces major challenges from inadequate soil fertility, and nematode infestation, yet synthetic fertilizers and nematicides are costly and harmful to the environment. This study explored the potential of chitin-fortified black soldier fly-composted organic fertilizer (BSFCOF) as a multipurpose organic fertilizer amendment for enhancing potato yield and suppressing potato cyst nematodes (PCN). The BSFCOF was applied at a rate equivalent to 150 kg N ha-1 and fortified with chitin from black soldier fly pupal exuviae at inclusion rates equivalent to 0.5, 1, 2, 3, 4 and 5% chitin. Data were collected on potato growth characteristics, PCN population densities, and soil chemical properties for two growing cycles. Results showed that chitin fortified BSFCOF significantly improved potato growth parameters, chlorophyll concentration, marketable tuber yield and number of marketable tubers. The marketable tuber yield achieved using chitin-fortified BSFCOF was 70 - 362%, and 69 - 238% higher than the values achieved using unfertilized soil during the first and second growing cycles, respectively. Soil amendment with chitin-fortified BSFCOF significantly reduced the number of cysts per 200 g soil-1, number of eggs and J2 per cyst-1, eggs g-1 soil and reproduction rate by 32 - 87%, 9 - 92%, 31- 98% and 31 - 98%, respectively. The PCN suppression increased with chitin inclusion rates. There were significantly higher values for soil pH, ammonium nitrogen, nitrate nitrogen, available phosphorus, calcium, magnesium, potassium, and cation exchange capacity in soil amended with BSFCOF compared to unamended soil. This study demonstrates that BSFCOF fortified with 5% chitin is an effective soil enhancer with multiple benefits, including improved soil fertility, potato performance, and effective management of potato cyst nematodes.

Seedcorn maggot response to planting date, cover crops, and tillage in organic cropping systems.

Seedcorn maggot, Delia platura (Meigen) (Diptera: Anthomyiidae), is an economically important early-season pest of corn and soybean in the United States. Adult seedcorn maggot is attracted to decomposing plant residues for oviposition, creating potential management issues where growers typically use tillage to incorporate fertility amendments and to create a seedbed. The use of growing degree-day models to time planting dates is an important tool for effectively managing this pest, but their use has not been examined in organic crop production. Here, we report the results of experiments to determine the effects of cover crops, tillage, and relative planting date on seedcorn maggot in corn and soybean in 2 experiments: The first during the transition to organic from conventional management and the second during the 3 yr following organic certification in central Pennsylvania, United States. Overall, delaying the planting date by 1-2 wk reduced fly emergence in corn, but not in soybean in both experiments. Seedcorn maggot emergence was also consistently greater in corn than in soybean, with 6 times more flies in corn than in soy. About 15 times more seedcorn maggot flies emerged from corn in treatments in which cover crops were managed with tillage compared to treatments in which cover crops were terminated with a roller-crimper followed by no-till planting of corn. Fly emergence was negatively related to the proportion of legumes in the cover crop mixture preceding corn. These results can help inform soil, cover crop, and crop decisions for organic growers in the Mid-Atlantic United States.

Use of Euclidean distance to evaluate Pistia stratiotes and Eichhornia crassipes as organic fertilizer amendments in Capsicum annuum

Use of Euclidean distance to evaluate Pistia stratiotes and Eichhornia crassipes as organic fertilizer amendments in Capsicum annuum

Maximizing Vegetable Growth Potential: Evaluating the Synergistic Impact of Vermicompost and NPK Fertilizer Amended Soil

Maximizing Vegetable Growth Potential: Evaluating the Synergistic Impact of Vermicompost and NPK Fertilizer Amended Soil

Assessing forage research and education needs of organic dairy farms in the United States

Abstract The viability of organic dairy operations in the United States (US) relies on forage production. The objectives of this study were to (1) assess producer and farm information regarding current forage production practices and producer knowledge gaps and (2) identify forage research and educational needs of organic dairy producers across the US. A survey was distributed to 643 organic dairy producers across the US, with 165 respondents (26% response rate). A focus group consisting of extension professionals, university researchers and staff, consultants, dairy industry representatives and organic dairy producers was also consulted for forage research needs. Results showed that approximately half (51%) of surveyed producers were somewhat satisfied with their forage production systems and sometimes experienced negative weather-related impacts on forage yield and quality. A majority (64%) of producers felt their knowledge to meet farm goals was adequate but they reported a lack of resources to implement this knowledge especially for balancing high-forage diets and selecting soil amendments. This study revealed that 54% of producers rely on peer experiences as information resources to make decisions on forage programs. Producer knowledge gaps included pasture renovation with reduced or no-tillage, forage mixtures that match their needs, and forage management practices aiming for high-quality forage. Based on the survey and focus group findings, forage research and educational activities should foster climate change resilience regarding forage diversity adapted to local and regional climatic conditions, improve forage quality, enhance economic returns from soil fertility amendments and pasture renovation, and introduce new forages and forage mixtures that suit economical, agronomical, and environmental needs.