Conventional Monoculture Research Articles

The Landscape Ecological Quality of Two Different Farm Management Models: Polyculture Agroforestry vs. Conventional

Low-intensity, diversified agricultural land use is needed to counteract the current decline in agrobiodiversity. Landscape ecology tools can support agrobiodiversity assessment efforts by investigating biodiversity-related ecological functions (pattern–process paradigm). In this study, we test a toolkit of landscape ecology analyses to compare different farm management models: polyculture agroforestry (POLY) vs. conventional monoculture crop management (CV). Farm-scale analyses are applied on temperate alluvial sites (Po Plain, Northern Italy), as part of a broader multi-scale analytical approach. We analyze the landscape ecological quality through landscape matrix composition, patch shape complexity, diversity, metastability, and connectivity indices. We assess farm differences through multivariate analyses and t-tests and test a farm classification tool, namely, a scoring system based on the relative contributions of POLY farms, considering their deviation from a local CV baseline. The results showed a separate ecological behavior of the two models. The POLY model showed better performance, with significant positive contributions to the forest and semi-natural component equipment and diversity; agricultural component diversity, metastability; total farm diversity, metastability, connectivity, and circuitry. A reference matrix for the ecological interpretation of the results is provided. Farm classification provides a quick synthesis of such contributions, facilitating farm comparisons. The methodology has a low cost and quickly provides information on ongoing ecological processes resulting from specific farm management practices; it is intended to complement field-scale assessments and could help to meet the need for a partially outcome-based assessment of good farm practice.

Soil-Microbial Interactions in Rice-Loach-Shrimp Integrated Farming: Multivariate Analysis of Ecological Intensification

Ecological intensification of agriculture is crucial for sustainable food production, yet the complex soil-microbial interactions in integrated farming systems remain poorly understood. This five-year study compared a Rice-Loach-Shrimp (RLS) integrated system with conventional Rice Monoculture (RM) using advanced multivariate techniques, including correlation analysis, Principal Component Analysis, Random Forest modeling, and Structural Equation Modeling. The RLS system exhibited higher values for key soil health indicators compared to RM, although the overall correlation patterns were similar. Stronger correlations among soil organic matter, enzyme activities, and microbial populations were observed in RLS, suggesting a more tightly coupled soil ecosystem. Available phosphorus and soil organic matter were identified as primary drivers of microbial community structure. The RLS system showed a slightly higher mean pH and weaker correlations between pH and other indicators compared to RM, indicating potential altered biogeochemical processes. Complex cascading effects among soil properties, enzyme activities, and microbial populations were revealed in RLS. These soil health benefits persisted throughout the study period, demonstrating the potential of RLS as an effective ecological intensification strategy for sustainable rice production.

Close-to-nature management of tropical timber plantations is economically viable and provides biodiversity benefits

Abstract Reforestation of tropical forests is crucial to mitigate the climate crisis and restore ecosystems. However, past efforts have been criticized for establishing monoculture timber plantations with exotic tree species. Close-to-nature (CTN) practices aim to minimize negative forest management impacts on forests ecosystems by mimicking natural dynamics. So far, CTN management practices are rarely applied in tropical plantation forestry. This study evaluates the economic, carbon sequestration, and biodiversity potential of CTN management in tropical mixed-species plantations in Central America using a simulation-optimization approach. To our knowledge, this study is the first to assess the potential of tropical CTN-managed plantations on the basis of detailed process-based forest growth simulations. CTN practices such as selective harvesting, retention forestry, and shelterwood cutting of mixed-species stands were compared to even-aged mixtures and conventional monoculture practices. Results showed that CTN management was economically viable for certain species mixtures and management practices at an 8 % discount rate and had the potential to increase carbon storage and biodiversity in the modeled plantations. At current carbon prices, CTN-managed plantations may only become financially competitive with monocultures, if monocultures are excluded from carbon certification schemes that increasingly aim at co-producing non-carbon benefits like biodiversity conservation. If carbon prices increase, the sale of carbon credits could finance the transformation of monocultures to CTN-managed mixed-species stands. The competitiveness of CTN management could also be improved through performance-based biodiversity payments, such as the sale of biodiversity credits.

Are agrochemical‐free and biodiversity‐friendly attributes substitutes or complements? Evidence from a coffee choice experiment

AbstractEco‐labels inform consumers about the sustainable attributes of a product, but consumer face challenges to differentiate and select for specific attributes. Certification programs are similarly challenged to incentivize adoption of sustainable practices in product supply chains when consumer ability to differentiate sustainable attributes is low. This study investigates consumers' Willingness to Pay (WTP) for different environmental attributes of coffee production, and whether attributes that conserve biodiversity and limit agrochemical usage are substitutes or complements. We designed and implemented a hypothetical coffee choice experiment combining coffee farm vegetation management attributes that impact biodiversity (conventional monoculture, shade‐grown, or “Bird Friendly” systems that conserve wildlife habitat) and chemical input (conventional, pesticide‐free, or organic) attributes. We found that consumers think of biodiversity and agrochemical management attributes as sustainability substitutes and have the highest WTP for pesticide‐free and organic attributes. Consumer groups with strong concern about the future of the environment had high WTP for all environmental attributes, but still considered the attributes to be substitutes. Our results suggest that eco‐label programs with biodiversity and agrochemical attributes, such as the Smithsonian Bird Friendly® coffee certification, could increase market participation by simplifying environmental sustainability messaging, simplifying farm‐level certification requirements, and targeting environmentally concerned consumers. [EconLit Citations: D12, Q01, Q13, L66].

Power-law productivity of highly biodiverse agroecosystems supports land recovery and climate resilience

Transformative change in primary food production is urgently needed in the face of climate change and biodiversity loss. Although there are a growing number of studies aimed at global policymaking, actual implementations require on-site analyses of social feasibility anchored by ecological rationale. This article reports the in-depth characterizations of low-input mixed polyculture of highly diverse crops managed on the self-organization of ecosystems, which performed better compared to conventional monoculture methods in Japan and Burkina Faso. Analyses on crop productivity and diversity showed that the primary production of ecosystems followed a power law, and through the underlying mechanisms excelled in (1) promoting diversity and total quantity of products along with the rapid increase of in-field biodiversity, especially useful for the recovery of local regime shift in a semi-arid environment; (2) a fundamental reduction of inputs and environmental load; and (3) ecosystem-based autonomous adaptation of the crop portfolio to climatic variability. The overall benefits imply substantial possibilities of a new typology of sustainable farming for smallholders sensitive to climate change, which could overcome the historical trade-off between productivity and biodiversity based on the human-guided augmentation of ecosystems.

Abstract LB317: TNBC cell co-culture with primary human lung fibroblasts identifies a paracrine-juxtacrine signaling loop promoting fibroblast activation and autophagy-dependent breast cancer cell therapy resistance

Abstract Triple negative breast cancer (TNBC) carries a poorer prognosis than other breast cancer subtypes due to high metastatic incidence, lack of molecular drug targets, and rapid development of chemoresistance. Cancer-associated fibroblasts (CAFs) are key extrinsic drivers of chemoresistance in primary TNBC tumors, but it is unknown whether resident fibroblasts in distant metastatic tissues also influence TNBC drug sensitivity. Since the lung is a top metastatic site in TNBC, we developed a breast cancer cell (BCC) - primary human donor-derived lung fibroblast (LF) co-culture model to identify therapeutic vulnerabilities and mechanisms of fibroblast-mediated extrinsic chemoresistance in lung-metastatic TNBC. We characterized the growth and chemoresistance phenotypes of BCC co-cultured with primary LFs via bioluminescence and fluorescence imaging and evaluated their transcriptional and secretory profiles using bulk and scRNAseq and multiplex cytokine analysis. Co-culture of human BCC and primary LFs resulted in BCC molecular subtype-dependent changes in cell growth and drug resistance compared with conventional monoculture. Moreover, we also observed increased LF secretion of the immunomodulatory cytokines IL-6 and CCL2 in response to both BCC co-culture and BCC-conditioned media. Transcriptomic analysis of LFs sorted from co-culture identified upregulation of pro-inflammatory and pro-fibrotic iCAF and myCAF-like gene signatures, while co-cultured TNBC cells upregulated interferon response-mediated multi-therapy resistance genes and cellular dormancy signatures. We applied this model in a high throughput screen of 846 kinase inhibitor compounds, which identified reproducible differential BCC responses to kinase inhibitors between monoculture and co-culture conditions. When co-cultured with LFs, BCC were broadly more resistant to kinase inhibitor compounds but showed increased sensitivity to inhibitors of the lipid kinase VPS34, an important initiator of autophagy. We subsequently established that autophagy is increased in co-cultured TNBC cells and contributes to LF-mediated resistance to kinase inhibitors. Moreover, we determined that while paracrine signals from BCC can promote LF activation indicated by enhanced cytokine secretion, cell-cell contact is required for LF modulation of TNBC therapy responses in co-culture. Thus, we conclude that breast cancer cell co-culture with primary lung fibroblasts is a scalable in vitro model that can facilitate therapeutic discovery and mechanistic evaluation of extrinsic modulation of therapy responses in metastatic breast cancer, and further demonstrate that BCC can promote paracrine activation of co-cultured LFs in association with juxtacrine induction of BCC autophagy and extrinsic therapy resistance. Citation Format: Marika L. Klosowski, Kathryn Cronise, Claire Stratton, Qiong Zhou, Hector Esquer, Daniel LaBarbera, Daniel Regan. TNBC cell co-culture with primary human lung fibroblasts identifies a paracrine-juxtacrine signaling loop promoting fibroblast activation and autophagy-dependent breast cancer cell therapy resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB317.

Promoting more sustainable agriculture in the Moroccan drylands by shifting from conventional wheat monoculture to a rotation with chickpea and lentils

Modern agriculture is linked to desertification, massive biodiversity loss and environmental degradation of the ecosystems. In contrast, crop rotation represents an agronomic approach included in conservation agriculture with important environmental and agronomic benefits, such as N fixation, pest and weed control, improvement of soil characteristics and reduction of crop fertilizer demand. Wheat is a staple food in Morocco, as are legumes, which are present in a wide variety of Moroccan recipes and represent an important source of energy and nutrients. The present study evaluates the environmental performance of incorporating chickpea and lentils in a crop rotation system in Morocco that aims to decrease the environmental footprint of the traditional wheat-based crop. An attributional Life Cycle Assessment was conducted in three cropping systems that are grown in two-year cycles: R1 (chickpea:wheat), R2 (lentil:wheat) and M (wheat:wheat). Emissions were quantified in terms of life-cycle related environmental impacts and compared between cropping systems based on two functional unit (kg of wheat harvested). Rotation systems stand out as the most environmentally friendly, with the most notable reductions in the categories of stratospheric ozone depletion and water scarcity (34 % and 50 %, respectively). The environmental improvement from crop rotations was most significant when considering the calculation basis of hectare cultivated versus kg of wheat, which is due to the estimated yield trade-offs in both approaches. In terms of biodiversity loss, no significant differences were observed between crop rotations and monoculture, as the impact on this indicator is mainly attributed to land conversion pressures. This study provides guidance for better formulating crop rotation strategies in the Mediterranean and similar arid regions. Future research should also assess the effects of agriculture on ecosystem services to provide a more comprehensive analysis to support decision making.

Modeling future carbon stock in melon cultivation agroecosystems under different climate scenarios

Intensive melon cultivation is based on conventional monoculture models that can inefficiently use natural resources, which, combined with inadequate management, contribute to climate change. The main objective of this study was to model the future carbon stock in melon cultivation agroecosystems under different climate scenarios. The study was conducted at the Bebedouro Experimental Field of Embrapa Semi-arid, Petrolina/PE, Brazil, in an area cultivated with yellow melon cv. Gladial, and eight cultivation cycles were considered. The experimental design was composed of two types of soil management (with and without tillage), two treatments using green manures consisting of 14 species with different proportions of legumes, grasses and oilseeds, and spontaneous vegetation, containing four replications divided into randomized blocks. After 70 days of development, the plants were cut and placed in the soil. Temperature and precipitation data were acquired from the BCC-CSM, MIROC5, CESM1-BGC, IPSL-CM5B-LR, and HadGEM2-AO climate models, following the RCP 4.5 and 8.5 climate scenarios. The carbon (C) stock was estimated until the year 2071 using the RothC model.

Optimizing ecosystem function multifunctionality with cover crops for improved agronomic and environmental outcomes in dryland cropping systems

CONTEXTIntegrating cover crop mixtures into dryland crop-fallow rotations may foster ecological intensification by enhancing ecosystem function multifunctionality compared with conventional fallows and monoculture cover crops. However, the expression of functional traits in cover crop mixtures is influenced by arrays of agronomic and environmental filters that differently influence cover crop performance. OBJECTIVETo (1) determine the identity and diversity effects of different cover crop functional types on ecosystem functions and trade-offs, and (2) determine the optimal cover crop mixture that maximizes ecosystem function multifunctionality in a subtropical dryland environment. METHODSUsing three-site-year field experiments, we assessed if cover crop mixtures enhanced ecosystem function multifunctionality (MF) above that of monoculture cover crops and conventional fallow. We measured a range of ecosystem functions as indicators of three major ecosystem service categories: 1) provisioning services (biomass production, cash crop yield, and profitability); 2) supporting services (weed suppression, soil active carbon accrual, soil aggregate distribution, nitrogen (N) mineralization, N supply, and N retention); and 3) regulating services (parasitic nematode suppression, promotion of free-living nematodes, soil respiration, and soil water conservation). RESULTS AND CONCLUSIONSWe found greater suite of ecosystem functions following mixture cover crops compared to monocultures, likely due to synergistic trait combinations that increased ecosystem function multifunctionality. The legume and forage brassica monocultures had consistently low multifunctionality (MF < 0.5). The oat:legume mixture resulted in the highest multifunctionality (MF > 0.5), driven by moderate water use and aboveground biomass production, and high groundcover residency, thus favouring higher cash crop yields and system profitability. They also generated overall improvements in soil health by providing additional carbon inputs, increasing the proportion of larger soil aggregates, and improving soil food web structure. We predicted the optimum cover crop mixture to maximize ecosystem function multifunctionality was 64% oat, 36% legume and 0% forage brassica. SIGNIFICANCEThis study offers novel insight into the agronomic and environmental impacts of replacing fallow with cover crops in a subtropical dryland. It shows that integrating mixture of oat:legume cover crops can increase multifunctionality. Further research is required on the extent of ecosystem trade-offs between competing ecosystem functions. The predicted optimum cover crop mixture composition will likely vary when different ecosystem functions are considered or if long-term experiment data are used. Hence, the recommended optimum cover crop mixture must be interpreted with caution and cover crop selection should be based on practical recommendations according to target management goals.

Meta-analysis unveils differential effects of agroforestry on soil properties in different zonobiomes

AimsCurrent comprehensive meta-analysis study aims to explore how agroforestry practices influence soil quality across different climate zones. Since numerous studies proposed agroforestry as the promising agroecological farming systems over conventional monoculture systems to maintain soil quality and to regenerate disturbed soil to counteract the negative consequences of global extensive agricultural approaches.MethodsBy employing the comprehensive meta-analysis technique on data from 125 studies conducted in tropical, temperate, and Mediterranean environments, we quantitatively assessed the effects of agroforestry on physical, chemical, and biological soil quality indicators.ResultsRates of soil erosion, the most important indication of land degradation, were improved in agroforestry systems compared to monocultures, especially in temperate (-138%) and Mediterranean soils (-40%), due to agroforestry-induced improved soil texture, aggregate stability, and soil water regulation. Soil acidification was decreased in tropical (-128%) and Mediterranean soils (-96%), but increased in temperate soils (+ 104%) due to agroforestry practices. Low temperate soil pH suggests high Ca2+ leaching losses as evidenced by decreased Ca2+ (-68%) and increased Fe2+ (+ 129%) and Al3+ (+ 235%) contents. Agroforestry systems increased organic matter accumulation in temperate (+ 86%) and Mediterranean soils (+ 65%), carbon sequestration in all climatic zones (+ 48%: 33–73%), and respiration rates in temperate (+ 119%) and tropical soils (+ 105%). Soil microbial communities, enzyme activities as well as nutrient cycling and availability were generally enhanced in agroforestry systems compared to monocultures.ConclusionsOur results provide compelling evidence that agroforestry practices can contribute substantially to sustainable improvement of global soil quality.

Comparative analysis of rhizobial and bacterial communities in experimental cotton fields: Impacts of conventional and conservation soil management in the Texas High Plains

Conservative agricultural management strategies pursue long-term ecological benefits through practices such as no-tillage, cover crop, and inherent soil properties management. Farmers, however, are often hesitant to adopt such practices due to lack of experience, initial expense, and concern for low crop productivity. Overcoming this barrier requires novel approaches, such as effectively managing the soil microbiome to attain high productivity at a low cost, especially in a semi-arid region. To study the potential of conservation agriculture, we investigated components of soil bacterial community and rhizobial diversity in long-term experimental cotton fields divided into conventional tillage monoculture systems with winter fallow (CT) and no-tillage with mixed cover crop (M-NT) system on the Texas High Plain (THP). We conducted next-generation amplicon sequencing targeting rpoB gene with collected soil samples from different soil managements and seasons. Our research revealed that although CT had significantly greater bacterial diversity and species richness than the M-NT management, rhizobial diversity and species richness were higher in M-NT than in CT management. Both bacterial and rhizobial diversity and richness were greater in summer than in fall. The abundance of the order Rhizobiales was consistently high in M-NT than in CT fields in both seasons. Soil management altered the dominant rhizobial genus associated with cotton production systems; Rhizobium and Pararhizobium dominated M-NT management, while Bradyrhizobium and Sinorhizobium were dominant under CT management. These outcomes suggest that incorporating legumes into a cover crop in this semi-arid cotton-growing region can initiate beneficial changes to the dynamics of the indigenous rhizobial assemblage. The high prediction accuracy of our machine learning model using bacterial community data classifying the managements as CT or M-NT validates the possibilities of a strong underlying relationship between soil management and the bacterial diversity in the soil.

Integration crop-livestock system increases the sustainability of soybean cultivation through improved soil health and plant physiology

This study aimed to evaluate how different cultivation systems in integration crop-livestock regimes affect soybean growth and physiology and understand how integrated systems change soil characteristics and soil CO2 flux. We conducted a comparative analysis of the plant physiology, growth, and soil characteristics of a conventional soybean monoculture (traditional cultivation method without any plant residues on the soil surface from the previous crop) and soybean cultivated in soil containing maize residues. Moreover, we conducted experiments to assess the effect of plant residues derived from maize intercropped within or between forage grasses on the effectiveness of integrating crop-livestock systems. Our main results indicated that when soybean was cultivated in all integration crop-livestock systems tested, soybean net photosynthesis rate and leaf chlorophyll content greatly increased, resulting in increased aboveground biomass production. Moreover, the integrated system decreased soil temperature and increased soil organic carbon content, total organic carbon content, and enzymatic activity, with no concomitant increase in soil respiration. However, fewer differences were observed between the sowing methods (maize in consortium with forages within and between rows). We conclude that all tested integrated crop-livestock systems greatly improved soybean physiology by increasing the amount of carbon assimilated into the ecosystem through photosynthesis, improving carbon sink potential, soil health, and maintaining a sustainable production system.

Trace elements accumulation and health risk assessment of Chinese mitten crab (Eriocheir sinensis) from monoculture and rice-crab co-culture mode

The rice-crab co-culture system has become the dominant mode of farming due to its advantageous production of crabs. To investigate the effects of different culture modes on trace element accumulation and health risks though consumption, we determined the concentrations of 16 trace elements (Ag, Al, As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Se, Tl, V, Zn) in Chinese mitten crabs (Eriocheir sinensis) from conventional monoculture (CM) and rice-crab co-culture system (RCCS) in two primary producing areas of China. Significant variations were found between CM and RCCS concerning trace element accumulation, with most trace elements showing higher levels in CM than in RCCS, except for Mn and Al. Correlation and PCA analysis indicate that RCCS has less environmental impact than CM. Moreover, the metal pollution index was also higher in CM than in RCCS. Based on the target hazard quotient (THQ), RCCS reduces the health risk associated with trace elements intake compared to CM. THQ values for both modes of culture are less than 1, indicating no or low health risks posed by trace elements in crabs. Further studies are needed in comparing the trace element accumulation in crabs from CM and RCCS within the same geographic area.

Integrated rice-aquatic animals culture systems promote the sustainable development of agriculture by improving soil fertility and reducing greenhouse gas emissions

Integrated rice–aquatic animals culture systems (RACSs) are of interest in sustainability research because they have been found to host diverse species and there is potential for positive synergistic effects between the plant (rice) and aquatic animal culture. However, their effect on soil fertility, rice productivity, and greenhouse gas (GHG) emissions, as well as the associations among them, remain unclear. A meta-analysis was conducted to systematically evaluate the sustainability of RACSs from the perspective of “rice productivity–GHG emissions–soil fertility” and their associations and to clarify how environmental factors and fertilizer-management practices affect responses of rice yield and GHG emissions to RACSs. We conducted a meta-analysis of 1807 paired observations collected from 78 published papers covering four countries that compared soil fertility, rice yield, and GHG emissions in a conventional rice monoculture system (CRMS) and in a RACS. Overall, the RACSs improved soil structure (soil bulk density declined by 5.8 % and total and capillary porosity increased by 6.4 % and 5.7 %, respectively), increased soil organic carbon (C, 7.9 %) and nitrogen (N, 6.6 %) storage, and reduced CH4 (9.2 %) and N2O (4.5 %) emissions; rice yield were little higher (by 2.0 %) than that of the CRMS. However, the effects varied under different RACS modes, environmental factors, and fertilizer-management practices. For instance, compared to CRMS, yields were 4.1 % higher in the rice–duck mode, 3.9 % lower in the rice–crayfish mode, and the no significantly change in the rice–fish system. The effects on GHG emissions and soil fertility were more pronounced in the rice–duck and rice–crayfish modes than in the rice–fish mode. Furthermore, paddy soils with low fertility (lower soil organic C and N) and less nutrient (nitrogen and phosphorus) input provide a higher rice yield and lower GHG emissions under RACSs. Overall, the RACSs stabilized rice productivity and reduced GHG emissions by improving the soil structure and increasing soil C and N sequestration; however, the effects varied by different RACS modes, initial soil properties, fertilizer input rate, and climate conditions. As such, environmental factors and nutrient management should be considered when designing and deciding what type of RACSs to employ. Our results also highlight the great potential of RACSs in the development of sustainable agriculture practices in the context of climate change. Future research and applications should consider the response of RACSs to climate and environmental factors and fertilizer-management practices, to achieve greater production and environmental benefits.

Hybrid planktonic-biofilm cultivation of a Nordic mixed-species photosynthetic consortium: A pilot study on carbon capture and nutrient removal

Mixed-species photosynthetic consortia have several advantages over conventional microalgal monocultures, including better carbon capture, more efficient wastewater treatment, and resilience to environmental stressors. In this study, a constructed photosynthetic consortium was investigated using a hybrid cultivation approach (combined planktonic and biofilm growth) in a pilot-scale raceway pond. A blend of locally-sourced waste streams was used as growth medium; biogas digestate and aquaculture effluent. The consortium performed well in terms of carbon capture, with 80.1% and 78.6% removal of inorganic and organic carbon species, respectively, over a 42-day cultivation period. Removal of phosphate and nitrogen species was suboptimal; 46.8% of phosphate had been consumed by the end of cultivation, but just 27.9% of total nitrogen had been removed. Despite inefficient total nitrogen removal, nitrite and ammonia were almost completely depleted after 15 days. Light microscopy was employed to monitor biofilm formation and changes in biodiversity over time, which helped to elucidate the processes responsible for nutrient and carbon flux, as well as biofilm formation and interspecies associations. Understanding how different mechanisms and biological functions can be encouraged or inhibited in mixed-species consortia is imperative for tailoring consortia to industrially-relevant applications, such as carbon capture, nutrient removal, or production of biomass or specific metabolites. The present study demonstrates not only the importance of cultivating dynamic, biodiverse, and adaptable consortia instead of fragile monocultures, but also the utility in real-time monitoring of such systems, so that environmental parameters can be adjusted for optimal performance.

Assessing the financial viability of growing industrial hemp with loblolly pine plantations in the southeastern United States

Industrial hemp (Cannabis sativa L. &amp;lt;0.3% THC), a non-psychoactive chemotype of cannabis, was reclassified and made legal for growing across the United States under the 2018 Farm Bill. Given that resources, knowledge, and interest for this novel crop are expanding rapidly, we explored the possibility of intercropping industrial hemp for fiber with loblolly pine (Pinus taeda) plantations, one of the most commercially widespread tree species in the southern United States. Following a previous greenhouse study confirming hemp’s ability to grow in pine-influenced soils, we examined the financial feasibility of this potential agroforestry system. We simulated the loblolly pine tree growth information using PTAEDA 4.0, a growth and yield model, and collected the enterprise budget data on hemp productivity, operating and fixed costs, and prices from various sources. Based on the capital budgeting analyses, results suggest that pine-hemp intercropping can yield higher economic returns –at least 25% higher net present value—than the conventional monoculture loblolly pine plantation. The early rotation cash flow and the complimentary benefits can result in a more financially viable loblolly pine plantation under the intercropping scenario. While new research continues to advance further with field trials and other analyses, this study provides valuable insights into the current market conditions and productivity level of industrial hemp cultivation that need to be addressed for hemp intercropping to succeed as an economically viable agroforestry investment.

Flavonoid Production: Current Trends in Plant Metabolic Engineering and De Novo Microbial Production.

Flavonoids are secondary metabolites that represent a heterogeneous family of plant polyphenolic compounds. Recent research has determined that the health benefits of fruits and vegetables, as well as the therapeutic potential of medicinal plants, are based on the presence of various bioactive natural products, including a high proportion of flavonoids. With current trends in plant metabolite research, flavonoids have become the center of attention due to their significant bioactivity associated with anti-cancer, antioxidant, anti-inflammatory, and anti-microbial activities. However, the use of traditional approaches, widely associated with the production of flavonoids, including plant extraction and chemical synthesis, has not been able to establish a scalable route for large-scale production on an industrial level. The renovation of biosynthetic pathways in plants and industrially significant microbes using advanced genetic engineering tools offers substantial promise for the exploration and scalable production of flavonoids. Recently, the co-culture engineering approach has emerged to prevail over the constraints and limitations of the conventional monoculture approach by harnessing the power of two or more strains of engineered microbes to reconstruct the target biosynthetic pathway. In this review, current perspectives on the biosynthesis and metabolic engineering of flavonoids in plants have been summarized. Special emphasis is placed on the most recent developments in the microbial production of major classes of flavonoids. Finally, we describe the recent achievements in genetic engineering for the combinatorial biosynthesis of flavonoids by reconstructing synthesis pathways in microorganisms via a co-culture strategy to obtain high amounts of specific bioactive compounds.

Comparative Study on the Structure of Plankton Community at Integrated Multi Trophic Aquaculture (IMTA) and Conventional Monoculture Net Cages at Coastal Area of Menjangan Besar, Karimunjawa Islands, Indonesia

Over the last decade, a modern sustainable aquaculture has become a driving force to speed up a production capacity but still pay attention to the carrying capacity of the environment for sustainability of the farming practice. We assessed the modern farming practice using stratified double net cage – Integrated Multi Trophic Aquaculture (SDNC-IMTA) to be compared to the conventional monoculture using structure of plankton community. The study was carried out at Menjangan Besar Island, Karimunjawa, Central Java during October 2021. The purpose of this study was to compare the plankton community's structure and determine the correlation between plankton abundance and water quality. Plankton sampling was carried out using the filtration method at three locations, i.e. monoculture cages, SDNC-IMTA cages, and reference sites. The abundance of phytoplankton and zooplankton were considerably higher at IMTA sites compared to the monoculture and reference sites. In particular, the highest abundance of zooplankton was found at the IMTA of 8569 ind.L-1, while the lowest abundance of zooplankton was found at the reference location of 3098 ind.L-1. The species considered as biological indicator were Ceratium sp., Dinophysis sp., Navicula sp., Pseudonitzchia sp., Oscillatoria sp., and Rhizolenia sp. The results of the NMDS ordination of phytoplankton data obtained a tendency of grouping the stations based on the three main sampling sites, while results from the zooplankton data did not show clustering between the sampling sites. The analysis of plankton abundance using with BIO ENV (Primary V 6.1.5) showed that the most abiotic factors affecting the abundance of plankton were temperature, turbidity, and salinity ( pvalue = 0.176).

Determination of Soil Cadmium Safety Thresholds for Food Production in a Rice-Crayfish Coculture System.

Previous studies have mainly focused on cadmium (Cd) contamination in conventional rice monocultures, and no research on rice-crayfish coculture has been reported. In this study, a Cd-contaminated (0-30 mg kg-1) rice-crayfish co-culture system was established by adding exogenous Cd. The results showed that the Cd concentration in each tissue of rice and each organ of crayfish increased with increasing soil Cd concentration. Specifically, the Cd concentration in each rice tissue was as follows: root &gt; stem &gt; leaf ≈ panicle &gt; grain &gt; brown rice, and the jointing and heading stages were critical periods for the rapid enrichment of Cd in the aboveground tissues of rice. The Cd concentration in each organ of crayfish was as follows: hepatopancreas &gt; gut &gt; gill ≈ exoskeleton &gt; abdominal muscle. Cd was gradually enriched in the abdominal muscle after 30 days of coculture between crayfish and rice. Pearson's correlation analysis showed that the soil's total Cd concentration, available Cd concentration, and water Cd concentration were positively correlated with Cd content in various tissues of rice and various organs of crayfish, whereas EC and TDS in water were markedly related to rice stems, leaves, stalks, and small crayfish. According to the maximum limit of Cd in grain (0.2 mg kg-1) and crustacean aquatic products (0.5 mg kg-1) in China, the safe threshold of soil Cd for rice and crayfish under the rice-crayfish coculture system is 3.67 and 14.62 mg kg-1, respectively. Therefore, when the soil Cd concentration in the rice-crayfish coculture system exceeds 3.67 mg kg-1, the safety risk to humans through the consumption of food from this coculture system will increase. This study provides a theoretical basis for safe food production in a rice-crayfish coculture system using the established Cd pollution model.

Soil greenhouse gas emissions and crop production with implementation of alley cropping in a Mediterranean citrus orchard

The implementation of alley cropping in orchards has been suggested as a sustainable strategy to increase farmer revenues by crop diversification, enhance soil organic matter (SOM) and fertility, water retention, overall biodiversity, and contribute to climate change mitigation. Thus, the objective of this study was to assess if alley cropping with annual crops can contribute to i) mitigate soil greenhouse gas (GHG) emissions, ii) enhance C sequestration in a semiarid Mediterranean irrigated citrus orchard, and iii) increase land productivity. For this, two different treatments were established: i) conventional mandarin monoculture (MC) with no alley cropping; and ii) mandarin diversified with alley cropping of barley/vetch and fava bean (DIV). Measurements of soil CO2 and N2O emissions were periodically performed (every 7–20 days) during two years. Soil CO2 emission rates followed the soil moisture trend, and showed no significant differences between treatments. As an average, soil CO2 emission rates were 147 mg m-2 h-1 in MC and 196 mg m-2 h-1 in DIV. Soil N2O emission rates were not correlated to soil moisture nor temperature, and showed average values of 0.026 mg m-2 h-1 in MC and − 0.002 mg m-2 h-1 in DIV. Alley cropping did not contribute to significantly increase soil organic C and total nitrogen in two years’ time. With regard to production, mandarin yield showed no significant differences between treatments, but alley crops contributed to complementary commodities to the main cash crop, increasing overall land productivity. Thus, alley cropping in irrigated Mediterranean orchards has no significant effect on soil C sequestration and GHG emissions at short-term, with increased land productivity owing to new commodities grown in the alleys. These results confirm that under semiarid Mediterranean climate, long periods are needed to efficiently assess soil C sequestration potential of sustainable practices in orchards.