Use Of Herbicides Research Articles

Efficacy of herbicides and reductant at different levels to control invasive tall reed (Phragmites karka) in oil palm plantations

Controlling Phragmites karka, a highly invasive weed, is critical for peat areas since this species is a significantand hard-to control weed in oil palm plantations. Herbicides are one of the most effective and efficient tools for controlling P. karka, and their use is increasing due to their ability to provide rapid and long-term results. However, herbicides must be applied responsibly and carefully to minimize any environmental impacts. The study included an evaluation of the effectiveness of several combinations of herbicides on P. karka in an oil palm plantation and a comparison of their efficiency and cost. Results showed that combination of 1.8 L/ha glyphosate, 0.045 L/ha topramezone and 0.3 L/ha reductant Y (G7) has a promising result in controlling P. karka (weed mortality of 97% until 8 WAA and 12% regrowth until 12 WAA) and was more cost-effective compared to estate practice, reducing cost up to 0.43% per hectare because of the use of pesticide reductant. The use of reductant technology in this treatment also showed an effectiveness in reducing application frequency. This study demonstrates that herbicides can effectively and efficiently control P. karka in oil palm plantations, especially in peat land. Reductant can be one of the solutions to reduce the use of herbicides without lessening the efficacy, affordably, and sustainably.

Comparison of several weed control and tillage techniques in suppressing weeds and increasing maize production for integrated weed control

The use of herbicides has received attention due to its effects on human health, sustainability, and biodiversity due to toxic chemicals in herbicides. Repeated use of herbicide active ingredients over a long period of time can result in the emergence of resistant weeds. One strategy to reduce the herbicide use without decreasing productivity is integrated weed control. This study aims to compare the effectiveness of several weed control techniques in integrated weed control and their role in suppressing weeds and increasing maize crop production. This study used a Randomized Group Design with 2 factorials. The first factor was weed control technique (W) with levels: no control (W0), cover crop (W1), pre-emergent herbicide (W2), post-emergent herbicide (W3), and weed-free (with weeding) (W4). And the second factor was tillage technique (T), namely: no tillage (T0) and conventional tillage (T1). The results showed that post-emergent herbicides were more effective in controlling weeds and the highest crop production with weed control techniques with pre-emergent herbicides. The tillage technique had no significant effect on weeds and maize crop production.

ADOPTION OF IMPROVED PRODUCTION TECHNOLOGIES AMONG RICE FARMERS IN WASE LOCAL GOVERNMENT AREA OF PLATEAU STATE, NIGERIA

This study assessed adoption of improved production technologies among rice farmers’ in Wase Local Government Areas of Plateau State, Nigeria. Multistage sampling technique was used in the selection of 160 respondents for the study. Descriptive statistics, four point Likert scale and Logit regression were used to achieve the objectives of the study. Findings from the study revealed the mean age of the farmers to be 40years. Majority (67%) of the respondents were males and 91% of them married. 44% of the respondents had secondary education and a mean farming experience of 8 years. Majority (64%) of the respondents had farming as their major occupation on average farm sizes of 1.6 hectares. The mean annual income of the farmers was N 202,356. Improved rice production technologies such as appropriate time of harvesting (3.44), land preparation by tractors (3.42), recommended time of weeding (3.41), appropriate planting dates (3.25), use of herbicides (3.24), improved seed varieties (3.11), application of recommended fertilizer (3.05), nursery practice and transplanting (2.73) all had high levels of awareness and adoption respectively among the farmers. Age, educational status, farming experience, farm size, extension contact and annual income were significant determinant of adoption of improved rice production technologies. High cost of technology (69%), inadequate extension contact (61%) inadequate credit access (48%) and lack of accessibility of some technologies (28.0) were the major constraints affecting adoption of improved rice production technologies. The study recommended the subsidization of inputs (improved seeds, fertilizers and agro-chemicals) by government to reduce cost of production.

Heavy metals contamination and ecological risks in agricultural soils of Uşak, western Türkiye: a geostatistical and multivariate analysis.

This research aimed to determine and evaluate the concentrations ofAs, Cu, Hg, Ni, and Pb, and the physicochemical properties of 48 agricultural soil samples, to identify potential ecological risks and their sources associated with heavy metals contamination in Usak, western Türkiye. Various methods were used to assess ecological risks, including geoaccumulation index (Igeo), enrichment factor (EF), degree of contamination (Cdeg), potential ecological risk (RI), and pollution load index (PLI). The heavy metals concentrations ranged from 4 to 61mg/kg for As, 8-48mg/kg for Cu, 0.01-0.06mg/kg for Hg, 30-813mg/kg for Ni, and 4-30mg/kg for Pb. The mean As and Ni concentrations were much greater than Earth's crustal average, the world's mean values, and mean values from many other emerging countries. Igeo and EF values for As, Ni, and Pb indicate various degrees of contamination. Cdeg values show that 96% of the study area is affected to some degree by contamination. For RI values, 38% indicate ecological risks ranging from moderate to considerable degrees. PLI values show that 75% of the agricultural soils are moderately polluted. Spatial distribution maps of Cdeg, RI, and PLI show that the northeastern and southwestern parts of the study area have been polluted to different levels by As, Ni, and Pb. Industrial activities and excessive use of fertilizers, pesticides, fungicides, and herbicides were identified as major sources of heavy metals contamination in the agricultural soils of Uşak.

Soil solarization as a non-chemical weed control method in tree nursery production systems of the Pacific Northwest, USA

IntroductionHerbicide application in tree nurseries is limited because of the potential for chemical injury to the large diversity of trees species grown, the lack of registered products, and increasing restrictions on herbicide use, necessitating the costly practice of hand weeding. Soil solarization can reduce the weed seedbank by trapping solar energy under clear plastic film, resulting in high soil temperatures lethal to imbibed weed seeds and seedlings. The objective of this study was to determine if soil solarization would be an effective weed management strategy in Pacific Northwest, USA, tree production systems.MethodsField studies were conducted at three commercial tree nurseries in Oregon and Washington over two years to test soil solarization in reducing the naturally occurring weed seedbank and the time required to hand weed fields. Further field and laboratory tests were conducted with five weed species: Poa annua, Polygonum pensylvanicum, Amaranthus retroflexus, Portulaca oleracea, and Cyperus esculentus. Weed seeds and tubers were buried in packets at 5 and 10 cm to determine their viability after 6 weeks of solarization. A laboratory study was conducted with all but C. esculentus to quantify the exposure time at 45, 50, and 55°C required for 90% death (T90).ResultsSoil solarization was particularly effective in reducing the emergence of naturally occurring weeds in the fall and winter, when weed emergence was reduced by 94-96%. Emergence was reduced 67-81% during the subsequent spring and early summer. Nine to ten months after solarization, solarized areas had a 52 – 69% reduction in hand weeding time compared to non-solarized areas. In field trials with buried seed and tuber packets, mortality differed by location and depth, with P. annua and P. pensylvanicum having the greatest percent seed mortality followed by A. retroflexus and variable results for P. oleracea and C. esculentus. In lab studies, seed mortality differed depending on species and temperature; however, at 55°C, there was a relatively rapid drop in seed viability for all species, and T90 values ranged from 1.2 to 41 h whereas at 45°C the range was 47 to > 3000 h. Similar to the field studies, P. annua and P. pensylvancium were more sensitive to heat, followed by A. retroflexus and P. oleracea.ConclusionSoil solarization can be an effective weed management tool in reducing the weed seedbank in Pacific Northwest tree nurseries and other fall-sown crops but may not work for certain, thermotolerant weed species such as C. esculentus.

Survey of herbicide and fungicide use in peanut in North Carolina and Virginia in the United States

Plain Language SummaryDiseases and weeds can reduce yield of peanut (Arachis hypogaea L.) if effective control measures including fungicides and herbicides are not used. A survey of 76 farmers in North Carolina and Virginia at Cooperative Extension Service meetings was completed relative to fungicide and herbicide use in 2021. Eighty‐two percent of farmers made between three and five herbicide applications, while 68% of farmers made between four and five fungicide applications. 2,4‐DB was the herbicide applied most frequently. The fungicide chlorothalonil was applied the most often. Pydiflumetofen was applied by 61% of farmers. Results from this survey can be used to inform regulatory agencies on pesticide use patterns by defining the relative importance of individual or groups of pesticides currently used to suppress pests and prevent or mitigate associated economic losses.

Herbicide‐resistant weeds from dryland agriculture in Argentina

AbstractWe reviewed and performed a quantitative synthesis on herbicide‐resistant weeds from rain‐fed crops in Argentina. Twenty‐four weed species distributed in the main extensive crops (soybean, maize, wheat, barley, oilseed rape, sunflower, chickpea and peanut) have evolved herbicide resistance. Of the total, 54% are grasses, 88% are annual species and 63% are cross‐pollinated species. The most representative families were Poaceae with 54% resistant species, followed by Brassicaceae with 17%, and Asteraceae with 13%. Buenos Aires, Santa Fe and Córdoba were the provinces with the most documented cases of resistance (35%, 33% and 30%, respectively). The proportion of cases resistant to pre‐emergence herbicides was 10%, whereas the proportion of cases resistant to post‐emergence herbicides was 90%. Glyphosate was the herbicide with the highest incidence (92%) of resistance among weed species, followed by 29% of species that evolved resistance to ALS‐inhibiting herbicides. Whereas resistance to auxin‐like herbicides comprised 17% of the weed species, acetyl‐CoA carboxylase (8%) and protoporphyrinogen oxidase (4%) inhibiting herbicides showed the least incidence of resistance evolution among weeds. The highest number of resistant species was identified in soybean (19), followed by maize (13), wheat/barley (10) and fallow (9). Weed species with a higher number of resistant populations to a higher number of herbicide mode of action were Amaranthus hybridus, A. palmeri, Lolium multiflorum and Raphanus sativus. The change in the production system since the mid‐1990s, based on the use of herbicides (glyphosate mainly) to control weeds, is likely to account for the notorious increase in the average rate of evolution of herbicide‐resistant weeds in Argentina.

Retaining the largest aspen stems during motor-manual release allows to control aspen suckering in young mixedwood stands

Mixedwood stands containing aspens (Populus tremuloides or P. grandidentata) often convert to hardwood-dominated stands after harvesting due to the rapid regeneration of aspen from root suckers, even when sites are promptly replanted with conifer seedlings. Without the use of herbicides, this problem is usually dealt with several passes of motor-manual (“manual”) release of overtopped seedlings. The aim of this study was to test a variation of thinning from below treatment (thinning; only 20% of the largest aspens are retained), and to compare it against two traditional release treatments: broadcast brushing (brushing; 100% removal of aspen) or crop tree release (CTR; removal of competing vegetation 60 to 90 cm around planted spruce) and an un-treated control. The thinning treatment left the 20% larger aspen stems in place, in order that they continue exerting apical dominance on smaller suckers and limit re-suckering of the treated plots. Aspen suckering and growth of planted black spruce seedlings (Picea mariana (Mill.) B.S.P) were measured two- and four-growing seasons following treatments. Results four years after release application showed that the thinning and CTR treatments reduced aspen density by 61% compared to the brushing treatment. In addition, aspen individual stem volume in the thinning treatment was almost 10 times larger than the brushing and twice that of the CTR treatments. Spruce height and ground collar diameter (GCD; 5 cm aboveground line) were both measured, and while height increment was similar in all treatments, diameter increment was greater in the thinning treatment (+42%) compared to the control, brushing and CTR treatments (+17%). Thinning yielded better short-term results than the brushing release in terms of aspen re-suckering and aspen sawlog potential, highlighting the need for adapted silvicultural treatments based on the species’ ecology.

Negative Effects of Butachlor on the Growth and Physiology of Four Aquatic Plants.

The increasing use of herbicides in intelligent agricultural production is driven by the time-consuming nature of manual weeding, as well as its ephemeral effectiveness. However, herbicides like butachlor degrade slowly and can be washed away by rainwater, ultimately flowing into the farm ponds and posing risks to aquatic plants. To identify and recommend superior restoration strategies that effectively address the challenges posed by butachlor, we investigated the impacts of butachlor on the growth and physiology of four common aquatic plants (i.e., Hydrilla verticillata, Ceratophyllum demersum, Potamogeton maackianus, and Myriophyllum aquaticum) and their potential role in mitigating environmental damage by reducing residual herbicide levels. Our findings indicated that M. aquaticum was tolerant to butachlor, exhibiting higher growth rates than other species when exposed to various butachlor concentrations. However, the concentration of butachlor negatively impacted the growth of H. verticillata, C. demersum, and P. maackianus, with higher concentrations leading to more significant inhibitory effects. After a 15-day experimental period, aquatic plants reduced the butachlor residuals in culture mediums across concentrations of 0.5 mg/L, 1 mg/L, and 2 mg/L compared to non-plant controls. Our findings classified P. maackianus as butachlor-sensitive and M. aquaticum as butachlor-tolerant species. This investigation represents novel research aimed at elucidating the contrasting effects of different concentrations of butachlor on four common aquatic species in the agricultural multi-pond system.

Dissipation Kinetics, Leaching, and Ecological Risk Assessment of S-Metolachlor and Benfluralin Residues in Soil

The use of selective herbicides is one of the best methods for weed management. However, the extensive use of herbicides can have adverse impacts on non-target organisms. The goals of this study were to assess the dissipation kinetics, leaching, and ecological risk assessment of S-metolachlor and benfluralin residues in silty loam soil planted with chickpea (Cicer arietinum L.). The experimental setup included four different layers with four replications corresponding to an experimental randomized complete block design consisting of 16 plots. The application doses of S-metolachlor and benfluralin were 1350 and 1920 g a.i./ha, respectively, according to manufacturer recommendations. Soil samples were split into four depths, 0 to 20 cm (Layer A), 20 to 40 cm (Layer B), 40 to 60 cm (Layer C), and 60 to 80 cm (Layer D), to determine the dissipation kinetics and the leaching behavior of the herbicides. Gas chromatography coupled with the electron capture detector (GC-ECD) method was developed and validated for the determination of S-metolachlor and benfluralin residues in soil. The analytes were extracted from the soil with distilled water and ethyl acetate followed by solid-phase extraction (SPE). The limit of quantification (LOQ) of the method was 0.1 μg/g, and the recoveries of S-metolachlor and benfluralin were in the ranges 81% to 97% and 88% to 101%, respectively, with relative standard deviations (RSD) of less than 9.7%. The dissipation kinetics of S-metolachlor and benfluralin in soil (0–20 cm) followed first-order kinetics with half-lives of 21.66 and 30.13 days, respectively. The results for samples obtained from the 20–80 cm soil profile showed that both benfluralin and S-metolachlor presented high leaching, following preferential flow. Also, a soil ecological risk assessment was conducted in the top 0–20 cm soil profile, estimating the toxicity–exposure ratio (TER) for four soil organisms and the risk quotient (RQ). The mean herbicide levels found at the studied soil profile at 0 days (2 h) and 60 days of the experiment were used for risk assessment. In the first case, the mean pesticide concentration (MPC) gives a worst-case scenario (ws); in the second case, a dissipation scenario (ds) is given using the respective MPC. In all cases, both TER and RQ values showed that benfluralin corresponds to a higher risk than S-metolachlor for soil organisms.

Review on Toxicity, Mechanisms and Health Effects of Herbicides and Prevention Mechanisms

In agricultural crop production, herbicides are typically used to prevent or control weeds and other plant pathogens by reducing crop losses and maintaining high product quality. This brief overview sheds light on the level of toxicity, mechanisms of toxicity, health effects and prevention strategies. Three main levels of toxicity have been identified in herbicides: acute (short-term exposure), sub-chronic (medium-term exposure), and chronic (long-term exposure). These levels of toxicity have detrimental effects on humans, animals, and the environment. Herbicides must be handled and administered appropriately to minimize or completely prevent their negative side effects. It is recommended to manage herbicide to its minimum residue level while using them in agriculture. On the hand, certain mechanisms of action must be followed including contact, absorption, movement, toxicity, and death in order to be effective in management of weed by herbicides. This mechanism of actions of herbicides are also applied to humans and animals too. Improper usage of herbicides has adverse health effects on humans such as carcinogenic, cardiovascular, respiratory, hormonal, metabolic, cellular and neurological effects. In order to eliminate or minimize their effect the preventive safety mechanisms/strategies such as employing alternative and less herbicide-dependent cropping systems, properly using all certified personal protective equipment (PPE), proper packaging and package leaflet, proper labeling and giving general awareness about the use or handle of herbicide for farmers or any others who are not familiar with the use of herbicides must applied before or after handling of herbicides. In order to minimize or totally avoid the negative impacts of herbicides on humans, animals, and the environment, it is not just the responsibility of farmers but also of other stakeholders (agricultural experts, policymakers, etc.).

The potential of seaweeds as a rich natural source for novel bioherbicide formulation/development

AbstractRecently, there has been emphasis on the need to shift away from the use of synthetic chemical herbicides to low-risk alternatives derived from natural sources. This is aimed at lowering or averting the negative impact synthetic herbicides have on the environment and dealing with the emergence of weed species resistant to these chemicals. As a result, more stringent measures or outright bans on the use of most synthetic herbicides have been put in place by regulatory bodies. As seaweeds are abundant resources in the marine environment that have the capacity to produce diverse bioactive compounds, they could serve as sustainably viable, natural, and low-risk alternatives/sources to explore for potential phytotoxic capabilities. This could in turn help to enhance or boost the availability of effective solutions in the global bioherbicide market. This review highlights the prospects of using seaweeds as novel biopesticides for the control and management of various plant pests, including weed species, and for the development of sustainable agriculture/forestry practices. More specifically, it focuses on their use as a rich natural source for novel bioherbicide development, a potential that has remained underexplored for many years. However, to unlock the full potential of seaweed-derived bioherbicides and to create a potential path toward their development, increased research and development efforts are urgently needed to tackle and overcome possible constraints posed in this novel area, such as variability in seaweed chemical composition, formulation technologies, stability and efficacy of seaweed bioactive compounds, cost and scalability, and environmental considerations.

Factors Affecting the Rice Yield During the Rainy Season Among Farmers in Southeastern Cambodia

A research study utilized the Cobb-Douglas production function to examine the elements influencing paddy production during the wet season in three rural provinces of Cambodia. This analysis was based on data gathered from a survey of farmers’ households conducted in 2022. The study discovered that the use of fertilizers and herbicides, the size of the family, and income from off-farm sources significantly impacted the output of wet-season paddy. A one percent increase in the use of fertilizer, herbicide, and family size resulted in an increase in rice output by 0.06 percent, 0.04 percent, and 0.05 percent respectively. Furthermore, a one percent increase in the age of the household head, hired labor, and off-farm income led to an increase in rice yield by 0.08 percent, 0.11 percent, and 0.05 percent respectively. The use of seeds, pesticides, household labor, and the education level of the household heads were found to enhance rice yields in southeastern Cambodia. However, these production relationships varied significantly across different regions. The study concluded that higher yields during the rainy season improved the effectiveness of paddy production, primarily due to the increased responsiveness to fertilizer application.

Towards a true conservation zero tillage system: “A proposed solution based on computer vision to herbicide resistance.”

The Zero Tillage (ZT) or Non-Tillage system constitutes an agricultural production approach designed for improved soil conservation, reduced fossil fuel usage, mitigation of waterway pollution, water and wind erosion, and addressing soil compaction, among other objectives. In this way, ZT promises more sustainable agriculture. However, current ZT production systems depend on herbicide applications for weed control. The use of herbicides with the same modes of action over many years has led to numerous resistant weed species, which end up threatening the success of the herbicide weed control and, consequently, the overall success of the ZT system. Being able to automatically detect and classify weed species directly under the sprayer during the chemical application is an alternative to control populations of weeds since it would allow selecting the herbicide and dose for those particular species. This study, conducted over 15 years in commercial fields utilizing Zero Tillage (ZT) management, examined various ground covers intrinsic to the ZT system originating from previous crops or residues post-harvest. ZT features a broad spectrum of contexts due to the complexity of different ground cover types, which challenge computer vision techniques. The assessment focused on the automatic detection and classification of among the most problematic monocotyledonous and dicotyledonous weed species in the province of Cordoba in Argentina, with the objective of enabling a more targeted and selective approach to their control. These are Amaranthus palmeri, Echinochloa crus-galli, Eleusine indica, Parietaria debilis and Conyza sumatrensis. Additionally, some species belong to the same botanical families with several morphological resemblances that defy vision algorithms. This work proceeded through a machine learning approach applied to computer vision features such as SIFT (scale-invariant feature transform), K-means (clustering), and Bag of Features over the Support Vector Machine for classification. The results showed an accuracy between 89 % and 98 % over the species, allowing a significant reduction of herbicide while applying the adequate active ingredient. Moreover, virtual binary maps from weed patches are devised to be implemented through ISOBUS protocol. Thus the current research contributes significantly to the issue of controlling populations of weeds in the ZT agriculture system.

Can absorbent polymers remove pesticides from the environment? A Data Mining study

Pesticides are essential for improving agriculture, which is necessary for our life. Nowadays, with population growth, these chemistry products are more explored and improved to improve food production and keep people alive. However, the excessive use of herbicides, insecticides, and fungicides can degrade the environment and cause health issues. For this reason, researchers look for ways to detect and remove pesticide residues from the environment. Moreover, they provide limits on the use of agrochemical products. Modern searches about polymers and their use in science show that they can be used for pesticide detection or remotion, which is more efficient than the latest. This paper shows the main issues covered in the articles on using polymers to detect agrochemical products from the environment. These analyses were made on the platforms Scopus and Web of Science. The results concluded that the principal search focus was on detecting high-hazard pesticides using polymers.

Weed detection and removal using robotic system

Weeding is one of the most significant practices in agricultural production. Weeds are unwanted plants that grow along with the crops and compete with the crops for space, light, water, and soil nutrients. Weeds propagate themselves either through seeding or creeping rootstalk and decrease yields, increase production costs, interfere with the harvest, and lower the product quality. The use of herbicides reduces labor requirements for weed control by up to 60 percent but affects environmental quality and can be toxic to a wide range of organisms. Hence it is necessary to develop an automated system to identify and remove weeds from the vegetable fields. The objective of the proposed work is to develop a mobility level tracked bot that identifies the weeds and removes them with the help of a robotic end effector and to develop a machine learning model to identify the weeds. This functional module will be processed in a Raspberry Pi processor and by using a Raspberry Pi camera module the bot will detect the weeds in vegetable fields. We performed weed detection with different machine learning models like Haar cascade, YOLOv5, and CNN. To evaluate the performance of the machine learning models used, the performance metrics accuracy, precision, recall, and F-measure are estimated and it has been found that CNN has better accuracy, precision, and recall as compared to YOLOv5 and Haar cascade. CNN has the highest F-measure among the three algorithms at 98%. The weed removal is done using a robotic end-effector which is controlled by the Arduino UNO based on the signal from Raspberry Pi.

Sustainability in Japan’s Agriculture: An Analysis of Current Approaches

Sustainable agriculture has gained prominence as a response to global concerns, such as climate change, population growth, and improving the quality of life. In this context, Japan presents specific characteristics regarding land, economy, and population; however, studies related to sustainable agricultural practices and government measures remain insufficient. To evaluate the state of Japan’s sustainable agriculture, this paper presents a comprehensive literature review. In this paper, a bibliographic review was carried out, including articles, books, and governmental data, to contextualize the current state of agriculture in Japan and demonstrate that sustainable agriculture is being applied and encouraged in Japan. According to the research, in general, agriculture in Japan has been suffering over the years due to population decline and an aging population, and fewer young people are interested in agriculture. However, when it comes to sustainability, the country, government, and farmers have adopted several measures to improve aspects such as decreasing herbicide and pesticide use, payment for environmentally friendly farmers, and promoting education about good agricultural practices. This study illuminates the importance of Japan’s efforts to advance sustainable agriculture, potentially offering insights that could contribute to the broader global discourse on sustainable food production. Although Japan presents distinct characteristics, certain patterns observed in its approach may have relevance in similar contexts in other countries. The policies implemented in Japan provide data for comparative studies that aim to assess their adaptability and effectiveness in different global contexts.

Soil quality and microbial communities in subtropical slope lands under different agricultural management practices.

Land degradation is a major threat to ecosystem. Long-term conventional farming practices can lead to severe soil degradation and a decline in crop productivity, which are challenging for both local and global communities. This study was conducted to clarify the responses on soil physicochemical properties and microbial communities to changes in farming practices. Slope land orchards under three agricultural management practices-conventional farming (CF), organic farming (OF), and ecofriendly farming (EFF)-were included in this study. We found that soil carbon stock increased by 3.6 and 5.1 times in surface soils (0-30 cm) under EFF and OF treatments, respectively. EFF and OF significantly increased the contents of total nitrogen by 0.33-0.46 g/kg, ammonia-N by 3.0-7.3 g/kg, and microbial biomass carbon by 0.56-1.04 g/kg but reduced those of pH by 0.6 units at least, and available phosphorous by 104-114 mg/kg. The application of phosphorous-containing herbicides and chemical fertilizers might increase the contents of phosphorous and nitrate in CF soil. High abundances of Acidobacteria and Actinobacteria were observed in EFF and OF soils, likely because of phosphorous deficiency in these soils. The abundance of fungi in OF soil indicated that plants' demand for available soil phosphorous induced the fungus-mediated mineralization of organic phosphorous. High abundances of Gammaproteobacteria, Planctomycetes, Firmicutes, and Nitrospirae were observed in CF soil, possibly because of the regular use of herbicides containing phosphorous and chemical fertilizers containing high total nitrogen contents.

Regulating pathway for bacterial diversities toward improved ecological benefits of thiencarbazone-methyl·isoxaflutole application: A field experiment

Herbicide abuse has a significantly negative impact on soil microflora and further influences the ecological benefit. The regulating measures and corresponding mechanisms mitigating the decreased bacterial diversity due to herbicide use have rarely been studied. A field experiment containing the application gradient of an efficient maize herbicide thiencarbazone-methyl·isoxaflutole was performed. The relationship between soil bacterial community and thiencarbazone-methyl·isoxaflutole use was revealed. Modified attapulgite was added to explore its impacts on soil microflora under the thiencarbazone-methyl·isoxaflutole application. Based on the analytic network process–entropy weighting method–TOPSIS method model, the ecological benefit focusing on microbial responses was quantitatively estimated along with technical effectiveness and economic benefit. The results showed that the diversity indices of soil microflora, especially the Inv_Simpson index, were reduced at the recommended, 5 and 10 times the recommended dosages of thiencarbazone-methyl·isoxaflutole use. The Flavisolibacter bacteria was negatively correlated with the residues in soils based on the random forest model and correlation analysis, indicating a potential degrader of thiencarbazone-methyl·isoxaflutole residues. The structural equation model further confirmed that the high soil water content and soil pH promoted the function of Flavisolibacter bacteria, facilitated the dissipation of thiencarbazone-methyl·isoxaflutole residues and further improved the diversity of soil microflora. In addition, the presence of modified attapulgite was found to increase the soil pH, which may improve bacterial diversity through the regulating pathway. This explained the high ecological benefits of the treatment where the thiencarbazone-methyl·isoxaflutole was applied at the recommended dosage rates in conjunction with modified attapulgite addition. Therefore, the comprehensive benefits of thiencarbazone-methyl·isoxaflutole application with a focus on ecological benefits can be improved by regulating the soil pH with modified attapulgite.

Enrichment of putative plant growth promoting microorganisms in biodynamic compared with organic agriculture soils

Abstract The potential of soils to maintain biological productivity, defined as soil health, is strongly influenced by human activity, such as agriculture. Therefore, soil management has always been a concern for sustainable agriculture and new methods that account for both soil health and crop yield must be found. Biofertilization using microbial inoculants emerges as a promising alternative to conventional interventions such as excessive mineral fertilization and herbicide use. Biodynamic preparations used as a central part of biodynamic agriculture have various effects on soil properties, such as microbial biomass and respiration. We conducted several biomarker experiments to infer the effect of biodynamic preparations on soil prokaryotic and fungal communities and compared results to organic management. Potential plant growth promoting amplicon sequence variants were quantified using a commercial database based on their taxonomic identity. We found significantly higher numbers of putative plant growth promoting amplicon sequence variants in biodynamically compared with organically treated soils. Furthermore, prokaryotic amplicon sequence variants enriched in biodynamic preparations were found in higher numbers in biodynamically treated soils, indicating successful colonization after treatment. Experiments were conducted at three locations in Germany and 21 locations in France covering different crops and soil types. Altogether, our results indicate that biodynamic preparations can act as biofertilizers that promote soil health by increasing the abundance of plant growth promoting microorganisms.