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1دورية أكاديمية
المؤلفون: Brodie, Eoin
مصطلحات موضوعية: Soil, Fertilizer, Microorganism, Nitrogen use efficiency, Agriculture, Nutrient loss, Nitrification, Semi-humic substance
الوصف: Under a collaborative research and development (CRADA) agreement, LBNL scientists investigated the effect of the semi-humic substance, Proximus, on nitrogen dynamics in two contrasting soils. We specifically tested four hypotheses that Proximus (1) binds ammonium and reduces nitrification; (2) does not bind ammonium but chemically inhibits nitrification; (3) stimulates microbial immobilization of N in biomass; (4) stimulates denitrification. We performed two primary experiments, one in the laboratory using a pure culture of a nitrifying bacterium, and one in a greenhouse setting testing the fate of nitrogen and response of microbial communities in soils with and without Proximus.Our findings can be summarized as follows:•Proximus does not chemically inhibit nitrification – this conclusion was reached by analysis of the response of Nitrosomonas europaea (ATCC 19718) to Proximus addition at field relevant concentrations, relative to the known nitrification inhibitor Nitropyrin. No inhibition of growth or ammonia oxidation to nitrite was observed at field relevant concentrations.•In soils with higher clay and silt content with relatively low N fertilizer application rates (100lbs/ac), the effect of Proximus on nitrogen concentrations and microbial communities was minimal. •In sandier soils with low organic matter and clay content and with relatively low N fertilizer application rates (100lbs/ac), Proximus aided delayed availability of inorganic nitrogen in the system. •Using a stable isotope tracer (15N) we observed differential effects of Proximus on N uptake by soil microbial biomass. In sandy soils, although Proximus slowed the release of NH4+ from fertilizer, Proximus did not have any significant effect on nitrogen assimilation by soil microbes. However, in more clay rich Iowa soils, while Proximus did not affect the magnitude or timing of total NH4+ or NO3- availability, it did reduce the availability of fertilizer N to soil microbes, delaying uptake into microbial biomass.•Proximus addition did not significantly affect overall microbial (bacterial, archaeal, fungal) community composition, although specific genera of bacteria and fungi were found to be enriched or repressed due to Proximus addition.•Over the 5 week observation period, Proximus did not stimulate any significant increase in denitrification relative to fertilizer alone. In summary, we see no evidence that Proximus inhibits nitrifiers or nitrification directly, nor does it stimulate more nitrogen loss through denitrification than fertilizer application alone. We do not find strong evidence for the direct role of microbial biomass stimulation as a Proximus mode of action. A consideration for future analyses and experimental design is the fertilization rate simulated in these experiments which may be considered low relative to more intensive agricultural practices. A study of dose dependence of Proximus application rate across soil types would also illuminate the importance of potential interactions with soil mineralogy. A further consideration is the interactions between plants and soil microorganisms not considered here. Root deposition of carbon enhances microbial growth and nutrient demand and we expect that Proximus impacts on the soil microbiome and nutrient retention would differ in the presence of growing plants.
وصف الملف: application/pdf
الوصول الحر: https://escholarship.org/uc/item/4kb9g57tTest
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2دورية أكاديمية
المؤلفون: Isabeli P. Bruno, Augusto G. Araújo, Gustavo H. Merten, Audilei S. Ladeira, Victor M. Pinto
المصدر: Nitrogen, Vol 5, Iss 2, Pp 329-348 (2024)
مصطلحات موضوعية: nitrogen, nutrient loss, cover crop, conservation agriculture, Ecology, QH540-549.5
الوصف: The intensive use of agricultural fertilizers containing nitrogen (N) can increase the risk of nitrate (NO3−) leaching. However, little information exists regarding its interaction with other factors that influence NO3− leaching, such as no-tillage, which is associated with different crop rotation schemes. The objective of this study was to quantify the leachate NO3− concentration and load below the root zone in two different crop rotations under no-tillage, with and without mineral N fertilizer. The experiment was conducted in a no-tillage area in Brazil between 2018 and 2020. The factors were two crop rotations (diversified and simplified) and two N fertilization managements (with and without N fertilizer). The soil solution was collected with suction lysimeters (1 m depth), the NO3− concentration (mg L−1) was spectrophotometrically determined, and the NO3− load (kg ha−1) was calculated from the volume of water drained and the NO3− concentration. The results were categorized into 24 evaluation periods. NO3− leaching was extremely low due to low rainfall throughout the experiment, with no significant differences between the factors and treatments. In the presence of N fertilization, leaching was substantially greater when rainfall increased, and vice versa. No significant difference was observed between the crop rotation schemes, except for one period in which the simplified soybean rotation exhibited high leaching. The evaluated treatments showed less NO3− leaching during the four periods when grass species were cultivated, indicating the importance of grasses in rotation systems.
وصف الملف: electronic resource
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3دورية أكاديمية
المؤلفون: Purwoko Hari Kuncoro, Krissandi Wijaya, Asna Mustofa, Arief Sudarmaji, Susanto Budi Sulistyo, Christian Soolany
المصدر: Jurnal Ilmiah Rekayasa Pertanian dan Biosistem, Vol 12, Iss 1, Pp 61-76 (2024)
مصطلحات موضوعية: drainage canal, horizontal-ridge, nutrient loss, runoff, soil loss, Agriculture (General), S1-972
الوصف: Previously, horizontal-ridge system has been shown effective in reducing soil erosion. But, it could cause water logging, which is detrimental to crop growth and yield. To solve this problem, drainage canal establishment might be reasonable. However, the evidence remains scarce. In this study, effect of drainage canal intervals on the volume of runoff, soil loss, and nutrient loss (N-total and P-total) were investigated. There were 4 drainage canal intervals applied to the 12 targeted plots (each sized 3 m x 3 m): R0, R1, R1.5, and R2 namely 0 m, 1 m, 1.5 m, and 2 m, respectively. In this case, R0 had no drainage canals and taken as the control. The measured runoff, soil loss, N-total loss, and P-total loss ranged 24.714 – 0.951 m3 ha-1, 0.002 – 0.507 ton ha-1, 0.849 – 204.881 kg ha-1, and 0.685 – 176.505 kg ha-1, respectively. The results revealed that existence of drainage canal increased runoff, soil loss, and nutrient loss compared to the control. Amongst them, R1 gave the highest values of soil and nutrient losses followed by R1.5, R2, and R0 as the lowest, which was probably due to the difference in number of drainage canal existing: 12, 7, 5, and 0, respectively. In addition, it was noticeable for a sufficient data trend conformity of the measured nutrient loss to the data of soil loss, runoff, and rainfall within a positive correlation amongst them. The data further confirmed the effect of soil structure condition on the volume changes of both runoff and soil loss.
وصف الملف: electronic resource
العلاقة: https://jrpb.unram.ac.id/index.php/jrpb/article/view/596Test; https://doaj.org/toc/2301-8119Test; https://doaj.org/toc/2443-1354Test
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4دورية أكاديمية
المؤلفون: D. G. Opoku, M. G. Healy, O. Fenton, K. Daly, T. Condon, P. Tuohy
المصدر: Frontiers in Environmental Science, Vol 12 (2024)
مصطلحات موضوعية: water quality, nutrient loss, grassland, drainage management, connectivity pathways, North Atlantic Europe, Environmental sciences, GE1-350
الوصف: Introduction: On dairy farms with poorly drained soils and high rainfall, open ditches receive nutrients from different sources along different pathways which are delivered to surface water. Recently, open ditches were ranked in terms of their hydrologic connectivity risk for phosphorus (P) along the open ditch network. However, the connectivity risk for nitrogen (N) was not considered in that analysis, and there remains a knowledge gap. In addition, the P connectivity classification system assumes all source–pathway interactions within open ditches are active, but this may not be the case for N. The objective of the current study, conducted across seven dairy farms, was to create an integrated connectivity risk ranking for P and N simultaneously to better inform where and which potential mitigation management strategies could be considered.Methods: First, a conceptual figure of known N open ditch source–pathway connections, developed using both the literature and observations in the field, was used to identify water grab sampling locations on the farms. During fieldwork, all open ditch networks were digitally mapped, divided into ditch sections, and classified in terms of the existing P connectivity classification system.Results and Discussion: The results showed that not all source–pathway connections were present across ditch categories for all species of N. This information was used to develop an improved open ditch connectivity classification system. Farmyard-connected ditches were the riskiest for potential point source losses, and outlet ditches had the highest connectivity risk among the other ditch categories associated with diffuse sources. Tailored mitigation options for P and N speciation were identified for these locations to intercept nutrients before reaching receiving waters. In ditches associated with diffuse sources, nitrate was introduced by subsurface sources (i.e., in-field drains and groundwater interactions from springs, seepage, and upwelling) and ammonium was introduced through surface connectivity pathways (i.e., runoff from internal roadways). On similar dairy farms where open ditches are prevalent, the integrated classification system and mapping procedure presented herein will enable a targeted and nutrient-specific mitigation plan to be developed. The same methodology may be applied to develop a bespoke integrated connectivity risk ranking for P and N along agricultural open ditches in other areas.
وصف الملف: electronic resource
العلاقة: https://www.frontiersin.org/articles/10.3389/fenvs.2024.1337857/fullTest; https://doaj.org/toc/2296-665XTest
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5دورية أكاديمية
المؤلفون: Bailian Xiong, Yang Gao, Junlong Liu, Xiong Yan
المصدر: Journal of Hydrology: Regional Studies, Vol 51, Iss , Pp 101645- (2024)
مصطلحات موضوعية: Epikarst fissure filled with soil, Rocky desertification slope, Underground runoff, Soil erosion, Nutrient loss, Physical geography, GB3-5030, Geology, QE1-996.5
الوصف: Study region: Karst region in Guizhou Province, China. Study focus: Epikarst fissure filled with soil (EFS) is an important pathway connecting the karst surface with karst underground pipelines, and a vital soil resource bank in rocky desertification regions. Being buried underground, EFS is difficult to study, and the characteristics and control mechanism of soil erosion and nutrient loss in EFS need to be further investigated. In this work, we constructed a simulated experimental device that separated the EFS from the whole karst slope, and studied the role of EFS in soil erosion and nutrient loss in karst rocky desertification region. New hydrological insights for the region: Sediment erodes from the bottom of EFS. The scouring effect surpasses the dilution effect, and dominating the process of carbon and nitrogen loss in the EFS. The 0–30 cm soil layer of EFS profile intercepts part of carbon and nitrogen in slope runoff, with a higher interception rate for carbon compared to nitrogen, thereby reducing the C/N ratio in underground runoff. EFS is an important pathway for dissolved total carbon (DTC) and dissolved total nitrogen (DTN) loss. These results reveal the important roles of EFS in soil erosion and C and N loss in karst rocky desertification region, and are promising to provide a theoretical basis on the application of EFS to the ecological restoration in this region.
وصف الملف: electronic resource
العلاقة: http://www.sciencedirect.com/science/article/pii/S2214581823003324Test; https://doaj.org/toc/2214-5818Test
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6دورية أكاديمية
المؤلفون: Ologunde, Olanrewaju Hameed1, Busari, Mutiu Abolanle1, 1, Olowokere, Florence Alaba1, Bhatt, Rajan2, Arora, Sanjay3
المصدر: Journal of Soil and Water Conservation 22(4):328-335. 2023
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7دورية أكاديمية
المؤلفون: Jane Eastham, Annette Creedon
المصدر: Food Frontiers, Vol 4, Iss 3, Pp 971-979 (2023)
مصطلحات موضوعية: food loss and waste, food systems, nutrient loss, transdisciplinary approach, Nutrition. Foods and food supply, TX341-641, Food processing and manufacture, TP368-456
الوصف: Abstract “Food systems” as a concept draws upon systems thinking and facilitates a transdisciplinary approach to address the complexity of delivering the Sustainable Development Goals in developed and developing food regimes. Extant literature has used a food supply chain/systems approach to evaluate sources of food loss and waste (FLW) and their impact on food accessibility and therefore nutrient availability. The maximization of nutrients available to a growing global population is a critical aspect in the sustainable agenda and it is acknowledged that the continued augmentation of food produce is no longer the sole solution. However, there is a drive for greater efficiency, not simply in the resources deployed, but in the utilization of the food produced. This paper argues that FLW are not the only sources of nutrient loss within a supply chain and that there is a loss of nutrient density as the food progresses through the supply chain with the deterioration of nutrients in food within the food supply chain. It is argued here that in parallel to the management of loss and waste, there is a further need for a research agenda to explore the reality of loss of nutrient density holistically as it passes from farm to fork, building on the existing scientific research at each tier within the supply chain.
وصف الملف: electronic resource
العلاقة: https://doaj.org/toc/2643-8429Test
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8دورية أكاديمية
المؤلفون: Opoku, D. G., Healy, Mark G., Fenton, Owen, Daly, K., Condon, T., Tuohy, Patrick
المساهمون: Teagasc
مصطلحات موضوعية: Agricultural ditches, water quality, nutrient loss, grassland, drainage management, connectivity pathways, North Atlantic Europe
الوصف: On dairy farms with poorly drained soils and high rainfall, open ditches receive nutrients from different sources along different pathways which are delivered to surface water. Recently, open ditches were ranked in terms of their hydrologic connectivity phosphorus (P) along the open ditch network. However, the connectivity risk for nitrogen (N) was not considered in that analysis, and remains a knowledge gap. In addition, the P connectivity classification system assumes all source-pathway interactions within open ditches are active, but this may not be the case for N. The objective of the current study, conducted across seven dairy farms, was to create an integrated connectivity risk ranking for P and N simultaneously, to better inform where and which potential mitigation management strategies could be considered. First, a conceptual figure of known N open ditch source-pathway connections, developed using both the literature and observations in the field, was used to identify water grab sampling locations on the farms. During field work, all open ditch networks were digitally mapped, divided into ditch sections, and classified in terms of the existing P connectivity classification system. Sampling was conducted during the hydrologically-active period to ensure maximum connectivity of source-pathways and open ditches. The results from these water samples enabled a qualitative validation of N source-pathway presence or absence for each ditch category. The results showed that not all source-pathways were present across ditch categories for all species of N. This information was used to develop an improved open ditch connectivity classification system. Results showed that farmyard connection ditches were the riskiest for potential point source losses and outlet ditches had the highest connectivity risk among the other ditches associated with diffuse sources. Tailored mitigation options for P and N speciation were identified for these locations to intercept nutrients before reaching receiving waters. Furthermore, in ...
وصف الملف: application/pdf
العلاقة: Frontiers Of Environmental Science & Engineering; Opoku, D. G., Healy, M. G., Fenton, O., Daly, K., Condon, T., & Tuohy, P. (2024). An integrated connectivity risk ranking for phosphorus and nitrogen along agricultural open ditches to inform targeted and specific mitigation management. Frontiers in Environmental Science, 12. doi:10.3389/fenvs.2024.1337857; http://hdl.handle.net/10379/18059Test
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9دورية أكاديمية
المؤلفون: Juan M. Cedeño, Juan-José Magán, Rodney Bruce Thompson, María-Dolores Fernández, Marisa Gallardo
المصدر: Horticulturae, Vol 10, Iss 3, p 232 (2024)
مصطلحات موضوعية: soilless cropping, nutrient management, nutrient uptake, nutrient retention, nutrient loss, nutrient balance, Plant culture, SB1-1110
الوصف: Two methods were compared to determine crop nutrient uptake by tomato crops in free-draining perlite substrate. They were the nutrient balance method (applied minus drained) and the dry matter method (DM) (nutrients in plant material). Uptake of N, P, K, Ca, Mg, and S was determined using both methods, in three consecutive tomato crops planted in the same perlite. Nutrient uptake determined using the balance method was consistently higher than with the DM method. Relative differences (balance minus dry matter, with respect to the DM method) were N: −1 to 16%, P: 27–45%, K: 14–46%, Ca: 17–87%, Mg: 28–111%, and S: 15–65%. There was a clear tendency for the difference between the methods to reduce with successive crops. The differences between the methods were reduced when the measured retention of nutrients in the perlite substrate and estimated nutrient retention in roots (using a model) were included. However, these data did not explain all of the observed differences between the two methods. Various retention and loss processes may explain the differences. The results suggest that the DM matter method estimates nutrient uptake by the crop, and the balance method estimates nutrient consumption by the cropping system.
وصف الملف: electronic resource
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10دورية أكاديمية
المؤلفون: Brodie, Eoin
مصطلحات موضوعية: Soil, Fertilizer, Microorganism, Nitrogen use efficiency, Agriculture, Nutrient loss, Nitrification, Semi-humic substance
الوصف: Under a collaborative research and development (CRADA) agreement, LBNL scientists investigated the effect of the semi-humic substance, Proximus, on nitrogen dynamics in two contrasting soils. We specifically tested four hypotheses that Proximus (1) binds ammonium and reduces nitrification; (2) does not bind ammonium but chemically inhibits nitrification; (3) stimulates microbial immobilization of N in biomass; (4) stimulates denitrification. We performed two primary experiments, one in the laboratory using a pure culture of a nitrifying bacterium, and one in a greenhouse setting testing the fate of nitrogen and response of microbial communities in soils with and without Proximus.Our findings can be summarized as follows:•Proximus does not chemically inhibit nitrification – this conclusion was reached by analysis of the response of Nitrosomonas europaea (ATCC 19718) to Proximus addition at field relevant concentrations, relative to the known nitrification inhibitor Nitropyrin. No inhibition of growth or ammonia oxidation to nitrite was observed at field relevant concentrations.•In soils with higher clay and silt content with relatively low N fertilizer application rates (100lbs/ac), the effect of Proximus on nitrogen concentrations and microbial communities was minimal. •In sandier soils with low organic matter and clay content and with relatively low N fertilizer application rates (100lbs/ac), Proximus aided delayed availability of inorganic nitrogen in the system. •Using a stable isotope tracer (15N) we observed differential effects of Proximus on N uptake by soil microbial biomass. In sandy soils, although Proximus slowed the release of NH4+ from fertilizer, Proximus did not have any significant effect on nitrogen assimilation by soil microbes. However, in more clay rich Iowa soils, while Proximus did not affect the magnitude or timing of total NH4+ or NO3- availability, it did reduce the availability of fertilizer N to soil microbes, delaying uptake into microbial biomass.•Proximus addition did not significantly affect overall microbial (bacterial, archaeal, fungal) community composition, although specific genera of bacteria and fungi were found to be enriched or repressed due to Proximus addition.•Over the 5 week observation period, Proximus did not stimulate any significant increase in denitrification relative to fertilizer alone. In summary, we see no evidence that Proximus inhibits nitrifiers or nitrification directly, nor does it stimulate more nitrogen loss through denitrification than fertilizer application alone. We do not find strong evidence for the direct role of microbial biomass stimulation as a Proximus mode of action. A consideration for future analyses and experimental design is the fertilization rate simulated in these experiments which may be considered low relative to more intensive agricultural practices. A study of dose dependence of Proximus application rate across soil types would also illuminate the importance of potential interactions with soil mineralogy. A further consideration is the interactions between plants and soil microorganisms not considered here. Root deposition of carbon enhances microbial growth and nutrient demand and we expect that Proximus impacts on the soil microbiome and nutrient retention would differ in the presence of growing plants.
وصف الملف: application/pdf
الوصول الحر: https://escholarship.org/uc/item/4kb9g57tTest
النص الكامل