Impact of historical soil management on the interaction of plant-growth-promoting bacteria with maize (Zea mays L.).

Edaphic factors can modulate the effects of microbial inoculants on crop yield promotion. Given the potential complexity of microbial inoculant responses to diverse soil management practices, we hypothesize that sustainable management of soil and water irrigation may improve soil quality and enhance the effects of plant growth-promoting bacteria (PGPB). Consequently, the primary objective was to assess the effectiveness of microbial inoculants formulated with Herbaspirillum seropedicae (Hs) and Azospirillum brasilense (Ab) on maize growth in soils impacted by different historical conservation management systems. We evaluated two soil management systems, two irrigation conditions, and four treatments: T0 - without bioinoculant and 100% doses of NPK fertilization; T1 - Hs + humic substances and 40% of NPK fertilization; T2 - Ab and 40% of NPK fertilization; T3 - co-inoculation (Hs + Ab) and 40% of NPK fertilization. Using a reduced fertilization dose (40% NPK) associated with microbial inoculants proved efficient in increasing maize shoot dry mass : on average, there was a 16% reduction compared to the treatment with 100% fertilization. In co-inoculation (Hs + Ab), the microbial inoculants showed a mutualistic effect on plant response, higher than isolate ones, especially increasing the nitrogen content in no-tillage systems irrigated by swine wastewater. Under lower nutrient availability and higher biological soil quality, the microbial bioinputs positively influenced root development, instantaneous water use efficiency, stomatal conductance, and nitrogen contents.

Effects of tillage and maturity stage on the yield, nutritive composition, and silage fermentation quality of whole-crop wheat.

Whole-crop wheat (Triticum aestivum, WCW) has a high nutritional value and digestibility. No-tillage (NT) can reduces energy and labor inputs in the agricultural production process, thus decreasing production costs. There are many studies on planting techniques of WCW at present, few being on no-tillage planting. This study aimed to compare the effects of different tillage methods and maturity stages on the yield, nutritive value, and silage fermentation quality of WCW. The experiment included two tillage methods (NT; conventional tillage, CT), two maturity stages (flowering stage; milk stage), and three years (2016-2017; 2017-2018; 2018-2019). Years had a strong influence on the yield and nutritional composition of WCW. This was mainly related to the amount of rainfall, as it affects the seedling emergence rate of wheat. Although tillage methods showed no significant effects on the yield, plant height, and stem number per plant of WCW (P > 0.05), compared to CT, the dry matter (DM) and crude protein (CP) yields of NT decreased by 0.74 t/ha and 0.13 t/ha. Tillage methods showed no significant effects on the nutritive composition of WCW (P > 0.05). The WCW at the milk stage had greater DM (5.25 t/ha) and CP (0.60 t/ha) yields than that at the flowering stage (3.19 t/ha and 0.39 t/ha) (P< 0.05). The acid detergent fiber concentration of WCW decreased by 34.5% from the flowering to the milk stage, whereas water-soluble carbohydrates concentration increased by 50.6%. The CP concentration at the milk stage was lower than that at the flowering stage (P< 0.05). The lactic acid concentration of NT (17.1 g/kg DM) silage was lower than that of CT (26.6 g/kg DM) silage (P< 0.05). The WCW silage at the milk stage had a lower NH3-N concentration (125 g/kg TN) than that at the flowering stage (169 g/kg TN) (P< 0.05). Wheat sown by NT and CT was of similar yield and nutritional value, irrespective of harvest stages. WCW harvested at the milk stage had greater yield and better nutritional composition and silage fermentation quality than that at the flowering stage. Based upon the results of the membership function analysis, no-tillage sowing of wheat was feasible and harvesting at milk stage was recommended.

Computed tomography scanning revealed macropore-controlled N2O emissions under long-term tillage and cover cropping practices.

Microscale alterations in soil physical characteristics resulting from long-term soil health practices can contribute to changes in soil nitrous oxide (N2O) emissions. In this study, we investigated soil N2O emissions in relation to pore characteristics influencing soil gas diffusivity under long-term tillage and cover cropping practices. Intact soil cores from tillage (conventional tillage, Conv. T versus no tillage, NT) and cover crop (hairy vetch, HV versus no cover crop, NC) treatments were used for N2O measurements and computed tomography (CT) scanning. Using X-ray CT technique with a resolution of 59 µm, pore structure parameters including macroporosity, number of macropores, anisotropy, fractal dimension, tortuosity, and connectivity were determined. The results showed that Conv. T and HV emitted significantly higher N2O than NT and NC, respectively. A similar trend was observed for macroporosity, Conv. T soils had 27.4 % higher CT-derived macroporosity than the NT soils and HV increased macroporosity by 31.1 % over the NC treatment. The number of macropores and fractal dimension were significantly higher whereas degree of anisotropy was significantly lower under HV compared to NC. In the upper 3 cm of soil, HV had a connected porosity, whereas the pores were disconnected and isolated in NC. These CT-derived properties; however, were not impacted by tillage treatments. N2O emissions were positively and significantly correlated to relative soil gas diffusivity, CT-derived macroporosity, number of macropores, and fractal dimension. Our results demonstrated that soil macroporosity and relative gas diffusivity could lead to improved understanding and predictability of N2O emissions under high soil moisture conditions.

[Effect of No-tillage on Soil Aggregates in Farmland：A Meta Analysis].

In order to clarify the impact of no-tillage on the quality of farmland soil aggregates in China and promote the adaptive application of no-tillage practices， a Meta-analysis was conducted by collecting data from 116 published studies. The effects of no-tillage on aggregate size distribution， mean weight diameter （MWD）， and aggregate-associated C were studied. The results showed that compared with that under tillage， no-tillage significantly increased the proportion of macroaggregates （10.9%） and MWD （12.8%） and decreased the proportion of clay and silt （-15.5%） but had no significant effect on soil microaggregate and aggregate-associated C. The subgroup and Meta regression analysis showed that no-tillage significantly increased the proportion of macroaggregates in Northwest China （17.6%） and MWD in North China （15.4%）. In upland and clay loam， no-tillage increased MWD by 12.6% and 18.4%， respectively. The effect of no-tillage on increasing the proportion of macroaggregates increased with the soil pH. When straw returned， no-tillage significantly increased the proportion of macroaggregates （9.6%） and MWD （11.6%）， but no significant effect of no-tillage on aggregates was found after straw removal. Regarding test duration， short-term （ < 5 a） no-tillage could significantly increase the proportion of macroaggregates， whereas long-term （ > 10 a） no-tillage could improve the MWD. In different soil layers， no-tillage could only significantly improve the aggregate size distribution and MWD in topsoil （0-20 cm） but had no effect in subsoil （ > 20 cm）. In summary， no-tillage could improve aggregate size distribution and stability but had no effect on aggregate-associated C. Production region， soil properties， field management methods， and other factors should be fully considered in production practice to effectively improve the quality of soil aggregates.

High leaching potential combined with a low leaching amount of fertilizer-derived nitrate in conservation tillage cropland of Northeast China.

Stover mulching in no-tillage farming has been widely proposed as an optimized agricultural management practice to increase soil carbon storage and improve fertilizer nitrogen (N) use efficiency in current agroecosystems. However, the regulation of soil internal gross N transformation dynamics on NO3--N leaching potential in response to long-term conservation tillage practices is still lacking. Here, based on a combination of 15N-tracing incubation and in situ monitoring experiments, we investigated the effect of 9-year no-tillage and maize stover mulching on the vertical migration of fertilizer-derived NO3--N into a deeper soil profile and the associated gross NO3--N transformation dynamics in the Mollisol of Northeast China. The net positive NO3--N production rates (varied from 3.14 to 6.22 mg N kg-1 d-1) were observed across all management practices in the studied Mollisol, indicating a relatively high NO3--N leaching potential in the cropland of Northeast China, which was further confirmed by an average of 7.4 % fertilizer-derived NO3--N being vertically transferred to the 80-100 cm soil layer after a complete maize growing period. Compared with traditional ridge tillage, long-term stover mulching in no-tillage farming significantly reduced total NO3--N production by decreasing autotrophic nitrification while simultaneously enhancing total NO3--N consumption by stimulating nitrate reduction and microbial NO3--N immobilization, revealing a markedly reduction of net NO3--N production in the no-tillage agroecosystem. Therefore, converting traditional ridge tillage toward no-tillage with maize stover mulching can effectively decrease fertilizer-derived NO3--N leaching amounts and thus formulate targeted mitigation strategies for sustainable agriculture in Mollisols of Northeast China.

No-Tillage System Can Improve Soybean Grain Production More Than Conventional Tillage System.

Soil management systems can directly interfere with crop yield via changes in the soil's physical and hydraulic properties. However, short- to medium-term experiments of conduction do not always demonstrate the modifications of the management systems in these properties. Thus, the aim of this study was to evaluate the physical properties of the soil in a long-term management system and to relate it to the storage and availability of water to plants, verifying its effect on soybean yield. The experiment was conducted in randomized blocks in a split-plot scheme with four replications. Plots were composed by soil management (conventional tillage and no-tillage), and subplots represented three soil depths (0.0-0.1, 0.1-0.2, and 0.2-0.4 m). The soil's physical and hydraulic properties, root development, and soybean yield were evaluated. The no-tillage system not only presented higher bulk density and soil resistance to compaction up to a depth of 0.2 m but also greater root development. This management also did not affect the process of water infiltration in the soil and presented an increase in soybean grain yield by 6.5%. The long-term no-tillage system (33 years) offers less risk of water stress to soybean plants; it contributes to greater grain yield of this crop when compared to the conventional tillage system.

Soil Alveolata diversity in the undisturbed steppe and wheat agrocenoses under different tillage.

Microeukaryotes are vital for maintaining soil quality and ecosystem functioning, however, their communities are less studied than bacterial and fungal ones, especially by high throughput sequencing techniques. Alveolates are important members of soil microbial communities, being consumers and/or prey for other microorganisms. We studied alveolate diversity in soil under the undisturbed steppe (US) and cropped for wheat using two tillage practices (conventional, CT, and no-till, NT) by amplifying the ITS2 marker with ITS3_KYO2/ITS4 primers and sequencing amplicons using Illumina MiSeq. A total of 198 Alveolata OTUs were identified, with 158 OTUs attributed to the Ciliophora phylum, containing five classes: Litostomatea, Spirotrichea and Oligohymenophorea, Nassophorea and Phyllopharyngea. Litostomatea and Phyllopharyngea were more abundant in US as compared with CT and NT. The observed OTU richness was higher in US than in CT and NT. The ß-biodiversity of soil ciliates also very distinctly differentiated the US field from CT and NT. In the US, Nassophorea and Spirotrichea correlated positively with sand and negatively with clay, silt and SOM contents. This is the first report about soil ciliates diversity in Siberia as assessed by metabarcoding technique. The revealed clear effect of land use on the relative abundance of some taxa and a lack of tillage effect suggest the importance of the quantity and quality of plant material input for shaping the prey for ciliates. The ITS-metabarcoding technique was used for the first time in the research of ciliates diversity; further studies, embracing diverse aspects of soil ciliates by combining -omics methodology with the traditional one, are needed to get a better insight on the ecological roles of the main ciliate taxa in the complex soil system.

West-Siberian Chernozem: How Vegetation and Tillage Shape Its Bacteriobiome.

Managing soil biodiversity using reduced tillage is a popular approach, yet soil bacteriobiomes in the agroecosystems of Siberia has been scarcely studied, especially as they are related to tillage. We studied bacteriobiomes in Chernozem under natural steppe vegetation and cropped for wheat using conventional or no tillage in a long-term field trial in the Novosibirsk region, Russia, by using the sequence diversity of the V3/V4 region of 16S rRNA genes. Actinobacteria, Acidobacteria, and Proteobacteria summarily accounted for 80% of the total number of sequences, with Actinobacteria alone averaging 51%. The vegetation (natural vs. crop) and tillage (ploughed vs. no-till) affected the bacterial relative abundance at all taxonomic levels and many taxa, e.g., hundreds of OTUs. However, such changes did not translate into α-biodiversity changes, i.e., observed and potential OTUs' richness, Shannon, and Simpson, excepting the slightly higher evenness and equitability in the top 0-5 cm of the undisturbed soil. As for the ß-biodiversity, substituting conventional ploughing with no tillage and maintaining the latter for 12 years notably shifted the soil bacteriobiome closer to the one in the undisturbed soil. This study, presenting the first inventory of soil bacteriobiomes under different tillage in the south of West Siberia, underscores the need to investigate the seasonality and longevity aspects of tillage, especially as they are related to crop production.

New evidence on the impact of No-tillage management on agricultural carbon emissions.

Controlling agricultural carbon emissions contributes to achieving peak carbon emissions and carbon neutrality. However, as a conservation management practice of farmland, the impact of No-tillage management (NTM) on agricultural carbon emissions needs to be further discussed. The main purpose of this paper is to assess the direct effect and spatial spillover effect of NTM on agricultural carbon emissions, revealing the regulating mechanism of NTM on agricultural carbon emissions and the combined application of NTM. Results indicate that NTM reduces agricultural carbon emissions, which is significant in the central and western regions, along with the primary grain, corn, and rice production areas, as well as the northern regions of the Huai River. Furthermore, the spatial spillover analysis reveals that the implementation of NTM increases agricultural carbon emissions in neighboring regions, but financial support and cross-regional services can negatively regulate the relationship between NTM and space agricultural carbon emissions. This paper also finds that combining straw-returning technology and NTM reduces agricultural carbon emissions. Building a cross-regional coordination mechanism, an incentive mechanism, and innovating the conservation tillage model is essential for promoting the NTM and achieving agricultural carbon reduction.

Effects of tillage patterns and stover mulching on N2O production, nitrogen cycling genes and microbial dynamics in black soil.

Stover-covered no-tillage (NT) is of great significance to the rational utilization of stover resources and improvement of cultivated land quality, and also has a profound impact on ensuring groundwater, food and ecosystem security. However, the effects of tillage patterns and stover mulching on soil nitrogen turnover remain elusive. Based on the long-term conservation tillage field experiment in the mollisol area of Northeast China since 2007, the shotgun metagenomic sequencing of soils and microcosm incubation were combined with physical and chemical analyses, alkyne inhibition analysis to elucidate the regulatory mechanisms of NT and stover mulching on the farmland soil nitrogen emissions and microbial nitrogen cycling genes. Compared with conventional tillage (CT), NT stover mulching significantly reduced the emission of N2O instead of CO2, especially when 33% mulching was adopted, and correspondingly the nitrate nitrogen of NT33 was higher than that of other mulching amounts. The stover mulching was associated with higher total nitrogen, soil organic carbon and pH. The abundance of AOB (ammonia-oxidizing bacteria)-amoA (ammonia monooxygenase subunit A) was substantially increased by stover mulching, while the abundance of denitrification genes was reduced in most cases. Under alkyne inhibition, the tillage mode, treatment time, gas condition and interactions between them noticeably influenced the N2O emission and nitrogen transformation. In CT, NT0 (no mulching) and NT100 (full mulching), the relative contribution of AOB to N2O production was markedly higher than that of ammonia oxidizing archaea. Different tillage modes were associated with distinct microbial community composition, albeit NT100 was closer to CT than to NT0. Compared with CT, the co-occurrence network of microbial communities was more complex in NT0 and NT100. Our findings suggest that maintaining a low-quantity stover mulching could regulate soil nitrogen turnover toward proficiently enhancing soil health and regenerative agriculture, and coping with global climate change.

Mechanisms of conservation tillage on nitrogen-fertilizer reduction and maize grain improvement in Mollisols of Northeast China: Insights from a 15N tracing study.

Conservation tillage is an important management practice to guarantee soil fertility in degraded Mollisols. It is still unclear, however, whether the improvement and stability of crop yield under conservation tillage can be sustainable with increasing soil fertility and reducing fertilizer-N application. Based on a long-term tillage experiment initiated in Lishu Conservation Tillage Research and Development Station by Chinese Academy of Sciences, we conducted a 15N tracing field micro-plot experiment to investigate the effects of reducing nitrogen application on maize yield and fertilizer-N transformation under long-term conservation tillage agroecosystem. There were four treatments, including conventional ridge tillage (RT), no-tillage with 0% (NT0), 100% (NTS) maize straw mul-ching, and 20% reduced fertilizer-N plus 100% maize stover mulching (RNTS). The results showed that after a complete cultivation round, the average percentages of fertilizer N recovery in soil residues, crop usage, and gaseous loss were 34%, 50%, and 16%, respectively. Compared with conventional ridge tillage, no-tillage with maize straw mulching (NTS and RNTS) significantly increased the use efficiency of fertilizer N in current season by 10% to 14%. From the perspective of N sourcing analysis, the average percentage of fertilizer N absorbed by crop parts (including seeds, straws, roots, and cobs) to the total N uptake reached nearly 40%, indicating that soil N pool was the main source of N for crop uptakes. In comparison with conventional ridge tillage, conservation tillage significantly increased total N storage in 0-40 cm by reducing soil disturbance and increasing organic inputs, and thus ensured the expansion and efficiency increment of soil N pool in degraded Mollisols. Compared with conventional ridge tillage, NTS and RNTS treatments significantly increased the maize yield from 2016 to 2018. In all, by improving fertilizer nitrogen utilization efficiency and maintaining the continuous supply of soil nitrogen, long-term management of no-tillage with maize straw mulching could achieve a stable and increasing maize yield in three consecutive growing seasons and simultaneously reduce environmental risks derived by fertilizer-N losses, even under the condition of 20% reduction of fertilizer-N application, and thus actualize the sustainable development of agriculture in Mollisols of Northeast China.

Effects of long-term no-tillage on the functional potential of microorganisms involved in the nitrogen, phosphorus and sulfur cycles of black soil.

Understanding the effects of different tillage practices on functional microbial abundance and composition in nitrogen (N), phosphorus (P) and sulfur (S) cycles are essential for the sustainable utilization of black soils. Based on an 8-year field experiment located in Changchun, Jilin Province, we analyzed the abundance and composition of N, P and S cycling microorganisms and their driving factors in different depths of black soil under no til-lage (NT) and conventional tillage (CT). Results showed that compared with CT, NT significantly increased soil water content (WC) and microbial biomass carbon (MBC) at soil depth of 0-20 cm. Compared with CT, NT significantly increased the abundances of functional and encoding genes related to N, P and S cycling, including the nosZ gene encoding N2O reductase, the ureC gene performing organic nitrogen ammoniation, the nifH gene encoding nitrogenase ferritin, the functional genes phnK and phoD driving organic phosphorus mineralization, the encoding pyrroloquinoline quinone synthase ppqC gene and the encoding exopolyphosphate esterase ppX gene, and the soxY and yedZ genes driving sulfur oxidation. The results of variation partitioning analysis and redundancy analysis showed that soil basic properties were the main factors affecting the microbial composition of N, P and S cycle functions (the total interpretation rate was 28.1%), and that MBC and WC were the most important drivers of the functional potential of soil microorganisms in N, P and S cycling. Overall, long-term no tillage could increase the abundance of functional genes of soil microorganisms by affecting soil environment. From the perspective of molecular biology, our results elucidated that no tillage could be used as an effective soil management measure to improve soil health and maintain green agricultural development.

Global-scale no-tillage impacts on soil aggregates and associated carbon and nitrogen concentrations in croplands: A meta-analysis.

No-tillage treatment, including no-tillage with straw retention (NTS) and without (NT), has been widely used as an efficient and sustainable alternative to conventional tillage with straw retention (CTS) and without (CT) and greatly affects soil physical quality and organic matter dynamics in cropland ecosystems. Although some studies have reported the effects of NTS on soil aggregate stability and soil organic carbon (SOC) concentration, the underlying mechanisms of how soil aggregates, aggregate-associated SOC and total nitrogen (TN) respond to no-tillage remain unclear. Through a global meta-analysis of 91 studies in cropland ecosystems, we evaluated the effects of no-tillage on soil aggregates and their associated SOC and TN concentrations. On average, no-tillage treatment significantly decreased the proportions of microaggregates (MA) by 21.4 % (95 % CI, -25.5 to -17.3 %) and silt+clay size particles (SIC) by 24.1 (95 % CI, -30.9 to -17.0 %), and increased the proportions of large macroaggregate (LA) by 49.5 % (95 % CI, 36.7-63.0 %) and small macroaggregate (SA) by 6.1 % (95 % CI, 2.0-10.9 %) compared to those in conventional tillage. The SOC concentrations for all three aggregate sizes increased significantly with no tillage: for LA by 28.2 % (95 % CI, 18.8-39.5 %), SA by 18.0 % (95 % CI, 12.8-23.3 %), and MA by 9.1 % (95 % CI, 2.6-16.8 %). TN also increased significantly for all sizes with no tillage, with LA by 13.6 % (95 % CI, 8.6-17.6 %), SA by 11.0 % (95 % CI, 5.0-17.0 %), MA by 11.7 % (95 % CI, 7.0-16.4 %), and SIC by 7.6 % (95 % CI, 2.4-13.8 %). The magnitude of the no-tillage treatment effect on soil aggregation, aggregate-associated SOC and TN varied with the environmental and experimental conditions. The positive effect on the proportions of LA occurred with initial soil organic matter (SOM) content >10 g kg-1, whereas SOM <10 g kg-1 did not change significantly. Additionally, the effect size of NTS compared with CTS was lower than that of NT compared with CT. These findings suggest that NTS may promote physically protective SOC accumulation through the formation of macroaggregates by reducing disturbance destruction and increasing plant-derived binding agents. The findings highlight that no-tillage may enhance the formation of soil aggregates and the associated SOC and TN concentrations in global cropland ecosystems.

Soil Fungistasis against Fusarium Graminearum under Different tillage Systems.

The establishment of the harmful pathogen Fusarium graminearum in different agroecosystems may strongly depend on the ability of the soils to suppress its development and survival. This study aimed to evaluate the influence of different soil tillage systems (i.e., conventional tillage, reduced tillage and no-tillage) on soil fungistasis against F. graminearum. Soil samples were collected three times during the plant growing season in 2016 and 2017 from a long-term, 20-year soil tillage experiment. The F. graminearum in the soil samples was quantified by real-time qPCR. The soil fungistasis was evaluated by the reduction in the radial growth of F. graminearum in an in vitro assay. The antagonistic activity of the soil bacteria was tested using the dual culture method. The F. graminearum DNA contents in the soils were negatively correlated with soil fungistasis (r = -0.649 *). F. graminearum growth on the unfumigated soil was reduced by 70-87% compared to the chloroform fumigated soil. After the plant vegetation renewal, the soil fungistasis intensity was higher in the conventionally tilled fields than in the no-tillage. However, no significant differences were obtained among the tillage treatments at the mid-plant growth stage and after harvesting. 23 out of 104 bacteria isolated from the soil had a moderate effect, and only 1 had a strong inhibitory effect on the growth of F. graminearum. This bacterium was assigned 100% similarity to the Bacillus amyloliquefaciens Hy7 strain (gene bank no: JN382250) according to the sequence of the 16S ribosome subunit coding gene. The results of our study suggest that the presence of F. graminearum in soil is suppressed by soil fungistasis; however, the role of tillage is influenced by other factors, such as soil biological activity, type and quantity of plant residues and environmental conditions.

Soil management affects carbon and nitrogen concentrations and stable isotope ratios in vine products.

Weeds reduce vineyard productivity and affect grape quality by competing with grapevines (Vitis vinifera L.) for water and nutrients. The increased banning of herbicides has prompted the evaluation of alternative soil management strategies. Cover cropping seems to be the best alternative for weed management. However, it may impact vine growth, grape yield, and quality. Quantitative studies on these changes are scarce. Our study aimed to investigate the combined effect of grass cover and water availability on vines of three cultivars, the white Chasselas and Petite Arvine and the red Pinot noir field-grown under identical climatic and pedological conditions and grafted onto the same rootstock. Soil management and irrigation experiments were performed during the 2020-2021 seasons. Two extreme soil management practices were established in the vineyard, based on 100 % bare soil (BS) by the application of herbicides with glufosinate or glyphosate as active ingredients and 100 % grass-covered soil (GS) by cover cropping with a mixture of plant species. Two water statuses were imposed by drip irrigation (DI) and no irrigation (NI). The level of vine-weed competition for water and nitrogen (N) was assessed in the vine, must, and wine solid residues (WSRs) by comparing measurements, i.e., the yeast assimilable N content, C/NWSR, carbon and N isotope ratios (δ13Cgrape-sugars, δ13CWSR, and δ15NWSR) among the different treatments (BS-DI, BS-NI, GS-DI, GS-NI). The increase in the δ13Cgrape-sugars and δ13CWSR values with increasing plant water deficit mimicked the observations in irrigation experiments on BS. The NWSR content and δ15NWSR values decreased with water stress and much more strongly in vines on GS. The dramatic N deficit in rainfed vines on GS could be alleviated with irrigation. The present study provides insights from chemical and stable isotope analyses into the potential impact of cover cropping in vineyards in the context of the banning of herbicides in a time of global water scarcity due to climate change.

Response of nitrate leaching to no-tillage is dependent on soil, climate, and management factors: A global meta-analysis.

No tillage (NT) has been proposed as a practice to reduce the adverse effects of tillage on contaminant (e.g., sediment and nutrient) losses to waterways. Nonetheless, previous reports on impacts of NT on nitrate ( NO 3 - ) leaching are inconsistent. A global meta-analysis was conducted to test the hypothesis that the response of NO 3 - leaching under NT, relative to tillage, is associated with tillage type (inversion vs non-inversion tillage), soil properties (e.g., soil organic carbon [SOC]), climate factors (i.e., water input), and management practices (e.g., NT duration and nitrogen fertilizer inputs). Overall, compared with all forms of tillage combined, NT had 4% and 14% greater area-scaled and yield-scaled NO 3 - leaching losses, respectively. The NO 3 - leaching under NT tended to be 7% greater than that of inversion tillage but comparable to non-inversion tillage. Greater NO 3 - leaching under NT, compared with inversion tillage, was most evident under short-duration NT (<5 years), where water inputs were low (<2 mm day-1 ), in medium texture and low SOC (<1%) soils, and at both higher (>200 kg ha-1 ) and lower (0-100 kg ha-1 ) rates of nitrogen addition. Of these, SOC was the most important factor affecting the risk of NO3 - leaching under NT compared with inversion tillage. Globally, on average, the greater amount of NO3 - leached under NT, compared with inversion tillage, was mainly attributed to corresponding increases in drainage. The percentage of global cropping land with lower risk of NO3 - leaching under NT, relative to inversion tillage, increased with NT duration from 3 years (31%) to 15 years (54%). This study highlighted that the benefits of NT adoption for mitigating NO 3 - leaching are most likely in long-term NT cropping systems on high-SOC soils.

The role of glyphosate-resistant weeds and starvation on biological, reproductive, and preference parameters of Chrysodeixis includens (Lepidoptera: Noctuidae).

Glyphosate-resistant weeds are difficult to manage and can serve as hosts for pests that threaten cultivated crops. Chrysodeixis includens (Walker) (Lepidoptera: Noctuidae) is one of the main polyphagous pests of soybean in Brazil that can benefit from weeds' presence during season and off-season. Despite its pest status, little is known about C. includens survival and development on alternative hosts, including those resistant to glyphosate. Therefore, we assessed the biology, reproduction, preference, and survival at different feeding periods of C. includens on seven glyphosate-resistant weeds (Sumatran fleabane, Italian ryegrass, sourgrass, goosegrass, smooth pigweed, wild poinsettia, hairy beggarticks) commonly found in Brazilian agroecosystems, under laboratory conditions. Our results showed that C. includens survival and reproduction were similar on soybean and wild poinsettia. Survival and reproduction were lower on smooth pigweed and hairy beggarticks. Also, these plants prolonged the larval stage. Larvae did not pupate when fed on sourgrass, goosegrass, Italian ryegrass, and Sumatran fleabane. However, on Sumatran fleabane their biomass was higher. The mean generation time was lower on wild poinsettia. This weed was preferred to soybean. An antifeeding factor was observed on Sumatran fleabane. Larvae fed for 11 days on soybean, wild poinsettia and smooth pigweed developed into pupae. In agricultural systems, farmers must pay attention to the management of these weeds, especially wild poinsettia, smooth pigweed, and hairy beggarticks, to interrupt the cycle of this pest, since these plants can serve as main sources of infestation for the soybean crop.

Impact of outsourced machinery services on farmers' green production behavior: Evidence from Chinese rice farmers.

As an important part of agricultural socialization services, outsourced machinery services are of great significance for promoting the green development of agriculture. Using the field survey data of 1080 rice growers in Sichuan Province, this paper empirically analyzes outsourced machinery services' impact and role path on farmers' green production behavior. Further, it analyzes the difference in influence from the perspective of group heterogeneity. The research results show that: (1) The outsourced machinery services significantly impact farmers' adoption of no-tillage technology, organic fertilizer application technology, and straw returning technology. The conclusion is still stable after considering endogeneity. (2) The outsourced machinery services indirectly affect farmers' green production behavior by promoting off-farm employment and expanding the scale of farmland. (3) The impact of outsourced machinery services on farmers' green production behavior is not significant in the male group and the group whose households own agricultural machinery. In conclusion, the study proposes to increase assistance to outsourced machinery services providers and encourage service entities to actively publicize and popularize green production technologies while providing services, to play an influential role in guiding and educating farmers.

A 40 % paddy surface soil organic carbon increase after 5-year no-tillage is linked with shifts in soil bacterial composition and functions.

Soil organic carbon (SOC) is related to soil fertility, crop yield, and climate change mitigation. Paddy soil is a significant carbon (C) sink, but its C sequestration potential has not been realized as the various driving factors are still not fully understood. We performed a 5-year paddy field experiment in southern China to estimate tillage effects on SOC accumulation and its relation with soil bacteria. The C input from rice residue, SOC content, CO2 flux, soil bacterial community composition, and predicted functions were analyzed. No-tillage (NT) increased (p < 0.05) rice residue C inputs (by 12.6 %-15.9 %), SOC (by 40 % at the surface soil layer compared with conventional tillage, CT), and CO2 fluxes compared with reduced tillage (RT) and CT. Also, NT significantly altered the soil bacterial community. The random forest model showed that the predicted bacterial functions of "Degradation/Utilization/Assimilation Other", "C1 Compound Assimilation", and "Amin and Polyamine Degradation" were the most important functions associated with SOC accumulation. Analysis of metabolic pathway differences indicated that NT significantly decreased the BENZCOA-PWY (anaerobic aromatic compound degradation) and the AST-PWY (L-arginine degradation II). Therefore, the rapid paddy SOC increase is associated with both residue C input (from higher rice yields) and the degradation functions regulated by soil bacteria.

Effectiveness of Residue and Tillage Management on Runoff Pollutant Reduction from Agricultural Areas.

Reduced tillage management conservation practices (No-till and Reduced-till) are widely adopted in agriculture; however, understanding their overall effectiveness for water quality protection is challenging. A meta-analysis was conducted to understand and quantify the effectiveness of residue and tillage management on runoff, sediment, and nutrient losses from agricultural fields. Annual runoff and the associated sediment, and nutrient (nitrogen and phosphorus) loads were compiled from 60 peer reviewed research articles published across the United States and Canada. A total of 1575 site-years of data were categorized into tillage (<30% surface cover), no-tillage (<30% surface cover), tillage with residue (>30% surface cover), no-tillage with residue (>30% surface cover), and pasture management. No-tillage, no-tillage-residue, and tillage-residue managements were evaluated for their effectiveness in reducing runoff, nutrients, and sediment loads compared to tillage. Synthesized and surveyed corn yield data were used to evaluate the economic cost effectiveness of no-tillage-residue management with respect to tillage. Across the site years (1968-2019) studied, median runoff depth for no-tillage and no-tillage-residue were 84% and 70% greater than tillage and tillage-residue management, respectively. No-tillage-residue management had up to 86% less sediment losses than tillage systems, on average, for both >30% and <30% surface cover. No-tillage-residue management was most effective, with a positive performance effectiveness of 65% to 90% in controlling sediments, particulate, and total nutrient losses in runoff compared to tillage. Cost effectiveness analysis revealed the benefits of no-tillage-residue management in reducing nutrient loads and increasing net-farm revenue by avoiding tillage operational costs. Except for dissolved phosphorus, no-tillage-residue management cost effectiveness for sediments and nutrient loads ranged from negative $6 to negative $102 per every Mg or kg of load reduction, indicating it had both economic and environmental benefits compared to tillage management. Overall, these results indicate that over the long-term, no-tillage and tillage, combined with greater than 30% residue cover, can effectively reduce sediment and nutrient losses. This work highlights the importance of crop residues on the soil surface to reduce runoff losses, even in no-tillage systems.