scholarly journals Breeding Beyond Monoculture: Putting the “Intercrop” Into Crops

2021 ◽  
Vol 12 ◽  
Author(s):  
Peter M. Bourke ◽  
Jochem B. Evers ◽  
Piter Bijma ◽  
Dirk F. van Apeldoorn ◽  
Marinus J. M. Smulders ◽  
...  

Intercropping is both a well-established and yet novel agricultural practice, depending on one’s perspective. Such perspectives are principally governed by geographic location and whether monocultural practices predominate. Given the negative environmental effects of monoculture agriculture (loss of biodiversity, reliance on non-renewable inputs, soil degradation, etc.), there has been a renewed interest in cropping systems that can reduce the impact of modern agriculture while maintaining (or even increasing) yields. Intercropping is one of the most promising practices in this regard, yet faces a multitude of challenges if it is to compete with and ultimately replace the prevailing monocultural norm. These challenges include the necessity for more complex agricultural designs in space and time, bespoke machinery, and adapted crop cultivars. Plant breeding for monocultures has focused on maximizing yield in single-species stands, leading to highly productive yet specialized genotypes. However, indications suggest that these genotypes are not the best adapted to intercropping systems. Re-designing breeding programs to accommodate inter-specific interactions and compatibilities, with potentially multiple different intercropping partners, is certainly challenging, but recent technological advances offer novel solutions. We identify a number of such technology-driven directions, either ideotype-driven (i.e., “trait-based” breeding) or quantitative genetics-driven (i.e., “product-based” breeding). For ideotype breeding, plant growth modeling can help predict plant traits that affect both inter- and intraspecific interactions and their influence on crop performance. Quantitative breeding approaches, on the other hand, estimate breeding values of component crops without necessarily understanding the underlying mechanisms. We argue that a combined approach, for example, integrating plant growth modeling with genomic-assisted selection and indirect genetic effects, may offer the best chance to bridge the gap between current monoculture breeding programs and the more integrated and diverse breeding programs of the future.

Soil Research ◽  
2021 ◽  
Vol 59 (1) ◽  
pp. 24
Author(s):  
Yui Osanai ◽  
Oliver Knox ◽  
Gunasekhar Nachimuthu ◽  
Brian Wilson

Agricultural practices (e.g. tillage, crop rotation and fertiliser application) have a strong influence on the balance between carbon (C) input and output by altering physicochemical and microbial properties that control decomposition processes in the soil. Recent studies suggest that the mechanisms by which agricultural practice impacts soil organic carbon (SOC) dynamics in the topsoil may not be the same as those in the subsoil. Here, we assessed SOC stock, soil organic fractions and nitrogen availability to 1.0 m in soils under a cotton (Gossypium hirsutum L.)-based cropping system, and assessed the impact of agricultural management (three historical cropping systems with or without maize (Zea mays L.) rotation) on SOC storage. We found that the maize rotation and changes in the particulate organic fraction influenced SOC stock in the topsoil, although the overall change in SOC stock was small. The large increase in subsoil SOC stock (by 31%) was dominated by changes in the mineral-associated organic fraction, which were influenced by historical cropping systems and recent maize rotation directly and indirectly via changes in soil nitrogen availability. The strong direct effect of maize rotation on SOC stock, particularly in the subsoil, suggests that the direct transfer of C into the subsoil SOC pool may dominate C dynamics in this cropping system. Therefore, agricultural management that affects the movement of C within the soil profile (e.g. changes in soil physical properties) could have a significant consequence for subsoil C storage.


2015 ◽  
Vol 18 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Jaroslav Jedlička ◽  
Oleg Paulen ◽  
Štefan Ailer

AbstractIn the study regarding with tomatoes, the impact of extremely low frequency electromagnetic fields on seed germination of tomato (Solanum lycopersicumL.) after treatment before sowing, as well as the growth following electromagnetic stimulation of young plants at a time before planting in the field, and fruittraits was investigated. In the experiments conducted in two consecutive years (2012 and 2013), we followed the time of seed germination of tomato variety “Pavlina”, plant growth and the fruitsize. Magnetization of seeds and young plants was carried out in laboratory conditions, and plant growth and fruits were followed in field conditions where plants were grown on experimental plots (25.0 m2). The plants were grown in accordance with the standards of agricultural practice for tomato. At the generative phase, fruits were collected at regular intervals, and their number and weight were evaluated. Low frequency electromagnetic fields acting at the three inductance levels (20, 40 and 60 mT) and exposure of 20 minutes a day with frequency of 50 Hz, significantly influenced the germination, plant growth and fruitsize of the studied tomato variety.


2019 ◽  
Vol 70 (8) ◽  
pp. 649
Author(s):  
Noura Bechtaoui ◽  
Abdelkhalek El Alaoui ◽  
Anas Raklami ◽  
Loubna Benidire ◽  
Abdel-ilah Tahiri ◽  
...  

Intercropping is a farming practice that fights pests and diseases and improves plant growth. The use of plant growth-promoting rhizobacteria (PGPR) strains to boost the yield of intercrops constitutes a promising tool in agricultural practice. This study investigated the impact of single inoculation and co-inoculation with PGPR on plant biomass and phosphorus (P) and nitrogen (N) concentrations under different cropping systems. Two PGPR strains with different traits were selected: PGP13 (Rahnella aquatilis) and PS11 (Pseudomonas sp.). A greenhouse experiment was designed using durum wheat (Triticum durum L.) and faba bean (Vicia faba L.), sole cropped or intercropped, including four inoculation treatments: (i) uninoculated, (ii) inoculated with PS11 (iii) inoculated with PGP13, and (iv) co-inoculated with PS11 + PGP13. Co-inoculation under the intercropping system improved plant dry matter and enhanced bean pod and wheat spike weights to 685.83% and 385.83%, respectively, of the values for uninoculated, intercropped plants. Higher P and N concentrations were detected in intercropped, co-inoculated plants and in bean pods and wheat spikes. The results were then submitted to principal component analysis, showing that treatments with higher biomass and nutrient concentrations were strongly correlated with intercropped, co-inoculated plants.


2021 ◽  
Vol 12 ◽  
Author(s):  
Emmanuelle Blanc ◽  
Pierre Barbillon ◽  
Christian Fournier ◽  
Christophe Lecarpentier ◽  
Christophe Pradal ◽  
...  

Increasing the cultivated diversity has been identified as a major leverage for the agroecological transition as it can help improve the resilience of low input cropping systems. For wheat, which is the most cultivated crop worldwide in terms of harvested area, the use of cultivar mixtures is spreading in several countries, but studies have seldom focused on establishing mixing rules based on plant architecture. Yet, the aerial architecture of plants and the overall canopy structure are critical for field performance as they greatly influence light interception, plant interactions and yield. The very high number of trait combinations in wheat mixtures makes it difficult to conduct experimentations on this issue, which is why a modeling approach appears to be an appropriate solution. In this study, we used WALTer, a functional structural plant model (FSPM), to simulate wheat cultivar mixtures and try to better understand how differences between cultivars in key traits of the aerial architecture influence mixture performance. We simulated balanced binary mixtures of cultivars differing for different critical plant traits: final height, leaf dimensions, leaf insertion angle and tillering capability. Our study highlights the impact of the leaf dimensions and the tillering capability on the performance of the simulated mixtures, which suggests that traits impacting the plants' leaf area index (LAI) have more influence on the performance of the stand than traits impacting the arrangement of the leaves. Our results show that the performance of mixtures is very variable depending on the values of the explored architectural traits. In particular, the best performances were achieved by mixing cultivars with different leaf dimensions and different tillering capability, which is in agreement with numerous studies linking the diversity of functional traits in plant communities to their productivity. However, some of the worst performances were also achieved by mixing varieties differing in their aerial architecture, which suggests that diversity is not a sufficient criterion to design efficient mixtures. Overall, these results highlight the importance of simulation-based explorations for establishing assembly rules to design efficient mixtures.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mohammad Radhi Sahib ◽  
Zahida H. Pervaiz ◽  
Mark A. Williams ◽  
Muhammad Saleem ◽  
Seth DeBolt

Abstract Although microbes influence plant growth, little is known about the impact of microbial diversity on plant fitness trade-offs, intraspecific-interactions, and soil nutrient dynamics in the context of biodiversity-ecosystem functioning (BEF) research. The BEF theory states that higher species richness can enhance ecosystem functioning. Thus, we hypothesize that rhizobacterial species richness will alter sorghum (Sorghum bicolor L.) growth, soil nutrient dynamics and interactions (antagonism or synergism) in a nutrient-poor greenhouse soil. Using six rhizobacterial species in a BEF experiment, we tested the impact of a species richness gradient (0, 1, 3, 5 or 6 species per community) on plant growth, nutrient assimilation, and soil nutrient dynamics via seed-inoculation. Our experiment included, one un-inoculated control, six rhizobacterial monoculture (Pseudomonas poae, Pseudomonas sp., Bacillus pumilus., Pantoea agglomerance., Microbacterium sp., and Serratia marcescens), and their nine mixture treatments in triplicate (48). Rhizobacterial species richness enhanced per pot above- or below-ground dry mass. However, the per plant growth and plant nutrient assimilation declined, most likely, due to microbial-driven competitive interactions among sorghum plants. But nevertheless, some rhizobacterial monoculture and mixture treatments improved per plant (shoot and root) growth and nutrient assimilation as well. Soil nutrient contents were mostly lower at higher plant-associated rhizobacterial diversity; among these, the soil Zn contents decreased significantly across the rhizobacterial diversity gradient. Rhizobacterial diversity promoted synergistic interactions among soil nutrients and improved root–soil interactions. Overall, our results suggest that a higher rhizobacterial diversity may enhance soil–plant interactions and total productivity under resource limited conditions.


2019 ◽  
Vol 39 (1) ◽  
Author(s):  
Nick Towner ◽  
Semisi Taumoepeau

Abstract Tuvalu and Nauru are isolated developing island nations located in the South Pacific Ocean. In contrast to the established larger Pacific destinations such as Fiji and Tahiti, the tourism industries on both Tuvalu and Nauru are in their infancy. Tourism development in these remote island nations faces a myriad of challenges which include a lack of infrastructure, environmental susceptibility, economic vulnerability, difficulties with access and considerable distances from major tourist markets. This paper reviews tourism on Tuvalu and Nauru and evaluates their current situation regarding potential tourism development through workshops with relevant stakeholders, surveys and subsequent SWOT analysis. The results of the paper outlined a large number of challenges faced by Tuvalu and Nauru due to their geographic location but also highlighted that both Islands possess fascinating and unique features that have the potential to attract niche tourism markets. A key finding of this paper is that the tourism stimulus or potential attraction can also be the chief threat to the islands’ economic survival hence the two edges of the sword. Further research is required to assess the effect of the withdrawal of the Refugee Processing Centre on Nauru’s economy and to evaluate the impact of climate change on Tuvalu’s society and potential adaption strategies.


Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 583
Author(s):  
Reda E. Abdelhameed ◽  
Nagwa I. Abu-Elsaad ◽  
Arafat Abdel Hamed Abdel Latef ◽  
Rabab A. Metwally

Important gaps in knowledge remain regarding the potential of nanoparticles (NPs) for plants, particularly the existence of helpful microorganisms, for instance, arbuscular mycorrhizal (AM) fungi present in the soil. Hence, more profound studies are required to distinguish the impact of NPs on plant growth inoculated with AM fungi and their role in NP uptake to develop smart nanotechnology implementations in crop improvement. Zinc ferrite (ZnFe2O4) NPs are prepared via the citrate technique and defined by X-ray diffraction (XRD) as well as transmission electron microscopy for several physical properties. The analysis of the XRD pattern confirmed the creation of a nanocrystalline structure with a crystallite size equal to 25.4 nm. The effects of ZnFe2O4 NP on AM fungi, growth and pigment content as well as nutrient uptake of pea (Pisum sativum) plants were assessed. ZnFe2O4 NP application caused a slight decrease in root colonization. However, its application showed an augmentation of 74.36% and 91.89% in AM pea plant shoots and roots’ fresh weights, respectively, compared to the control. Moreover, the synthesized ZnFe2O4 NP uptake by plant roots and their contents were enhanced by AM fungi. These findings suggest the safe use of ZnFe2O4 NPs in nano-agricultural applications for plant development with AM fungi.


2021 ◽  
Vol 43 (4) ◽  
Author(s):  
Agnieszka Ostrowska ◽  
Maciej T. Grzesiak ◽  
Tomasz Hura

AbstractSoil drought is a major problem in plant cultivation. This is particularly true for thermophilic plants, such as maize, which grow in areas often affected by precipitation shortage. The problem may be alleviated using plant growth and development stimulators. Therefore, the aim of the study was to analyze the effects of 5-aminolevulinic acid (5-ALA), zearalenone (ZEN), triacontanol (TRIA) and silicon (Si) on water management and photosynthetic activity of maize under soil drought. The experiments covered three developmental stages: three leaves, stem elongation and heading. The impact of these substances applied during drought stress depended on the plant development stage. 5-ALA affected chlorophyll levels, gas exchange and photochemical activity of PSII. Similar effects were observed for ZEN, which additionally induced stem elongation and limited dehydration. Beneficial effects of TRIA were visible at the stage of three leaves and involved leaf hydration and plant growth. A silicon preparation applied at the same developmental stage triggered similar effects and additionally induced changes in chlorophyll levels. All the stimulators significantly affected transpiration intensity at the heading stage.


Atmosphere ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 36
Author(s):  
Qing Zhang ◽  
Wen Zhang ◽  
Yongqiang Yu ◽  
Tingting Li ◽  
Lijun Yu

Responses of crop growth to climate warming are fundamental to future food security. The response of crops to climate change may be subtly different at their growing stages. Close insights into the differentiated stage-dependent responses of crops are significantly important in making adaptive adjustments of crops’ phenological optimization and cultivar improvement in diverse cropping systems. Using the Agro-C model, we studied the influence of past climate warming on crops in typical cropping systems in China. The results showed that while the temperature had increased distinctly from the 1960s to 2000s, the temperature frequency distributions in the growth season of crops moved to the high-temperature direction. The low temperature days during the crop growth periods that suppress crop growth decreased in the winter wheat area in North and East China, rice and maize areas in Northeast China, and the optimum temperature days increased significantly. As a result, the above ground biomass (AGB) of rice and maize in Northeast China and winter wheat in North and East China increased distinctly, while that of rice in South China had no significant change. A comparison of the key growth periods before and after heading (silking) showed that the warming before heading (silking) made a great contribution to the increase in the AGB, especially for winter wheat.


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