Richard F. Smith, M. Cahn, T. Hartz, D. Geisseler, Patricia Love
Organic cool-season vegetable growers on the Central Coast face challenges in applying nitrogen (N) to balance yields with new environmental regulations. It is hard to time fertilizer applications while calculating N mineralization of soil organic matter and organic fertilizers to plant-available N. Organic fertilizers with high phosphorus (P) to N ratios may elevate P levels and harm surface water quality. In this study, we evaluated (1) mineralization of soil organic matter and fertilizers, (2) effectiveness of residual soil nitrate-N tests and (3) long-term impacts of organic fertilizers on P levels and soil microbial activity. We found that mineralization of N from soil organic matter provided limited N to leafy green vegetables. Soil tests were more reliable in heavier than sandier soils. Application rates of 4-4-2 were calculated to meet N demands, resulting in an oversupply of P. However, only 9% to 17% of fertilizer P solubilized without elevating available soil P levels. While it's difficult for organic vegetable growers to use cover crops, organic fertilizers increased carbon levels, resulting in higher levels of soil microbial activity.
{"title":"Fine-tuning fertilizer applications in organic cool-season leafy green crops can increase soil quality and yields","authors":"Richard F. Smith, M. Cahn, T. Hartz, D. Geisseler, Patricia Love","doi":"10.3733/ca.2022a0010","DOIUrl":"https://doi.org/10.3733/ca.2022a0010","url":null,"abstract":"Organic cool-season vegetable growers on the Central Coast face challenges in applying nitrogen (N) to balance yields with new environmental regulations. It is hard to time fertilizer applications while calculating N mineralization of soil organic matter and organic fertilizers to plant-available N. Organic fertilizers with high phosphorus (P) to N ratios may elevate P levels and harm surface water quality. In this study, we evaluated (1) mineralization of soil organic matter and fertilizers, (2) effectiveness of residual soil nitrate-N tests and (3) long-term impacts of organic fertilizers on P levels and soil microbial activity. We found that mineralization of N from soil organic matter provided limited N to leafy green vegetables. Soil tests were more reliable in heavier than sandier soils. Application rates of 4-4-2 were calculated to meet N demands, resulting in an oversupply of P. However, only 9% to 17% of fertilizer P solubilized without elevating available soil P levels. While it's difficult for organic vegetable growers to use cover crops, organic fertilizers increased carbon levels, resulting in higher levels of soil microbial activity.","PeriodicalId":9409,"journal":{"name":"California Agriculture","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44263499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hannah L. Freund, M. Maltz, Mark P. Swenson, Talyssa M. Topacio, Vanessa A. Montellano, W. Porter, E. Aronson
Although the Salton Sea was once a thriving destination for humans and wildlife, it has now degraded to the point of ecosystem collapse. Increases in local dust emissions have introduced aeolian (wind-blown) microorganisms that travel, along with contaminants and minerals, into the atmosphere, detrimentally impacting inhabitants of the region. Proliferation of certain microbial groups in regions of the Sea may have a disproportionate impact on local ecological systems. Yet, little is known about how the biogeochemical processes of this drying lakebed influence microbial community composition and dispersal. To elucidate how these microorganisms contribute, and adapt, to the Sea's volatile conditions, we synthesize research on three niche-specific microbiomes — exposed lakebed (playa), the Sea, and aeolian — and highlight modern molecular techniques, such as metagenomics, coupled with physical science methodologies, including transport modeling, to predict how the drying lakebed will affect microbial processes. We argue that an explicit consideration of microbial groups within this system is needed to provide vital information about the distribution and functional roles of ecologically pertinent microbial groups. Such knowledge could help inform regulatory measures aimed at restoring the health of the Sea's human and ecological systems.
{"title":"Microbiome interactions and their ecological implications at the Salton Sea","authors":"Hannah L. Freund, M. Maltz, Mark P. Swenson, Talyssa M. Topacio, Vanessa A. Montellano, W. Porter, E. Aronson","doi":"10.3733/ca.2022a0002","DOIUrl":"https://doi.org/10.3733/ca.2022a0002","url":null,"abstract":"Although the Salton Sea was once a thriving destination for humans and wildlife, it has now degraded to the point of ecosystem collapse. Increases in local dust emissions have introduced aeolian (wind-blown) microorganisms that travel, along with contaminants and minerals, into the atmosphere, detrimentally impacting inhabitants of the region. Proliferation of certain microbial groups in regions of the Sea may have a disproportionate impact on local ecological systems. Yet, little is known about how the biogeochemical processes of this drying lakebed influence microbial community composition and dispersal. To elucidate how these microorganisms contribute, and adapt, to the Sea's volatile conditions, we synthesize research on three niche-specific microbiomes — exposed lakebed (playa), the Sea, and aeolian — and highlight modern molecular techniques, such as metagenomics, coupled with physical science methodologies, including transport modeling, to predict how the drying lakebed will affect microbial processes. We argue that an explicit consideration of microbial groups within this system is needed to provide vital information about the distribution and functional roles of ecologically pertinent microbial groups. Such knowledge could help inform regulatory measures aimed at restoring the health of the Sea's human and ecological systems.","PeriodicalId":9409,"journal":{"name":"California Agriculture","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45319992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
While the Salton Sea was a relatively stable ecosystem for most of the 20th century, recent agricultural-to-urban water transfers have caused significant impacts on the region's ecology, including the expected loss of all fish and the fish-eating birds that are reliant on them. Photo: California DWR. The Salton Sea, located in Southern California, is a saline terminal lake that has had many identities over the past century or so. Since its reincarnation in 1905 due to lower Colorado River flooding that partially refilled the Salton Sink, it has been California’s largest lake by surface area, covering approximately 350 square miles (Water Education Foundation 2001). In the second half of the 20th century, it was referred to as one of the most productive fisheries in the world, drawing more than 1.5 million annual visitors in the 1960s — more than visited Yosemite National Park at the time — the majority of whom were there for fishing (Cohn 2000; Harris et al. 1969). Throughout the 20th century, with a habitat that supported over 400 species of migratory and resident birds and served as an important stopover along the Pacific Flyway, the Sea warranted recognition as one of the premier bird watching locations in the United States, if not the world (CNRA 2006; Cowan 2014; Schwabe et al. 2008). Yet with nearly 90% of its inflow comprised of agricultural drainage waters from the approximately 500,000 acres of irrigated farmland in the Imperial Irrigation District (IID), and exposure to an extremely arid climate that results in excessive evaporation (~ 1.3 million acre-feet annually), the Sea’s natural attractions have faded as the lake has become more polluted and nearly twice as saline as the ocean (Fogel and Schwabe 2021; Lyons and Hung 2021). Such an outcome was not unexpected given that while the Sea has played many roles in the past, its most well-known if not primary role from a management and water rights perspective has been as a “reservoir for irrigation drainage” (Littleworth and Garner 2017, p. 256). With the passage of the 2002 Quantification Settlement Agreement (QSA) — a local-state-federal
{"title":"The Salton Sea: An introduction to an evolving system and the role of science","authors":"K. Schwabe","doi":"10.3733/ca.2022a0006","DOIUrl":"https://doi.org/10.3733/ca.2022a0006","url":null,"abstract":"While the Salton Sea was a relatively stable ecosystem for most of the 20th century, recent agricultural-to-urban water transfers have caused significant impacts on the region's ecology, including the expected loss of all fish and the fish-eating birds that are reliant on them. Photo: California DWR. The Salton Sea, located in Southern California, is a saline terminal lake that has had many identities over the past century or so. Since its reincarnation in 1905 due to lower Colorado River flooding that partially refilled the Salton Sink, it has been California’s largest lake by surface area, covering approximately 350 square miles (Water Education Foundation 2001). In the second half of the 20th century, it was referred to as one of the most productive fisheries in the world, drawing more than 1.5 million annual visitors in the 1960s — more than visited Yosemite National Park at the time — the majority of whom were there for fishing (Cohn 2000; Harris et al. 1969). Throughout the 20th century, with a habitat that supported over 400 species of migratory and resident birds and served as an important stopover along the Pacific Flyway, the Sea warranted recognition as one of the premier bird watching locations in the United States, if not the world (CNRA 2006; Cowan 2014; Schwabe et al. 2008). Yet with nearly 90% of its inflow comprised of agricultural drainage waters from the approximately 500,000 acres of irrigated farmland in the Imperial Irrigation District (IID), and exposure to an extremely arid climate that results in excessive evaporation (~ 1.3 million acre-feet annually), the Sea’s natural attractions have faded as the lake has become more polluted and nearly twice as saline as the ocean (Fogel and Schwabe 2021; Lyons and Hung 2021). Such an outcome was not unexpected given that while the Sea has played many roles in the past, its most well-known if not primary role from a management and water rights perspective has been as a “reservoir for irrigation drainage” (Littleworth and Garner 2017, p. 256). With the passage of the 2002 Quantification Settlement Agreement (QSA) — a local-state-federal","PeriodicalId":9409,"journal":{"name":"California Agriculture","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48573610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The condition of the Salton Sea, California's largest lake, has profound implications for people and wildlife both near and far. Colorado River irrigation water has supported agricultural productivity in the basin's Coachella and Imperial valleys since the Sea formed over 100 years ago, bringing billions of dollars per year to the region and helping to feed households across the United States. The runoff, which drains into the Sea, has historically maintained water levels and supported critical fish and migratory bird habitats. However, since 2018, a large portion of the water previously allocated for agriculture has been diverted to urban regions, causing the Sea to shrink and become increasingly saline. This poses major threats to the Sea's ecology, as well as risks to human health, most notably in the noxious dust produced by the drying lakebed. To ensure continued agricultural and ecological productivity and protect public health, management of the Sea and surrounding wetlands will require increased research and mitigation efforts.
{"title":"Ecological transitions at the Salton Sea: Past, present and future","authors":"Timothy Bradley, H. Ajami, W. Porter","doi":"10.3733/ca.2022a0004","DOIUrl":"https://doi.org/10.3733/ca.2022a0004","url":null,"abstract":"The condition of the Salton Sea, California's largest lake, has profound implications for people and wildlife both near and far. Colorado River irrigation water has supported agricultural productivity in the basin's Coachella and Imperial valleys since the Sea formed over 100 years ago, bringing billions of dollars per year to the region and helping to feed households across the United States. The runoff, which drains into the Sea, has historically maintained water levels and supported critical fish and migratory bird habitats. However, since 2018, a large portion of the water previously allocated for agriculture has been diverted to urban regions, causing the Sea to shrink and become increasingly saline. This poses major threats to the Sea's ecology, as well as risks to human health, most notably in the noxious dust produced by the drying lakebed. To ensure continued agricultural and ecological productivity and protect public health, management of the Sea and surrounding wetlands will require increased research and mitigation efforts.","PeriodicalId":9409,"journal":{"name":"California Agriculture","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44714613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Trevor A. Biddle, Rajrupa Chakraborty, Qi Li, M. Maltz, J. Gerrard, David D. Lo
The Salton Sea is a drying salt lake in an arid region with high aerosol particulate-matter concentrations. This region is plagued by a high incidence of asthma, attributed in part to the aerosols surrounding the Sea. But the connection between the Sea and asthma may be more than simple calculations of dust concentrations. While dusts might contain toxic substances that impact the lungs of residents, the complex dynamics related to the environmental degradation of the Salton Sea may be generating additional toxins relevant to public health, such as microcystins produced by algal blooms. This collection of pollutants may be driving inflammatory responses in the lungs of residents through multiple mechanisms. As such, examination of the full range of potential environmental triggers of lung inflammation promises to yield a better understanding of key mechanisms driving the high incidence of asthma in local residents. Our discussion provides a perspective aiming to re-frame the issue in the context of the historical theory of “miasma” and the linkages between environmental change and health impacts.
{"title":"The drying Salton Sea and asthma: A perspective on a “natural” disaster","authors":"Trevor A. Biddle, Rajrupa Chakraborty, Qi Li, M. Maltz, J. Gerrard, David D. Lo","doi":"10.3733/ca.2022a0003","DOIUrl":"https://doi.org/10.3733/ca.2022a0003","url":null,"abstract":"The Salton Sea is a drying salt lake in an arid region with high aerosol particulate-matter concentrations. This region is plagued by a high incidence of asthma, attributed in part to the aerosols surrounding the Sea. But the connection between the Sea and asthma may be more than simple calculations of dust concentrations. While dusts might contain toxic substances that impact the lungs of residents, the complex dynamics related to the environmental degradation of the Salton Sea may be generating additional toxins relevant to public health, such as microcystins produced by algal blooms. This collection of pollutants may be driving inflammatory responses in the lungs of residents through multiple mechanisms. As such, examination of the full range of potential environmental triggers of lung inflammation promises to yield a better understanding of key mechanisms driving the high incidence of asthma in local residents. Our discussion provides a perspective aiming to re-frame the issue in the context of the historical theory of “miasma” and the linkages between environmental change and health impacts.","PeriodicalId":9409,"journal":{"name":"California Agriculture","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45642321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaochi Ma, H. Dahlke, R. Duncan, D. Doll, Paul Martinez, B. Lampinen, Astrid Volder
California signed the Sustainable Groundwater Management Act (SGMA) into law in 2014. SGMA requires groundwater-dependent regions to halt overdraft and develop plans to reach an annual balance of pumping and recharge. Groundwater aquifers can be recharged by flooding agricultural fields when fallow, but this has not been an option for perennial crops such as fruit and nut trees. While flooding these crops might be possible during the dormant season, it is not known what impact flooding might have on tree-root systems, health and yield. We followed root production, tree water status and yield in two almond orchards in Northern California for 2 years to test the impact of applying captured winter water runoff for groundwater recharge purposes on tree performance. Results showed that more than 90% of the water applied to sandy soil and 80% of the water applied to loamy soil percolated past the root zones, with no measured adverse effects on tree water status, canopy development or yield. Groundwater recharge did not negatively affect new root production and tended to extend root lifespan. Based upon these data, applying additional water in late December and January is not likely to have negative impacts on almond orchards in moderately drained to well-drained soils.
{"title":"Winter flooding recharges groundwater in almond orchards with limited effects on root dynamics and yield","authors":"Xiaochi Ma, H. Dahlke, R. Duncan, D. Doll, Paul Martinez, B. Lampinen, Astrid Volder","doi":"10.3733/ca.2022a0008","DOIUrl":"https://doi.org/10.3733/ca.2022a0008","url":null,"abstract":"California signed the Sustainable Groundwater Management Act (SGMA) into law in 2014. SGMA requires groundwater-dependent regions to halt overdraft and develop plans to reach an annual balance of pumping and recharge. Groundwater aquifers can be recharged by flooding agricultural fields when fallow, but this has not been an option for perennial crops such as fruit and nut trees. While flooding these crops might be possible during the dormant season, it is not known what impact flooding might have on tree-root systems, health and yield. We followed root production, tree water status and yield in two almond orchards in Northern California for 2 years to test the impact of applying captured winter water runoff for groundwater recharge purposes on tree performance. Results showed that more than 90% of the water applied to sandy soil and 80% of the water applied to loamy soil percolated past the root zones, with no measured adverse effects on tree water status, canopy development or yield. Groundwater recharge did not negatively affect new root production and tended to extend root lifespan. Based upon these data, applying additional water in late December and January is not likely to have negative impacts on almond orchards in moderately drained to well-drained soils.","PeriodicalId":9409,"journal":{"name":"California Agriculture","volume":"22 21 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69778477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. York, Jacob I. Levine, Daniel E. Foster, S. Stephens, B. Collins
A significant expansion of prescribed fire activity will be necessary to mitigate growing wildfire hazard in California forests. Forest managers can facilitate this expansion by promoting forest structures that allow for more effective implementation of prescribed fire, for both initial-entry and repeat burns. We analyzed changes in surface fuel during a series of three burns in replicated mixed-conifer stands following a period of over 100 years of fire suppression and exclusion. Total fuel load, proportion of pine present, canopy cover and basal area of live trees were relevant forest-structure components that influenced plot-scale fuel consumption. The study highlighted the importance of pre-fire fuel load and the relative proportion of pine in the overstory, which both led to greater amounts of fuel consumption. The initial-entry burn dramatically reduced all fuel categories (fine fuel, coarse wood and duff). Following each burn, fuel recovered until the next burn reduced loads enough to maintain low fuel levels. We apply the results to provide an example of how to determine the timing of prescribed fires.
{"title":"Silviculture can facilitate repeat prescribed burn programs with long-term strategies","authors":"R. York, Jacob I. Levine, Daniel E. Foster, S. Stephens, B. Collins","doi":"10.3733/ca.2021a0016","DOIUrl":"https://doi.org/10.3733/ca.2021a0016","url":null,"abstract":"A significant expansion of prescribed fire activity will be necessary to mitigate growing wildfire hazard in California forests. Forest managers can facilitate this expansion by promoting forest structures that allow for more effective implementation of prescribed fire, for both initial-entry and repeat burns. We analyzed changes in surface fuel during a series of three burns in replicated mixed-conifer stands following a period of over 100 years of fire suppression and exclusion. Total fuel load, proportion of pine present, canopy cover and basal area of live trees were relevant forest-structure components that influenced plot-scale fuel consumption. The study highlighted the importance of pre-fire fuel load and the relative proportion of pine in the overstory, which both led to greater amounts of fuel consumption. The initial-entry burn dramatically reduced all fuel categories (fine fuel, coarse wood and duff). Following each burn, fuel recovered until the next burn reduced loads enough to maintain low fuel levels. We apply the results to provide an example of how to determine the timing of prescribed fires.","PeriodicalId":9409,"journal":{"name":"California Agriculture","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69778275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Taylor S. Nelsen, Michael Rodriguez, Ethan McCullough, Serena N. Lewin, D. Geisseler, Konrad Mathesius, Taylor Becker, Gabriel G. Rosa, M. Lundy
Small-grain crop growers need to match their crops' nitrogen (N) needs with fertilizer applications. This can be challenging because small grains are grown under diverse conditions and their growing season interacts with unpredictable precipitation. Resulting conditions can lead to nitrate-N leaching and runoff losses. More widespread and accurate soil N testing could help growers improve N fertilizer use efficiency, reduce the risk of N loss, and fulfill regulatory requirements. Soil samples from across California small-grain growing regions were tested with a soil nitrate quick test as well as standard laboratory procedures. The quick test is inexpensive and easy to use, and it provides rapid results. A correction factor was developed to convert the quick test values to lab and fertilizer equivalents. The correction factor is based on site-specific soil bulk density and the extracting solution used. An interactive webtool was developed that integrates this information for users. The quick tests provide accurate, real-time estimates of soil nitrate-N in the field to help improve fertilizer use efficiency and reduce N losses.
{"title":"Improvements to the soil nitrate quick test for California small grains","authors":"Taylor S. Nelsen, Michael Rodriguez, Ethan McCullough, Serena N. Lewin, D. Geisseler, Konrad Mathesius, Taylor Becker, Gabriel G. Rosa, M. Lundy","doi":"10.3733/ca.2022a0009","DOIUrl":"https://doi.org/10.3733/ca.2022a0009","url":null,"abstract":"Small-grain crop growers need to match their crops' nitrogen (N) needs with fertilizer applications. This can be challenging because small grains are grown under diverse conditions and their growing season interacts with unpredictable precipitation. Resulting conditions can lead to nitrate-N leaching and runoff losses. More widespread and accurate soil N testing could help growers improve N fertilizer use efficiency, reduce the risk of N loss, and fulfill regulatory requirements. Soil samples from across California small-grain growing regions were tested with a soil nitrate quick test as well as standard laboratory procedures. The quick test is inexpensive and easy to use, and it provides rapid results. A correction factor was developed to convert the quick test values to lab and fertilizer equivalents. The correction factor is based on site-specific soil bulk density and the extracting solution used. An interactive webtool was developed that integrates this information for users. The quick tests provide accurate, real-time estimates of soil nitrate-N in the field to help improve fertilizer use efficiency and reduce N losses.","PeriodicalId":9409,"journal":{"name":"California Agriculture","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69778586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The amount of soil organic matter is a critical indicator of soil health. Applying compost or manure, growing cover crops, reducing tillage, and increasing crop diversity may increase soil organic matter. However, soil organic matter can vary dramatically in different environments, regardless of management practices. This calls for a framework to recommend place-based soil health practices and evaluate their outcomes. We used a new framework that groups soil survey data into seven regions in California's Central Valley and Central Coast. These regions either have performance limitations, such as root restrictive horizons, salinity, and shrink-swell behavior, or have relatively homogeneous, coarse-to-loamy soils ideal for agriculture. These inherent conditions affect a soil's response to practices designed to improve soil health. Looking at vineyards as an example, we find significant soil organic matter contrasts between soil health regions but not among contrasting management approaches within a given region. We also show that conservation practices improve or help maintain soil health in several long-term experiments, but inherent soil properties and types of cropping systems affect outcomes.
{"title":"Soil health practices have different outcomes depending on local soil conditions","authors":"Scott M. Devine, K. Steenwerth, A. O’Geen","doi":"10.3733/ca.2022a0005","DOIUrl":"https://doi.org/10.3733/ca.2022a0005","url":null,"abstract":"The amount of soil organic matter is a critical indicator of soil health. Applying compost or manure, growing cover crops, reducing tillage, and increasing crop diversity may increase soil organic matter. However, soil organic matter can vary dramatically in different environments, regardless of management practices. This calls for a framework to recommend place-based soil health practices and evaluate their outcomes. We used a new framework that groups soil survey data into seven regions in California's Central Valley and Central Coast. These regions either have performance limitations, such as root restrictive horizons, salinity, and shrink-swell behavior, or have relatively homogeneous, coarse-to-loamy soils ideal for agriculture. These inherent conditions affect a soil's response to practices designed to improve soil health. Looking at vineyards as an example, we find significant soil organic matter contrasts between soil health regions but not among contrasting management approaches within a given region. We also show that conservation practices improve or help maintain soil health in several long-term experiments, but inherent soil properties and types of cropping systems affect outcomes.","PeriodicalId":9409,"journal":{"name":"California Agriculture","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47259485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Grapevine trunk diseases (GTDs) are currently considered some of the most important challenges for viticulture, curtailing vineyard longevity and productivity in nearly every raisin, table and wine grape production region in California and worldwide. Pruning wounds provide the main entry point for fungal pathogens responsible for these diseases; pathogens enter the wounds following precipitation events. The aim of this study was to evaluate the efficacy of selected chemical and experimental biological fungicides for protection of pruning wounds against two of the most common and virulent fungal pathogens causing GTDs: Eutypa lata and Neofusicoccum parvum. This study was conducted on sauvignon blanc at the UC Davis Department of Plant Pathology Field Station. Results showed that several chemical and biological fungicides, notably the chemical fungicide Luna Sensation, the biofungicide Vintec and a combination of the biofungicides Bio-Tam and CrabLife Powder, provided significant protection against at least one of the two canker pathogens used in this study. However, the majority of products tested did not provide simultaneous control of both E. lata and N. parvum pathogens, highlighting the continuing challenge of controlling GTDs.
{"title":"Biological and chemical pruning wound protectants reduce infection of grapevine trunk disease pathogens","authors":"R. Blundell, A. Eskalen","doi":"10.3733/ca.2021a0018","DOIUrl":"https://doi.org/10.3733/ca.2021a0018","url":null,"abstract":"Grapevine trunk diseases (GTDs) are currently considered some of the most important challenges for viticulture, curtailing vineyard longevity and productivity in nearly every raisin, table and wine grape production region in California and worldwide. Pruning wounds provide the main entry point for fungal pathogens responsible for these diseases; pathogens enter the wounds following precipitation events. The aim of this study was to evaluate the efficacy of selected chemical and experimental biological fungicides for protection of pruning wounds against two of the most common and virulent fungal pathogens causing GTDs: Eutypa lata and Neofusicoccum parvum. This study was conducted on sauvignon blanc at the UC Davis Department of Plant Pathology Field Station. Results showed that several chemical and biological fungicides, notably the chemical fungicide Luna Sensation, the biofungicide Vintec and a combination of the biofungicides Bio-Tam and CrabLife Powder, provided significant protection against at least one of the two canker pathogens used in this study. However, the majority of products tested did not provide simultaneous control of both E. lata and N. parvum pathogens, highlighting the continuing challenge of controlling GTDs.","PeriodicalId":9409,"journal":{"name":"California Agriculture","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45912044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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