Improving crop yield and resilience through photosynthesis optimisation: panacea or pipe dream?

Author(s):  
José L Araus ◽  
Ruth Sanchez-Bragado ◽  
Rubén Vicente

Abstract Increasing the speed of breeding to enhance crop productivity and adaptation to abiotic stresses is urgently needed. The perception that a second Green Revolution should be implemented is widely established within the scientific community and among stakeholders. In recent decades, different alternatives have been proposed for elevating crop yield through manipulation of leaf photosynthetic efficiency. However, none of these have delivered practical or relevant outputs. Indeed, the actual increases in photosynthetic rates are not expected to translate into yield increases beyond 10-15%. Furthermore, instantaneous rates of leaf photosynthesis are not necessarily the reference target for research. Yield is the result of canopy photosynthesis, understood as the contribution of laminar and non-laminar organs over time, within which concepts such as canopy architecture, stay-green or non-laminar photosynthesis need to be taken into account. Moreover, retrospective studies show that photosynthetic improvements have been more common at the canopy level. Nevertheless, it is crucial to place canopy photosynthesis in the context of whole-plant functioning, which includes sink/source balance and transport of photoassimilates, and the availability and uptake of nutrients, such as nitrogen in particular. Overcoming this challenge will only be feasible if a multiscale crop focus combined with a multidisciplinary scientific approach is adopted.

2010 ◽  
Vol 37 (7) ◽  
pp. 592 ◽  
Author(s):  
Francisco Pérez-Alfocea ◽  
Alfonso Albacete ◽  
Michel E. Ghanem ◽  
Ian C. Dodd

Salinity decreases crop yield first by reducing growth of assimilate-consuming sink organs and, second, by decreasing assimilate production in photosynthetically active source tissues. Although much work has focussed on controlling the accumulation of toxic ions (mainly Na+ and Cl–), the search for primary growth limiting factor(s) continues. The root, by sensing environmental constraints of the soil, may influence root-to-shoot signalling to control shoot growth and physiology, and ultimately agricultural productivity. Hormonal signals, such as cytokinins, ABA, the ethylene precursor 1-aminocyclopropane-1-carboxylic acid and the auxin indole-3-acetic acid may coordinate assimilate production and usage in competing sinks (biomass partitioning). Hormonal regulation of source–sink relations during the osmotic phase of salinity (independent of specific ions) affects whole-plant energy availability to prolong the maintenance of growth, root function and ion homeostasis, and could be critical to delay the accumulation of Na+ or any other ion to toxic levels. This viewpoint emphasises that simultaneously maintaining growth and delaying early leaf senescence is necessary to increase crop yield in salt-affected soils.


Author(s):  
G. S. Khush ◽  
S. Peng

World food crops have been improved progressively since their domestication about 10,000 years ago. Progress was especially rapid after the rediscovery of Mendel’s laws of inheritance, when scientific principles could be applied to crop improvement. Modern varieties of wheat and rice, which ushered the so-called green revolution and led to the doubling of cereal production in a 25-year period, are examples of recent achievements in increasing crop productivity. The present world population of 5.8 billion is likely to reach 7 billion in 2010 and 8 billion in 2025. Per caput food intake will increase due to improved living standards. It is estimated that we will have to produce 50% more food by 2025. Food grain production in Africa will have to increase almost 400%, in Latin America 200%, and in Asia 60%. In the past, food production grew as a result of increased yield potential of new crop varieties, as well as increases in cropped area. In the future, major increases in cropped area are unlikely. In fact, in most Asian countries the cultivated area is declining due to pressures of urbanization and industrialization. Pesticide use is dropping as a result of concerns about their harmful effects on the environment and on human health. Increasingly, the industrial base is competing with agriculture for water and labor. Thus, we will have to produce more food from less land, with less pesticides, less labor, and less water. Increases in crop productivity are therefore essential to feed the world in the next century. One way to increase crop productivity is to develop crop cultivars with higher yield potential. Of the various strategies for increasing the yield potential, two are reviewed in this chapter. Selection for semidwarf stature in the late 1950s for rice (Oryza sativa L.) and wheat (Triticum aestivum L.) is the most striking example of a successful improvement in plant type. Although selections were guided by short stature, resistance to lodging, and efficient biomass partitioning between grain and straw, breeders were unintentionally selecting for improved canopy architecture, light penetration, and other favorable agronomic characteristics (as reviewed by Takeda, 1984).


Author(s):  
Sujata Mulik

Agriculture sector in India is facing rigorous problem to maximize crop productivity. More than 60 percent of the crop still depends on climatic factors like rainfall, temperature, humidity. This paper discusses the use of various Data Mining applications in agriculture sector. Data Mining is used to solve various problems in agriculture sector. It can be used it to solve yield prediction.  The problem of yield prediction is a major problem that remains to be solved based on available data. Data mining techniques are the better choices for this purpose. Different Data Mining techniques are used and evaluated in agriculture for estimating the future year's crop production. In this paper we have focused on predicting crop yield productivity of kharif & Rabi Crops. 


Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 126
Author(s):  
Judit Barroso ◽  
Nicholas G. Genna

Russian thistle (Salsola tragus L.) is a persistent post-harvest issue in the Pacific Northwest (PNW). Farmers need more integrated management strategies to control it. Russian thistle emergence, mortality, plant biomass, seed production, and crop yield were evaluated in spring wheat and spring barley planted in 18- or 36-cm row spacing and seeded at 73 or 140 kg ha−1 in Pendleton and Moro, Oregon, during 2018 and 2019. Russian thistle emergence was lower and mortality was higher in spring barley than in spring wheat. However, little to no effect of row spacing or seeding rate was observed on Russian thistle emergence or mortality. Russian thistle seed production and plant biomass followed crop productivity; higher crop yield produced higher Russian thistle biomass and seed production and lower crop yield produced lower weed biomass and seed production. Crop yield with Russian thistle pressure was improved in 2018 with 18-cm rows or by seeding at 140 kg ha−1 while no effect was observed in 2019. Increasing seeding rates or planting spring crops in narrow rows may be effective at increasing yield in low rainfall years of the PNW, such as in 2018. No effect may be observed in years with higher rainfall than normal, such as in 2019.


Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 43
Author(s):  
Adeel Khan ◽  
Munir Ahmad ◽  
Mukhtar Ahmed ◽  
M. Iftikhar Hussain

Temperature across the globe is increasing continuously at the rate of 0.15–0.17 °C per decade since the industrial revolution. It is influencing agricultural crop productivity. Therefore, thermotolerance strategies are needed to have sustainability in crop yield under higher temperature. However, improving thermotolerance in the crop is a challenging task for crop scientists. Therefore, this review work was conducted with the aim of providing information on the wheat response in three research areas, i.e., physiology, breeding, and advances in genetics, which could assist the researchers in improving thermotolerance. The optimum temperature for wheat growth at the heading, anthesis, and grain filling duration is 16 ± 2.3 °C, 23 ± 1.75 °C, and 26 ± 1.53 °C, respectively. The high temperature adversely influences the crop phenology, growth, and development. The pre-anthesis high temperature retards the pollen viability, seed formation, and embryo development. The post-anthesis high temperature declines the starch granules accumulation, stem reserve carbohydrates, and translocation of photosynthates into grains. A high temperature above 40 °C inhibits the photosynthesis by damaging the photosystem-II, electron transport chain, and photosystem-I. Our review work highlighted that genotypes which can maintain a higher accumulation of proline, glycine betaine, expression of heat shock proteins, stay green and antioxidant enzymes activity viz., catalase, peroxidase, super oxide dismutase, and glutathione reductase can tolerate high temperature efficiently through sustaining cellular physiology. Similarly, the pre-anthesis acclimation with heat treatment, inorganic fertilizer such as nitrogen, potassium nitrate and potassium chloride, mulches with rice husk, early sowing, presoaking of a 6.6 mM solution of thiourea, foliar application of 50 ppm dithiothreitol, 10 mg per kg of silicon at heading and zinc ameliorate the crop against the high temperature. Finally, it has been suggested that modern genomics and omics techniques should be used to develop thermotolerance in wheat.


2020 ◽  
Vol 2 ◽  
Author(s):  
Nathalie Colbach ◽  
Sandrine Petit ◽  
Bruno Chauvel ◽  
Violaine Deytieux ◽  
Martin Lechenet ◽  
...  

The growing recognition of the environmental and health issues associated to pesticide use requires to investigate how to manage weeds with less or no herbicides in arable farming while maintaining crop productivity. The questions of weed harmfulness, herbicide efficacy, the effects of herbicide use on crop yields, and the effect of reducing herbicides on crop production have been addressed over the years but results and interpretations often appear contradictory. In this paper, we critically analyze studies that have focused on the herbicide use, weeds and crop yield nexus. We identified many inconsistencies in the published results and demonstrate that these often stem from differences in the methodologies used and in the choice of the conceptual model that links the three items. Our main findings are: (1) although our review confirms that herbicide reduction increases weed infestation if not compensated by other cultural techniques, there are many shortcomings in the different methods used to assess the impact of weeds on crop production; (2) Reducing herbicide use rarely results in increased crop yield loss due to weeds if farmers compensate low herbicide use by other efficient cultural practices; (3) There is a need for comprehensive studies describing the effect of cropping systems on crop production that explicitly include weeds and disentangle the impact of herbicides from the effect of other practices on weeds and on crop production. We propose a framework that presents all the links and feed-backs that must be considered when analyzing the herbicide-weed-crop yield nexus. We then provide a number of methodological recommendations for future studies. We conclude that, since weeds are causing yield loss, reduced herbicide use and maintained crop productivity necessarily requires a redesign of cropping systems. These new systems should include both agronomic and biodiversity-based levers acting in concert to deliver sustainable weed management.


2021 ◽  
Vol 11 (2) ◽  
pp. 750
Author(s):  
Roberta Pastorelli ◽  
Giuseppe Valboa ◽  
Alessandra Lagomarsino ◽  
Arturo Fabiani ◽  
Stefania Simoncini ◽  
...  

Digestate from biogas production can be recycled to the soil as conditioner/fertilizer improving the environmental sustainability of the energy supply chain. In a three-year maize-triticale rotation, we investigated the short-term effects of digestate on soil physical, chemical, and microbiological properties and evaluated its effectiveness in complementing the mineral fertilizers. Digestate soil treatments consisted of combined applications of the whole digestate and its mechanically separated solid fraction. Digestate increased soil total organic C, total N and K contents. Soil bulk density was not affected by treatments, while aggregate stability showed a transient improvement due to digestate treatments. A decrement of the transmission pores proportion and an increment of fissures was observed in digestate treated soils. Soil microbial community was only transiently affected by digestate treatments and no soil contamination from Clostridiaceae-related bacteria were observed. Digestate can significantly impair seed germination when applied at low dilution ratios. Crop yield under digestate treatment was similar to ordinary mineral-based fertilization. Overall, our experiment proved that the agronomic recycling of digestate from biogas production maintained a fair crop yield and soil quality. Digestate was confirmed as a valid resource for sustainable management of soil fertility under energy-crop farming, by combining a good attitude as a fertilizer with the ability to compensate for soil organic C loss.


SOIL ◽  
2016 ◽  
Vol 2 (2) ◽  
pp. 147-162 ◽  
Author(s):  
Ariane Krause ◽  
Thomas Nehls ◽  
Eckhard George ◽  
Martin Kaupenjohann

Abstract. Andosols require the regular application of phosphorus (P) to sustain crop productivity. On an Andosol in NW Tanzania, we studied the short-term effects of amending standard compost, biogas slurry and CaSa compost (containing biochar and sanitized human excreta) on (i) the soil's physico-chemical properties, on (ii) biomass growth and crop productivity, and on (iii) the plants' nutrient status. The practice-oriented experiment design included the intercropping of seven locally grown crop species planted on 9 m2 plots with five repetitions arranged as a Latin rectangle. Differences in plant growth (biomass production and crop yield, e.g., of Zea mays) and crop nutrition (total C, N, P, K, Ca, Mg, Zn, etc.) were related to pH, CEC (cation exchange capacity), total C and the availability of nutrients (N, P, K, etc.) and water (water retention characteristics, bulk density, etc.) in the soil. None of the amendments had any significant effect on soil water availability, so the observed variations in crop yield and plant nutrition are attributed to nutrient availability. Applying CaSa compost increased the soil pH from 5.3 to 5.9 and the level of available P from 0.5 to 4.4 mg per kg. Compared to the control, adding biogas slurry, standard compost and CaSa compost increased the aboveground biomass of Zea mays by, respectively, 140, 154 and 211 %. The grain yields of maize on soil treated with biogas slurry, standard compost and CaSa compost were, respectively, 2.63, 3.18 and 4.40 t ha−1, compared to only 1.10 t ha−1 on unamended plots. All treatments enhanced crop productivity and increased the uptake of nutrients into the maize grains. The CaSa compost was most effective in mitigating P deficiency and soil acidification. We conclude that all treatments are viable as a substitute for synthetic fertilizers. Nevertheless, further steps are required to integrate the tested soil amendments into farm-scale nutrient management and to balance the additions and removals of nutrients, so that the cycle can be closed.


2019 ◽  
Vol 126 (4) ◽  
pp. 601-614 ◽  
Author(s):  
Qingfeng Song ◽  
Venkatraman Srinivasan ◽  
Steve P Long ◽  
Xin-Guang Zhu

Abstract Background and Aims Understanding how climate change influences crop productivity helps in identifying new options to increase crop productivity. Soybean is the most important dicotyledonous seed crop in terms of planting area. Although the impacts of elevated atmospheric [CO2] on soybean physiology, growth and biomass accumulation have been studied extensively, the contribution of different factors to changes in season-long whole crop photosynthetic CO2 uptake [gross primary productivity (GPP)] under elevated [CO2] have not been fully quantified. Methods A 3-D canopy model combining canopy 3-D architecture, ray tracing and leaf photosynthesis was built to: (1) study the impacts of elevated [CO2] on soybean GPP across a whole growing season; (2) dissect the contribution of different factors to changes in GPP; and (3) determine the extent, if any, of synergism between [CO2] and light on changes in GPP. The model was parameterized from measurements of leaf physiology and canopy architectural parameters at the soybean Free Air CO2 Enrichment (SoyFACE) facility in Champaign, Illinois. Key Results Using this model, we showed that both a CO2 fertilization effect and changes in canopy architecture contributed to the large increase in GPP while acclimation in photosynthetic physiological parameters to elevated [CO2] and altered leaf temperature played only a minor role in the changes in GPP. Furthermore, at early developmental stages, elevated [CO2] increased leaf area index which led to increased canopy light absorption and canopy photosynthesis. At later developmental stages, on days with high ambient light levels, the proportion of leaves in a canopy limited by Rubisco carboxylation increased from 12.2 % to 35.6 %, which led to a greater enhancement of elevated [CO2] to GPP. Conclusions This study develops a new method to dissect the contribution of different factors to responses of crops under climate change. We showed that there is a synergestic effect of CO2 and light on crop growth under elevated CO2 conditions.


2020 ◽  
Author(s):  
A. Karthik ◽  
M. Uma Maheswari

Food security is one of the major concerns for all developing countries of the world. Even though we had attained the highest food production with the use of new technologies, we may not able to feed the burgeoning population adequately in coming years due to stagnant crop productivity. Natural source of nutrients like organic manures and external source of nutrients, viz. fertilizers, are considered as the two eyes in plant nutrient management. Nutrient use efficiency of fertilizer is very low due to numerous pathways of losses such as leaching, denitrification, microbial immobilization, fixation and runoff. It has been estimated that around 40-70% of nitrogen, 80-90% of phosphorus, 50-70% of potassium and more than 95% of micronutrient content of applied fertilizers are lost in to the environment and results in pollution (Kanjana, 2017). Smart fertilizers like slow and controlled release fertilizers, nanofertilizers and bioformulation fertilizers are the new technologies to enhance the nutrient use efficiency their by improving crop yield in sustainable manner. The use of slow and controlled release fertilizers increase nutrient use efficiency, minimize the risks like leaf burning, water contamination and eutrophication. Nano-fertilizers are the nano-particles-based fertilizers, where supply of the nutrients is made precisely for maximum plant growth, have higher use efficiency, exploiting plant unavailable nutrients in the rhizosphere and can be delivered on real time basis into the rhizosphere or by foliar spray (Priyanka Solangi et al., 2015). The small size, high specific surface area and reactivity of nano fertilizers increase the solubility, diffusion and availability of nutrients to plants and enhance crop productivity. Bioformulation is microbial preparations containing specific beneficial microorganisms which are capable of fixing or solubilizing or mobilizing plant nutrients for promoting plant growth and crop yield. Smart fertilizers are the better option for the farmers to increase their crop yield with low input cost in sustainable way without degrading natural environment.


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