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Background and Aim: Continuous monocropping with high nitrogen (N) fertilizer input substantially increases greenhouse gas (GHG) emissions in maize-based agroecosystems in the North China Plain (NCP). Introducing soybeans as an intercrop with maize and partially substituting urea with manure might effectively decrease GHG emissions. The aim of this study was to quantify the synergistic effect of maize-soybean intercropping and manure on soil GHG emissions. Methods: A two-year field experiment with three cropping systems (maize monocrop, soybean monocrop, and maize-soybean intercrop) and four N treatments (control, urea, manure, and manure + urea) was carried out at Luancheng Agro-Ecosystem Experimental Station in the NCP. All N treatments, except the control, received 150 kg N ha−1season−1, either full dose as a basal application or two equal split applications. Results: Results showed that all treatments contributed as a net source of N2O and CO2 fluxes but acted as a net sink of CH4 fluxes. In both cropping seasons, intercrops had significantly lower N2O emissions compared to monocropping systems, with 38% and 14% less emissions than maize monocrops in 2018 and 2019, respectively. Additionally, maize monocrops had significantly higher soil CO2 emissions than other systems, while maize-soybean intercropping had 12% and 13% less CO2 emissions than maize monocrops in 2018 and 2019, respectively. Among fertilized treatments, manure-treated soils emit notably lower N2O fluxes compared to sole urea treatments. In this study, N2O and CO2 fluxes had a strong positive correlation with soil mineral N concentrations, soil temperature, and moisture content. Possibly due to more efficient N utilization, intercrop soils exhibited significantly lower NH4+ and NO3− concentrations, leading to reduced nitrification and denitrification in the system, resulting in lower N2O emissions from maize-soybean intercrops. Conclusion: Our findings indicate that intercropping maize and soybean reduces soil NH4+ and NO3– concentrations, as well as significantly decreasing soil N2O and CO2 emissions when compared to traditional maize monoculture. Therefore, due to its potential for reducing soil GHG emissions, maize-soybean intercropping can be regarded as an effective alternative cropping system to the prevailing maize-dominant monoculture to develop a sustainable agroecosystem in the NCP region. [ABSTRACT FROM AUTHOR]

The long-term (AD 1300–1800), multi-scale interactions of monocropping and subaltern agri-food systems of Andalus (Spain) and coastal Peru reveal the entangled transformations of the Plantationocene. Historically convergent colonial monocultures (wheat, sugar, cotton, sheep, cattle) entangled with the divergence and plurality of resilient yet precarious diverse-food affordances of subaltern groups (peasants, indigenous people, enslaved persons, Mudejares, Moriscos). Using political ecology, the comparative cases illuminate how Plantationocene colonial entanglements were shaped through spatial movements and social-environmental affordances of biota, populations, and institutions. New empirical understanding and a novel conceptual and analytical framework offer insight into Plantationocene pathways, alternatives, and struggles. [ABSTRACT FROM AUTHOR]

The present study demonstrates the application of biostimulants during the cultivation of wheat and chickpeas in intercropping farming. This study examined the effect of seaweed on the increasing amount of nitrogen, yield, and nutrient quality of wheat and chickpeas. In north India, rabi crops were grown for three seasons from 2019 to 2021 in the intercropping farming system. The main crop (wheat) was sown with chickpea (legumes) to enhance the yield of two crops in one season as chickpea also helps in nitrogen fixation in soil. There was a total of 36 rows each of 6 m, of which nine rows each were for wheat and chickpea and the other nine were for one row of wheat and another of chickpea. Results of the study, exhibit the significant effect of the amount of nitrogen which was a maximum of 4.33 mg/kg in intercropping treated with seaweed as compared to intercropping with control 4.23 mg/kg. AE (Agronomic Efficiency) in the intercropping with seaweed treatment was 3.27 kg/kg as compared to 3.23 kg/kg in the control. The yield and harvest index of seaweed with intercropping was higher than intercropping in control with chemical fertilizers like urea. Hence, biostimulants along with intercropping were found to be effective in increasing the yield and nutritional value of crops. [ABSTRACT FROM AUTHOR]

Tobacco bacterial wilt caused by Ralstonia solanacearum often occurs under monocropping. Crop rotation significantly reduces disease by changing the microbial communities, both taxonomically and functionally, in the tobacco rhizosphere. In this study, tobacco rhizosphere soils were sampled from monocropping and tobacco-maize rotation fields. Based on metagenomic sequencing, measurements of soil properties, and the quantification of R. solanacearum, the results showed that rotation with maize increased the microbial diversity, complexity of microbial networks, and soil nutrient level in the tobacco rhizosphere and led to better tobacco growth. Tobacco rhizosphere microbes in monocropping fields were enriched for proteins related to pathogenicity and host infection processes. Moreover, microbes from the tobacco-maize rotation field had the strongest negative correlations with R. solanacearum. These microbes were mainly Actinobacteria, especially Solirubrobacter. Although the abundance of R. solanacearum did not significantly differ between monocropping and crop rotation fields, R.solanacearum did not cause outbreaks in tobacco-maize rotation fields, as there were no disease symptoms on tobacco. Based on structural equation modeling, we identified that general disease suppression had a stronger influence on R. solanacearum and tobacco performance than specific disease suppression. Moreover, general disease suppression may facilitate the establishment of specific disease suppression. This study revealed the functional changes in the rhizosphere microbiome and the mechanisms of disease suppression under tobacco-maize rotation. Our study further indicated that crop rotation could lead to the establishment of specific disease suppression in the longer term. [ABSTRACT FROM AUTHOR]

Introduction: In achieving food security and sustainable agricultural development, improving and maintaining soil health is considered as a key driving factor. The improvement based on different forms of nitrogen fertilization has aroused great public interest in improving and restoring monocropping obstacles for specific soil problems. Methods: For this, a short-term cucumber cropping field experiment was conducted in the subtropical region of China under four fertilization treatments: ammonium (AN), nitrate (NN), ammonium with dicyandiamide (AN +DCD), nitrate with dicyandiamide (NN+DCD). In this study, we measured the effects of nitrogen forms addition on plant productivity and soil health in a monocropping system over seven seasons. Results: To systematically evaluate soil health, a wide range of soil environmental factors were measured and incorporated into the soil health index (SHI) by entropy method. Compared with ammonium treatment (SHIAN = 0.059, SHIAN +DCD = 0.081), the positive effect of nitrate was mainly reflected in improving soil health (SHINN = 0.097, SHINN+DCD = 0.094), which was positively correlated with the increase in plant productivity of cucumber after seven seasons of monocropping. The most critical factor affecting SHI is soil ammonium nitrogen content, which was negatively correlated with plant productivity. Discussion: Nitrate promotes soil health and plant productivity by optimizing soil environmental factors. The study thus emphasized the necessity of nitrate input for the sustenance of soil-crop ecosystems, with the consequent possibility of application of the results in planning monoculture obstacle prevention and management measures. [ABSTRACT FROM AUTHOR]

This work aimed to identify the allelochemicals released by Glehnia littoralis Fr. Schmidt ex Miq. in soil and to study their allelopathic activity on Brassica pekinensis (Lour.) Rupr. In seedling tray assays, the rhizosphere soil from G. littoralis continuous monocropping drastically inhibited the growth of B. pekinensis. In Petri dish assays, Methanolic extracts from control soil (CK), soil under first G. littoralis cropping (FS), and continuous cropping (CS) were tested on germination and seedlings growth of B. pekinensis. These extracts inhibited the germination potential, germination rate, shoot height and root length of Brassica pekinensis. GC-MS analysis of the methanolic extracts revealed the presence of dibutyl phthalate (DBP) and 2,4-Di-tert-butylphenol (2,4-DTBP). These allelochemicals inhibited the seedling growth of B. pekinensis in Petri dish assays, and had deleterious effects on photosynthetic system and redox balance. Activities of peroxidase (POD) and catalase (CAT) increased, whereas, superoxide dismutase (SOD) decreased, chlorophyll content was lowered, but hydrogen peroxide (H2O2) and malondialdehyde (MDA) were increased. Our results suggested that under monocropping G. littoralis releases allelochemicals (DBP and 2,4-DTBP) into the soil. [ABSTRACT FROM AUTHOR]

'Monocrops' is a key concept needed to understand agrarian dynamics today. Strictly speaking, it means cultivation of a single crop in a transformed and simplified landscape. Broadly, it means the violent imposition of a pattern of power predicated upon the concentration of control over nature, labor, inputs, production, profits and knowledge, in the form of homogeneous, simplified landscapes. I examine the concept in relation to processes of empire and conquest and the modernization of agriculture through the Green Revolution and beyond. I discuss how thinking against monocrops can help us imagine how to create a more inclusive, just and healthy world. [ABSTRACT FROM AUTHOR]

It was of great significance to clarify the laws and characteristics of nitrogen loss in tea plantation intercropping for scientifically evaluating the emission reduction effect of agricultural non-point source pollution in the ecological tea plantations. By taking the ecological tea plantation in Huanxi Town, Fuzhou City, Fujian Province as the research object, the long-term location experiment was carried out by using the runoff plot method. The volume of runoff from tea plantations under the conditions of monocropping along the downward slope (T1), intercropping along the downward slope (T2), monocropping in the terrace (T3) and intercropping in the terrace (T4) in 16 rainfall events from 2016 to 2018 was observed, in order to analyze the variation of nitrogen concentration and its loss amout in runoff. The intercropping plant was Paspalum notatum. The results showed that: according to the runoff volume in the downward slope (T1, T2) and terrace (T3, T4), the volume of runoff from tea plantations in intercropping was lower than that in monocropping. Along the downward slope, the TN concentration, AN concentration, NN concentration, TN loss amount, AN loss amount and NN loss amount in intercropping decreased by 32.0%, 44.4%, 23.8%, 38.5%, 49.8% and 30.8% compared with that in monocropping. In the terrace, the TN concentration, AN concentration, NN concentration, TN loss amount, AN loss amount and NN loss amount in intercropping decreased by 26.4%, 37.9%, 21.9%, 49.5%, 51.7% and 53.3% compared with that in monocropping. There was a significant correlation between the rainfall and runoff volume. [ABSTRACT FROM AUTHOR]

Natural rubber consumption has led to the expansion of rubber (Hevea brasiliensis) plantations which affects the deforestation and ecosystem. However, no study of the long-term effect of rubber plantations on soil biodiversity has been carried out yet. This study aimed to assess the long-term impact of continuous rubber monocropping on soil biodiversity, focusing on soil macrofauna and nematode diversity. Three successive rubber rotations at young and old ages were compared with the adjacent forest in Suratthani province, Thailand. Soil biodiversity quality index was calculated from a set of indicators which were combined into a single score to present a functional assessment of the gradient of disturbance. The results showed three negative effects on soil biodiversity (i) the biodiversity quality index immediately declined after deforestation (ii) the old age rubber plantations had a lower soil biodiversity as the nematodes were a main driver of diversity in the young plantation, and (iii) similarly, for the soil chemical properties, the long-term effect of rubber chronosequence evidenced deterioration in the third rotation. Therefore, two rotations of rubber plantation (around 50 years) seemed to be the maximum length of rubber monocropping in terms of soil biodiversity recovery.

Background and aims: Long-term monocultures seriously compromise crop productivity, which is known as replanting obstacle. Flowers are the most valuable tissue in annual plants and closely associated with pollen production, fertilization and seed set, however, their roles in replanting obstacle are unknown. We here explored how long-term monocropping impacts flowers, and revealed the potential acclimation mechanisms employing by flowers to monocropping. Methods: Field trial and pot experiments with peanut monocropped and rotated regimes were performed to study the response of peanut flowers to monocropping with physiological, transcriptomic and fungal community analyses. Results: Long-term monocropping reduced flower formation, pollen viability, pollen germination and tube growth, thereby reducing seed set in peanut. The transcriptome of flowers revealed that genes associated with the anther dehiscence, heat stress response, flavonoid biosynthesis, glutathione metabolism and potassium uptake were enriched by monocropping, which indicated that flowers experienced water deficit and oxidative stress. Inhibition of reactive oxygen species (ROS) synthesis or scavenging excess ROS rescued pollen activity decline under monocropping. By screening flower physiology and soil physicochemical properties, combined with drought and soil aggregate composition mimic experiments, we confirmed that flower water deficit and oxidative stress under monocropping were mediated by the soil structure alterations, especially large macro-aggregates (> 2 mm) reduction. Conclusion: Long-term monocropping alters soil structures, resulting in a water deficit and ROS accumulation in the flowers, which decreases pollen activity, and a multi-faceted actions including accelerated anther dehiscence, enhanced potassium absorption and better ROS scavenging capacity, are taken by flowers to acclimate to monocropping. [ABSTRACT FROM AUTHOR]

In monocropping systems autotoxins, such as phenolic compounds, could accumulate in soil and affects the soil microbial communities, however, the specific effects on microbial species are unknown. We determined the responses of cucumber rhizosphere Fusarium and Bacillus spp. communities to exogenously applied p-coumaric acid (0.02, 0.05, 0.1, 0.2 μmol/g soil) by polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) technique. Results showed that all concentrations of p-coumaric acid changed the community structure of Fusarium spp. and p-coumaric acid at 0.2 μmol/g soil decreased the number of bands as indicated by Shannon-Wiener and evenness index of Fusarium spp. community. However, p-coumaric acid did not affect the structure of Bacillus spp. community. These results indicated that the p-coumaric acid showed different effects on Fusarium and Bacillus spp. communities. [ABSTRACT FROM AUTHOR]

Intercropping is the process of planting two or more crops simultaneously in the same field in order to provide greater ecosystem services (i.e. services related to sustainable land and water use, climate change mitigation, and ecosystem restoration). In southern Mexico, the cereal-legume intercropping is a traditional cropping practice that is declining overtime. This paper provides a literature review of the potential benefits and constraints of a maize-legume intercropping for small-scale farms in southern Mexico. This review explored and elucidated the different ecosystem services delivered by maize-legume intercropping systems. This information will help farmers know how to make a better use of cereal-legume intercropping systems to increase maize yields, improve their socioeconomic conditions, and enhance conservation agricultural practices in southern Mexico. [ABSTRACT FROM AUTHOR]

Fritillaria hupehensis, a well-known medicinal perennial herb, is used as an antitussive and an expectorant. Continuous cropping and monoculture cultivation usually negativly affect the growth of F. hupehensis. Compared with the monoculture system, the F. hupehensis-Magnolia officinalis intercropping system significantly increases the yield of F. hupehensis. However, changes in steroidal alkaloid metabolites (the most important bioactive components) and their molecular regulatory mechanisms in F. hupehensis intercropping system remain unclear. We performed comparative transcriptomic and metabolomic analyses of F. hupehensis bulbs grown in monocropping and intercropping systems. A total of 40 alkaloids were identified, including 26 steroidal alkaloids, 4 plumeranes, 3 phenolamines, 1 pyridine alkaloid, and 6 other alkaloids. The results showed that intercropping significantly increased the levels of peimine, peiminine, hupehenine, korseveridine, verticinone N-oxide, delafrine, tortifoline, pingbeinone, puqienine B, puqienine E, jervine, ussuriedine, hydroxymandelonitrile, Nferuloylputrescine, and N-benzylmethylene isomethylamine in F. hupehensis, but decreased the levels of indole, p-coumaroylputrescine, and Nbenzylformamide. Transcriptome sequencing identified 11,466 differentially expressed unigenes in F. hupehensis under the intercropping system, of which 5,656 genes were up-regulated and 5,810 genes were downregulated. We proposed a possible steroidal alkaloid biosynthesis pathway, in which 12 differentially expressed genes were identified. The higher expressions of these genes in the intercropping system positively correlated with the high accumulation of peimine, peiminine, and hupehenine, further validating our proposal. Moreover, the biological processes of oxidative phosphorylation and plant hormone signal transduction, cytochrome P450 enzymes, ATP-binding cassette transporters, and transcription factors may play pivotal roles in the regulation of steroidal alkaloid biosynthesis. This study revealed the underlying molecular mechanisms of intercropping in improving steroidal alkaloids in F. hupehensis at the transcriptome and metabolome levels. These findings provided a theoretical foundation for sustainable development of this ecological planting method. [ABSTRACT FROM AUTHOR]

Monocropping of perennial cash crops providing livelihood for smallholders is replacing native forest throughout the tropics, but there is no direct empirical evidence on the impact on soil organic carbon (SOC) and nitrogen (N) relative to multistrata-agroforestry-based cash cropping. In particular, the impact of the conversion of forests and multistrata-agroforestry-based cash cropping to a rapidly expanding perennial monocropping of khat (Catha edulis Forskal) is not known. We investigated the potential of cash cropping integrated in multistrata agroforestry to alleviate SOC and N loss from converted native forest, relative to cash monocropping. We assessed empirically SOC and N stocks in the 40-cm-deep soil surface layer of three matched adjacent plots of native forest, multistrata agroforestry, and perennial cash monocropping, within nine replicate groups of the three land uses. The fixed mass method was applied. The estimated rates of the annual SOC and N losses were 3.0 and 3.4 times greater, respectively, in areas converted to khat monocropping than in agroforestry systems producing both coffee (Coffea arabica) and khat. Additionally, the carbon and N contents in leaf litter and fine roots were greater in agroforestry than in khat. The results indicated that multistrata-agroforestry-based cash cropping maintains most of the SOC and N stocks of converted native forests lost in conversion to cash monocropping khat than in agroforestry-based cash cropping. This warrants economic incentives to prevent the loss of the current stocks, while enabling cash crop income by smallholders. Reducing forest SOC and N stock decline in agroforestry through system management deserves attention as well. [ABSTRACT FROM AUTHOR]

Monocropping is commonly practiced by small-scale banana farmers for ease of management; however, concerns arise regarding its long-term effects on soil health and ecosystem stability. In order to ascertain the fact, this study investigated the impact of different durations of monocropping Lakatan banana on soil health as reflected by nematode community structure. For the extraction of nematodes, soil and root samples were collected from various banana farms practicing monocropping for 2-4, 5-9 and 10-15 years. Farms with prolonged monocropping showed an increased population of plant-parasitic nematodes compared to free-living nematodes. Nematode family Hoplolaimidae was recorded as the most dominant (59.59%-80.49%) across all monocropping durations. Shannon and Simpson's diversity indices were lowest at 10-15 years of continuous monocropping period, as compared to 2-4 years and 5-9-years. Maturity index (MI, 2.26) was highest at 5-9 years of continuous cultivation while structure index (SI, 68.93), and enrichment index (EI, 73.74) were highest in banana farms with monocropping periods of 2-4 years, and lower in banana farms with longer monocropping periods. Higher plant parasite index (PPI, 2.89-2.93) and PPI/MI (1.37) ratios were observed in monocropping periods of 10-15 years. Analysis of the c-p data indicated that soil conditions approach stress levels when farms are cultivated under 10-15 years of monoculture. Soil food web analysis revealed disturbances in the soil ecosystem, particularly in banana monocropping farms used for 5-15 years. Continuous monocropping for 5-15 years could disrupt the soil conditions, as evidenced by changes in the nematode community structure. These findings highlight that nematode communities can serve as sensitive indicators of soil quality and have the potential to elucidate the impact of farming management on soil health. [ABSTRACT FROM AUTHOR]

Natural rubber consumption has led to the expansion of rubber (Hevea brasiliensis) plantations which affects the deforestation and ecosystem. However, no study of the long-term effect of rubber plantations on soil biodiversity has been carried out yet. This study aimed to assess the long-term impact of continuous rubber monocropping on soil biodiversity, focusing on soil macrofauna and nematode diversity. Three successive rubber rotations at young and old ages were compared with the adjacent forest in Suratthani province, Thailand. Soil biodiversity quality index was calculated from a set of indicators which were combined into a single score to present a functional assessment of the gradient of disturbance. The results showed three negative effects on soil biodiversity (i) the biodiversity quality index immediately declined after deforestation (ii) the old age rubber plantations had a lower soil biodiversity as the nematodes were a main driver of diversity in the young plantation, and (iii) similarly, for the soil chemical properties, the long-term effect of rubber chronosequence evidenced deterioration in the third rotation. Therefore, two rotations of rubber plantation (around 50 years) seemed to be the maximum length of rubber monocropping in terms of soil biodiversity recovery. [ABSTRACT FROM AUTHOR]

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This study evaluates the effect of maize, sorghum and cowpea as intercrops with okra (at ratio of main: intercrop- of 1:1 and 2:1) against okra shoot and fruit borer Earias spp. incidence. The results revealed that the least shoot damage (5.00%) was observed with okra + cowpea (1:1) intercropping followed by okra + cowpea (2:1) and okra + sorghum (1:1). Maximum shoot damage (6.65%) was registered in okra + maize (2:1) as against mono-cropping (7.69%). Similarly, the least fruit damage (12.25%) was in okra + cowpea (1:1) crop statistically on par with that of okra + cowpea (2:1), okra + sorghum (1:1) and okra + sorghum (2:1); maximum (16.41%) was observed with okra + maize (2:1) and okra as a sole crop (18.42%). The okra + cowpea (1:1) recorded the maximum land equivalent ratio (1.31) followed by okra + cowpea 1.20 at 2:1 and okra+ sorghum 1.19 at 1:1 crop ratio. Okra intercropped with maize (2:1) was found less effective (0.99) than the okra sole. The maximum okra equivalent yield (111.4 q/ ha) was obtained with okra + cowpea intercropping (1:1), while the least (100.9 q/ ha) was in okra + maize (2:1). [ABSTRACT FROM AUTHOR]

Feedbacks between plants and soil microbes are critical for ecosystem regulation and restoration. Soil microbial diversity is largely dependent on plant diversity, yet these relationships have received little attention at the landscape scale. In agricultural landscapes, the presence of different plant cover types (landscape elements) can modulate these feedbacks by adding spatial heterogeneity through changes in the amount and composition of plant residues. Furthermore, it can also influence the soil biota. Therefore, the more diverse the landscape elements of farmlands, the higher the increase of their heterogeneity. We investigated the microbial catabolic profiles and respiration rates of soils from different plant cover types through the manipulation of plant residues and microbial communities. In individual microcosms, we incubated sterilized soils sampled from five different cover types of a temperate agricultural landscape: Soybean Monocropping, two crop rotations (Rotation and Intensified Rotation) and two uncropped margins: Herbaceous and Woody spontaneous vegetation. We amended them with each of two plant residues: wheat stubble (Wheat) and a mix of spontaneous vegetation (Mix). Soils were also inoculated with each of two soil microbial communities: Soybean Monocropping and Woody margins. We predict that soils treated with the Mix residue and the Woody margins community will show higher catabolic diversity and respiration than those treated with Wheat stubble and Soybean Monocropping community. In turn, we predict that soils from Woody margins, with higher carbon content, will respire more and amplify the effects of plant residue and microbial community. The microbial catabolic profile changed with plant residue and microbial community whereas the microbial respiration changed with cover type. After 30 days of incubation, soils inoculated with Woody margin community sustained higher diversity than those inoculated with Soybean Monocropping community. Conversely, Wheat stubble increased microbial diversity with respect to the Mix, particularly in soils from Woody margins while Mix residue increased the microbial diversity of soils from Soybean Monocropping. Finally, microbial respiration of soils from Woody margins showed the greatest respiration and Soybean Monocropping the lowest, in correlation with their carbon contents. Despite the complex interactions between soil carbon contents and plant residue composition, our results suggest that internal transfers of soil and plant residue between the different landscape elements might contribute to increasing the resilience of agricultural landscapes. • The microbial catabolic profiles changed with plant residues and microbial community. • Wheat residues increased microbial diversity of soils from woody margins. • Mix residue increased microbial diversity of soils from soybean monocropping. • Soil microbes from woody margins had the highest diversity across all soils. • Soil microbial respiration was only affected by cover type. [ABSTRACT FROM AUTHOR]

This paper analyzes the socioeconomic factors influencing crop diversity and the likelihood of adopting monocropping as among rural households in the Esmeraldas province. With data of a household survey (n=226) conducted in October 2020 and by means of multivariate analysis techniques, it was possible determine that households with heads holding a university degree, receive non-farm income, are not recipients of the Bono de Desarrollo Humano and spend more on agricultural inputs have lower crop diversity in their farms. In terms of adoption of monocropping, households with higher endowments of education, that own larger farms, spend more on agricultural inputs and have been granted with credit are more likely to adopt monocropping as a production system. The implications of this findings for policy are discussed in the conclusion section. [ABSTRACT FROM AUTHOR]

Land terracing is a vital means to minimize soil erosion in steep slopes of north eastern region of India. Monocropping of turmeric is one of the main production systems in these terraces, resulting in poor land productivity and profitability. Hence, a fixed plot field experiment was undertaken during five consecutive years (2012–17) at ICAR Research Complex for NEH Region, Meghalaya by involving five vertical cropping combinations, viz. turmeric (Curcuma longa)+cucumber (Cucumis sativus), turmeric+bottlegourd (Lagenaria siceraria), turmeric+sponge gourd (Luffa aegyptiaca), turmeric+squash (Sechium edule) and turmeric sole (open cultivation) to find out the best cucurbits for vertical integration with turmeric for efficient utilization of natural resources and profit maximization. Results revealed that integration of bottle gourd with turmeric in vertical fashion recorded the maximum system productivity (33.94 t/ha), profitability (` 1308 ha/day) and B:C ratio (3.37). Over all, vertical integration of cucurbits increased 38.52% yield of turmeric over open cultivation. Maximum enhancement in soil organic carbon (SOC) (2.18%), available N (241 kg/ha), P (22.2 kg/ha) and K (194.7 kg/ha) were recorded when squash was integrated with turmeric followed by turmeric + bottlegourd vertical cropping system. Integration of cucurbits with turmeric improves soil microbial biomass carbon (SMBC) level by 9.85% over the open cultivation of turmeric in dry terraces. Hence, vertical integration of cucurbits with turmeric not only enhances the system productivity and monetary returns of dry terraces but also improves the soil fertility status over open cultivation of turmeric.

Background and aims: Repeated planting of the same or closely-related crop species often results in negative soil feedbacks, manifested as reduced plant growth. This is commonly attributed to accumulation of plant pathogenic organisms, but there is increasing evidence that other microbes may contribute as well. Since individual members of the bacterial soil microbiome display distinct preferences for specific root exudates, we hypothesize that enrichment of a small subset of bacterial species in the rhizosphere by monocropping will decrease overall diversity and thus negatively influence the performance of the crop. Methods: To test this, we examined soil feedbacks for peanut plants inoculated with bacterial suspensions obtained from monocropped and rotated plots in closed cultivation systems. Results: Partial 16S rRNA gene amplicon sequence analysis revealed significant effects of cropping system on the bacterial composition of peanut rhizospheres. When added to peanut seedling rhizospheres, soil suspensions derived from monocropped plots produced a significant reduction in rhizosphere microbiome species richness (number of OTUs). And, bacterial species including Sphingomonas sp., Herbaspirillum sp., and Arthrobacter sp. were enriched in peanut rhizosphere. However, monocropping-derived soil suspension inoculants showed significant deleterious effects on peanut development compared to rotation-derived inoculants. Further bioassays determined that some enriched bacterial strains that were isolated from the monocropping treatment repressed peanut hypocotyl extension. Conclusions: Our results suggest that bacterial composition assembly in peanut rhizosphere in monocropping system especially that enriches particular deleterious bacterial taxa could lead to clear reductions in plant performance even in the absence of disease or signs of pathogenesis. [ABSTRACT FROM AUTHOR]

Understanding the complex relationships among soil quality, crop productivity, and management practices would help to develop more sustainable agricultural production systems. In this study, we investigated the combined effects of crop rotations and fertilization treatments on soil quality and crop yield in a long term (about 50 years) field experiment. Crop rotations included continuous corn (Zea mays L.), a 2 year corn-wheat (Triticum aestivum L.) rotation, and a 9 year corn-wheat-corn-wheat-corn-wheat-alfalfa-alfalfa-alfalfa (Medicago sativa L.) rotation. Fertilization treatments included control, mineral fertilization with urea and triple superphosphate, and amendment with cattle manure. Crop rotations and fertilization treatments were combined in a factorial experimental design with two replications for each rotation and six replications for each fertilization treatment. The continuous corn and the corn-wheat rotations had negative effects on the main soil quality indicators considered (carbon (C) and nitrogen (N) pools, microbial biomass and activity). On the contrary, the 9 year rotation had positive effects on soil organic carbon (+24%) and total nitrogen (+23%) but resulted in impoverished available P (−5%). Positive effects on soil microbial biomass (+37% of microbial biomass C and +23% of microbial biomass N) and activity (+19%) were also observed. Soil amendment with manure built up soil organic carbon (+13%), increased nutrient content (+31% of extractable C and +19% of extractable N), including that of available P (+47%), and stimulated microbial growth (+34%) and activity (+8%). As compared to manure, mineral fertilization increased the soil nutrient content to a lesser extent. This study showed that the combined use of rotations, including legume forage crops, and soil amendment with manure may help preserve soil quality and crop productivity in the long term.

Rural communities worldwide are increasingly confronted with the simultaneous impacts of environmental change dynamics and processes of economic restructuring that diminish traditional sources of state support while shifting investments toward large-scale intensive production models. A key question in this context is how livelihoods are affected by these interacting forces of change and whether new production models can contribute to resilience at the household and community scales. Here we examine the impacts of oil palm production on marginal rural communities in Mexico that have experienced both the economic changes associated with neoliberal policy reforms and the dynamics of environmental change. We find that oil palm production can contribute to livelihood resilience when community members participate in its management and governance and when production is associated with state support, but that the kinds of neoliberal policies promoting oil palm expansion may exacerbate existing community vulnerabilities in the face of environmental change. [ABSTRACT FROM AUTHOR]

Root-knot nematodes (RKNs) are one of the major phytopathological problems that limit potential yields in intensive agriculture worldwide. Grafting with resistant rootstocks has been demonstrated to be a viable technique to manage Meloidogyne incognita in several crops (tomato, melon, watermelon, etc.). However, little research has been conducted on sweet pepper (Capsicum annuum L.) grown in greenhouses under Mediterranean-climate conditions. Therefore, we studied a susceptible scion variety (Gacela) grafted onto resistant rootstocks (C19, C25, and RT17), in comparison with ungrafted and self-grafted (GAL) plants. The RKN produced significant root galling in ungrafted and GAL plants; however, RT17 was unaffected. This differing response to infection is discussed from physiological and agronomic perspectives. Thus, following the inoculation of susceptible rootstocks, leaf photosynthesis was impaired by altered stomatal regulation and photochemical efficiency (chlorophyll a fluorescence), which led to unbalanced fruit nutrient concentrations (especially Ca) and to enhanced allocation of carbon from photosynthesis to the production of biochemical defense compounds. Consequently, total phenolics and carotenoids were significantly affected, as was the amino acid profile. These results provide new insights into the traits that can identify RKN-resistant rootstocks, and therefore new tools to induce resistance, while avoiding the use of disinfectants in the soil. • RKN differentially affected photosynthesis in grafted and ungrafted plants. • RKN altered leaf gas exchange, disturbing the fruit nutrient composition. • RKN resistance modulated total phenolics and carotenoids, but not total amino acids. • The yield advantage due to grafting was effective only for RKN-infested soils. • New traits are provided that reveal physiological processes that confer RKN tolerance. [ABSTRACT FROM AUTHOR]

Abstract The long-term use of Cu-containing fungicides contaminates vineyards soils, which can induce Cu toxicity and nutrient imbalances in several plant species. The aim of this work was to evaluate the effect of Cu toxicity on two grapevine rootstocks, Fercal and 196.17, and to elucidate if intercropping with oat can alleviate grapevine Cu toxicity. Plants were hydroponically-cultivated and treated with different Cu concentrations. At harvest the biomass accumulation, the SPAD index and the symplastic and apoplastic root and leaves ionome were measured to evaluate possible synergistic and/or antagonistic effects on other micro- and macronutrients. The root exudation analysis was correlated with genes expression (VvPEZ-like), whereas PCA analysis performed on the grapevine and oat ionome revealed that both mono- and intercropped 196.17 rootstock display a positive effect on Zn and Mn in the root tissues at high Cu concentrations. An increase of Zn and Mn in roots was also reported for the intercropped Fercal rootstock at high Cu concentrations while an antagonistic relation was reported for root Zn concentration in the monocropped Fercal rootstock. Our results showed that grapevine and oat compete for nutrient uptake and that this phenomenon can possibly alleviate grapevine Cu toxicity. However, Fercal rootstock is able to take advantage from oat, while 196.17 is disadvantaged by the intercropping system. Even though intercropping system seems to be a valuable tool to counteract grapevine Cu toxicity, the application of this agricultural practice has shown to be species dependent and should be evaluated for each rootstock. Highlights • 196.17 performs better than Fercal in monocropping systems in Cu toxicity. • Phenolic compounds are involved in alleviating Cu toxicity. • The grapevine exudation pattern was influenced by the intercropping with oat. • Ionomic analysis of intercropped plants reveals a competition between plant species. • The effectiveness of intercropping is rootstock dependent. [ABSTRACT FROM AUTHOR]

A preliminary survey of farmers conducted at Chikkamaranahalli village of Nelamangala Taluk, Bangalore rural district under National Innovation in Climate Resilient Agriculture (NICRA) project revealed that the area was dominated by resource poor marginal and small farmers. The predominant resources, crops and cropping system of the area were assessed through participatory rural appraisal (PRA) techniques. Monocropping of finger millet with akkadi crops was dominated in the domain besides other problems like imbalanced fertilizer use, delayed onset of monsoon, intermittent dry spells, lack of awareness about improved varieties and dryland production practices. Therefore an investigation was carried out from 2014-15 to 2017-18, to find out a sustainable cropping system model, which is economically viable by integrating the different components like crops, livestock and fishery in an area of 2.5 acre land holding. Four cropping system models viz., F1: finger millet based cropping system, F2: Groundnut based cropping system, F3: Pulse based cropping system and F4: Mango based Agri-Horti system were developed to find out the best package on the landholding suitable for the region. Intercropping of finger millet - pigeonpea in 8:2 proportions fetched higher net returns of Rs. 7622 ha-1 compared to farmers practice of growing akkadi finger millet (Rs. 4129 ha-1). Similar was the trend in groundnut based cropping system, where in intercropping of pigeonpea with groundnut (8:2) resulted in higher groundnut pod equivalent yield of 434 kg ha-1 and B:C ratio of 3.43. With respect to pulse based intercropping system, intercropping of pigeonpea with field bean fetched higher returns (Rs.7936 ha-1) compared to that of with cowpea (Rs. 6767 ha-1). In mango based agri-horti system growing of finger millet/ horsegram along with mango not only helped in generating additional remunerative income of (Rs. 2804 ha-1) but also enhanced the soil fertility status compared to growing sole mango crop. Livestock was an integral part of farming system along with other agricultural components like horticulture, vegetables, agro forestry etc. Integration of fisheries along with livestock components fetched net returns of Rs.6000 and 39650/year respectively and required higher man days 235 over conventional cropping system. Thus integrated farming system with livestock + fisheries along with profitable intercropping system was most beneficial system which could augment in increasing the income of farmers to improve their socio-economic status. [ABSTRACT FROM AUTHOR]

Soil microbial communities have profound effects on the growth, nutrition and health of plants in agroecosystems. Understanding soil microbial dynamics in cropping systems can assist in determining how agricultural practices influence soil processes mediated by microorganisms. In this study, soil bacterial communities were monitored in a continuously monocropped Jerusalem artichoke (JA) system, in which JA was successively monocropped for 3 years in a wheat field. Soil bacterial community compositions were estimated by amplicon sequencing of the 16S rRNA gene. Abundances of ammonia-oxidizing and denitrifying bacteria were estimated by quantitative PCR analysis of the amoA, nirS, and nirK genes. Results showed that 1–2 years of monocropping of JA did not significantly impact the microbial alpha diversity, and the third cropping of JA decreased the microbial alpha diversity (P < 0.05). Principal coordinates analysis and permutational multivariate analysis of variance analyses revealed that continuous monocropping of JA changed soil bacterial community structure and function profile (P < 0.001). At the phylum level, the wheat field was characterized with higher relative abundances of Latescibacteria, Planctomycetes, and Cyanobacteria, the first cropping of JA with Actinobacteria, the second cropping of JA with Acidobacteria, Armatimonadetes, Gemmatimonadetes, and Proteobacteria. At the genus level, the first cropping of JA was enriched with bacterial species with pathogen-antagonistic and/or plant growth promoting potentials, while members of genera that included potential denitrifiers increased in the second and third cropping of JA. The first cropping of JA had higher relative abundances of KO terms related to lignocellulose degradation and phosphorus cycling, the second cropping of JA had higher relative abundances of KO terms nitrous-oxide reductase and nitric-oxide reductase, and the third cropping of JA had higher relative abundances of KO terms nitrate reductase and nitrite reductase. The abundances of amoA genes decreased while nirK increased in the third cropping of JA, nirS continuously increased in the second and third cropping of JA (P < 0.05). Redundancy analysis and Mantel test found that soil organic carbon and Olsen phosphorus contents played important roles in shaping soil bacterial communities. Overall, our results revealed that continuous monocropping of JA changed soil bacterial community composition and its functional potentials.

Introduction: In achieving food security and sustainable agricultural development, improving and maintaining soil health is considered as a key driving factor. The improvement based on different forms of nitrogen fertilization has aroused great public interest in improving and restoring monocropping obstacles for specific soil problems., Methods: For this, a short-term cucumber cropping field experiment was conducted in the subtropical region of China under four fertilization treatments: ammonium (AN), nitrate (NN), ammonium with dicyandiamide (AN+DCD), nitrate with dicyandiamide (NN+DCD). In this study, we measured the effects of nitrogen forms addition on plant productivity and soil health in a monocropping system over seven seasons., Results: To systematically evaluate soil health, a wide range of soil environmental factors were measured and incorporated into the soil health index (SHI) by entropy method. Compared with ammonium treatment (SHI AN = 0.059, SHI AN+DCD = 0.081), the positive effect of nitrate was mainly reflected in improving soil health (SHI NN = 0.097, SHI NN+DCD = 0.094), which was positively correlated with the increase in plant productivity of cucumber after seven seasons of monocropping. The most critical factor affecting SHI is soil ammonium nitrogen content, which was negatively correlated with plant productivity., Discussion: Nitrate promotes soil health and plant productivity by optimizing soil environmental factors. The study thus emphasized the necessity of nitrate input for the sustenance of soil-crop ecosystems, with the consequent possibility of application of the results in planning monoculture obstacle prevention and management measures., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Zhu, Liang, Wang, Shi, Li, Wang, Wang and Guo.)