Agricultural & Environmental Letters最新文献

{"title":"Evaluating how operator experience level affects efficiency gains for precision agricultural tools","authors":"Tulsi P. Kharel,&nbsp;Amanda J. Ashworth,&nbsp;Phillip R. Owens","doi":"10.1002/ael2.20085","DOIUrl":"10.1002/ael2.20085","url":null,"abstract":"<p>Tractor guidance (TG) improve environmental gains relative to nonprecision technologies; however, studies evaluating how tractor operator experience for nonguidance comparisons affect gains are nonexistent. This study explores spatial relationships of overlaps and gaps with operator experience level (0–1, 2–3, 6+ yr) during fertilizer and herbicide applications based on terrain attributes. Tractor paths recorded by global navigation satellite systems were used to create overlap polygons. Results illustrate operator experience level is critical for better efficiency gains estimation (for non-TG comparisons). Operators with 6+ yr of experience reduced overlap by 7.7 and 20.6% compared with operators with 2–3 and 0–1 yr of experience, respectively. New operators had consistently higher overlap across all slope (&lt;0.5, 0.5–1, 1–2, 2–5, 5–9, and 9–15%) and roughness classes (&lt;0.1, 0.1–0.2, 0.2–0.3, 0.3–0.5, 0.5–0.7, 0.7–1 and &gt;1). A low interpersonal reliability value of 0.02–0.03 indicates operator experience is crucial to estimate TG efficiency gains and consistent drivers experience levels are needed when evaluating economic and environmental gains from TG.</p>","PeriodicalId":48502,"journal":{"name":"Agricultural & Environmental Letters","volume":"7 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2022-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/ael2.20085","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48654780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pollinator research provides conservation management implications in North Dakota","authors":"Katherine C. Kral-O'Brien,&nbsp;Savannah Adams,&nbsp;Adrienne Antonsen,&nbsp;Cayla Bendel,&nbsp;Hailey Keen,&nbsp;C. K. Pei,&nbsp;Bethany Roberton,&nbsp;Benjamin Geaumont,&nbsp;Ryan Limb,&nbsp;Torre Hovick,&nbsp;Jason Harmon","doi":"10.1002/ael2.20086","DOIUrl":"10.1002/ael2.20086","url":null,"abstract":"<p>Pollinator declines have driven research and increased monitoring efforts. Within North Dakota, USA, our research group initiated research in 2015 on pollinator conservation and management. We synthesized results across five projects, producing 12 publications and providing baseline data on pollinator diversity and rangeland management to improve conservation efforts while land-sharing with livestock. We detected 76 species of butterflies and ∼318 bee species. Butterfly diversity and relative abundance were driven by floral resources and less exotic plant invasions, with a positive relationship between flowers and pollinators. Invasive forbs were visited by pollinators, primarily honey bees. We also found management influenced vegetation characteristics within pastures, but landscape context was important for determining the specific outcome. Although pollinator abundance did not distinctly respond to management, diversity was affected by regime and grazer type. Using fire and grazing may benefit flowers to support pollinators. Our research will help guide rangeland management decisions that promote land sharing and benefit pollinator conservation efforts.</p><p><b>Core Ideas</b>\u0000 \u0000 </p>","PeriodicalId":48502,"journal":{"name":"Agricultural & Environmental Letters","volume":"7 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2022-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/ael2.20086","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45958084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probing deep to express root-zone enrichment of soil-test biological activity on southeastern U.S. farms","authors":"Alan J. Franzluebbers","doi":"10.1002/ael2.20087","DOIUrl":"10.1002/ael2.20087","url":null,"abstract":"<p>Soil organic carbon (C) and nitrogen (N) accumulation contributes to improved soil health condition, particularly after a history of tillage-intensive land use. Soil-test biological activity (STBA) is an active fraction of organic matter that is responsive to conservation management. This essay summarizes the need, concept, and method of calculating root-zone enrichment of STBA and other organic C and N fractions on private farms. Calculation of root-zone enrichment separates the pedogenic influence on organic matter content from that of contemporary management. This separation is particularly important when attempting to determine STBA or soil organic C stock change in response to management across variable landscapes. Reasonable farm-level estimates of STBA and stocks of soil organic C and N can be obtained from one to two dozen sampling sites on farms with differences in land use, a process that could help propel in-depth assessments of soil health condition and C stock change.</p>","PeriodicalId":48502,"journal":{"name":"Agricultural & Environmental Letters","volume":"7 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2022-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/ael2.20087","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44748194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Addressing conservation practice limitations and trade-offs for reducing phosphorus loss from agricultural fields","authors":"Peter J. A. Kleinman,&nbsp;Deanna L. Osmond,&nbsp;Laura E. Christianson,&nbsp;Don N. Flaten,&nbsp;James A. Ippolito,&nbsp;Helen P. Jarvie,&nbsp;Jason P. Kaye,&nbsp;Kevin W. King,&nbsp;April B. Leytem,&nbsp;Joshua M. McGrath,&nbsp;Nathan O. Nelson,&nbsp;Amy L. Shober,&nbsp;Douglas R. Smith,&nbsp;Kenneth W. Staver,&nbsp;Andrew N. Sharpley","doi":"10.1002/ael2.20084","DOIUrl":"10.1002/ael2.20084","url":null,"abstract":"<p>Conservation practices that reduce nutrient and soil loss from agricultural lands to water are fundamental to watershed management programs. Avoiding trade-offs of conservation practices is essential to the successful mitigation of watershed phosphorus (P) losses. We review documented trade-offs associated with conservation practices, particularly those practices that are intended to control and trap P from agricultural sources. A regular theme is the trade-off between controlling P loss linked to sediment while increasing dissolved P losses (no-till, cover crops, vegetated buffers, constructed wetlands, sediment control basins). A variety of factors influence the degree to which these trade-offs occur, complicated by their interaction and uncertainties associated with climate change. However, acknowledging these trade-offs and anticipating their contribution to watershed outcomes are essential to the sustainability of conservation systems.</p>","PeriodicalId":48502,"journal":{"name":"Agricultural & Environmental Letters","volume":"7 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2022-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/ael2.20084","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43408206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mercury accumulation in honey bees trends upward with urbanization in the USA","authors":"Prashant Waiker,&nbsp;Yener Ulus,&nbsp;Martin Tsz-Ki Tsui,&nbsp;Olav Rueppell","doi":"10.1002/ael2.20083","DOIUrl":"10.1002/ael2.20083","url":null,"abstract":"<p>Urbanization has profound implications for associated ecosystems and organisms. Monitoring pollutants inform risk assessments for human and wildlife health. Honey bees (<i>Apis mellifera</i>) forage widely and collect food from many sources. Thus, they may be a robust integrator of environmental pollutants. Here, we collected honey bees from 10 different locations across the United States to quantify their content of total mercury (THg) and methylmercury (MeHg). Although our limited sample size prevented a meaningful statistical evaluation, we found that bees from urbanized areas had higher THg than those from rural areas, with suburban samples intermediate. The MeHg concentrations in all samples were below the detection limit. Despite its limited scope, this first preliminary dataset on Hg levels in honey bees across the United States suggests that urbanization may play a role in increasing Hg exposure to these pollinators, and that honey bees may be a useful biomonitor of the environmental presence of chemical pollutants.</p>","PeriodicalId":48502,"journal":{"name":"Agricultural & Environmental Letters","volume":"7 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2022-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/ael2.20083","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45052836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Missing the grassland for the cows: Scaling grass-finished beef production entails tradeoffs—Comment on “Grazed perennial grasslands can match current beef production while contributing to climate mitigation and adaptation”","authors":"Matthew Hayek","doi":"10.1002/ael2.20073","DOIUrl":"10.1002/ael2.20073","url":null,"abstract":"&lt;p&gt;In a recent commentary article, Randall Jackson (&lt;span&gt;2022&lt;/span&gt;) claims that U.S. maize croplands currently growing cattle feed can be converted to perennial pastures without incurring either a loss of beef production or agricultural expansion. Grass-finished cattle fatten up slower and reach lower slaughter weights than grain-finished cattle (Pelletier et al., &lt;span&gt;2010&lt;/span&gt;). Therefore, to support present beef production using only pastures, more finishing cattle must be raised and slaughtered. The author recognizes this and attempts to quantify whether current maize production regions could instead grow sufficient perennial grasses and forages. He finds that an additional 7.6 million finishing cattle must be raised to produce exclusively grass-fed beef. He then calculates that 4.9 million ha of maize croplands growing cattle feed could, instead, grow sufficient grass to support these cattle.&lt;/p&gt;&lt;p&gt;However, the author makes a fundamental oversight—those 7.6 million additional finishing cattle must come from somewhere; they need mothers. Finishing cattle are supported on the “back end” by large cow-calf and stocker herds on pastures, who replace the current finishing cattle when they are slaughtered. Unlike pigs and chickens who can have many offspring per year, cows have long gestation periods of 9 mo, like humans, birthing at most one offspring each year. Cow gestation periods are so long and cattle maturity is so slow that cattle on pastures outnumber finishing cattle in feedlots by nearly five to one (Figure 1).&lt;/p&gt;&lt;p&gt;To raise 7.6 million more grass-finished cattle, U.S. ranchers would need to raise 7.7 million more cows, along with 7.8 million more calves and stocker cattle on pastures. Altogether, an exclusively grass-finished system requires 23.1 million (30%) more cattle to produce the same quantity of beef (Table 1), not 7.6 million (10%) more as the author models. We published these findings in a study that was cited by the author (Hayek &amp; Garrett, &lt;span&gt;2018&lt;/span&gt;), but he missed this central finding.&lt;/p&gt;&lt;p&gt;Larger grass-finished cattle herds require additional resources. Optimistically, a maximum of 71% of current production could be met if the United States shifted its maize feed crops for finishing cattle to perennial forages (Hayek &amp; Garrett, &lt;span&gt;2018&lt;/span&gt;). We assumed a similar potential forage yield on current maize croplands of 10.3 dry matter (DM) ha&lt;sup&gt;–1&lt;/sup&gt; yr&lt;sup&gt;–1&lt;/sup&gt;, which lies within the author's range of 8–12 DM ha&lt;sup&gt;–1&lt;/sup&gt; yr&lt;sup&gt;–1&lt;/sup&gt;. Maintaining these yields requires fertilizer inputs: we assumed forages were produced using conventional hay and alfalfa production, and the author's range of 8–12 DM ha&lt;sup&gt;–1&lt;/sup&gt; yr&lt;sup&gt;–1&lt;/sup&gt; is derived from a study of U.S. Upper Midwest pastures that applied fertilizer at a rate of 57 kg N ha&lt;sup&gt;–1&lt;/sup&gt; yr&lt;sup&gt;–1&lt;/sup&gt; (Oates et al., &lt;span&gt;2011&lt;/span&gt;). These findings are consistent with multiple other studies, which demonstrate that grass-f","PeriodicalId":48502,"journal":{"name":"Agricultural & Environmental Letters","volume":"7 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2022-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/ael2.20073","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43017128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reply to “Missing the grassland for the cows: Scaling grass-finished beef production entails tradeoffs—Comment on ‘Grazed perennial grasslands can match current beef production while contributing to climate mitigation and adaptation’ ”","authors":"Randall D. Jackson","doi":"10.1002/ael2.20082","DOIUrl":"10.1002/ael2.20082","url":null,"abstract":"&lt;p&gt;Matthew Hayek's response to my commentary (Jackson, &lt;span&gt;2022&lt;/span&gt;) is a valuable contribution to an important conversation about how we can provide for our wants and needs while improving our environment. My commentary purposefully simplified a complex topic to encourage interrogation of whether we have the capacity to meet current beef supply (5.9 billion kg yr&lt;sup&gt;–1&lt;/sup&gt;) by finishing cattle on grassland rather than grain in feedlots. Hayek and I agree that this would require 7.6 million additional finishing cattle because grass-finished cattle take longer to finish and grow less overall (Hayek &amp; Garrett, &lt;span&gt;2018&lt;/span&gt;). My assessment was that we would need ∼16.1 million ha for all 20 million finishing cattle and that we could use the 4.9 million ha currently growing maize for cattle in feedlots, plus ∼12 million ha growing maize for ethanol, which constitutes a net loss of energy coupled with devastating environmental outcomes (Lark, &lt;span&gt;2020&lt;/span&gt;). We seem to agree that there's enough land for the finishing cattle, but Hayek encourages us to consider the upstream supply chain and its ramifications.&lt;/p&gt;&lt;p&gt;Hayek observes that these additional finishing cattle would require more cows, calves, and stocker cattle (∼23.1 million more animals) to reproduce and replace the finishing cattle (Hayek &amp; Garrett, &lt;span&gt;2018&lt;/span&gt;), resulting in ∼18.6 million more grassland ha needed for grazing these feeder cattle. I argue that we desperately &lt;i&gt;need&lt;/i&gt; this increased demand for grassland, especially if it replaces cropping systems prone to soil, carbon, and nutrient loss to the atmosphere and waters, where conservation interventions such as no-till, cover crops, and semi-annual forages (e.g., alfalfa) improve, but do not stop, these losses (Lintern et al., &lt;span&gt;2020&lt;/span&gt;; Osterholz et al., &lt;span&gt;2019&lt;/span&gt;; Roland et al., &lt;span&gt;2022&lt;/span&gt;). Inasmuch as most of this feeder-cattle rearing is currently done on rangelands of the West, nearly half of this could occur on the ∼9 million ha of Great Plains land growing corn, soybeans, and alfalfa irrigated with water that is drawing down the Ogallala Aquifer (Carnes &amp; Sanderson, &lt;span&gt;2022&lt;/span&gt;; Evett et al., &lt;span&gt;2020&lt;/span&gt;). Much of these products are fed to livestock, but according to the Iowa Corn website (www.iowacorn.org), much of the corn grain in the United States is exported (11% or ∼4.4 million ha) and much of it is considered “surplus” for “residual use” (9% or ∼3.6 million ha). It is important to note that the exports are sold by aggregator corporations to relatively affluent countries to build corporate wealth and often the surplus corn grain is “dumped” on global markets to suppress prices elsewhere (Hansen-Kuhn &amp; Murphy, &lt;span&gt;2017&lt;/span&gt;).&lt;/p&gt;&lt;p&gt;In more humid regions where feeder cattle are raised on pastures, most of this is done with continuous grazing, which undermines the yield potential of the pastures compared with well-managed rotational grazing t","PeriodicalId":48502,"journal":{"name":"Agricultural & Environmental Letters","volume":"7 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2022-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/ael2.20082","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43789109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Post-harvest drone flights to measure weed growth and yield associations","authors":"Jarrod O. Miller,&nbsp;Amy L. Shober,&nbsp;Mark J. VanGessel","doi":"10.1002/ael2.20081","DOIUrl":"10.1002/ael2.20081","url":null,"abstract":"<p>Drone flights are often only performed during the growing season, with no data collected once harvest has been completed, although they could be used to measure winter annual weed growth. Using a drone mounted with a multispectral sensor, we flew small plot corn (<i>Zea mays</i> L.) fertility, cover crop, and population studies at black layer and 0–14 d after harvest (DAH). Yields had positive correlations to normalized difference vegetation index (NDVI) at black layer but often had negative correlations to corn yields 0–14 DAH. After harvest, NDVI could be associated with weed growth, and negative correlations to yield could point to reduced corn canopy allowing light to reach late-season weeds. In fertility studies, excess nitrogen appears to increase weed biomass after harvest, which can be easily identified through drone imagery. Flights should be performed after corn harvest as weed growth may provide additional insight into management decisions.</p>","PeriodicalId":48502,"journal":{"name":"Agricultural & Environmental Letters","volume":"7 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2022-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/ael2.20081","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43995427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Overlooked tools for studying soil nitrogen depolymerization: Aminopeptidase assays using nitroanilide substrates","authors":"Andrew J Margenot,&nbsp;Rachel C Daughtridge","doi":"10.1002/ael2.20079","DOIUrl":"10.1002/ael2.20079","url":null,"abstract":"<p>Aminopeptidases are one of the extracellular hydrolytic enzymes that catalyze organic nitrogen (N) depolymerization and are commonly assayed using fluorogenic substrates. However, chromogenic substrates based on <i>para</i>-nitroaniline (<i>p</i>NA) developed for the study of aminopeptidases in the 1960s have been underutilized. To gauge the use of <i>p</i>NA substrates to assay soil aminopeptidases, a systematic literature review was conducted. We identified 61 studies that were nearly all limited to measuring leucine and/or glycine aminopeptidases, despite the commercial availability of at least six other aminopeptidase-specific <i>p</i>NA substrates. Assay parameters of scale (slurry vs. direct incubations), matrix type, buffer pH, substrate concentration, assay duration and temperature, termination, and colorimetry indicated a lack of standardization and a confusion of <i>p</i>NA with <i>p</i>NP substrates despite important differences in abiotic hydrolysis and absorbance maxima. Future studies should systematically evaluate and standardize these parameters and assess the sensitivity of other amino acid-specific aminopeptidases to carbon (C), N, and sulfur (S) cycling.</p>","PeriodicalId":48502,"journal":{"name":"Agricultural & Environmental Letters","volume":"7 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2022-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/ael2.20079","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42447096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How can we estimate optimum fertilizer rates with accuracy and precision?","authors":"Fernando E. Miguez,&nbsp;Hanna Poffenbarger","doi":"10.1002/ael2.20075","DOIUrl":"10.1002/ael2.20075","url":null,"abstract":"<p>For decades, agronomists have invested time and resources to identify the optimum nitrogen (N) rates for cereal crops. The most common method for estimating the agronomic optimum N rate (AONR) is to design a field experiment with several N fertilizer rates and fit a regression model to the yield observations. Here, we concentrate on its accuracy and precision given choices of experimental design and statistical analysis. Our first finding is that the choice of functional form has a large agronomic effect on the estimate of the AONR, and this depends on the data-generating model. Our second finding is that improving the precision and accuracy of AONR estimates will demand an increase in the number of N rates and replications. Finally, we propose that using either the best-fitting model or a weighted model is preferable to always choosing either the linear-plateau (negative bias) or quadratic-plateau (positive bias) models.</p>","PeriodicalId":48502,"journal":{"name":"Agricultural & Environmental Letters","volume":"7 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2022-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/ael2.20075","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46443744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}