Special Issue "Nitrogen Fertilization in Vegetable Crops"

A special issue of Agronomy (ISSN 2073-4395). This special issue belongs to the section "Horticultural and Floricultural Crops".

Deadline for manuscript submissions: 31 August 2020.

Special Issue Editors

Dr. Alessandro Miceli
Website
Guest Editor
Department of Agricultural, Food and Forest Sciences, University of Palermo, Viale delle Scienze, Ed. 5 90128 Palermo, Italy
Interests: crop eco-physiology; plant hormones; protected cultivation; hydroponics; mineral nutrition of vegetable crops; plant growth-promoting microorganisms; abiotic stresses; postharvest; vegetable quality; hygienic safety of vegetables
Dr. Alessandra Moncada
Website
Guest Editor
Department of Agricultural, Food and Forest Sciences, University of Palermo, Viale delle Scienze, Ed. 5 90128 Palermo, Italy
Interests: crop eco-physiology; plant hormones; protected cultivation; grafting; hydroponics; mineral nutrition of vegetable crops; plant growth-promoting microorganisms; abiotic stresses
Dr. Leo Sabatino
Website
Guest Editor
Department of Agricultural, Food and Forest Sciences, University of Palermo, 90128 Palermo, Italy
Interests: vegetable crops production; herbaceous grafting; soilless vegetables production; nutritional and nutraceutical vegetable fruit quality linked to cultivation condition and practices; biofortification of leafy and fruiting vegetable crops, propagation of ornamental plants

Special Issue Information

Dear Colleagues,

After the mineral nutrition of plants was established as a scientific discipline (nineteenth century), large amounts of inorganic nitrogen (N) were used to improve crop performance. Nitrogen is an essential nutrient element for plant growth. N deficiency may cause many biochemical and physiological disorders, leading to overall plant performance reductions. The urgency to increase crop productivity in order to ensure sufficient food for most of the global population has raised the use of nitrogen fertilizers considerably in the last decades. In the main vegetable production areas, N fertilizer application rates can reach and overcome 1000 kg N ha−1. This excessive use is proven to cause a number of environmental and ecological problems within and outside farmlands (groundwater pollution, greenhouse gas emissions, eutrophication, deposition, and disruptions to natural ecosystems) and is closely monitored by European laws. Furthermore, a high nitrogen fertilization rate may cause health problems for humans because of the overaccumulation of N in vegetables, which may have deleterious effects on their biochemical composition and quality. Therefore, achieving a worldwide reduction of the total N input is a major challenge that requires sustained actions to improve nitrogen management practices (both for organic and synthetic N fertilizers), and to reduce nitrogen loss into the environment.

An increased knowledge of the mechanisms controlling the plant N economy is crucial for improving N use efficiency (NUE) and for reducing nitrogen overdose, while maintaining an acceptable yield and sufficient profit margin for the farmers. The understanding of the biological and agronomic basis of NUE in vegetable crops is still an important research issue that needs to be investigated, using innovative agronomic, analytical, physiological, biochemical, and molecular biology approaches.

This Special Issue aims to collect research papers and reviews focusing on “Nitrogen Fertilization in Vegetable Crops”. Therefore, research articles, reviews, short notes, and opinion articles related to inorganic and organic nitrogen fertilizer application and management solutions, NUE and horticultural crop yield response in open fields, protected cultivation, and in hydroponic systems are welcome for this Special Issue.

Dr. Alessandro Miceli
Dr. Alessandra Moncada
Dr. Leo Sabatino
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Agronomy is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • vegetable crops
  • N use efficiency
  • inorganic nitrogen
  • organic nitrogen
  • nitrogen management
  • sustainable fertilization
  • hydroponics
  • yield
  • quality
  • nitrate accumulation

Published Papers (13 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Open AccessArticle
Combining Green Manuring and Fertigation Maximizes Tomato Crop Yield and Minimizes Nitrogen Losses
Agronomy 2020, 10(7), 977; https://doi.org/10.3390/agronomy10070977 - 08 Jul 2020
Abstract
The aim of this experiment was to evaluate the effect of fertilizing processing tomato by coupling the green manuring of fall-winter cover crops with fertigation in spring-summer. In a two-year experiment, seven fertilization treatments were compared: green manuring of pure barley (B100) and [...] Read more.
The aim of this experiment was to evaluate the effect of fertilizing processing tomato by coupling the green manuring of fall-winter cover crops with fertigation in spring-summer. In a two-year experiment, seven fertilization treatments were compared: green manuring of pure barley (B100) and pure vetch (V100) sown at 100% of their ordinary seeding rates, green manuring of a barley-vetch mixture at a ratio of 75:25 of their own seed rates (B75V25), fertigation with drip irrigation at a rate of 200 kg ha−1 of nitrogen (N) (Fert_N200), fertigation combined with B100 and B75V25 at a N rate complementary to 200 kg N ha−1 (B100 + Fert and B75V25 + Fert, respectively), and an unfertilized control (N0) with no cover crops for green manuring prior to tomato transplanting or fertigation. The Fert_N200 treatment resulted in maximum tomato N uptake, growth and yield, but caused high N leaching, especially during the no-cover fall-winter period, as was also the case for N0. The V100 treatment promoted quite good tomato N status and yield, but did not reduce N leaching. The B100 and B75V25 treatments reduced N leaching but decreased tomato N uptake, growth and yield. The B100 + Fert and B75V25 + Fert treatments reduced N leaching, likely increased soil N stock, and facilitated optimal tomato N nutrition and maximum yields. Combining fertigation with green manuring of cover crops composed of pure grass or grass-legume mixtures appears to be a very effective and environmentally sound practice for fertilizing high N-demanding spring-summer crops like processing tomato. Full article
(This article belongs to the Special Issue Nitrogen Fertilization in Vegetable Crops)
Show Figures

Figure 1

Open AccessArticle
Agronomic Performance of Different Open-Pollinated Beetroot Genotypes Grown Under Organic Farming Conditions
Agronomy 2020, 10(6), 812; https://doi.org/10.3390/agronomy10060812 - 08 Jun 2020
Abstract
Due to the increase of the organic cultivation of beetroot and its growing importance as a functional food, the potential advantages of open-pollinated genotypes as an alternative for F1 hybrid genotypes has been investigated. In this regard, six field experiments were carried out [...] Read more.
Due to the increase of the organic cultivation of beetroot and its growing importance as a functional food, the potential advantages of open-pollinated genotypes as an alternative for F1 hybrid genotypes has been investigated. In this regard, six field experiments were carried out in 2017 and 2018 in three different locations to investigate the agronomic potential of new and existing open-pollinated genotypes of beetroot and their performance under the specific conditions of organic agriculture. Fifteen beetroot genotypes, including one F1 hybrid as a commercial control and one breeding line, were compared regarding their total and marketable yield, individual beet weight, diameter of beet, and leaves-growth-base width. Furthermore, five randomly selected beetroots meeting common marketable criteria were evaluated optically with regard to skin smoothness, corky surface, root tail, scab incidence, and uniformity. Results of this study indicated a significant impact of genotype on eight of the assessed traits. The cylindrical-shaped genotype, Carillon RZ, demonstrated significantly higher total and marketable yields, with 53.28 ± 3.34 t ha−1 and 44.96 ± 3.50 t ha−1, respectively, compared to the yellow-colored genotype, Burpees Golden, which obtained the lowest total yield, 36.06 ± 3.38 t ha−1, and marketable yield, 27.92 ± 3.55 t ha−1. Moreover, the comparison of the open-pollinated genotypes with the F1 hybrid, Monty RZ F1, revealed that except for the traits yield, scab, and uniformity, the open-pollinated genotypes indicated desirable competitive outcomes and thus offer suitable alternatives for organic cropping systems. Overall, the observed genetic variability can be beneficial for breeding and food product development. Full article
(This article belongs to the Special Issue Nitrogen Fertilization in Vegetable Crops)
Show Figures

Figure 1

Open AccessArticle
Recovery of 15N Labeled Nitrogen Fertilizer by Fertigated and Drip Irrigated Greenhouse Vegetable Crops
Agronomy 2020, 10(5), 741; https://doi.org/10.3390/agronomy10050741 - 21 May 2020
Abstract
The stable isotope 15N was used to assess the recovery of mineral N fertilizer applied to fertigated and drip-irrigated spring muskmelon and autumn-winter sweet pepper crops grown in greenhouse soil plots. They received 92–96% of mineral N fertilizer as NO3 [...] Read more.
The stable isotope 15N was used to assess the recovery of mineral N fertilizer applied to fertigated and drip-irrigated spring muskmelon and autumn-winter sweet pepper crops grown in greenhouse soil plots. They received 92–96% of mineral N fertilizer as NO3. 15N-labeled Ca (NO3)2 fertilizer was applied to crops during vegetative growth and fruit production phases. Crops were grown with either conventional management or combined improved N and irrigation management. Improved management for both irrigation and N was based on the combined use of models, to estimate crop requirements, and of monitoring of soil parameters. In sweet pepper, from conventional management, 15N recoveries from the 15N applications made during vegetative growth and fruit production were 66% and 58%, respectively. With improved management in sweet pepper, the corresponding 15N recoveries were 82% and 77%. In muskmelon, 15N recoveries from conventional management from the 15N applications made during vegetative growth and fruit production were 71% and 42%, respectively. With improved management, the corresponding 15N recoveries were 68% and 44%, respectively. The results demonstrated that combined drip irrigation and fertigation systems with frequent irrigation and N fertilizer application can have very high recovery of applied N fertilizer, of 77–82%. Full article
(This article belongs to the Special Issue Nitrogen Fertilization in Vegetable Crops)
Show Figures

Figure 1

Open AccessArticle
The Optimization of Nitrogen Fertilization Regulates Crop Performance and Quality of Processing Tomato (Solanum lycopersicum L. cv. Heinz 3402)
Agronomy 2020, 10(5), 715; https://doi.org/10.3390/agronomy10050715 - 16 May 2020
Cited by 1
Abstract
In this study, we evaluated the effect of various fertilization regimes on processing tomato (Solanum lycopersicum L. cv. Heinz 3402) yield and quality by applying the following treatments: (i) control (C), (ii) conventional fertilizer (21-0-0, N-P-K) (CF), (iii) slow release nitrogen fertilizer [...] Read more.
In this study, we evaluated the effect of various fertilization regimes on processing tomato (Solanum lycopersicum L. cv. Heinz 3402) yield and quality by applying the following treatments: (i) control (C), (ii) conventional fertilizer (21-0-0, N-P-K) (CF), (iii) slow release nitrogen fertilizer 46-0-0 (SR), (iv) conventional fertilizer (21-0-0, N-P-K) + Zeolite (CFZ), and v) composted sheep manure (M). The results of the study showed that the SR and CFZ treatments resulted in the highest fruit yield per hectare compared to the rest of the fertilizer and the control treatments. Fruit firmness was higher for the treatments C, M and SR, while color parameters (chroma and hue angle) were higher for the C and M treatments, respectively. Moreover, the total soluble solids content (TSS; °Brix) was higher when manure (M) was applied. In terms of chemical composition, the total and individual tocopherols and sugars were the highest for the M and C treatments, respectively, whereas the oxalic, malic and total organic acid contents were the highest for the CFZ treatment. Moreover, the tested treatments showed a varied response in different antioxidant assays, although the M treatment exhibited a high antioxidant capacity in most of the assays, except for the β-carotene/linoleate assay. The carotenoid and chlorophyll contents were the highest for the control treatment. The main detected fatty acid was linoleic acid, followed by palmitic, oleic and α-linolenic acid, while the CFZ treatment had the highest content of polyunsaturated fatty acids (PUFA) due to its high content of linoleic acid. In conclusion, although the application of fertilizers increased yield, the quality parameters and chemical composition showed a varied response to the fertilization regime, especially the TSS content and juice pH and electric conductivity (EC), which are significant for the marketability of the final product. Full article
(This article belongs to the Special Issue Nitrogen Fertilization in Vegetable Crops)
Open AccessFeature PaperArticle
Use of Gibberellic Acid to Increase the Salt Tolerance of Leaf Lettuce and Rocket Grown in a Floating System
Agronomy 2020, 10(4), 505; https://doi.org/10.3390/agronomy10040505 - 02 Apr 2020
Abstract
Hydroponics need water of good quality to prepare a balanced nutrient solution that could allow plants to reach their maximum yield potential. The rising difficulties in finding water with good quality have led to the compelling necessity of identifying sustainable ways to use [...] Read more.
Hydroponics need water of good quality to prepare a balanced nutrient solution that could allow plants to reach their maximum yield potential. The rising difficulties in finding water with good quality have led to the compelling necessity of identifying sustainable ways to use saline water, limiting its negative effect on crop yield and quality. The exogenous supplementation of plant growth regulators, such as gibberellic acid (GA3), can be effective in increasing plant growth and vigor, thus helping plants to better cope with salt stress. The aim of this study was to evaluate the feasibility to increase the salt tolerance of leaf lettuce and rocket grown in a floating system by adding GA3 (10−6 M) to mineral nutrient solutions (MNS) with increasing salinity (0, 10, and 20 mM NaCl). Leaf lettuce and rocket plants suffered a significant reduction of growth and yield, determined by the reduction of biomass, leaf number, and leaf area, even with moderate salt stress (10 mM NaCl). The supplementation of exogenous GA3 through the MNS allowed plants to substantially counterbalance salt stress by enhancing various morphological and physiological traits, such as biomass accumulation, leaf expansion, stomatal conductance and water and nitrogen use efficiency. The effects of salt stress and GA3 treatment varied according to the species, thus indicating that this interaction may improve salt tolerance by activating different adaptation systems. Full article
(This article belongs to the Special Issue Nitrogen Fertilization in Vegetable Crops)
Show Figures

Graphical abstract

Open AccessArticle
The Impact of Fertilization Regime on the Crop Performance and Chemical Composition of Potato (Solanum tuberosum L.) Cultivated in Central Greece
Agronomy 2020, 10(4), 474; https://doi.org/10.3390/agronomy10040474 - 30 Mar 2020
Cited by 2
Abstract
Potato cultivation is quite demanding in inorganic nutrients and adequate fertilization is a key factor for maximizing yield and producing tubers of high quality. In the present study, a field experiment was carried out to evaluate the effect of various forms of fertilization [...] Read more.
Potato cultivation is quite demanding in inorganic nutrients and adequate fertilization is a key factor for maximizing yield and producing tubers of high quality. In the present study, a field experiment was carried out to evaluate the effect of various forms of fertilization on crop performance and the nutritional value and chemical composition of two potato varieties (cv. Spunta and cv. Kennebec). For this purpose, five different fertilizer treatments were applied namely: control (C), standard fertilizer (T1), standard fertilizer + zeolite (T2), manure (T3) and slow release nitrogen fertilizer (T4). According to the results, it was observed that slow release treatment (T4) achieved the highest yield for both varieties, while the control treatment presented significantly lower yield compared to the studied fertilization regimes. The dry matter of leaves and shoots was higher in T1 treatment for cv. Kennebec and in T2 and T4 treatments for cv. Spunta, whereas the control treatment presented the highest dry matter content in tubers for cv. Kennebec and T2 and T3 treatments for cv. Spunta. A significant effect of the fertilization regime was also observed on the nutritional value of tubers and more specifically the protein, ash and fat content was increased by treatments T1 and T4, while carbohydrate content was also increased by T3 and T4 treatments for both varieties. Similarly, the total sugars, organic acids, β-carotene and lycopene content was increased in T3 treatment for the Spunta variety, while the antioxidant capacity showed a varied response depending on the fertilizer regime and the tested variety. In conclusion, the fertilization regime has a significant effect not only on the tuber yield but also on the quality of the final product and should be considered as an effective tool to increase the added value of potato crop. Full article
(This article belongs to the Special Issue Nitrogen Fertilization in Vegetable Crops)
Show Figures

Figure 1

Open AccessArticle
Nitrogen Fertilizer Management and Maize Straw Return Modulate Yield and Nitrogen Balance in Sweet Corn
Agronomy 2020, 10(3), 362; https://doi.org/10.3390/agronomy10030362 - 05 Mar 2020
Cited by 2
Abstract
Nitrogen fertilizer is an important component of crop production; however, its excessive application could result in N loss that could have serious environmental concerns. Straw incorporation in the soil after crop harvest is one of the most feasible straw management techniques, however, the [...] Read more.
Nitrogen fertilizer is an important component of crop production; however, its excessive application could result in N loss that could have serious environmental concerns. Straw incorporation in the soil after crop harvest is one of the most feasible straw management techniques, however, the optimization of nitrogen (N) fertilizer management and maize straw incorporation to modulate the crop yield and to maintain N balance in sweet corn is necessary to get better yields on a sustained basis. The present study was comprised of two straw management treatments i.e., (i) no straw return (S0), and (ii) incorporation of crushed corn ears by into the soil using rotary tiller (S100) and four N fertilizer management treatments i.e., (i) common farmer practice with total N applied at 300 kg ha−1 with 50%, 5%, 30%, and 15% splits at basal, 3-leaf stage (V3), at hilling stage (V8) and at tasseling/flowering stage (RT), respectively (FM); (ii) application of total N at 225 kg ha−1 with 40%, 10% and 50% at basal, 3-leaf stage (V3) and at hilling stage (V8), respectively (OMI); (iii) application of total N at 150 kg ha−1 with 40%, 10% and 50% at basal, 3-leaf stage (V3), and at hilling stage (V8), respectively (OMII); and (iv) the treatment without any fertilizer application (N0). The hybrid sweet corn cultivar ‘Yuetian 28’ was grown during the spring and autumn growing seasons of 2016 and 2017. The results showed that the N management treatments substantially improved the fresh ear yield, ear number and ear weight, partial factor productivity from nitrogen (PFPN), recovery efficiency from nitrogen (REN), and agronomic efficiency from nitrogen (AEN). Compared with FM, the OMI and OMII treatments significantly increased the AEN and PFPN whilst decreased the apparent N loss, however, the fresh ear yield, ear number and ear weight in OMI treatment were found to be statistically similar (p ˃ 0.05) to FM. Moreover, the S100 treatment did not affect the fresh ear yield and yield components significantly. Overall, straw return combined with an optimized N fertilizer application could improve the yield of sweet corn on a sustained basis with minimum and/or negligible N loss. Full article
(This article belongs to the Special Issue Nitrogen Fertilization in Vegetable Crops)
Open AccessArticle
Can Trichoderma-Based Biostimulants Optimize N Use Efficiency and Stimulate Growth of Leafy Vegetables in Greenhouse Intensive Cropping Systems?
Agronomy 2020, 10(1), 121; https://doi.org/10.3390/agronomy10010121 - 14 Jan 2020
Cited by 1
Abstract
The present study addresses the effects of Trichoderma-based biostimulants and nitrogen (N) fertilization levels on agronomic performance and functional quality of two important greenhouse leafy vegetables: lettuce and rocket. A factorial analysis of the relative effects of Trichoderma-based biostimulants (Trichoderma [...] Read more.
The present study addresses the effects of Trichoderma-based biostimulants and nitrogen (N) fertilization levels on agronomic performance and functional quality of two important greenhouse leafy vegetables: lettuce and rocket. A factorial analysis of the relative effects of Trichoderma-based biostimulants (Trichoderma harzianum strain T22 and Trichoderma virens strain GV41) and N fertilization levels (sub-optimal, optimal, and supra-optimal) was carried out to evaluate crop productive behavior (marketable and unmarketable yields, leaf dry matter content, and biomass production), nitrogen nutrition (N uptake, apparent N recovery, and nitrogen use efficiency (NUE)) as well as phytochemical qualitative components (antioxidant activity and total polyphenols). The soil plant analysis development (SPAD) index in both leafy vegetables and leaf colorimetry only in rocket were mainly affected by N fertilization levels but not by Trichoderma-based biostimulants. The contribution of native mineral N was 60 and 100 kg N ha−1 of the total uptake in lettuce and rocket, respectively, and N surpluses were observed in both crops, even under optimal fertilization conditions. Trichoderma virens GV41-based biostimulant increased lettuce marketable yield and biomass production, both under optimal and sub-optimal fertilization. In addition, the same treatment increased NUE up to 116% under recommended N fertilization, that was also associated to an increase in phenol content and antioxidant activity. Rocket showed a clear effect of the Trichoderma virens GV41 treatment, only in absence of fertilization, demonstrating an increase in marketable yield and N uptake. Thus, the inoculation of rocket with this Trichoderma biostimulant can be considered as a useful management tool in leafy vegetable cropping systems for the efficient use of residual fertilizers from previous crops, enhancing NUE within the crop rotations. Nevertheless, the application of microbial biostimulant treatments requires good monitoring of soil N fertility in order to avoid an overexploitation of soil N supplying potential. Full article
(This article belongs to the Special Issue Nitrogen Fertilization in Vegetable Crops)
Show Figures

Figure 1

Open AccessArticle
Effects of Nitrogen Management on Biomass Production and Dry Matter Distribution of Processing Tomato Cropped in Southern Italy
Agronomy 2019, 9(12), 855; https://doi.org/10.3390/agronomy9120855 - 05 Dec 2019
Cited by 6
Abstract
Processing tomato is an important worldwide horticultural crop. It is generally grown in high-input systems; nevertheless, plant responses to nitrogen fertilization, in terms of the effects on dry matter production and allocation to different plant organs, have yet to be investigated in depth. [...] Read more.
Processing tomato is an important worldwide horticultural crop. It is generally grown in high-input systems; nevertheless, plant responses to nitrogen fertilization, in terms of the effects on dry matter production and allocation to different plant organs, have yet to be investigated in depth. Moreover, information on the crop marginal net return and global warming potential (as an index of the environmental impact of crop cultivation) at different nitrogen rates is still scarce. Therefore, the aim of this work was to study the effects of different nitrogen rates (0, 50, 100, 150, 200, and 250 kg of N ha−1) on the agronomic, economic, and environmental aspects of processing tomato grown under conventional management in the Mediterranean area. The results of the two-year trials indicated 200 kg of nitrogen ha−1 as the best rate, ensuring the highest values of marketable and total yields, brix ton ha−1, and marginal net return and the lowest global warming potential per ton of marketable yield. However, since plants fertilized with 200 kg of N ha−1 did not record the highest values of nitrogen use efficiency and nitrogen uptake efficiency, our finding suggest the possibility to select better-performing cultivars for these physiological parameters by adopting specific tomato breeding programs. Full article
(This article belongs to the Special Issue Nitrogen Fertilization in Vegetable Crops)
Show Figures

Figure 1

Open AccessArticle
Nitrogen Nutrition Optimization in Organic Greenhouse Tomato Through the Use of Legume Plants as Green Manure or Intercrops
Agronomy 2019, 9(11), 766; https://doi.org/10.3390/agronomy9110766 - 17 Nov 2019
Cited by 2
Abstract
In the present study, in addition to farmyard manure (FYM), cowpea was applied as green manure and faba bean as an intercrop in an organic greenhouse tomato crop, aiming to increase the levels of soil N. Three experiments (E1, E2, E3) were carried [...] Read more.
In the present study, in addition to farmyard manure (FYM), cowpea was applied as green manure and faba bean as an intercrop in an organic greenhouse tomato crop, aiming to increase the levels of soil N. Three experiments (E1, E2, E3) were carried out, in which legumes were either noninoculated or inoculated with rhizobia alone or together with plant growth, promoting rhizobacteria. Inoculation of legumes with rhizobia considerably increased N2 fixation in E1 but had no impact on N2 fixation in E2 and E3. In E1, the application of cowpea decreased yield because it imposed a stronger nematode infection as the cowpea plants acted as a good host for Meloidogyne. However, in E2 and E3 the nematode infection was successfully controlled and the legumes significantly increased the tomato yield when inoculated in E2, irrespective of legume inoculation in E3. The total N concentration in the tomato plant tissues was significantly increased by legume application in E2 and E3, but not in E1. These results show that legumes applied as green manure can successfully complement N supply via FYM in organic greenhouse tomato, while legume inoculation with rhizobia can increase the amounts of nitrogen provided to the crop via green manure. Full article
(This article belongs to the Special Issue Nitrogen Fertilization in Vegetable Crops)
Show Figures

Figure 1

Open AccessArticle
Distillery Anaerobic Digestion Residues as Fertilizers for Field Vegetable Crops: Performance and Efficiency in Mid-term Successions
Agronomy 2019, 9(8), 463; https://doi.org/10.3390/agronomy9080463 - 17 Aug 2019
Cited by 1
Abstract
Understanding nitrogen use efficiency (NUE) of crops plays an important role in achieving sustainable production. Intensive agriculture has adversely affected social and environmental issues worldwide over the past few decades. Anaerobic digested residues from the distillery industry (DADRs) can be used in agriculture, [...] Read more.
Understanding nitrogen use efficiency (NUE) of crops plays an important role in achieving sustainable production. Intensive agriculture has adversely affected social and environmental issues worldwide over the past few decades. Anaerobic digested residues from the distillery industry (DADRs) can be used in agriculture, thereby recycling valuable organic materials that can supply organic N. An experiment using DADRs in horticulture was conducted to evaluate the performance of different treatments on yield and NUE. The experiment was conducted for five years, growing lettuce, cauliflower, chicory, potato, Swiss chard, catalogna chicory, tomato, pepper, and melon in two different succession schemes. Five fertilization treatments were designed, including a mineral fertilization control, in which nitrogen (N) was supplied according to standard recommendations in the area. The other treatments were an unfertilized control and three treatments in which 50%, 75%, and 100% of the N were supplied by DADRs and the remaining with common chemical fertilizer. Major findings were: (1) Spring–summer crops showed the lowest N-uptake and N recovery, during this period high chemical fertilization can cause environmental problems such as N leaching, and fertilization with 100% DADRs is a viable alternative; (2) fall–winter crops can be fertilized by combining 50% mineral N and 50% organic N, supplying the nutrients required by the crops during the growing cycle. Full article
(This article belongs to the Special Issue Nitrogen Fertilization in Vegetable Crops)
Show Figures

Figure 1

Open AccessArticle
Morphological and Physiological Responses Induced by Protein Hydrolysate-Based Biostimulant and Nitrogen Rates in Greenhouse Spinach
Agronomy 2019, 9(8), 450; https://doi.org/10.3390/agronomy9080450 - 14 Aug 2019
Cited by 12
Abstract
Plant-derived protein hydrolysates (PHs) are gaining prominence as biostimulants due to their potential to improve yield and nutritional quality even under suboptimal nutrient regimens. In this study, we investigated the effects of foliar application of a legume-derived PH (0 or 4 mL L [...] Read more.
Plant-derived protein hydrolysates (PHs) are gaining prominence as biostimulants due to their potential to improve yield and nutritional quality even under suboptimal nutrient regimens. In this study, we investigated the effects of foliar application of a legume-derived PH (0 or 4 mL L−1) on greenhouse baby spinach (Spinacia oleracea L.) under four nitrogen (N) fertilization levels (0, 15, 30, or 45 kg ha−1) by evaluating morphological and colorimetric parameters, mineral composition, carbohydrates, proteins, and amino acids. The fresh yield in untreated and biostimulant-treated spinach plants increased in response to an increase in N fertilization from 1 up to 30 kg ha−1, reaching a plateau thereafter indicating the luxury consumption of N at 45 kg ha−1. Increasing N fertilization rate, independently of PH, lead to a significant increase of all amino acids with the exception of alanine, GABA, leucine, lysine, methionine, and ornithine but decreased the polyphenols content. Interestingly, the fresh yield at 0 and 15 kg ha−1 was clearly greater in PH-treated plants compared to untreated plants by 33.3% and 24.9%, respectively. This was associated with the presence in of amino acids and small peptides PH ‘Trainer®’, which act as signaling molecules eliciting auxin- and/or gibberellin-like activities on both leaves and roots and thus inducing a “nutrient acquisition response” that enhances nutrients acquisition and assimilation (high P, Ca, and Mg accumulation) as well as an increase in the photochemical efficiency and activity of photosystem II (higher SPAD index). Foliar applications of the commercial PH decreased the polyphenols content, but on the other hand strongly increased total amino acid content (+45%, +82%, and +59% at 0, 15, and 30 kg ha−1, respectively) but not at a 45-kg ha−1-rate. Overall, the use of PH could represent a sustainable tool for boosting yield and nitrogen use efficiency and coping with soil fertility problems under low input regimens. Full article
(This article belongs to the Special Issue Nitrogen Fertilization in Vegetable Crops)
Show Figures

Figure 1

Open AccessArticle
Effect of Fertilization on Yield and Quality of Sisymbrium officinale (L.) Scop. Grown as Leafy Vegetable Crop
Agronomy 2019, 9(7), 401; https://doi.org/10.3390/agronomy9070401 - 19 Jul 2019
Abstract
Sisymbrium officinale is a wild Brassicaceae species that is known for its use in the alleviation of vocal inflammatory states. Since this species is particularly rich in bioactive compounds, there is an interest for developing cultivation protocols to use this plant as a [...] Read more.
Sisymbrium officinale is a wild Brassicaceae species that is known for its use in the alleviation of vocal inflammatory states. Since this species is particularly rich in bioactive compounds, there is an interest for developing cultivation protocols to use this plant as a leafy vegetable harvested at the 13th BBCH growth stage. Two wild populations of S. officinale (L.) Scop., denominate MI (Milan) and BG (Bergamo), have been used, and three different levels of nutrients (g/m2) have been provided such as 13 N, 7 P2O5, 8 K2O (100%); 9 N, 5 P2O5, 5.5 K2O (70%); and 6.5 N, 3.5 P2O5, 4.0 K2O (50%). The effects of different fertilization levels were evaluated on the yield, leaf pigments (chlorophylls, carotenoids), nitrate concentration, sugars content, and on the antioxidant compounds such as anthocyanins, total phenols and glucosinolates (GLS). Plant stress monitoring was performed by measuring the chlorophyll a fluorescence. Results indicated that yield was not affected and ranged from 0.18 to 0.47 kg/m2, and differences were not statistically significant for chlorophylls, carotenoids, and total sugars content. Nitrate concentrations were higher in the BG wild population (4388.65 mg/kg FW) during the second cultivation cycle and lower (1947.21 mg/kg FW) in the same wild population during the first cultivation cycle, both at the 100% fertilization level. Total phenols and anthocyanins were higher in the highest fertilization rate in the MI wild population during the second cycle. The GLS were higher in the lowest fertilization rate in the BG wild population (19 µmol/g FW) grown at the fertilization level of the 50%, and significant differences were observed in the second cycle. In conclusion, the 50% fertilization level can be considered the most suitable for our experimental conditions. Full article
(This article belongs to the Special Issue Nitrogen Fertilization in Vegetable Crops)
Show Figures

Figure 1

Back to TopTop