Records 1 - 20 / 1122
The governance challenge of implementing long-term sustainability objectives with present-day investment decisions
Pot, Wieke D. - \ 2020
Journal of Cleaner Production 280 (2020)2. - ISSN 0959-6526
Causal mechanisms - Governance - Public–private partnerships - Sustainability objectives - Water infrastructure
Grand sustainability challenges and international sustainability agreements require national and local governments to further incorporate sustainability as part of their present-day investments in infrastructure. To strengthen public procurement as a policy tool for enhancing sustainability, recent systematic literature reviews call for more research on the interactions between actors in tender processes. Therefore, this article combines a governance lens with a process tracing approach to explain why it is difficult for governments to reach sustainability objectives with their present-day investment decisions. The results derive from a longitudinal case study of the investment process in a Dutch water pumping station and are based on primary documents, interviews, and observations of the tender procedure between 2017 and 2019. The research reveals that risk avoidance, goal satisfaction, and budget compliance interfere with the implementation of national and international sustainability objectives at the local level. There is need for more attention on learning as part of procurement procedures, scale flexibility to realize sustainability objectives efficiently and effectively, and prioritization of conflicting long-term objectives to avoid implementation gaps.
Response of common bean (Phaseolus vulgaris L.) growth to soil contaminated with microplastics
Meng, Fanrong ; Yang, Xiaomei ; Riksen, Michel ; Xu, Minggang ; Geissen, Violette - \ 2020
Science of the Total Environment 755 (2020)2. - ISSN 0048-9697
Biodegradable microplastics - Microplastics - Plant growth - Soil-plant system
Although concerns surrounding microplastics (MPs) in terrestrial ecosystems have been growing in recent years, little is known about the responses of plant growth to MPs pollution. Here, we conducted a pot experiment in a net house under natural condition by adding two types of MPs, low-density polyethylene (LDPE-MPs) and polylactic acid (PLA) mixed with poly-butylene-adipate-co-terephthalate (PBAT, Bio-MPs), to sandy soil at 5 doses (0.5%, 1.0%, 1.5%, 2.0%, 2.5% ω/ω dry soil weight). The effects of LDPE-MPs and Bio-MPs on common bean (Phaseolus vulgaris L) were tested. Compared to control (no MPs addition), LDPE-MPs showed no significant effects on shoot, root and fruit biomass while ≥1.0% LDPE-MPs showed significant higher specific root nodules (n·g−1 dry root biomass) and only 2.5% LDPE-MPs showed significant higher specific root length (cm·g−1 dry root biomass). 1.0% LDPE-MPs caused significant higher leaf area and 0.5% LDPE-MPs caused significant lower leaf relative chlorophyll content. For Bio-MPs treatment, compared to control, ≥1.5% Bio-MPs showed significant lower shoot and root biomass. ≥2.0% Bio-MPs showed significant lower leaf area and fruit biomass. All Bio-MPs treatments showed significant higher specific root length and specific root nodules as compared to control. The results of the current research show that both MPs induced the responses of common bean growth, and ≥1.5% Bio-MPs exerted stronger effects. Further studies of their ecological impacts on soil-plant systems are urgently needed.
Symbiotic interactions between chickpea (Cicer arietinum L.) genotypes and Mesorhizobium strains
Gunnabo, A.H. ; Heerwaarden, J. van; Geurts, R. ; Wolde-meskel, E. ; Degefu, T. ; Giller, K.E. - \ 2020
Symbiosis (2020). - ISSN 0334-5114
AMMI - Genotype-strain combinations - Rhizobium genotypes - Symbiotic effectiveness
Legume genotype (GL) x rhizobium genotype (GR) interaction in chickpea was studied using a genetically diverse set of accessions and rhizobium strains in modified Leonard Jars. A subset of effective GL x GR combinations was subsequently evaluated in a pot experiment to identify combinations of chickpea genotypes and rhizobium strains with stable and superior symbiotic performance. A linear mixed model was employed to analyse the occurrence of GL x GR interaction and an additive main effects and multiplicative interaction (AMMI) model was used to study patterns in the performance of genotype-strain combinations. We found statistically significant interaction in jars in terms of symbiotic effectiveness that was entirely due to the inclusion of one of the genotypes, ICC6263. No interaction was found in a subsequent pot experiment. The presence of two genetic groups (Kabuli and Desi genepools) did not affect interaction with Mesorhizobium strains. With the exception of a negative interaction with genotype ICC6263 in the jar experiment, the type strain Mesorhizobium ciceri LMG 14989 outperformed or equalled other strains on all chickpea genotypes in both jar and pot experiments. Similar to earlier reports in common bean, our results suggest that efforts to find more effective strains may be more rewarding than aiming for identification of superior combinations of strains and genotypes.
Deciding for tomorrow, today : what makes governmental decisions about water infrastructure forward looking?
Pot, Wieke D. - \ 2020
Wageningen University. Promotor(en): A. Dewulf; C.J.A.M. Termeer, co-promotor(en): G.R. Biesbroek. - Wageningen : Wageningen University - ISBN 9789463953917 - 285
Bio-organic fertilizers stimulate indigenous soil Pseudomonas populations to enhance plant disease suppression
Tao, Chengyuan ; Li, Rong ; Xiong, Wu ; Shen, Zongzhuan ; Liu, Shanshan ; Wang, Beibei ; Ruan, Yunze ; Geisen, Stefan ; Shen, Qirong ; Kowalchuk, George A. - \ 2020
Microbiome 8 (2020). - ISSN 2049-2618
Plant diseases caused by fungal pathogen result in a substantial economic impact on the global food and fruit industry. Application of organic fertilizers supplemented with biocontrol microorganisms (i.e. bioorganic fertilizers) has been shown to improve resistance against plant pathogens at least in part due to impacts on the structure and function of the resident soil microbiome. However, it remains unclear whether such improvements are driven by the specific action of microbial inoculants, microbial populations naturally resident to the organic fertilizer or the physical-chemical properties of the compost substrate. The aim of this study was to seek the ecological mechanisms involved in the disease suppressive activity of bio-organic fertilizers.
To disentangle the mechanism of bio-organic fertilizer action, we conducted an experiment tracking Fusarium wilt disease of banana and changes in soil microbial communities over three growth seasons in response to the following four treatments: bio-organic fertilizer (containing Bacillus amyloliquefaciens W19), organic fertilizer, sterilized organic fertilizer and sterilized organic fertilizer supplemented with B. amyloliquefaciens W19. We found that sterilized bioorganic fertilizer to which Bacillus was re-inoculated provided a similar degree of disease suppression as the non-sterilized bioorganic fertilizer across cropping seasons. We further observed that disease suppression in these treatments is linked to impacts on the resident soil microbial communities, specifically by leading to increases in specific Pseudomonas spp.. Observed correlations between Bacillus amendment and indigenous Pseudomonas spp. that might underlie pathogen suppression were further studied in laboratory and pot experiments. These studies revealed that specific bacterial taxa synergistically increase biofilm formation and likely acted as a plant-beneficial consortium against the pathogen.
Together we demonstrate that the action of bioorganic fertilizer is a product of the biocontrol inoculum within the organic amendment and its impact on the resident soil microbiome. This knowledge should help in the design of more efficient biofertilizers designed to promote soil function.
Governing long-term policy problems: Dilemmas and strategies at a Dutch water authority
Pot, Wieke D. ; Dewulf, Art ; Termeer, Catrien J.A.M. - \ 2020
Public Management Review (2020). - ISSN 1471-9037
Ethnography - long-term governance - public sector - strategic agility - strategic planning
Despite the increasing need to address long-term challenges, public sector organizations are incentivized to focus on short-term results. This article uses an ethnographic approach to analyse how members of a regional water authority understand and deal with long-term policy problems as part of their everyday practices. It reveals three specific dilemmas: investing in the realization of objects or objectives, adopting a stable or responsive approach, and taking a proactive or reactive stance towards the external environment. The concept of strategic agility enables organizations to respond proactively to unexpected developments by devising strategies to steer as well as to accommodate change.
Substraat, water, voeding en beweging gewas bepalen de vorm van wortels. Dicht substraat zorgt voor compacte pot- en perkplanten
Delden, S.H. van; Heuvelink, E. - \ 2020
Onder Glas 17 (2020)9. - p. 52 - 53.
Watering techniques and zero-valent iron biochar pH effects on As and Cd concentrations in rice rhizosphere soils, tissues and yield
Islam, Md Shafiqul ; Chen, Yali ; Weng, Liping ; Ma, Jie ; Khan, Zulqarnain Haider ; Liao, Zhongbin ; Magid, Abdoul Salam Issiaka Abdoul ; Li, Yongtao - \ 2020
Journal of Environmental Sciences 100 (2020). - ISSN 1001-0742 - p. 144 - 157.
Brown rice As - Brown rice Cd - Grain yield - Paddy soils - Water management - Zero-valent iron biochar
Zero-valent iron amended biochar (ZVIB) has been proposed as a promising material in immobilizing heavy metals in paddy fields. In this study, the impacts of pH of ZVIB (pH 6.3 and pH 9.7) and watering management techniques (watering amount in the order of CON (control, 5/72)>3/72>1–3/72>3/100>1/72, with 5/72, for example, representing irrigation given to 5 cm above soil surface in 72 hr regular interval) on As and Cd bioavailability for rice and its grain yield (YieldBR) were investigated in a pot experiment. Brown rice As (AsBR) content was irrelative to the watering treatments, while significantly decreased (>50%) with the addition of both ZVIB materials. The diminutions of brown rice Cd (CdBR) content as well as the YieldBR were highly dependent on both the soil amendment materials’ pH and watering amount. Among all the watering treatments, 3/72 treatment (15% less irrigation water than the CON) with ZVIB 6.3 amendment was the optimum fit for simultaneous reduction of AsBR (50%) and CdBR contents (19%) as well as for significant increment (12%) of the YieldBR. Although high pH (9.7) ZVIB application could also efficiently decrease As and Cd contents in brown rice, it might risk grain yield lost if appropriate (e.g. 3/72 in our study) watering management technique was not chosen. Therefore, ZVIB would be an environmentally friendly option as an amendment material with proper selection of watering management technique to utilize As and Cd co-contaminated arable soils safely for paddy cultivation.
|Towards climate-neutral pot plant cultivation
Weerheim, C. - \ 2020
In Greenhouses : the international magazine for greenhouse growers 9 (2020)3. - ISSN 2215-0633 - p. 43 - 43.
No evidence of modulation of indirect plant resistance of Brassica rapa plants by volatiles from soil-borne fungi
Moisan, Kay ; Lucas-Barbosa, Dani ; Villela, Alexandre ; Greenberg, Liana O. ; Cordovez, Viviane ; Raaijmakers, Jos M. ; Dicke, Marcel - \ 2020
Ecological Entomology 45 (2020)5. - ISSN 0307-6946 - p. 1200 - 1211.
HIPVs - parasitoids - predators - recruitment
Upon herbivory, plants emit specific herbivore-induced plant volatiles (HIPVs) that can attract natural enemies of the herbivore thus serving as indirect plant resistance. Not only insect herbivores, but microorganisms may also affect HIPV emission before or after plant colonisation, which in turn can affect behaviour of natural enemies of the herbivore. Yet, it remains elusive whether volatiles from microorganisms influence HIPV emission and indirect plant resistance. In this study, we investigated whether exposure of Brassica rapa roots to volatiles from soil-borne fungi influence HIPV emission and the recruitment of natural enemies of Pieris brassicae larvae. Using a two-compartment pot system, we performed greenhouse and common-garden experiments, and we profiled plant HIPV emission. We found that exposure of plant roots to fungal volatiles did not affect the number of P. brassicae larvae recollected from the plants, suggesting a neutral effect of the fungal volatiles on natural predation. Likewise, in a greenhouse, similar numbers of larvae were parasitised by Cotesia glomerata wasps on control plants as on fungal volatile-exposed plants. Additionally, chemical analysis of HIPV profiles revealed no qualitative and quantitative differences between control plants and fungal volatile-exposed plants that were both infested with P. brassicae larvae. Together, our data indicate that root exposure to fungal volatiles did not affect indirect plant resistance to an insect herbivore. These findings provide new insight into the influence of indirect plant resistance by fungal volatiles that are discussed together with the effects of fungal volatiles on direct plant resistance.
Monitoring and tackling genetic selection in the potato cyst nematode Globodera pallida
Grenier, E. ; Kiewnick, S. ; Smant, G. ; Fournet, S. ; Montarry, J. ; Holterman, M. ; Helder, J. ; Goverse, A. - \ 2020
EFSA Supporting Publications 17 (2020)6. - ISSN 2397-8325 - 23 p.
Management of plant pests is probably the most serious challenge in sustainable food production and the maintenance of food security. Due to the strict regulation of or ban on major categories of pesticide, the potato cyst nematode Globodera pallida has been managed by a combination of crop rotation and the potato resistance locus Grp1 , a relatively narrow range resistance gene which was introgressed into a range of commercial potato cultivars in Europe. However, in 2014, G. pallida populations were described that can no longer be controlled by Grp1 . Most likely similar highly virulent populations will also emerge in all major potato growing areas in North Western Europe where production practices are very similar. Except for laborious, costly and often moderately accurate pot experiments, there is currently no rapid and reliable method to identify virulent populations. This represents a strong limitation and prevents an accurate and durable management of infestations. The PalAdapt project funded by EFSA represents the first step of a European battle plan against the emergence of virulent G. pallida populations and aims at improving the methods and tools for a fast identification of virulence outbreaks. Four main research questions were investigated during the project: (i) Do resistance breaking populations correspond to novel introductions into Europe? (ii) Can miniaturized in vitro tests be used to get more rapidly an accurate identification of the virulence status?, (iii) Is cyst size a life history trait useful to estimate the virulence status of a population?, (iv) Can we identify polymorphism to design molecular tools for an accurate virulence monitoring? The EFSA partnering grants initiative was an accurate way to improve the EU risk assessment capacity through a knowledge exchange among partners having complementary resources and expertise.
Field performance of different maize varieties in growth cores at natural and reduced mycorrhizal colonization : yield gains and possible fertilizer savings in relation to phosphorus application
Wang, Xin Xin ; Werf, Wopke van der; Yu, Yang ; Hoffland, Ellis ; Feng, Gu ; Kuyper, Thomas W. - \ 2020
Plant and Soil 450 (2020)1-2. - ISSN 0032-079X - p. 613 - 624.
Crop - Genetic variation - In-growth cores - Landrace - Maize - Mycorrhizal colonization - Phosphorus
Aims: The benefits of arbuscular mycorrhizal fungi (AMF) on yield and phosphorus (P) uptake of crops have commonly been studied by inoculating a single mycorrhizal fungal species in pot experiments. Yet, how the native AMF community affects the performance of different maize varieties under field conditions remains obscure. Methods: In-growth cores with and without rotation were used in three soils that differed in P application to assess shoot biomass, P uptake, and mycorrhizal colonization of three maize varietal groups, encompassing four inbred lines, 12 hybrids, and four landraces. Results: Rotating cores drastically reduced mycorrhizal colonization, biomass and P uptake for each varietal group at every P level. Performance of plants at natural mycorrhizal colonization at 30 kg P ha−1 was equal to that of reduced-mycorrhizal plants at 60 kg P ha−1, suggesting the potential for adequate mycorrhizal management to save P fertilizer. Conclusion: There were no significant differences between varietal groups for mycorrhizal responsiveness, confirming that the ability to associate with and benefit from AMF has been maintained in modern breeding. Mycorrhizal plants both exhibited higher P acquisition efficiency and higher P use efficiency than reduced-mycorrhizal plants. Disadvantages of in-growth cores should be duly considered.
Responses of Lowland, Upland and Aerobic Rice Genotypes to Water Limitation During Different Phases
Vijayaraghavareddy, Preethi ; Xinyou, Yin ; Struik, Paul C. ; Makarla, Udayakumar ; Sreeman, Sheshshayee - \ 2020
Rice Science 27 (2020)4. - ISSN 1672-6308 - p. 345 - 354.
Aerobic - Oryza sativa - Phenology - Upland - Water limitation - yield
Rice yield reduction due to water limitation depends on its severity and duration and on the phenological stage of its occurrence. We exposed three contrasting rice genotypes, IR64, UPLRi7 and Apo (adapted to lowland, upland and aerobic conditions, respectively), to three water regimes (puddle, 100% and 60% field capacity) in pots during the vegetative (GSI), flowering (GSII) and grain filling (GSIII) stages. Stress at all the three stages significantly reduced yield especially in lowland genotype IR64. Effect of water limitation was more severe at GSII than at the other two stages. Stress at GSI stage reduced both source activity (leaf area and photosynthetic rate) and sink capacity (tiller number or panicle number per pot). When stress was imposed at GSII, spikelet fertility was most affected in all the three genotypes. In both GSII and GSIII, although leaf area was constant in all the three water regimes, estimated relative whole-plant photosynthesis was strongly associated with yield reduction. Reduced photosynthesis due to stress at any given stage was found to have direct impact on yield. Compared to the other genotypes, Apo had deeper roots and maintained a better water relation, thus, higher carbon gain and spikelet viability, and ultimately, higher biomass and productivity under water-limited conditions. Therefore, screening for these stage-dependent adaptive mechanisms is crucial in breeding for sustained rice production under water limitation.
Accelerated grain-filling rate increases seed size and grain yield of recent naked oat cultivars under well-watered and water-deficit conditions
Wang, Tao ; Li, Feng Min ; Turner, Neil C. ; Wang, Bing Ru ; Wu, Fan ; Anten, Niels P.R. ; Du, Yan Lei - \ 2020
European Journal of Agronomy 116 (2020). - ISSN 1161-0301
abscisic acid concentration - endosperm cell number - fertile spike number - starch synthesis - water stress
Increased seed size has greater contribution in yield improvement in recent naked oat (Avena sativa L. subsp. nudisativa) cultivars than cultivars derived from landraces. However, the underlying grain-filling mechanisms associated with seed size and grain yield in naked oat have received limited study. Two field experiments and a pot experiment compared grain-filling mechanisms, seed size and grain yield of ten naked oat cultivars, including old (landraces, released before 1950s) and new (released since 2008) cultivars. In both well-watered and water-deficit conditions, the new cultivars had higher grain yields, higher thousand kernel weights (TKW) and higher grain numbers per spike, but fewer fertile spikes per unit area or per plant, and no significant differences in grain number per unit area or per plant, than old cultivars. The findings in both the field and pot experiments demonstrated that increased grain-filling rate, rather than duration, enhanced seed size (TKW) and grain yield in the new cultivars. The increased grain-filling rate in a new cultivar was associated with higher rates of endosperm cell division and higher number of endosperm cells, compared to that in an old cultivar, but there were no significant differences in starch synthesis enzyme activity and ABA concentration between the old and new cultivars. As a result of current breeding and selection, the increased the grain yield of new cultivars of naked oat is primarily due to increased seed size (increased sink size) arising from a greater number of endosperm cells per grain, and not because of increased enzyme or phytohormonal activity. The larger seed size is important in the production of oats for food rather than for forage.
Increased arbuscular mycorrhizal fungal colonization reduces yield loss of rice (Oryza sativa L.) under drought
Chareesri, A. ; Deyn, G.B. de; Sergeeva, L. ; Polthanee, Anan ; Kuijper, T.W.M. - \ 2020
Mycorrhiza 30 (2020). - ISSN 0940-6360 - p. 315 - 328.
Drought reduces the availability of soil water and the mobility of nutrients, thereby limiting the growth and productivity of rice. Under drought, arbuscular mycorrhizal fungi (AMF) increase P uptake and sustain rice growth. However, we lack knowledge of how the AMF symbiosis contributes to drought tolerance of rice. In the greenhouse, we investigated mechanisms of AMF symbiosis that confer drought tolerance, such as enhanced nutrient uptake, stomatal conductance, chlorophyll fluorescence, and hormonal balance (abscisic acid (ABA) and indole acetic acid (IAA)). Two greenhouse pot experiments comprised three factors in a full factorial design with two AMF treatments (low- and high-AMF colonization), two water treatments (well-watered and drought), and three rice varieties. Soil water potential was maintained at 0 kPa in the well-watered treatment. In the drought treatment, we reduced soil water potential to − 40 kPa in experiment 1 (Expt 1) and to − 80 kPa in experiment 2 (Expt 2). Drought reduced shoot and root dry biomass and grain yield of rice in both experiments. The reduction of grain yield was less with higher AMF colonization. Plants with higher AMF colonization showed higher leaf P concentrations than plants with lower colonization in Expt 1, but not in Expt 2. Plants with higher AMF colonization exhibited higher stomatal conductance and chlorophyll fluorescence than plants with lower colonization, especially under drought. Drought increased the levels of ABA and IAA, and AMF colonization also resulted in higher levels of IAA. The results suggest both nutrient-driven and plant hormone-driven pathways through which AMF confer drought tolerance to rice.
Feeding the melting pot: inclusive strategies for the multi‑ethnic city
Brons, Anke ; Oosterveer, P.J.M. ; Wertheim-Heck, S.C.O. - \ 2020
Agriculture and Human Values (2020). - ISSN 0889-048X - 14 p.
Food consumption - Healthy and sustainable food - Food environment - Multi-ethic city - Migrants - Inclusiveness - Practice theories
The need for a shift toward healthier and more sustainable diets is evident and is supported by universalized standards for a “planetary health diet” as recommended in the recent EAT-Lancet report. At the same time, differences exist in tastes, preferences and food practices among diverse ethnic groups, which becomes progressively relevant in light of Europe’s increasingly multi-ethnic cities. There is a growing tension between current sustainable diets standards and how diverse ethnic resident groups relate to it within their ‘culturally appropriate’ foodways, raising questions around inclusion. What are dynamics of inclusiveness in migrant food practices? And what does this mean towards the transition to healthy and sustainable food? We study this question among Syrian migrants with different lengths of stay in the Netherlands. Our theoretical framework is based on practice theories, which emphasize the importance of socio-material context and of bodily routines and competences. We use qualitative methods, combining in-depth semi-structured life-history interviews with participant observation. Our findings indicate that inclusiveness takes different forms as migrants’ food practices and the food environment change. Regarding health and sustainability in food practices, understandings and competences around particularly fresh food change over time among both short- and long-term migrants, replacing making things from scratch with seasonal products with buying more processed products and out-of-season vegetables and fruits. We conclude that the performances of food practices and their configurations in food environments and lifestyles are dynamic and cannot unequivocally be interpreted as in- or exclusive, but that a more nuanced understanding is required.
Chrono-nutrition and diet quality in adolescents with delayed sleep-wake phase disorder
Berendsen, Maxime ; Boss, Myrthe ; Smits, Marcel ; Pot, Gerda K. - \ 2020
Nutrients 12 (2020)2. - ISSN 2072-6643
Adolescents - Chrono-nutrition - Circadian rhythms - Delayed sleep-wake phase disorder - Diet quality - Meal timing
Background: Delayed sleep-wake phase disorder (DSPD), characterized by delayed sleep-onset and problems with awakening in the morning, is mostly prevalent in adolescents. Several studies have suggested chrono-nutrition could present a possible modifiable risk factor for DSPD. Objective: To describe differences in chrono-nutrition and diet quality in adolescents with DSPD compared to age-related controls. Methods: Chrono-nutrition and diet quality of 46 adolescents with DSPD, aged 13–20 years, and 43 controls were assessed via questionnaires. Diet quality included the Dutch Healthy Diet index (DHD-index) and Eating Choices Index (ECI). Results were analysed using logistic regression and Spearman’s partial correlation. Results: Compared with controls, DSPD patients consumed their first food of the day significantly later on weekdays (+32 ± 12 min, p = 0.010) and weekends (+25 ± 8 min, p = 0.005). They consumed their dinner more regularly (80.4% vs. 48.8%, p = 0.002) and consumed morning-snacks less frequently (3.0 ± 2.1 days vs. 4.2 ± 1.7 days, p = 0.006). No differences in clock times of breakfast, lunch, or dinner were found. Moreover, no significant differences in overall diet quality were observed. Conclusion: This descriptive study showed chrono-nutritional differences between adolescents with and without DPSD. Further studies are needed to explore features of chrono-nutrition as a possible treatment of DPSD.
Bosveld, Margaret ; Bondt, Nico ; Pot, Wieke ; Waarts, Yuca ; Wolfert, Sjaak - \ 2020
Application of bio-desalinization for reclamation of salt-affected soil under composted cow manure and deficit irrigation with saline water
Kalanaki, Mahdi ; Ritzema, Henk ; Bamshad, Roghayeh ; Jones, Edward ; Fazilatnia, Mojtaba - \ 2020
Paddy and Water Environment 18 (2020). - ISSN 1611-2490 - p. 469 - 479.
Application of common leaching and flushing methods is often impractical due to freshwater scarcity, groundwater pollution and a lack of suitable drainage systems. To address these problems, a pot experiment testing the cultivation of Salicornia persica Akhani was conducted in three replicates. Three saline irrigation treatments (EC = 7.2 dS m−1) were used: full irrigation with saline water (SI), deficit irrigation with 75% of SI (DSI75) and deficit irrigation with 55% of SI (DSI55). Two soil conditions also were considered, namely a combination of soil with 10% composted cow manure (CM) and soil without manure (WA). Our results show that the highest values for stem diameter (3.1 mm), height (110.1 mm) and dry weight (0.5 g) were observed in SI–CM. Conversely, the highest values for root length with 16.9 mm and root weight with 0.7 g were obtained for DSI75-CM. The best treatment for water-use efficiency (WUE) was DSI75-CM with 2.6 g l−1, and the lowest WUE of 1.33 g l−1 was observed for DSI55-WA. DSI increased all examined chemical parameters. The use of CM only resulted in increased values of carbohydrate, protein and proline, with no significant effects found for other parameters. Significant reductions in both EC (38.6%) and Na+ (16.8%) occurred in both soil treatments, with reductions under WA higher than reductions under CM. Overall, our results suggest that the proposed methods could be used for decreasing soil salinity levels while simultaneously allowing for the use of saline water for agricultural production.
The hidden potential of saprotrophic fungi in arable soil: Patterns of short-term stimulation by organic amendments
Clocchiatti, Anna ; Hannula, S.E. ; Berg, Marlies van den; Korthals, Gerard ; Boer, Wietse de - \ 2020
Applied Soil Ecology 147 (2020). - ISSN 0929-1393
Ascomycetes - Fungal biomass - Organic amendments - Saprotrophic fungi - Sustainable agriculture - Wood sawdust
Saprotrophic fungi are abundant in soils of (semi-)natural ecosystems, where they play a major role in ecosystem functioning. On the contrary, saprotrophic fungal biomass is remarkably low in intensively managed soils and this can have a negative impact on soil functioning. Nevertheless, arable soils harbour a diverse pool of fungi, which can be stimulated by organic amendments. Management targeted towards increasing soil organic matter often coincides with an increase of fungal biomass, but it can take years before effects are seen. However, a rapid stimulation of fungal biomass at the start of the growing season could immediately benefit crop production, by improving nutrient availability, soil structure and suppression of soil-borne diseases. The objective of this study is to realize a rapid increase of saprotrophic fungal biomass with organic amendments. In controlled pot experiments, dried and milled organic materials of different quality were added to an arable sandy soil. Ergosterol-based fungal biomass and ITS2-based fungal community structure were measured over a period of two months. Wood sawdust of deciduous tree species and paper pulp resulted in a high and lasting increase of fungal biomass, as opposed to transient effects given by cover crops and other non-woody plant materials. Little or no stimulation of fungi was seen for coniferous wood sawdust and agro-industrial by-products. Nitrogen immobilization induced by sawdust and paper pulp was compensated by supplementing mineral nitrogen, which enhanced the stimulation of saprotrophic fungi. The composition of the stimulated fungi was influenced by the quality of organic amendments. In particular, deciduous wood sawdust and paper pulp favoured saprotrophic ascomycete fungi (mainly Sordariomycetes), with no increment in potential plant-pathogenic fungi. Overall, our results point at a good perspective to use woody materials as sustainable soil improver via stimulation of saprotrophic fungi.