Carrot Production Research Articles

From Root to Seed: Unearthing the Potential of Carrot Processing and Comprehensive Utilization

ABSTRACTCarrots, a globally cultivated root vegetable crop, are renowned for their nutritional and functional properties. However, the deep utilization and development of carrots and their derived products are limited in numerous countries, with a particular deficiency in advanced deep‐processing and transformation technologies. Consequently, the value of carrot products is diminished and resources are wasted. This review explores the nutritional value and characteristics of different carrot varieties, providing a comprehensive overview of the current state of carrot product processing. These products include primary processed products such as minimally processed carrots, dried carrots, pickles, preserves, fruit purees, yoghurt, juice, and essential oils, as well as processed by‐products including functional phytochemical extractions such as carotenoids, polyphenols, dietary fibers, active peptides, and glycoproteins. This review also covers other by‐products, including feeds, fast food boxes, and bioethanol production. Furthermore, cutting‐edge technologies related to carrot processing are discussed. The ultimate goal of this review is to provide researchers and practitioners with an in‐depth understanding of the present status of carrot production.

A diagnostic gap to fill: Development of molecular tools to distinguish the cyst-forming nematode species Heterodera carotae and Heterodera cruciferae

The carrot cyst nematode, Heterodera carotae, is an important pest causing qualitative and quantitative production losses across several countries worldwide. In culture crops, Heterodera carotae and Heterodera cruciferae, can be found in mixture and are virtually unrecognizable from a morphological point of view. However, only H. carotae is able to develop on carrot. To monitor carrot production and set up suitable H. carotae control plans, simple and reliable diagnostic methods to detect and identify these two species are needed. In this study, we developed and successfully tested two real-time PCR protocols (SYBR Green singleplex and TaqMan multiplex real-time PCRs) against both species: H. carotae and H. cruciferae. Using two specific sets of primers, we managed, whatever the methods, to distinguish the two species. Moreover, we showed a higher specificity using the TaqMan assays but a better sensitivity with the SYBR Green assays. In this study, we are proposing two useful and reliable diagnostic tools to enable farmers and scientists to rapidly detect two morphologically and genetically closely related species and supervise agricultural management.

Productivity and economics of carrot (Daucus carota) as influenced by interactive effect of potassium and micronutrients

Deficiency and insufficient nutrients application are the major factor responsible to reduced carrot root yield. Nutrients in balanced amount are critical aspect for getting optimal root yield for a particular agro-climatic condition. An appropriate nutrient management including potassium and micronutrients might rise and improve the productivity of carrot. The experiment was conducted at Sri Karan Narendra Agriculture University, Jobner, Jaipur, Rajasthan to study the effect of variable potassium and micronutrients formulations on performance of carrot. Results were found to be significant for the yield attributes, yield and economics of carrot. Soil application of potassium (MOP) @150 kg/ ha significantly enhanced the average root weight (189.3 g), root diameter (3.7 cm), shoot: root ratio (0.5), edible root length (23.7 cm), root yield (28.3 t/ha), net returns (₹205161/ha) and B:C ratio (2.7) of carrot. Among the micronutrients formulations, significantly higher average root weight (182.8 g), root diameter (3.7 cm), shoot: root ratio (0.5), edible root length (24.2 cm), root yield (27.8 t/ha), net returns (₹202576/ha) and B:C ratio (2.7) were noticed in foliar application of ZnSO4 @0.5%. Results of interaction shown that soil application of potassium (MOP) @150 kg/ha and ZnSO4 @0.5% significantly better in the average root weight (209.6 g), root yield (31.4 t/ha), net returns (₹2,35,918/ha) and B:C ratio (3.03).

Challenges and Opportunities in the Sustainable Improvement of Carrot Production.

From an agricultural perspective, carrots are a significant tap root vegetable crop in the Apiaceae family because of their nutritional value, health advantages, and economic importance. The edible part of a carrot, known as the storage root, contains various beneficial compounds, such as carotenoids, anthocyanins, dietary fiber, vitamins, and other nutrients. It has a crucial role in human nutrition as a significant vegetable and raw material in the nutraceutical, food, and pharmaceutical industries. The cultivation of carrot fields is susceptible to a wide range of biotic and abiotic hazards, which can significantly damage the plants' health and decrease yield and quality. Scientific research mostly focuses on important biotic stressors, including pests, such as nematodes and carrot flies, as well as diseases, such as cavity spots, crown or cottony rot, black rot, and leaf blight, caused by bacteria, fungi, and oomycetes. The emerging challenges in the field include gaining a comprehensive understanding of the interaction between hosts and pathogens in the carrot-pathogen system, identifying the elements that contribute to disease development, expanding knowledge of systemic treatments, exploring host resistance mechanisms, developing integrated control programs, and enhancing resistance through breeding approaches. In fact, the primary carrot-growing regions in tropical and subtropical climates are experiencing abiotic pressures, such as drought, salinity, and heat stress, which limit carrot production. This review provides an extensive, up-to-date overview of the literature on biotic and abiotic factors for enhanced and sustainable carrot production, considering the use of different technologies for the shelf-life extension of carrots. Therefore, it addresses the current issues in the carrot production chain, opening new perspectives for the exploration of carrots both as a food commodity and as a source of natural compounds.

Phenological and yield response of primed carrot (Daucus carota L) seeds under deficit irrigation

Seedling emergence and stand establishment of carrot seeds are often slow and erratic which results in low productivity. Poor seed quality together with lack of pre-sowing seed treatments and improper irrigation management can be mentioned as the major factors that influence the yield and productivity of carrot. The present study was carried out with the objective to evaluate the effects of different seed priming techniques on early seedling establishment, growth and yield of carrot (Daucus carota L. cultivated variety Nantes) exposed to different irrigation intervals, under field conditions at Gerado, South Wollo, Ethiopia. Four seed priming treatments (no priming, hydro priming, halo priming and hormonal priming) and three irrigation intervals (4, 7 and 10 days) were combined as factorial RCBD in split plot arrangement with three replications. The irrigation intervals were assigned to main plots and the seed priming techniques to sub plots. Result indicated that the interaction effects of priming techniques and irrigation intervals significantly affected the phenological and yield parameters. Distilled water treatment in seven and ten days irrigation interval recorded the highest marketable carrot root yields of 33.73 t h-1 and 30.63 t h-1, respectively. Hence, hydro priming and seven days irrigation interval can be recommended for the production of carrot in the study area and similar agro-ecologies. Given the promising results obtained, further repetitions of the study are recommended to validate the use of these techniques in further locations and in different seasons.

Assessing the effect of Lake Erie dredged sediment on soil properties and specialty crops development

AbstractTo maintain harbour navigability, significant quantities of sediments are annually dredged and disposed of in the vicinities of Lake Erie. This study aimed to assess the impact of Lake Erie sediment on the productivity of tomatoes, lettuce, and carrots. Using a greenhouse setting, this experiment evaluates different sediment‐farm soil ratios: 100% farm soil (Farm Soil), 100% lake sediment (Sediment), and a blend of 10% dredge sediment and 90% farm soil (Mixture). We evaluated the chemical and physical composition of the treatments and the development of the roots, leaves, and fruit production for each crop. Additionally, Total Organic Carbon (TOC), Total Nitrogen (TN), and Total Phosphorus (TP) were assessed post‐harvest for each crop's roots, leaves, and fruit biomass. The Sediment treatment showed higher pH, Cation Exchange Capacity (CEC), Calcium, and TOC but lower magnesium, phosphate, and potassium compared to Farm Soil. The Sediment and Mixture treatments exhibited higher root and leaf dry weights for lettuce compared to Farm Soil, with the Sediment treatment showing the longest roots. Sediment and Mixture treatments in carrots led to greater root weight and length. Tomatoes submitted to the Sediment treatment excelled in all variables except stem diameter. Lettuce and carrot biomass analysis revealed no statistical differences in TOC and TN among the treatments. Tomato biomass analysis showed no differences among the three treatments. The use of Lake Erie dredged sediment led to increased crop biomass in the greenhouse production of tomatoes, carrots, and lettuce.

Study of an auxiliary trimming device for cracked carrots

AbstractCracked carrots account for a large proportion of defective carrots, which are usually discarded or used as feed, resulting in resource waste and economic benefit loss. Cracked carrots can be used as raw materials for further processed carrot products after being trimmed. So, an auxiliary device was developed combining PLC (Programmable Logic Controller) and machine vision to achieve clamping and crack defect localization for intelligent trimming of crack defect. The carrot was orientated based on the area method, rotated by flexible jaws and a rotating cylinder to make the carrot head and tail aligned. The clamping device could non‐destructively clamp carrot in axial and radial direction with a force threshold of 10 and 22 N respectively, and rotate carrot to make the crack defect upwards. The results showed that the recognition accuracy of carrot head and tail orientation was 98%, the average deviation of carrot centroid clamping position was less than 9 mm at a speed of 300 mm/s, the rotational positioning time was less than 3 s and the number of adjustments were no more than 2 at a motor speed of 180 rpm, which could meet the subsequent trimming requirements.Practical applicationsTrimming the cracked area of carrots can reduce bacterial growth and decay, which is beneficial for subsequent processing and reduces resource waste. This article designs a carrot auxiliary trimming device, which uses image processing technology to recognize the orientation of the head and tail of carrots and the cracked area, and uses automated equipment to achieve stable clamping of carrots and make the cracked area face the trimming tool. This study is beneficial for the refined management of agricultural products.

Seed priming with potassium nitrate alleviates the high temperature stress by modulating growth and antioxidant potential in carrot seeds and seedlings

Early season carrot (Daucus carota) production is being practiced in Punjab, Pakistan to meet the market demand but high temperature hampers the seed germination and seedling establishment which cause marked yield reduction. Seed priming with potassium nitrate breaks the seed dormancy and improves the seed germination and seedling growth potential but effects vary among the species and ecological conditions. The mechanism of KNO3 priming in high temperature stress tolerance is poorly understood yet. Thus, present study aimed to evaluate high temperature stress tolerance potential of carrot seeds primed with potassium nitrate and impacts on growth, physiological, and antioxidant defense systems. Carrot seeds of a local cultivar (T-29) were primed with various concentration of KNO3 (T0: unprimed (negative control), T1: hydroprimed (positive control), T2: 50 mM, T3:100mM, T4: 150 mM, T5: 200 mM, T6: 250 mM and T7: 300 mM) for 12 h each in darkness at 20 ± 2℃. Seed priming with 50 mM of KNO3 significantly enhanced the seed germination (36%), seedling growth (28%) with maximum seedling vigor (55%) and also exhibited 16.75% more carrot root biomass under high temperature stress as compared to respective control. Moreover, enzymatic activities including peroxidase, catalase, superoxidase dismutase, total phenolic contents, total antioxidants contents and physiological responses of plants were also improved in response to seed priming under high temperature stress. By increasing the level of KNO3, seed germination, growth and root biomass were reduced. These findings suggest that seed priming with 50 mM of KNO3 can be an effective strategy to improve germination, growth and yield of carrot cultivar (T-29) under high temperature stress in early cropping. This study also proposes that KNO3 may induces the stress memory by heritable modulations in chromosomal structure and methylation and acetylation of histones that may upregulate the hormonal and antioxidant activities to enhance the stress tolerance in plants.

Effect of Foliar Fertilizer and Irrigation Levels on Carrot Productivity

Effect of Foliar Fertilizer and Irrigation Levels on Carrot Productivity

Análise espacial da produtividade da cenoura irrigada em função das propriedades físicas do solo

ABSTRACT Understanding soil, plant attributes, and carrot crop dynamics is vital for optimizing site-specific management practices and enhancing crop yield and soil quality. This study aimed to ascertain the dependence and spatial variability between irrigated carrot yield and soil physical attributes in a clayey Oxisol. The research took place during the 2021 growing season in a commercial carrot production area in Campos Altos, MG, Brazil. One hundred sampling points were established within the irrigated area, distributed across a square expanse of 40,000 m², positioned at the centers of 20 × 20 m grids. The study revealed high yield in the irrigated carrot crop (99.74 t ha-1) with moderate variability. Soil attributes displayed a range of heterogeneity, ranging from low to extremely high, contingent on the variable assessed, as determined by the coefficient of variation. Among the variables exhibiting spatial dependence, particle density exhibited a minimum range of 40 m, which is recommended for further studies on irrigated carrot cultivation in a clayey Oxisol. Total soil water availability demonstrated a positive spatial correlation and proved to be the recommended variable for estimating the spatial variability of carrot crop yield.

An economic analysis of carrot production in Bulandshahr district of Uttar Pradesh, India

An economic analysis of carrot production in Bulandshahr district of Uttar Pradesh, India

Optimal Timing of Carrot Crop Monitoring and Yield Assessment Using Sentinel-2 Images: A Machine-Learning Approach

Remotely sensed images provide effective sources for monitoring crop growth and the early prediction of crop productivity. To monitor carrot crop growth and yield estimation, three 27 ha center-pivot irrigated fields were studied to develop yield prediction models using crop biophysical parameters and vegetation indices (VIs) extracted from Sentinel-2A (S2) multi-temporal satellite data. A machine learning (ML)-based image classification technique, the random forest (RF) algorithm, was used for carrot crop monitoring and yield analysis. The VIs (NDVI, RDVI, GNDVI, SIPI, and GLI), extracted from S2 satellite data for the crop ages of 30, 45, 60, 75, 90, 105, and 120 days after plantation (DAP), and the chlorophyll content, SPAD (Soil Plant Analysis Development) meter readings, were incorporated as predictors for the RF algorithm. The RMSE of the five RF scenarios studied ranged from 7.8 t ha−1 (R2 ≥ 0.82 with Scenario 5) to 26.2 t ha−1 (R2 ≤ 0.46 with Scenario 1). The optimal window for monitoring the carrot crop for yield prediction with the use of S2 images could be achieved between the 60 DAP and 75 DAP with an RMSE of 8.6 t ha−1 (i.e., 12.4%) and 11.4 t ha−1 (16.2%), respectively. The developed RF algorithm can be utilized in carrot crop yield monitoring and decision-making processes for the self-sustainability of carrot production.

Evaluation of shoot-growth variation in diverse carrot (Daucus carota L.) germplasm for genetic improvement of stand establishment.

Carrot (Daucus carota L.) is a high value, nutritious, and colorful crop, but delivering carrots from seed to table can be a struggle for carrot growers. Weed competitive ability is a critical trait for crop success that carrot and its apiaceous relatives often lack owing to their characteristic slow shoot growth and erratic seedling emergence, even among genetically uniform lines. This study is the first field-based, multi-year experiment to evaluate shoot-growth trait variation over a 100-day growing season in a carrot diversity panel (N=695) that includes genetically diverse carrot accessions from the United States Department of Agriculture National Plant Germplasm System. We report phenotypic variability for shoot-growth characteristics, the first broad-sense heritability estimates for seedling emergence (0.68 < H2 < 0.80) and early-season canopy coverage ( 0.61 < H2 < 0.65), and consistent broad-sense heritability for late-season canopy height (0.76 < H2 < 0.82), indicating quantitative inheritance and potential for improvement through plant breeding. Strong correlation between emergence and canopy coverage (0.62 < r < 0.72) suggests that improvement of seedling emergence has great potential to increase yield and weed competitive ability. Accessions with high emergence and vigorous canopy growth are of immediate use to breeders targeting stand establishment, weed-tolerance, or weed-suppressant carrots, which is of particular advantage to the organic carrot production sector, reducing the costs and labor associated with herbicide application and weeding. We developed a standardized vocabulary and protocol to describe shoot-growth and facilitate collaboration and communication across carrot research groups. Our study facilitates identification and utilization of carrot genetic resources, conservation of agrobiodiversity, and development of breeding stocks for weed-competitive ability, with the long-term goal of delivering improved carrot cultivars to breeders, growers, and consumers. Accession selection can be further optimized for efficient breeding by combining shoot growth data with phenological data in this study's companion paper to identify ideotypes based on global market needs.

First Field Evaluation of a Polylactic Acid-based Weed Barrier with Compost for Carrot Production

Hand weeding is a common but expensive weed management practice in organic carrot (Daucus carota) production. To improve weed suppression and reduce hand weeding in these systems, we developed and tested different biobased polylactic acid (PLA) mulch and compost combinations for carrot production. Carrot was direct-seeded onto PLA mulches and top-dressed with a layer of compost to facilitate carrot germination and rooting through the semipermeable mulch surface. This PLA mulch reduced total weed emergence by 90% relative to bare soil. Yields were not significantly different among mulch types and bare soil controls, partly because weeds were removed weekly after counting. The PLA mulch reduced plant available soil nitrate by 47% relative to bare soil controls. The results suggest that PLA mulch paired with compost is an effective alternative to hand weeding in carrot production. Future research should seek to address the observed nitrogen immobilization.

Evaluation of different fertilizer sources for sustainable carrot production in Tehuledere district, northern Ethiopia

The demand for organic agriculture has been growing due to concerns about the environmental and health impacts of chemical-intensive farming. The study aimed to investigate the effects organic fertilizers on carrot (Nantes) growth and yield in Tehuledere district. The experiment was conducted at two sites (Gobeya and Libannos) using four fertilizer types (vermicompost, conventional compost, mixture of the two, and inorganic fertilizer) and a control. The experiment was laid out in randomized complete block design with three replications, and data were analyzed using R-software. The study analyzed various growth (emergence percentage, plant height, leaf number, fresh weight, and dry weight of leaves), and yield (root length, root diameter, fresh weight of roots, marketable root yield, unmarketable root yield, and total root yield) parameters. Generally, fertilizer application improved (p < 0.001) growth and yield compared to the control. Vermicompost and inorganic fertilizer (NPSB) showed similar results (p > 0.001) but the highest values (p < 0.001) for most of the parameters (marketable yield was 41.7 t/ha±0.76 for vermicompost and 42.5 t/ha±1.14 for NPSB). However, NPSB could pose negative environmental impact that could not result in sustainability if used in excess and inappropriate (method and time) in particular. Therefore, carrot production using vermicompost is recommended for farmers of Tehuledere district and similar agroecological areas to enhance productivity while contributing to sustainable agriculture. The results have implications for policy makers, researchers, and farmers interested in promoting environmentally friendly and sustainable carrot production.

Management of bacterial blight ofcarrots by phenolic compounds treatment.

Bacterial blight is a serious disease of carrot production worldwide. Under favorable conditions, the causal organism Xanthomonas hortorum pv. carotae causes serious loss especially in seed production because of its seed-borne character. Unlike fungal diseases, the treatment of bacterial diseases is limited and methods such as hot water or sodium hypochlorite (bleach) treatment are mainly used by seed companies. Here, we compared the efficacy of hot water treatment, sodium hypochlorite treatment and treatment with three phenolic compounds-carvacrol, thymol and eugenol, to eliminate Xanthomonas growth in vitro and subsequently in vivo on seeds of Xhc low, medium and highly infested carrot seed lots. The complete elimination of Xhc from germinated plants was obtained only for Xhc low infested seed lot with 1% sodium hypochlorite and carvacrol solutions in concentrations of 0.0196%- 0.313%. The significant reduction of Xhc presence in germinated plants of Xhc medium infested seed lot was achieved with 1% sodium hypochlorite treatment and hot water treatment. However, hot water treatment resulted in a significant reduction of seed germination percentage as well. Considering the elimination of Xhc infection from germinated plants and the effect on seed germination and plant vigor, 0.0196% carvacrol solution was suggested as an alternative to 1% sodium hypochlorite treatment regarding additional costs related to the liquidation of used treated water and to hot water treatment that has been proved to be insufficient to obtain disease-free plants.

Changes in the prevalence of fungal species causing post‐harvest diseases of carrot in Finland

AbstractPost‐harvest diseases cause significant economic losses in the carrot production chain. In this study, storage losses and fungal pathogens causing them were analysed in the carrot yield from 52 different field plots in four areas in Finland in 3 years (2016–2018). Over 30,000 carrots were sampled and analysed at three time points during cold storage at 0–1°C. In March, after 5–6 months' storage, the average loss due to diseases was 20%–21% every year. Decay of the root tip was the most common disease symptom, followed by pits on the side and black rot in the crown, detected in 69.2%, 15.0% and 9.0% of the symptomatic samples, respectively. Both intensive carrot cultivation practice and early timing of harvest increased storage losses. Pathogens in 3057 symptomatic carrot tissue samples were isolated by culturing, and fungal species were identified. The most common fungal species detected were Mycocentrospora acerina, Botrytis cinerea and Fusarium spp., especially F. avenaceum. However, the frequency of different pathogens varied between the different years and time points during storage. Species‐specific PCR tests revealed that M. acerina and F. avenaceum were present in many early time‐point samples where they could not yet be detected by the culturing method. In Finland, this study on carrot post‐harvest diseases is the first large‐scale survey in which the fungal pathogens were isolated and identified by laboratory tests. In comparison with the previous studies, Fusarium spp. were detected more frequently in this study, while grey mould and Sclerotinia rot were less frequent.

Evaluating the Response of Carrot (Daucus carota L.) to Different Macronutrients and Harvesting Time

The growth and production of carrot influenced by macronutrients and harvesting time, thus a field experiment was conducted at Horticultural Research Field of Sher-e-Bangla Agricultural University, Dhaka, between December 2020 and March 2021 during the Rabi season to evaluate the response of carrot to different macro nutrients and harvesting time. The experiment consisted of two factors i.e., macro nutrients and harvesting time, and laid out using Randomized Complete Block Design (RCBD) with three replications. Factor A: Different levels of macronutrients (4) i.e., F0= Control, F1= N160P50K120S30 kg ha-1, F2 = N185P70K140S40 kg ha-1, F3 = N210P90K160S50 kg ha-1 and Factor B: A Harvesting time (3) i.e., H1 = 90 days after sowing, H2 = 100 days after sowing and H3 = 110 days after sowing. Experimental results revealed that different levels of macronutrients and harvesting time significantly influenced the growth and yield of carrot. In case of combination treatment (macro nutrients and harvesting time) the highest brix percentage of carrot root (8.20 %), marketable root yield per plot of carrot (6.40 kg) and marketable root yield of carrots per hectare (26.67 t) were observed in the F2H2 treatment combination comparable to others treatment combinations. Therefore, it was suggested that cultivation of carrot through application of fertilizer @ N185P70K140S40 kg ha-1 (F2) and harvesting at 100 days after sowing (H2), appeared to be best for achieving higher growth, yield and quality root of carrot.

EVALUATION OF SOIL CHEMICAL PROPERTIES AND CARROT PERFORMANCE AS INFLUENCED BY INTEGRATED APPLICATION OF POULTRY MANURE AND COCOA POD HUSK IN THE RAINFOREST AGROECOLOGICAL ZONE OF NIGERIA

The high cost of inorganic fertilizer, difficulties involved in its use, its scarcity, coupled with its adverse effects associated with its continuous use on soil quality prompted the need to research into cheap, locally available organic materials to combat soil fertility problems. Field experiments were conducted in 2019 and 2020 to evaluate the effects of the integrated application of poultry manure (PM) and cocoa pod husk (CPH) on soil chemical properties, growth, leaf nutrients content and yield of carrot at Igba in the rainforest ecology of southwest Nigeria. The treatments consisted of PM and CPH each at three levels (0, 5, 10 t ha-1) in a 2 x 3 factorial experiment laid into randomized complete block design with three replicates. Data were collected on soil chemical properties, growth parameters, leaf nutrients content and yield parameters. Data collected were subjected to analysis of variance using Statistical Analysis System Institute Package (SAS, 2000). The soil was slightly acidic (pH 5.5.), low in nitrogen (0.12g kg), available phosphorus (8 mg kg-1). Integrated application of PM and CPH significantly (P&lt; 0.05) improved soil pH, organic carbon, total N, available P, exchangeable bases and lowered exchangeable acidity. Plots with integrated application of PM and CPH had higher values of soil pH, exchangeable bases, ECEC, total N, total organic carbon, available P and lower values of exchangeable acidity and micronutrients than the plots with their sole applications. There were reductions in soil pH, exchangeable bases, ECEC, total N and organic carbon in the control plots in the second cropping seasons. Growth parameters were better enhanced in plots with the integrated application of PM and CPH than either of their sole. There were significant improvements in plant height, leaf length and shoot diameter in the second cropping season in plots amended with PM, CPH and their integrations as against control plots where reductions in the growth characteristics were obtained. The leaf content of N, P, K and Ca were significantly (P&lt; 0.05) enhanced in plots with integrated application of PM and CPH than the plots with their sole application. Carrot root yield characteristics were significantly (P &lt; 0.05) enhanced in plots with the integrated application of PM and CPH than plots with the sole application of PM or CPH. Root yield was increased in the second cropping season in plots treated with the sole application of PM, CPH and their integrations, while there were reductions in root yield parameters in the control plots. Improvements in soil nutrients status, growth, leaf nutrients content and root yield of carrot in both cropping season in the amended plots when compared to the control plots, imply that integrated use of PM and CPH could be used in the enhancement of production of carrot on sustainable basis in the study area.

Optimized Fertilizer–Water Management Improves Carrot Quality and Soil Nutrition and Reduces Greenhouse Gas Emissions on the North China Plain

In order to improve carrot quality and soil nutrition and reduce the environmental pollution caused by intensive carrot production, more comprehensive combined water–fertilizer management strategies are necessary. This study hypothesizes that optimal management of water and fertilizer can improve carrot yield and quality and reduce greenhouse gas emissions and soil nutrient residues. Thus, coordinated water–fertilizer management strategies were tested for carrot production on the North China Plain over two consecutive growing seasons. Four treatments were tested: local standard fertilization and irrigation practices (FNP); optimized irrigation and chemical nitrogen, phosphorus, and potassium fertilizer (OPT); OPT treatment with partial replacement of chemical fertilizer with peanut shell (PS); and OPT treatment with partial replacement of chemical fertilizer with mushroom residue (M). Compared to the FNP treatment, there were statistically significant increases in soluble sugars (12–27%) and free amino acids (14–26%), and decreases in the nitrate content (7–17%) of fleshy root in the OPT, PS, and M treatments. In autumn carrots, the OPT and M treatments decreased yield, whereas PS increased yield; spring carrot yield was significantly decreased in the OPT, PS, and M groups compared to the FNP group. There were no significant effects of the treatment group on carrot growth rates, nutrient accumulation, or nutrient distribution. However, the OPT, PS, and M treatments were associated with significantly increased partial productivity of phosphate fertilizer (233–363%), reduced residual levels of nitrate and available phosphorus in the top 80 cm of soil, and decreased greenhouse gas emissions by 8–18% compared to the FNP treatment. These results highlight the effectiveness of partial organic fertilizer substitution and integrated water–fertilizer management to produce high-quality carrots with minimal environmental damage.